chore: Export validation function (#1301)

* feat(client): Add support for SSH tunneling

* Fix test

.examples/docker-compose-multiple-config-files/config/global.yaml

@@ -1,5 +1,4 @@
 metrics: true
-debug: false
 ui:
   header: Example Company
   link: https://example.org

.examples/nixos/README.md

@@ -0,0 +1,4 @@
+# NixOS
+
+Gatus is implemented as a NixOS module. See [gatus.nix](./gatus.nix) for example
+usage.

.examples/nixos/gatus.nix

@@ -0,0 +1,23 @@
+{
+  services.gatus = {
+    enable = true;
+
+    settings = {
+      web.port = 8080;
+
+      endpoints = [
+        {
+          name = "website";
+          url = "https://twin.sh/health";
+          interval = "5m";
+
+          conditions = [
+            "[STATUS] == 200"
+            "[BODY].status == UP"
+            "[RESPONSE_TIME] < 300"
+          ];
+        }
+      ];
+    };
+  };
+}

.github/codecov.yml

@@ -1,12 +1,15 @@
 ignore:
-  - "watchdog/watchdog.go"
   - "storage/store/sql/specific_postgres.go" # Can't test for postgres
-
+  - "watchdog/endpoint.go"
+  - "watchdog/external_endpoint.go"
+  - "watchdog/suite.go"
+  - "watchdog/watchdog.go"
+comment: false
 coverage:
   status:
     patch: off
     project:
       default:
-        target: 75%
+        target: 70%
         threshold: null
 

.github/dependabot.yml

@@ -7,7 +7,7 @@ updates:
       interval: "daily"
   - package-ecosystem: "gomod"
     directory: "/"
-    open-pull-requests-limit: 1
+    open-pull-requests-limit: 3
     labels: ["dependencies"]
     schedule:
       interval: "daily"

.github/workflows/benchmark.yml

@@ -18,13 +18,13 @@ jobs:
   build:
     name: benchmark
     runs-on: ubuntu-latest
-    timeout-minutes: 5
+    timeout-minutes: 15
     steps:
-      - uses: actions/setup-go@v5
+      - uses: actions/setup-go@v6
         with:
-          go-version: 1.22.2
+          go-version: 1.24.4
           repository: "${{ github.event.inputs.repository || 'TwiN/gatus' }}"
           ref: "${{ github.event.inputs.ref || 'master' }}"
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v5
       - name: Benchmark
         run: go test -bench=. ./storage/store

.github/workflows/labeler.yml

@@ -0,0 +1,46 @@
+name: labeler
+on:
+  pull_request_target:
+    types:
+      - opened
+  issues:
+    types:
+      - opened
+jobs:
+  labeler:
+    runs-on: ubuntu-latest
+    timeout-minutes: 5
+    permissions:
+      issues: write
+      pull-requests: write
+    steps:
+      - name: Label
+        continue-on-error: true
+        env:
+          TITLE: ${{ github.event.issue.title }}${{ github.event.pull_request.title }}
+          GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+          GH_REPO: ${{ github.repository }}
+          NUMBER: ${{ github.event.issue.number }}${{ github.event.pull_request.number }}
+        run: |
+          if [[ $TITLE == "feat"* ]]; then
+            gh issue edit "$NUMBER" --add-label "feature"
+          elif [[ $TITLE == "fix"* ]]; then
+            gh issue edit "$NUMBER" --add-label "bug"
+          elif [[ $TITLE == "docs"* ]]; then
+            gh issue edit "$NUMBER" --add-label "documentation"
+          fi
+          if [[ $TITLE == *"alerting"* || $TITLE == *"provider"* || $TITLE == *"alert"* ]]; then
+            gh issue edit "$NUMBER" --add-label "area/alerting"
+          fi
+          if [[ $TITLE == *"(ui)"* || $TITLE == *"ui:"* ]]; then
+            gh issue edit "$NUMBER" --add-label "area/ui"
+          fi
+          if [[ $TITLE == *"storage"* || $TITLE == *"postgres"* || $TITLE == *"sqlite"* ]]; then
+            gh issue edit "$NUMBER" --add-label "area/storage"
+          fi
+          if [[ $TITLE == *"security"* || $TITLE == *"oidc"* || $TITLE == *"oauth2"* ]]; then
+            gh issue edit "$NUMBER" --add-label "area/security"
+          fi
+          if [[ $TITLE == *"metric"* || $TITLE == *"prometheus"* ]]; then
+            gh issue edit "$NUMBER" --add-label "area/metrics"
+          fi

.github/workflows/publish-custom.yml

@@ -0,0 +1,40 @@
+name: publish-custom
+run-name: "${{ inputs.tag }}"
+on:
+  workflow_dispatch:
+    inputs:
+      tag:
+        description: Custom tag to publish
+jobs:
+  publish-custom:
+    runs-on: ubuntu-latest
+    timeout-minutes: 60
+    steps:
+      - uses: actions/checkout@v5
+      - name: Set up QEMU
+        uses: docker/setup-qemu-action@v3
+      - name: Set up Docker Buildx
+        uses: docker/setup-buildx-action@v3
+      - name: Get image repository
+        run: echo GHCR_IMAGE_REPOSITORY=$(echo ghcr.io/${{ github.actor }}/${{ github.event.repository.name }} | tr '[:upper:]' '[:lower:]') >> $GITHUB_ENV
+      - name: Login to GitHub Container Registry
+        uses: docker/login-action@v3
+        with:
+          registry: ghcr.io
+          username: ${{ github.actor }}
+          password: ${{ secrets.GITHUB_TOKEN }}
+      - name: Docker meta
+        id: meta
+        uses: docker/metadata-action@v5
+        with:
+          images: ${{ env.GHCR_IMAGE_REPOSITORY }}
+          tags: |
+            type=raw,value=${{ inputs.tag }}
+      - name: Build and push Docker image
+        uses: docker/build-push-action@v6
+        with:
+          platforms: linux/amd64
+          pull: true
+          push: true
+          tags: ${{ steps.meta.outputs.tags }}
+          labels: ${{ steps.meta.outputs.labels }}

.github/workflows/publish-experimental.yml

@@ -3,9 +3,9 @@ on: [workflow_dispatch]
 jobs:
   publish-experimental:
     runs-on: ubuntu-latest
-    timeout-minutes: 20
+    timeout-minutes: 60
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v5
       - name: Set up QEMU
         uses: docker/setup-qemu-action@v3
       - name: Set up Docker Buildx
@@ -17,10 +17,18 @@ jobs:
         with:
           username: ${{ secrets.DOCKER_USERNAME }}
           password: ${{ secrets.DOCKER_PASSWORD }}
+      - name: Docker meta
+        id: meta
+        uses: docker/metadata-action@v5
+        with:
+          images: ${{ env.IMAGE_REPOSITORY }}
+          tags: |
+            type=raw,value=experimental
       - name: Build and push Docker image
         uses: docker/build-push-action@v6
         with:
           platforms: linux/amd64
           pull: true
           push: true
-          tags: ${{ env.IMAGE_REPOSITORY }}:experimental
+          tags: ${{ steps.meta.outputs.tags }}
+          labels: ${{ steps.meta.outputs.labels }}

.github/workflows/publish-latest-to-ghcr.yml

@@ -1,38 +0,0 @@
-name: publish-latest-to-ghcr
-on:
-  workflow_run:
-    workflows: [test]
-    branches: [master]
-    types: [completed]
-concurrency:
-  group: ${{ github.event.workflow_run.head_repository.full_name }}::${{ github.event.workflow_run.head_branch }}::${{ github.workflow }}
-  cancel-in-progress: true
-jobs:
-  publish-latest-to-ghcr:
-    runs-on: ubuntu-latest
-    if: ${{ (github.event.workflow_run.conclusion == 'success') && (github.event.workflow_run.head_repository.full_name == github.repository) }}
-    permissions:
-      contents: read
-      packages: write
-    timeout-minutes: 60
-    steps:
-      - uses: actions/checkout@v4
-      - name: Set up QEMU
-        uses: docker/setup-qemu-action@v3
-      - name: Set up Docker Buildx
-        uses: docker/setup-buildx-action@v3
-      - name: Get image repository
-        run: echo IMAGE_REPOSITORY=$(echo ghcr.io/${{ github.actor }}/${{ github.event.repository.name }} | tr '[:upper:]' '[:lower:]') >> $GITHUB_ENV
-      - name: Login to Registry
-        uses: docker/login-action@v3
-        with:
-          registry: ghcr.io
-          username: ${{ github.actor }}
-          password: ${{ secrets.GITHUB_TOKEN }}
-      - name: Build and push Docker image
-        uses: docker/build-push-action@v6
-        with:
-          platforms: linux/amd64,linux/arm/v7,linux/arm64
-          pull: true
-          push: true
-          tags: ${{ env.IMAGE_REPOSITORY }}:latest

.github/workflows/publish-latest.yml

@@ -11,24 +11,42 @@ jobs:
   publish-latest:
     runs-on: ubuntu-latest
     if: ${{ (github.event.workflow_run.conclusion == 'success') && (github.event.workflow_run.head_repository.full_name == github.repository) }}
-    timeout-minutes: 60
+    timeout-minutes: 240
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v5
       - name: Set up QEMU
         uses: docker/setup-qemu-action@v3
       - name: Set up Docker Buildx
         uses: docker/setup-buildx-action@v3
       - name: Get image repository
-        run: echo IMAGE_REPOSITORY=$(echo ${{ secrets.DOCKER_USERNAME }}/${{ github.event.repository.name }} | tr '[:upper:]' '[:lower:]') >> $GITHUB_ENV
+        run: |
+          echo DOCKER_IMAGE_REPOSITORY=$(echo ${{ secrets.DOCKER_USERNAME }}/${{ github.event.repository.name }} | tr '[:upper:]' '[:lower:]') >> $GITHUB_ENV
+          echo GHCR_IMAGE_REPOSITORY=$(echo ghcr.io/${{ github.actor }}/${{ github.event.repository.name }} | tr '[:upper:]' '[:lower:]') >> $GITHUB_ENV
       - name: Login to Docker Registry
         uses: docker/login-action@v3
         with:
           username: ${{ secrets.DOCKER_USERNAME }}
           password: ${{ secrets.DOCKER_PASSWORD }}
+      - name: Login to GitHub Container Registry
+        uses: docker/login-action@v3
+        with:
+          registry: ghcr.io
+          username: ${{ github.actor }}
+          password: ${{ secrets.GITHUB_TOKEN }}
+      - name: Docker meta
+        id: meta
+        uses: docker/metadata-action@v5
+        with:
+          images: |
+            ${{ env.DOCKER_IMAGE_REPOSITORY }}
+            ${{ env.GHCR_IMAGE_REPOSITORY }}
+          tags: |
+            type=raw,value=latest
       - name: Build and push Docker image
         uses: docker/build-push-action@v6
         with:
           platforms: linux/amd64,linux/arm/v7,linux/arm64
           pull: true
           push: true
-          tags: ${{ env.IMAGE_REPOSITORY }}:latest
+          tags: ${{ steps.meta.outputs.tags }}
+          labels: ${{ steps.meta.outputs.labels }}

.github/workflows/publish-release-to-ghcr.yml

@@ -1,37 +0,0 @@
-name: publish-release-to-ghcr
-on:
-  release:
-    types: [published]
-jobs:
-  publish-release-to-ghcr:
-    runs-on: ubuntu-latest
-    permissions:
-      contents: read
-      packages: write
-    timeout-minutes: 60
-    steps:
-      - uses: actions/checkout@v4
-      - name: Set up QEMU
-        uses: docker/setup-qemu-action@v3
-      - name: Set up Docker Buildx
-        uses: docker/setup-buildx-action@v3
-      - name: Get image repository
-        run: echo IMAGE_REPOSITORY=$(echo ghcr.io/${{ github.actor }}/${{ github.event.repository.name }} | tr '[:upper:]' '[:lower:]') >> $GITHUB_ENV
-      - name: Get the release
-        run: echo RELEASE=${GITHUB_REF/refs\/tags\//} >> $GITHUB_ENV
-      - name: Login to Registry
-        uses: docker/login-action@v3
-        with:
-          registry: ghcr.io
-          username: ${{ github.actor }}
-          password: ${{ secrets.GITHUB_TOKEN }}
-      - name: Build and push Docker image
-        uses: docker/build-push-action@v6
-        with:
-          platforms: linux/amd64,linux/arm/v7,linux/arm64
-          pull: true
-          push: true
-          tags: |
-            ${{ env.IMAGE_REPOSITORY }}:${{ env.RELEASE }}
-            ${{ env.IMAGE_REPOSITORY }}:stable
-            ${{ env.IMAGE_REPOSITORY }}:latest

.github/workflows/publish-release.yml

@@ -6,15 +6,17 @@ jobs:
   publish-release:
     name: publish-release
     runs-on: ubuntu-latest
-    timeout-minutes: 60
+    timeout-minutes: 240
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v5
       - name: Set up QEMU
         uses: docker/setup-qemu-action@v3
       - name: Set up Docker Buildx
         uses: docker/setup-buildx-action@v3
       - name: Get image repository
-        run: echo IMAGE_REPOSITORY=$(echo ${{ secrets.DOCKER_USERNAME }}/${{ github.event.repository.name }} | tr '[:upper:]' '[:lower:]') >> $GITHUB_ENV
+        run: |
+          echo DOCKER_IMAGE_REPOSITORY=$(echo ${{ secrets.DOCKER_USERNAME }}/${{ github.event.repository.name }} | tr '[:upper:]' '[:lower:]') >> $GITHUB_ENV
+          echo GHCR_IMAGE_REPOSITORY=$(echo ghcr.io/${{ github.actor }}/${{ github.event.repository.name }} | tr '[:upper:]' '[:lower:]') >> $GITHUB_ENV
       - name: Get the release
         run: echo RELEASE=${GITHUB_REF/refs\/tags\//} >> $GITHUB_ENV
       - name: Login to Docker Registry
@@ -22,13 +24,28 @@ jobs:
         with:
           username: ${{ secrets.DOCKER_USERNAME }}
           password: ${{ secrets.DOCKER_PASSWORD }}
+      - name: Login to GitHub Container Registry
+        uses: docker/login-action@v3
+        with:
+          registry: ghcr.io
+          username: ${{ github.actor }}
+          password: ${{ secrets.GITHUB_TOKEN }}
+      - name: Docker meta
+        id: meta
+        uses: docker/metadata-action@v5
+        with:
+          images: |
+            ${{ env.DOCKER_IMAGE_REPOSITORY }}
+            ${{ env.GHCR_IMAGE_REPOSITORY }}
+          tags: |
+            type=raw,value=${{ env.RELEASE }}
+            type=raw,value=stable
+            type=raw,value=latest
       - name: Build and push Docker image
         uses: docker/build-push-action@v6
         with:
           platforms: linux/amd64,linux/arm/v7,linux/arm64
           pull: true
           push: true
-          tags: |
-            ${{ env.IMAGE_REPOSITORY }}:${{ env.RELEASE }}
-            ${{ env.IMAGE_REPOSITORY }}:stable
-            ${{ env.IMAGE_REPOSITORY }}:latest
+          tags: ${{ steps.meta.outputs.tags }}
+          labels: ${{ steps.meta.outputs.labels }}

.github/workflows/test-ui.yml

@@ -0,0 +1,18 @@
+name: test-ui
+on:
+  pull_request:
+    paths:
+      - 'web/**'
+  push:
+    branches:
+      - master
+    paths:
+      - 'web/**'
+jobs:
+  test-ui:
+    runs-on: ubuntu-latest
+    timeout-minutes: 30
+    steps:
+      - uses: actions/checkout@v5
+      - run: make frontend-install-dependencies
+      - run: make frontend-build

.github/workflows/test.yml

@@ -14,12 +14,12 @@ on:
 jobs:
   test:
     runs-on: ubuntu-latest
-    timeout-minutes: 10
+    timeout-minutes: 30
     steps:
-      - uses: actions/setup-go@v5
+      - uses: actions/setup-go@v6
         with:
-          go-version: 1.22.2
-      - uses: actions/checkout@v4
+          go-version: 1.24.4
+      - uses: actions/checkout@v5
       - name: Build binary to make sure it works
         run: go build
       - name: Test
@@ -28,7 +28,7 @@ jobs:
         # was configured by the "Set up Go" step (otherwise, it'd use sudo's "go" executable)
         run: sudo env "PATH=$PATH" "GOROOT=$GOROOT" go test ./... -race -coverprofile=coverage.txt -covermode=atomic
       - name: Codecov
-        uses: codecov/codecov-action@v4.5.0
+        uses: codecov/codecov-action@v5.5.1
         with:
           files: ./coverage.txt
           token: ${{ secrets.CODECOV_TOKEN }}

.gitignore

@@ -17,4 +17,5 @@ node_modules
 *.db-shm
 *.db-wal
 gatus
-config/config.yml
+config/config.yml
+config.yaml

Dockerfile

@@ -1,5 +1,5 @@
 # Build the go application into a binary
-FROM golang:alpine as builder
+FROM golang:alpine AS builder
 RUN apk --update add ca-certificates
 WORKDIR /app
 COPY . ./
@@ -15,6 +15,8 @@ FROM scratch
 COPY --from=builder /app/gatus .
 COPY --from=builder /app/config.yaml ./config/config.yaml
 COPY --from=builder /etc/ssl/certs/ca-certificates.crt /etc/ssl/certs/ca-certificates.crt
-ENV PORT=8080
+ENV GATUS_CONFIG_PATH=""
+ENV GATUS_LOG_LEVEL="INFO"
+ENV PORT="8080"
 EXPOSE ${PORT}
 ENTRYPOINT ["/gatus"]

Makefile

@@ -6,7 +6,11 @@ install:
 
 .PHONY: run
 run:
-	GATUS_CONFIG_PATH=./config.yaml ./$(BINARY)
+	ENVIRONMENT=dev GATUS_CONFIG_PATH=./config.yaml go run main.go
+
+.PHONY: run-binary
+run-binary:
+	ENVIRONMENT=dev GATUS_CONFIG_PATH=./config.yaml ./$(BINARY)
 
 .PHONY: clean
 clean:
@@ -34,6 +38,9 @@ docker-build-and-run: docker-build docker-run
 # Front end #
 #############
 
+frontend-install-dependencies:
+	npm --prefix web/app install
+
 frontend-build:
 	npm --prefix web/app run build
 

alerting/alert/alert.go

@@ -6,14 +6,20 @@ import (
 	"errors"
 	"strconv"
 	"strings"
+	"time"
+
+	"github.com/TwiN/logr"
+	"gopkg.in/yaml.v3"
 )
 
 var (
 	// ErrAlertWithInvalidDescription is the error with which Gatus will panic if an alert has an invalid character
 	ErrAlertWithInvalidDescription = errors.New("alert description must not have \" or \\")
+
+	ErrAlertWithInvalidMinimumReminderInterval = errors.New("minimum-reminder-interval must be either omitted or be at least 5m")
 )
 
-// Alert is a endpoint.Endpoint's alert configuration
+// Alert is endpoint.Endpoint's alert configuration
 type Alert struct {
 	// Type of alert (required)
 	Type Type `yaml:"type"`
@@ -32,17 +38,24 @@ type Alert struct {
 	// SuccessThreshold defines how many successful executions must happen in a row before an ongoing incident is marked as resolved
 	SuccessThreshold int `yaml:"success-threshold"`
 
+	// MinimumReminderInterval is the interval between reminders
+	MinimumReminderInterval time.Duration `yaml:"minimum-reminder-interval,omitempty"`
+
 	// Description of the alert. Will be included in the alert sent.
 	//
 	// This is a pointer, because it is populated by YAML and we need to know whether it was explicitly set to a value
 	// or not for provider.ParseWithDefaultAlert to work.
-	Description *string `yaml:"description"`
+	Description *string `yaml:"description,omitempty"`
 
 	// SendOnResolved defines whether to send a second notification when the issue has been resolved
 	//
 	// This is a pointer, because it is populated by YAML and we need to know whether it was explicitly set to a value
 	// or not for provider.ParseWithDefaultAlert to work. Use Alert.IsSendingOnResolved() for a non-pointer
-	SendOnResolved *bool `yaml:"send-on-resolved"`
+	SendOnResolved *bool `yaml:"send-on-resolved,omitempty"`
+
+	// ProviderOverride is an optional field that can be used to override the provider's configuration
+	// It is freeform so that it can be used for any provider-specific configuration.
+	ProviderOverride map[string]any `yaml:"provider-override,omitempty"`
 
 	// ResolveKey is an optional field that is used by some providers (i.e. PagerDuty's dedup_key) to resolve
 	// ongoing/triggered incidents
@@ -67,6 +80,9 @@ func (alert *Alert) ValidateAndSetDefaults() error {
 	if alert.SuccessThreshold <= 0 {
 		alert.SuccessThreshold = 2
 	}
+	if alert.MinimumReminderInterval != 0 && alert.MinimumReminderInterval < 5*time.Minute {
+		return ErrAlertWithInvalidMinimumReminderInterval
+	}
 	if strings.ContainsAny(alert.GetDescription(), "\"\\") {
 		return ErrAlertWithInvalidDescription
 	}
@@ -111,3 +127,11 @@ func (alert *Alert) Checksum() string {
 	)
 	return hex.EncodeToString(hash.Sum(nil))
 }
+
+func (alert *Alert) ProviderOverrideAsBytes() []byte {
+	yamlBytes, err := yaml.Marshal(alert.ProviderOverride)
+	if err != nil {
+		logr.Warnf("[alert.ProviderOverrideAsBytes] Failed to marshal alert override of type=%s as bytes: %v", alert.Type, err)
+	}
+	return yamlBytes
+}

alerting/alert/alert_test.go

@@ -3,6 +3,7 @@ package alert
 import (
 	"errors"
 	"testing"
+	"time"
 )
 
 func TestAlert_ValidateAndSetDefaults(t *testing.T) {
@@ -36,6 +37,61 @@ func TestAlert_ValidateAndSetDefaults(t *testing.T) {
 			expectedFailureThreshold: 10,
 			expectedSuccessThreshold: 5,
 		},
+		{
+			name: "valid-minimum-reminder-interval-0",
+			alert: Alert{
+				MinimumReminderInterval: 0,
+				FailureThreshold:        10,
+				SuccessThreshold:        5,
+			},
+			expectedError:            nil,
+			expectedFailureThreshold: 10,
+			expectedSuccessThreshold: 5,
+		},
+		{
+			name: "valid-minimum-reminder-interval-5m",
+			alert: Alert{
+				MinimumReminderInterval: 5 * time.Minute,
+				FailureThreshold:        10,
+				SuccessThreshold:        5,
+			},
+			expectedError:            nil,
+			expectedFailureThreshold: 10,
+			expectedSuccessThreshold: 5,
+		},
+		{
+			name: "valid-minimum-reminder-interval-10m",
+			alert: Alert{
+				MinimumReminderInterval: 10 * time.Minute,
+				FailureThreshold:        10,
+				SuccessThreshold:        5,
+			},
+			expectedError:            nil,
+			expectedFailureThreshold: 10,
+			expectedSuccessThreshold: 5,
+		},
+		{
+			name: "invalid-minimum-reminder-interval-1m",
+			alert: Alert{
+				MinimumReminderInterval: 1 * time.Minute,
+				FailureThreshold:        10,
+				SuccessThreshold:        5,
+			},
+			expectedError:            ErrAlertWithInvalidMinimumReminderInterval,
+			expectedFailureThreshold: 10,
+			expectedSuccessThreshold: 5,
+		},
+		{
+			name: "invalid-minimum-reminder-interval-1s",
+			alert: Alert{
+				MinimumReminderInterval: 1 * time.Second,
+				FailureThreshold:        10,
+				SuccessThreshold:        5,
+			},
+			expectedError:            ErrAlertWithInvalidMinimumReminderInterval,
+			expectedFailureThreshold: 10,
+			expectedSuccessThreshold: 5,
+		},
 	}
 	for _, scenario := range scenarios {
 		t.Run(scenario.name, func(t *testing.T) {

alerting/alert/type.go

@@ -11,6 +11,9 @@ const (
 	// TypeCustom is the Type for the custom alerting provider
 	TypeCustom Type = "custom"
 
+	// TypeDatadog is the Type for the datadog alerting provider
+	TypeDatadog Type = "datadog"
+
 	// TypeDiscord is the Type for the discord alerting provider
 	TypeDiscord Type = "discord"
 
@@ -32,9 +35,24 @@ const (
 	// TypeGotify is the Type for the gotify alerting provider
 	TypeGotify Type = "gotify"
 
+	// TypeHomeAssistant is the Type for the homeassistant alerting provider
+	TypeHomeAssistant Type = "homeassistant"
+
+	// TypeIFTTT is the Type for the ifttt alerting provider
+	TypeIFTTT Type = "ifttt"
+
+	// TypeIlert is the Type for the ilert alerting provider
+	TypeIlert Type = "ilert"
+
+	// TypeIncidentIO is the Type for the incident-io alerting provider
+	TypeIncidentIO Type = "incident-io"
+
 	// TypeJetBrainsSpace is the Type for the jetbrains alerting provider
 	TypeJetBrainsSpace Type = "jetbrainsspace"
 
+	// TypeLine is the Type for the line alerting provider
+	TypeLine Type = "line"
+
 	// TypeMatrix is the Type for the matrix alerting provider
 	TypeMatrix Type = "matrix"
 
@@ -44,6 +62,9 @@ const (
 	// TypeMessagebird is the Type for the messagebird alerting provider
 	TypeMessagebird Type = "messagebird"
 
+	// TypeNewRelic is the Type for the newrelic alerting provider
+	TypeNewRelic Type = "newrelic"
+
 	// TypeNtfy is the Type for the ntfy alerting provider
 	TypeNtfy Type = "ntfy"
 
@@ -53,18 +74,54 @@ const (
 	// TypePagerDuty is the Type for the pagerduty alerting provider
 	TypePagerDuty Type = "pagerduty"
 
+	// TypePlivo is the Type for the plivo alerting provider
+	TypePlivo Type = "plivo"
+
 	// TypePushover is the Type for the pushover alerting provider
 	TypePushover Type = "pushover"
 
+	// TypeRocketChat is the Type for the rocketchat alerting provider
+	TypeRocketChat Type = "rocketchat"
+
+	// TypeSendGrid is the Type for the sendgrid alerting provider
+	TypeSendGrid Type = "sendgrid"
+
+	// TypeSignal is the Type for the signal alerting provider
+	TypeSignal Type = "signal"
+
+	// TypeSIGNL4 is the Type for the signl4 alerting provider
+	TypeSIGNL4 Type = "signl4"
+
 	// TypeSlack is the Type for the slack alerting provider
 	TypeSlack Type = "slack"
 
+	// TypeSplunk is the Type for the splunk alerting provider
+	TypeSplunk Type = "splunk"
+
+	// TypeSquadcast is the Type for the squadcast alerting provider
+	TypeSquadcast Type = "squadcast"
+
 	// TypeTeams is the Type for the teams alerting provider
 	TypeTeams Type = "teams"
 
+	// TypeTeamsWorkflows is the Type for the teams-workflows alerting provider
+	TypeTeamsWorkflows Type = "teams-workflows"
+
 	// TypeTelegram is the Type for the telegram alerting provider
 	TypeTelegram Type = "telegram"
 
 	// TypeTwilio is the Type for the twilio alerting provider
 	TypeTwilio Type = "twilio"
+
+	// TypeVonage is the Type for the vonage alerting provider
+	TypeVonage Type = "vonage"
+
+	// TypeWebex is the Type for the webex alerting provider
+	TypeWebex Type = "webex"
+
+	// TypeZapier is the Type for the zapier alerting provider
+	TypeZapier Type = "zapier"
+
+	// TypeZulip is the Type for the Zulip alerting provider
+	TypeZulip Type = "zulip"
 )

alerting/config.go

@@ -1,7 +1,6 @@
 package alerting
 
 import (
-	"log"
 	"reflect"
 	"strings"
 
@@ -9,6 +8,7 @@ import (
 	"github.com/TwiN/gatus/v5/alerting/provider"
 	"github.com/TwiN/gatus/v5/alerting/provider/awsses"
 	"github.com/TwiN/gatus/v5/alerting/provider/custom"
+	"github.com/TwiN/gatus/v5/alerting/provider/datadog"
 	"github.com/TwiN/gatus/v5/alerting/provider/discord"
 	"github.com/TwiN/gatus/v5/alerting/provider/email"
 	"github.com/TwiN/gatus/v5/alerting/provider/gitea"
@@ -16,18 +16,37 @@ import (
 	"github.com/TwiN/gatus/v5/alerting/provider/gitlab"
 	"github.com/TwiN/gatus/v5/alerting/provider/googlechat"
 	"github.com/TwiN/gatus/v5/alerting/provider/gotify"
+	"github.com/TwiN/gatus/v5/alerting/provider/homeassistant"
+	"github.com/TwiN/gatus/v5/alerting/provider/ifttt"
+	"github.com/TwiN/gatus/v5/alerting/provider/ilert"
+	"github.com/TwiN/gatus/v5/alerting/provider/incidentio"
 	"github.com/TwiN/gatus/v5/alerting/provider/jetbrainsspace"
+	"github.com/TwiN/gatus/v5/alerting/provider/line"
 	"github.com/TwiN/gatus/v5/alerting/provider/matrix"
 	"github.com/TwiN/gatus/v5/alerting/provider/mattermost"
 	"github.com/TwiN/gatus/v5/alerting/provider/messagebird"
+	"github.com/TwiN/gatus/v5/alerting/provider/newrelic"
 	"github.com/TwiN/gatus/v5/alerting/provider/ntfy"
 	"github.com/TwiN/gatus/v5/alerting/provider/opsgenie"
 	"github.com/TwiN/gatus/v5/alerting/provider/pagerduty"
+	"github.com/TwiN/gatus/v5/alerting/provider/plivo"
 	"github.com/TwiN/gatus/v5/alerting/provider/pushover"
+	"github.com/TwiN/gatus/v5/alerting/provider/rocketchat"
+	"github.com/TwiN/gatus/v5/alerting/provider/sendgrid"
+	"github.com/TwiN/gatus/v5/alerting/provider/signal"
+	"github.com/TwiN/gatus/v5/alerting/provider/signl4"
 	"github.com/TwiN/gatus/v5/alerting/provider/slack"
+	"github.com/TwiN/gatus/v5/alerting/provider/splunk"
+	"github.com/TwiN/gatus/v5/alerting/provider/squadcast"
 	"github.com/TwiN/gatus/v5/alerting/provider/teams"
+	"github.com/TwiN/gatus/v5/alerting/provider/teamsworkflows"
 	"github.com/TwiN/gatus/v5/alerting/provider/telegram"
 	"github.com/TwiN/gatus/v5/alerting/provider/twilio"
+	"github.com/TwiN/gatus/v5/alerting/provider/vonage"
+	"github.com/TwiN/gatus/v5/alerting/provider/webex"
+	"github.com/TwiN/gatus/v5/alerting/provider/zapier"
+	"github.com/TwiN/gatus/v5/alerting/provider/zulip"
+	"github.com/TwiN/logr"
 )
 
 // Config is the configuration for alerting providers
@@ -38,12 +57,16 @@ type Config struct {
 	// Custom is the configuration for the custom alerting provider
 	Custom *custom.AlertProvider `yaml:"custom,omitempty"`
 
+	// Datadog is the configuration for the datadog alerting provider
+	Datadog *datadog.AlertProvider `yaml:"datadog,omitempty"`
+
 	// Discord is the configuration for the discord alerting provider
 	Discord *discord.AlertProvider `yaml:"discord,omitempty"`
 
 	// Email is the configuration for the email alerting provider
 	Email *email.AlertProvider `yaml:"email,omitempty"`
 
+
 	// GitHub is the configuration for the github alerting provider
 	GitHub *github.AlertProvider `yaml:"github,omitempty"`
 
@@ -58,10 +81,25 @@ type Config struct {
 
 	// Gotify is the configuration for the gotify alerting provider
 	Gotify *gotify.AlertProvider `yaml:"gotify,omitempty"`
+  
+	// HomeAssistant is the configuration for the homeassistant alerting provider
+	HomeAssistant *homeassistant.AlertProvider `yaml:"homeassistant,omitempty"`
+
+	// IFTTT is the configuration for the ifttt alerting provider
+	IFTTT *ifttt.AlertProvider `yaml:"ifttt,omitempty"`
+  
+	// Ilert is the configuration for the ilert alerting provider
+	Ilert *ilert.AlertProvider `yaml:"ilert,omitempty"`
+
+	// IncidentIO is the configuration for the incident-io alerting provider
+	IncidentIO *incidentio.AlertProvider `yaml:"incident-io,omitempty"`
 
 	// JetBrainsSpace is the configuration for the jetbrains space alerting provider
 	JetBrainsSpace *jetbrainsspace.AlertProvider `yaml:"jetbrainsspace,omitempty"`
 
+	// Line is the configuration for the line alerting provider
+	Line *line.AlertProvider `yaml:"line,omitempty"`
+
 	// Matrix is the configuration for the matrix alerting provider
 	Matrix *matrix.AlertProvider `yaml:"matrix,omitempty"`
 
@@ -71,6 +109,9 @@ type Config struct {
 	// Messagebird is the configuration for the messagebird alerting provider
 	Messagebird *messagebird.AlertProvider `yaml:"messagebird,omitempty"`
 
+	// NewRelic is the configuration for the newrelic alerting provider
+	NewRelic *newrelic.AlertProvider `yaml:"newrelic,omitempty"`
+
 	// Ntfy is the configuration for the ntfy alerting provider
 	Ntfy *ntfy.AlertProvider `yaml:"ntfy,omitempty"`
 
@@ -80,20 +121,56 @@ type Config struct {
 	// PagerDuty is the configuration for the pagerduty alerting provider
 	PagerDuty *pagerduty.AlertProvider `yaml:"pagerduty,omitempty"`
 
+	// Plivo is the configuration for the plivo alerting provider
+	Plivo *plivo.AlertProvider `yaml:"plivo,omitempty"`
+
 	// Pushover is the configuration for the pushover alerting provider
 	Pushover *pushover.AlertProvider `yaml:"pushover,omitempty"`
 
+	// RocketChat is the configuration for the rocketchat alerting provider
+	RocketChat *rocketchat.AlertProvider `yaml:"rocketchat,omitempty"`
+
+	// SendGrid is the configuration for the sendgrid alerting provider
+	SendGrid *sendgrid.AlertProvider `yaml:"sendgrid,omitempty"`
+
+	// Signal is the configuration for the signal alerting provider
+	Signal *signal.AlertProvider `yaml:"signal,omitempty"`
+
+	// SIGNL4 is the configuration for the signl4 alerting provider
+	SIGNL4 *signl4.AlertProvider `yaml:"signl4,omitempty"`
+
 	// Slack is the configuration for the slack alerting provider
 	Slack *slack.AlertProvider `yaml:"slack,omitempty"`
 
+	// Splunk is the configuration for the splunk alerting provider
+	Splunk *splunk.AlertProvider `yaml:"splunk,omitempty"`
+
+	// Squadcast is the configuration for the squadcast alerting provider
+	Squadcast *squadcast.AlertProvider `yaml:"squadcast,omitempty"`
+
 	// Teams is the configuration for the teams alerting provider
 	Teams *teams.AlertProvider `yaml:"teams,omitempty"`
 
+	// TeamsWorkflows is the configuration for the teams alerting provider using the new Workflow App Webhook Connector
+	TeamsWorkflows *teamsworkflows.AlertProvider `yaml:"teams-workflows,omitempty"`
+
 	// Telegram is the configuration for the telegram alerting provider
 	Telegram *telegram.AlertProvider `yaml:"telegram,omitempty"`
 
 	// Twilio is the configuration for the twilio alerting provider
 	Twilio *twilio.AlertProvider `yaml:"twilio,omitempty"`
+
+	// Vonage is the configuration for the vonage alerting provider
+	Vonage *vonage.AlertProvider `yaml:"vonage,omitempty"`
+
+	// Webex is the configuration for the webex alerting provider
+	Webex *webex.AlertProvider `yaml:"webex,omitempty"`
+
+	// Zapier is the configuration for the zapier alerting provider
+	Zapier *zapier.AlertProvider `yaml:"zapier,omitempty"`
+
+	// Zulip is the configuration for the zulip alerting provider
+	Zulip *zulip.AlertProvider `yaml:"zulip,omitempty"`
 }
 
 // GetAlertingProviderByAlertType returns an provider.AlertProvider by its corresponding alert.Type
@@ -110,7 +187,7 @@ func (config *Config) GetAlertingProviderByAlertType(alertType alert.Type) provi
 			return fieldValue.Interface().(provider.AlertProvider)
 		}
 	}
-	log.Printf("[alerting.GetAlertingProviderByAlertType] No alerting provider found for alert type %s", alertType)
+	logr.Infof("[alerting.GetAlertingProviderByAlertType] No alerting provider found for alert type %s", alertType)
 	return nil
 }
 

alerting/provider/awsses/awsses.go

@@ -1,30 +1,73 @@
 package awsses
 
 import (
+	"errors"
 	"fmt"
 	"strings"
 
 	"github.com/TwiN/gatus/v5/alerting/alert"
 	"github.com/TwiN/gatus/v5/config/endpoint"
+	"github.com/TwiN/logr"
 	"github.com/aws/aws-sdk-go/aws"
 	"github.com/aws/aws-sdk-go/aws/awserr"
 	"github.com/aws/aws-sdk-go/aws/credentials"
 	"github.com/aws/aws-sdk-go/aws/session"
 	"github.com/aws/aws-sdk-go/service/ses"
+	"gopkg.in/yaml.v3"
 )
 
 const (
 	CharSet = "UTF-8"
 )
 
-// AlertProvider is the configuration necessary for sending an alert using AWS Simple Email Service
-type AlertProvider struct {
+var (
+	ErrDuplicateGroupOverride = errors.New("duplicate group override")
+	ErrMissingFromOrToFields  = errors.New("from and to fields are required")
+	ErrInvalidAWSAuthConfig   = errors.New("either both or neither of access-key-id and secret-access-key must be specified")
+)
+
+type Config struct {
 	AccessKeyID     string `yaml:"access-key-id"`
 	SecretAccessKey string `yaml:"secret-access-key"`
 	Region          string `yaml:"region"`
 
 	From string `yaml:"from"`
 	To   string `yaml:"to"`
+}
+
+func (cfg *Config) Validate() error {
+	if len(cfg.From) == 0 || len(cfg.To) == 0 {
+		return ErrMissingFromOrToFields
+	}
+	if !((len(cfg.AccessKeyID) == 0 && len(cfg.SecretAccessKey) == 0) || (len(cfg.AccessKeyID) > 0 && len(cfg.SecretAccessKey) > 0)) {
+		// if both AccessKeyID and SecretAccessKey are specified, we'll use these to authenticate,
+		// otherwise if neither are specified, then we'll fall back on IAM authentication.
+		return ErrInvalidAWSAuthConfig
+	}
+	return nil
+}
+
+func (cfg *Config) Merge(override *Config) {
+	if len(override.AccessKeyID) > 0 {
+		cfg.AccessKeyID = override.AccessKeyID
+	}
+	if len(override.SecretAccessKey) > 0 {
+		cfg.SecretAccessKey = override.SecretAccessKey
+	}
+	if len(override.Region) > 0 {
+		cfg.Region = override.Region
+	}
+	if len(override.From) > 0 {
+		cfg.From = override.From
+	}
+	if len(override.To) > 0 {
+		cfg.To = override.To
+	}
+}
+
+// AlertProvider is the configuration necessary for sending an alert using AWS Simple Email Service
+type AlertProvider struct {
+	DefaultConfig Config `yaml:",inline"`
 
 	// DefaultAlert is the default alert configuration to use for endpoints with an alert of the appropriate type
 	DefaultAlert *alert.Alert `yaml:"default-alert,omitempty"`
@@ -35,36 +78,37 @@ type AlertProvider struct {
 
 // Override is a case under which the default integration is overridden
 type Override struct {
-	Group string `yaml:"group"`
-	To    string `yaml:"to"`
+	Group  string `yaml:"group"`
+	Config `yaml:",inline"`
 }
 
-// IsValid returns whether the provider's configuration is valid
-func (provider *AlertProvider) IsValid() bool {
+// Validate the provider's configuration
+func (provider *AlertProvider) Validate() error {
 	registeredGroups := make(map[string]bool)
 	if provider.Overrides != nil {
 		for _, override := range provider.Overrides {
 			if isAlreadyRegistered := registeredGroups[override.Group]; isAlreadyRegistered || override.Group == "" || len(override.To) == 0 {
-				return false
+				return ErrDuplicateGroupOverride
 			}
 			registeredGroups[override.Group] = true
 		}
 	}
-	// if both AccessKeyID and SecretAccessKey are specified, we'll use these to authenticate,
-	// otherwise if neither are specified, then we'll fall back on IAM authentication.
-	return len(provider.From) > 0 && len(provider.To) > 0 &&
-		((len(provider.AccessKeyID) == 0 && len(provider.SecretAccessKey) == 0) || (len(provider.AccessKeyID) > 0 && len(provider.SecretAccessKey) > 0))
+	return provider.DefaultConfig.Validate()
 }
 
 // Send an alert using the provider
 func (provider *AlertProvider) Send(ep *endpoint.Endpoint, alert *alert.Alert, result *endpoint.Result, resolved bool) error {
-	sess, err := provider.createSession()
+	cfg, err := provider.GetConfig(ep.Group, alert)
 	if err != nil {
 		return err
 	}
-	svc := ses.New(sess)
+	awsSession, err := provider.createSession(cfg)
+	if err != nil {
+		return err
+	}
+	svc := ses.New(awsSession)
 	subject, body := provider.buildMessageSubjectAndBody(ep, alert, result, resolved)
-	emails := strings.Split(provider.getToForGroup(ep.Group), ",")
+	emails := strings.Split(cfg.To, ",")
 
 	input := &ses.SendEmailInput{
 		Destination: &ses.Destination{
@@ -82,26 +126,24 @@ func (provider *AlertProvider) Send(ep *endpoint.Endpoint, alert *alert.Alert, r
 				Data:    aws.String(subject),
 			},
 		},
-		Source: aws.String(provider.From),
+		Source: aws.String(cfg.From),
 	}
-	_, err = svc.SendEmail(input)
-
-	if err != nil {
+	if _, err = svc.SendEmail(input); err != nil {
 		if aerr, ok := err.(awserr.Error); ok {
 			switch aerr.Code() {
 			case ses.ErrCodeMessageRejected:
-				fmt.Println(ses.ErrCodeMessageRejected, aerr.Error())
+				logr.Error(ses.ErrCodeMessageRejected + ": " + aerr.Error())
 			case ses.ErrCodeMailFromDomainNotVerifiedException:
-				fmt.Println(ses.ErrCodeMailFromDomainNotVerifiedException, aerr.Error())
+				logr.Error(ses.ErrCodeMailFromDomainNotVerifiedException + ": " + aerr.Error())
 			case ses.ErrCodeConfigurationSetDoesNotExistException:
-				fmt.Println(ses.ErrCodeConfigurationSetDoesNotExistException, aerr.Error())
+				logr.Error(ses.ErrCodeConfigurationSetDoesNotExistException + ": " + aerr.Error())
 			default:
-				fmt.Println(aerr.Error())
+				logr.Error(aerr.Error())
 			}
 		} else {
 			// Print the error, cast err to awserr.Error to get the Code and
 			// Message from an error.
-			fmt.Println(err.Error())
+			logr.Error(err.Error())
 		}
 
 		return err
@@ -109,6 +151,16 @@ func (provider *AlertProvider) Send(ep *endpoint.Endpoint, alert *alert.Alert, r
 	return nil
 }
 
+func (provider *AlertProvider) createSession(cfg *Config) (*session.Session, error) {
+	awsConfig := &aws.Config{
+		Region: aws.String(cfg.Region),
+	}
+	if len(cfg.AccessKeyID) > 0 && len(cfg.SecretAccessKey) > 0 {
+		awsConfig.Credentials = credentials.NewStaticCredentials(cfg.AccessKeyID, cfg.SecretAccessKey, "")
+	}
+	return session.NewSession(awsConfig)
+}
+
 // buildMessageSubjectAndBody builds the message subject and body
 func (provider *AlertProvider) buildMessageSubjectAndBody(ep *endpoint.Endpoint, alert *alert.Alert, result *endpoint.Result, resolved bool) (string, string) {
 	var subject, message string
@@ -139,29 +191,38 @@ func (provider *AlertProvider) buildMessageSubjectAndBody(ep *endpoint.Endpoint,
 	return subject, message + description + formattedConditionResults
 }
 
-// getToForGroup returns the appropriate email integration to for a given group
-func (provider *AlertProvider) getToForGroup(group string) string {
-	if provider.Overrides != nil {
-		for _, override := range provider.Overrides {
-			if group == override.Group {
-				return override.To
-			}
-		}
-	}
-	return provider.To
-}
-
 // GetDefaultAlert returns the provider's default alert configuration
 func (provider *AlertProvider) GetDefaultAlert() *alert.Alert {
 	return provider.DefaultAlert
 }
 
-func (provider *AlertProvider) createSession() (*session.Session, error) {
-	config := &aws.Config{
-		Region: aws.String(provider.Region),
+// GetConfig returns the configuration for the provider with the overrides applied
+func (provider *AlertProvider) GetConfig(group string, alert *alert.Alert) (*Config, error) {
+	cfg := provider.DefaultConfig
+	// Handle group overrides
+	if provider.Overrides != nil {
+		for _, override := range provider.Overrides {
+			if group == override.Group {
+				cfg.Merge(&override.Config)
+				break
+			}
+		}
 	}
-	if len(provider.AccessKeyID) > 0 && len(provider.SecretAccessKey) > 0 {
-		config.Credentials = credentials.NewStaticCredentials(provider.AccessKeyID, provider.SecretAccessKey, "")
+	// Handle alert overrides
+	if len(alert.ProviderOverride) != 0 {
+		overrideConfig := Config{}
+		if err := yaml.Unmarshal(alert.ProviderOverrideAsBytes(), &overrideConfig); err != nil {
+			return nil, err
+		}
+		cfg.Merge(&overrideConfig)
 	}
-	return session.NewSession(config)
+	// Validate the configuration
+	err := cfg.Validate()
+	return &cfg, err
+}
+
+// ValidateOverrides validates the alert's provider override and, if present, the group override
+func (provider *AlertProvider) ValidateOverrides(group string, alert *alert.Alert) error {
+	_, err := provider.GetConfig(group, alert)
+	return err
 }

alerting/provider/awsses/awsses_test.go

@@ -7,59 +7,61 @@ import (
 	"github.com/TwiN/gatus/v5/config/endpoint"
 )
 
-func TestAlertDefaultProvider_IsValid(t *testing.T) {
+func TestAlertProvider_Validate(t *testing.T) {
 	invalidProvider := AlertProvider{}
-	if invalidProvider.IsValid() {
+	if err := invalidProvider.Validate(); err == nil {
 		t.Error("provider shouldn't have been valid")
 	}
-	invalidProviderWithOneKey := AlertProvider{From: "from@example.com", To: "to@example.com", AccessKeyID: "1"}
-	if invalidProviderWithOneKey.IsValid() {
+	invalidProviderWithOneKey := AlertProvider{DefaultConfig: Config{From: "from@example.com", To: "to@example.com", AccessKeyID: "1"}}
+	if err := invalidProviderWithOneKey.Validate(); err == nil {
 		t.Error("provider shouldn't have been valid")
 	}
-	validProvider := AlertProvider{From: "from@example.com", To: "to@example.com"}
-	if !validProvider.IsValid() {
+	validProvider := AlertProvider{DefaultConfig: Config{From: "from@example.com", To: "to@example.com"}}
+	if err := validProvider.Validate(); err != nil {
 		t.Error("provider should've been valid")
 	}
-	validProviderWithKeys := AlertProvider{From: "from@example.com", To: "to@example.com", AccessKeyID: "1", SecretAccessKey: "1"}
-	if !validProviderWithKeys.IsValid() {
+	validProviderWithKeys := AlertProvider{DefaultConfig: Config{From: "from@example.com", To: "to@example.com", AccessKeyID: "1", SecretAccessKey: "1"}}
+	if err := validProviderWithKeys.Validate(); err != nil {
 		t.Error("provider should've been valid")
 	}
 }
 
-func TestAlertProvider_IsValidWithOverride(t *testing.T) {
+func TestAlertProvider_ValidateWithOverride(t *testing.T) {
 	providerWithInvalidOverrideGroup := AlertProvider{
 		Overrides: []Override{
 			{
-				To:    "to@example.com",
-				Group: "",
+				Config: Config{To: "to@example.com"},
+				Group:  "",
 			},
 		},
 	}
-	if providerWithInvalidOverrideGroup.IsValid() {
+	if err := providerWithInvalidOverrideGroup.Validate(); err == nil {
 		t.Error("provider Group shouldn't have been valid")
 	}
 	providerWithInvalidOverrideTo := AlertProvider{
 		Overrides: []Override{
 			{
-				To:    "",
-				Group: "group",
+				Config: Config{To: ""},
+				Group:  "group",
 			},
 		},
 	}
-	if providerWithInvalidOverrideTo.IsValid() {
+	if err := providerWithInvalidOverrideTo.Validate(); err == nil {
 		t.Error("provider integration key shouldn't have been valid")
 	}
 	providerWithValidOverride := AlertProvider{
-		From: "from@example.com",
-		To:   "to@example.com",
+		DefaultConfig: Config{
+			From: "from@example.com",
+			To:   "to@example.com",
+		},
 		Overrides: []Override{
 			{
-				To:    "to@example.com",
-				Group: "group",
+				Config: Config{To: "to@example.com"},
+				Group:  "group",
 			},
 		},
 	}
-	if !providerWithValidOverride.IsValid() {
+	if err := providerWithValidOverride.Validate(); err != nil {
 		t.Error("provider should've been valid")
 	}
 }
@@ -124,64 +126,124 @@ func TestAlertProvider_GetDefaultAlert(t *testing.T) {
 	}
 }
 
-func TestAlertProvider_getToForGroup(t *testing.T) {
-	tests := []struct {
+func TestAlertProvider_getConfigWithOverrides(t *testing.T) {
+	scenarios := []struct {
 		Name           string
 		Provider       AlertProvider
 		InputGroup     string
-		ExpectedOutput string
+		InputAlert     alert.Alert
+		ExpectedOutput Config
 	}{
 		{
 			Name: "provider-no-override-specify-no-group-should-default",
 			Provider: AlertProvider{
-				To:        "to@example.com",
+				DefaultConfig: Config{
+					From: "from@example.com",
+					To:   "to@example.com",
+				},
 				Overrides: nil,
 			},
 			InputGroup:     "",
-			ExpectedOutput: "to@example.com",
+			InputAlert:     alert.Alert{},
+			ExpectedOutput: Config{From: "from@example.com", To: "to@example.com"},
 		},
 		{
 			Name: "provider-no-override-specify-group-should-default",
 			Provider: AlertProvider{
-				To:        "to@example.com",
+				DefaultConfig: Config{
+					From: "from@example.com",
+					To:   "to@example.com",
+				},
 				Overrides: nil,
 			},
 			InputGroup:     "group",
-			ExpectedOutput: "to@example.com",
+			InputAlert:     alert.Alert{},
+			ExpectedOutput: Config{From: "from@example.com", To: "to@example.com"},
 		},
 		{
 			Name: "provider-with-override-specify-no-group-should-default",
 			Provider: AlertProvider{
-				To: "to@example.com",
+				DefaultConfig: Config{
+					From: "from@example.com",
+					To:   "to@example.com",
+				},
 				Overrides: []Override{
 					{
-						Group: "group",
-						To:    "to01@example.com",
+						Group:  "group",
+						Config: Config{To: "groupto@example.com"},
 					},
 				},
 			},
 			InputGroup:     "",
-			ExpectedOutput: "to@example.com",
+			InputAlert:     alert.Alert{},
+			ExpectedOutput: Config{From: "from@example.com", To: "to@example.com"},
 		},
 		{
 			Name: "provider-with-override-specify-group-should-override",
 			Provider: AlertProvider{
-				To: "to@example.com",
+				DefaultConfig: Config{
+					From: "from@example.com",
+					To:   "to@example.com",
+				},
 				Overrides: []Override{
 					{
-						Group: "group",
-						To:    "to01@example.com",
+						Group:  "group",
+						Config: Config{To: "groupto@example.com", SecretAccessKey: "wow", AccessKeyID: "noway"},
 					},
 				},
 			},
 			InputGroup:     "group",
-			ExpectedOutput: "to01@example.com",
+			InputAlert:     alert.Alert{},
+			ExpectedOutput: Config{From: "from@example.com", To: "groupto@example.com", SecretAccessKey: "wow", AccessKeyID: "noway"},
+		},
+		{
+			Name: "provider-with-override-specify-group-but-alert-override-should-override-group-override",
+			Provider: AlertProvider{
+				DefaultConfig: Config{
+					From: "from@example.com",
+					To:   "to@example.com",
+				},
+				Overrides: []Override{
+					{
+						Group:  "group",
+						Config: Config{From: "from@example.com", To: "groupto@example.com", SecretAccessKey: "sekrit"},
+					},
+				},
+			},
+			InputGroup: "group",
+			InputAlert: alert.Alert{
+				ProviderOverride: map[string]any{
+					"to":            "alertto@example.com",
+					"access-key-id": 123,
+				},
+			},
+			ExpectedOutput: Config{To: "alertto@example.com", From: "from@example.com", AccessKeyID: "123", SecretAccessKey: "sekrit"},
 		},
 	}
-	for _, tt := range tests {
-		t.Run(tt.Name, func(t *testing.T) {
-			if got := tt.Provider.getToForGroup(tt.InputGroup); got != tt.ExpectedOutput {
-				t.Errorf("AlertProvider.getToForGroup() = %v, want %v", got, tt.ExpectedOutput)
+	for _, scenario := range scenarios {
+		t.Run(scenario.Name, func(t *testing.T) {
+			got, err := scenario.Provider.GetConfig(scenario.InputGroup, &scenario.InputAlert)
+			if err != nil {
+				t.Fatalf("unexpected error: %s", err)
+			}
+			if got.From != scenario.ExpectedOutput.From {
+				t.Errorf("expected From to be %s, got %s", scenario.ExpectedOutput.From, got.From)
+			}
+			if got.To != scenario.ExpectedOutput.To {
+				t.Errorf("expected To to be %s, got %s", scenario.ExpectedOutput.To, got.To)
+			}
+			if got.AccessKeyID != scenario.ExpectedOutput.AccessKeyID {
+				t.Errorf("expected AccessKeyID to be %s, got %s", scenario.ExpectedOutput.AccessKeyID, got.AccessKeyID)
+			}
+			if got.SecretAccessKey != scenario.ExpectedOutput.SecretAccessKey {
+				t.Errorf("expected SecretAccessKey to be %s, got %s", scenario.ExpectedOutput.SecretAccessKey, got.SecretAccessKey)
+			}
+			if got.Region != scenario.ExpectedOutput.Region {
+				t.Errorf("expected Region to be %s, got %s", scenario.ExpectedOutput.Region, got.Region)
+			}
+			// Test ValidateOverrides as well, since it really just calls GetConfig
+			if err = scenario.Provider.ValidateOverrides(scenario.InputGroup, &scenario.InputAlert); err != nil {
+				t.Errorf("unexpected error: %s", err)
 			}
 		})
 	}

alerting/provider/custom/custom.go

@@ -2,6 +2,7 @@ package custom
 
 import (
 	"bytes"
+	"errors"
 	"fmt"
 	"io"
 	"net/http"
@@ -10,11 +11,14 @@ import (
 	"github.com/TwiN/gatus/v5/alerting/alert"
 	"github.com/TwiN/gatus/v5/client"
 	"github.com/TwiN/gatus/v5/config/endpoint"
+	"gopkg.in/yaml.v3"
 )
 
-// AlertProvider is the configuration necessary for sending an alert using a custom HTTP request
-// Technically, all alert providers should be reachable using the custom alert provider
-type AlertProvider struct {
+var (
+	ErrURLNotSet = errors.New("url not set")
+)
+
+type Config struct {
 	URL          string                       `yaml:"url"`
 	Method       string                       `yaml:"method,omitempty"`
 	Body         string                       `yaml:"body,omitempty"`
@@ -23,64 +27,66 @@ type AlertProvider struct {
 
 	// ClientConfig is the configuration of the client used to communicate with the provider's target
 	ClientConfig *client.Config `yaml:"client,omitempty"`
+}
+
+func (cfg *Config) Validate() error {
+	if len(cfg.URL) == 0 {
+		return ErrURLNotSet
+	}
+	return nil
+}
+
+func (cfg *Config) Merge(override *Config) {
+	if override.ClientConfig != nil {
+		cfg.ClientConfig = override.ClientConfig
+	}
+	if len(override.URL) > 0 {
+		cfg.URL = override.URL
+	}
+	if len(override.Method) > 0 {
+		cfg.Method = override.Method
+	}
+	if len(override.Body) > 0 {
+		cfg.Body = override.Body
+	}
+	if len(override.Headers) > 0 {
+		cfg.Headers = override.Headers
+	}
+	if len(override.Placeholders) > 0 {
+		cfg.Placeholders = override.Placeholders
+	}
+}
+
+// AlertProvider is the configuration necessary for sending an alert using a custom HTTP request
+// Technically, all alert providers should be reachable using the custom alert provider
+type AlertProvider struct {
+	DefaultConfig Config `yaml:",inline"`
 
 	// DefaultAlert is the default alert configuration to use for endpoints with an alert of the appropriate type
 	DefaultAlert *alert.Alert `yaml:"default-alert,omitempty"`
+
+	// Overrides is a list of Override that may be prioritized over the default configuration
+	Overrides []Override `yaml:"overrides,omitempty"`
 }
 
-// IsValid returns whether the provider's configuration is valid
-func (provider *AlertProvider) IsValid() bool {
-	if provider.ClientConfig == nil {
-		provider.ClientConfig = client.GetDefaultConfig()
-	}
-	return len(provider.URL) > 0 && provider.ClientConfig != nil
+// Override is a case under which the default integration is overridden
+type Override struct {
+	Group  string `yaml:"group"`
+	Config `yaml:",inline"`
 }
 
-// GetAlertStatePlaceholderValue returns the Placeholder value for ALERT_TRIGGERED_OR_RESOLVED if configured
-func (provider *AlertProvider) GetAlertStatePlaceholderValue(resolved bool) string {
-	status := "TRIGGERED"
-	if resolved {
-		status = "RESOLVED"
-	}
-	if _, ok := provider.Placeholders["ALERT_TRIGGERED_OR_RESOLVED"]; ok {
-		if val, ok := provider.Placeholders["ALERT_TRIGGERED_OR_RESOLVED"][status]; ok {
-			return val
-		}
-	}
-	return status
-}
-
-func (provider *AlertProvider) buildHTTPRequest(ep *endpoint.Endpoint, alert *alert.Alert, resolved bool) *http.Request {
-	body, url, method := provider.Body, provider.URL, provider.Method
-	body = strings.ReplaceAll(body, "[ALERT_DESCRIPTION]", alert.GetDescription())
-	url = strings.ReplaceAll(url, "[ALERT_DESCRIPTION]", alert.GetDescription())
-	body = strings.ReplaceAll(body, "[ENDPOINT_NAME]", ep.Name)
-	url = strings.ReplaceAll(url, "[ENDPOINT_NAME]", ep.Name)
-	body = strings.ReplaceAll(body, "[ENDPOINT_GROUP]", ep.Group)
-	url = strings.ReplaceAll(url, "[ENDPOINT_GROUP]", ep.Group)
-	body = strings.ReplaceAll(body, "[ENDPOINT_URL]", ep.URL)
-	url = strings.ReplaceAll(url, "[ENDPOINT_URL]", ep.URL)
-	if resolved {
-		body = strings.ReplaceAll(body, "[ALERT_TRIGGERED_OR_RESOLVED]", provider.GetAlertStatePlaceholderValue(true))
-		url = strings.ReplaceAll(url, "[ALERT_TRIGGERED_OR_RESOLVED]", provider.GetAlertStatePlaceholderValue(true))
-	} else {
-		body = strings.ReplaceAll(body, "[ALERT_TRIGGERED_OR_RESOLVED]", provider.GetAlertStatePlaceholderValue(false))
-		url = strings.ReplaceAll(url, "[ALERT_TRIGGERED_OR_RESOLVED]", provider.GetAlertStatePlaceholderValue(false))
-	}
-	if len(method) == 0 {
-		method = http.MethodGet
-	}
-	bodyBuffer := bytes.NewBuffer([]byte(body))
-	request, _ := http.NewRequest(method, url, bodyBuffer)
-	for k, v := range provider.Headers {
-		request.Header.Set(k, v)
-	}
-	return request
+// Validate the provider's configuration
+func (provider *AlertProvider) Validate() error {
+	return provider.DefaultConfig.Validate()
 }
 
 func (provider *AlertProvider) Send(ep *endpoint.Endpoint, alert *alert.Alert, result *endpoint.Result, resolved bool) error {
-	request := provider.buildHTTPRequest(ep, alert, resolved)
-	response, err := client.GetHTTPClient(provider.ClientConfig).Do(request)
+	cfg, err := provider.GetConfig(ep.Group, alert)
+	if err != nil {
+		return err
+	}
+	request := provider.buildHTTPRequest(cfg, ep, alert, result, resolved)
+	response, err := client.GetHTTPClient(cfg.ClientConfig).Do(request)
 	if err != nil {
 		return err
 	}
@@ -92,7 +98,83 @@ func (provider *AlertProvider) Send(ep *endpoint.Endpoint, alert *alert.Alert, r
 	return err
 }
 
+func (provider *AlertProvider) buildHTTPRequest(cfg *Config, ep *endpoint.Endpoint, alert *alert.Alert, result *endpoint.Result, resolved bool) *http.Request {
+	body, url, method := cfg.Body, cfg.URL, cfg.Method
+	body = strings.ReplaceAll(body, "[ALERT_DESCRIPTION]", alert.GetDescription())
+	url = strings.ReplaceAll(url, "[ALERT_DESCRIPTION]", alert.GetDescription())
+	body = strings.ReplaceAll(body, "[ENDPOINT_NAME]", ep.Name)
+	url = strings.ReplaceAll(url, "[ENDPOINT_NAME]", ep.Name)
+	body = strings.ReplaceAll(body, "[ENDPOINT_GROUP]", ep.Group)
+	url = strings.ReplaceAll(url, "[ENDPOINT_GROUP]", ep.Group)
+	body = strings.ReplaceAll(body, "[ENDPOINT_URL]", ep.URL)
+	url = strings.ReplaceAll(url, "[ENDPOINT_URL]", ep.URL)
+	resultErrors := strings.ReplaceAll(strings.Join(result.Errors, ","), "\"", "\\\"")
+	body = strings.ReplaceAll(body, "[RESULT_ERRORS]", resultErrors)
+	url = strings.ReplaceAll(url, "[RESULT_ERRORS]", resultErrors)
+	if resolved {
+		body = strings.ReplaceAll(body, "[ALERT_TRIGGERED_OR_RESOLVED]", provider.GetAlertStatePlaceholderValue(cfg, true))
+		url = strings.ReplaceAll(url, "[ALERT_TRIGGERED_OR_RESOLVED]", provider.GetAlertStatePlaceholderValue(cfg, true))
+	} else {
+		body = strings.ReplaceAll(body, "[ALERT_TRIGGERED_OR_RESOLVED]", provider.GetAlertStatePlaceholderValue(cfg, false))
+		url = strings.ReplaceAll(url, "[ALERT_TRIGGERED_OR_RESOLVED]", provider.GetAlertStatePlaceholderValue(cfg, false))
+	}
+	if len(method) == 0 {
+		method = http.MethodGet
+	}
+	bodyBuffer := bytes.NewBuffer([]byte(body))
+	request, _ := http.NewRequest(method, url, bodyBuffer)
+	for k, v := range cfg.Headers {
+		request.Header.Set(k, v)
+	}
+	return request
+}
+
+// GetAlertStatePlaceholderValue returns the Placeholder value for ALERT_TRIGGERED_OR_RESOLVED if configured
+func (provider *AlertProvider) GetAlertStatePlaceholderValue(cfg *Config, resolved bool) string {
+	status := "TRIGGERED"
+	if resolved {
+		status = "RESOLVED"
+	}
+	if _, ok := cfg.Placeholders["ALERT_TRIGGERED_OR_RESOLVED"]; ok {
+		if val, ok := cfg.Placeholders["ALERT_TRIGGERED_OR_RESOLVED"][status]; ok {
+			return val
+		}
+	}
+	return status
+}
+
 // GetDefaultAlert returns the provider's default alert configuration
 func (provider *AlertProvider) GetDefaultAlert() *alert.Alert {
 	return provider.DefaultAlert
 }
+
+// GetConfig returns the configuration for the provider with the overrides applied
+func (provider *AlertProvider) GetConfig(group string, alert *alert.Alert) (*Config, error) {
+	cfg := provider.DefaultConfig
+	// Handle group overrides
+	if provider.Overrides != nil {
+		for _, override := range provider.Overrides {
+			if group == override.Group {
+				cfg.Merge(&override.Config)
+				break
+			}
+		}
+	}
+	// Handle alert overrides
+	if len(alert.ProviderOverride) != 0 {
+		overrideConfig := Config{}
+		if err := yaml.Unmarshal(alert.ProviderOverrideAsBytes(), &overrideConfig); err != nil {
+			return nil, err
+		}
+		cfg.Merge(&overrideConfig)
+	}
+	// Validate the configuration
+	err := cfg.Validate()
+	return &cfg, err
+}
+
+// ValidateOverrides validates the alert's provider override and, if present, the group override
+func (provider *AlertProvider) ValidateOverrides(group string, alert *alert.Alert) error {
+	_, err := provider.GetConfig(group, alert)
+	return err
+}

alerting/provider/custom/custom_test.go

@@ -12,24 +12,18 @@ import (
 	"github.com/TwiN/gatus/v5/test"
 )
 
-func TestAlertProvider_IsValid(t *testing.T) {
+func TestAlertProvider_Validate(t *testing.T) {
 	t.Run("invalid-provider", func(t *testing.T) {
-		invalidProvider := AlertProvider{URL: ""}
-		if invalidProvider.IsValid() {
+		invalidProvider := AlertProvider{DefaultConfig: Config{URL: ""}}
+		if err := invalidProvider.Validate(); err == nil {
 			t.Error("provider shouldn't have been valid")
 		}
 	})
 	t.Run("valid-provider", func(t *testing.T) {
-		validProvider := AlertProvider{URL: "https://example.com"}
-		if validProvider.ClientConfig != nil {
-			t.Error("provider client config should have been nil prior to IsValid() being executed")
-		}
-		if !validProvider.IsValid() {
+		validProvider := AlertProvider{DefaultConfig: Config{URL: "https://example.com"}}
+		if err := validProvider.Validate(); err != nil {
 			t.Error("provider should've been valid")
 		}
-		if validProvider.ClientConfig == nil {
-			t.Error("provider client config should have been set after IsValid() was executed")
-		}
 	})
 }
 
@@ -47,7 +41,7 @@ func TestAlertProvider_Send(t *testing.T) {
 	}{
 		{
 			Name:     "triggered",
-			Provider: AlertProvider{},
+			Provider: AlertProvider{DefaultConfig: Config{URL: "https://example.com"}},
 			Alert:    alert.Alert{Description: &firstDescription, SuccessThreshold: 5, FailureThreshold: 3},
 			Resolved: false,
 			MockRoundTripper: test.MockRoundTripper(func(r *http.Request) *http.Response {
@@ -57,7 +51,7 @@ func TestAlertProvider_Send(t *testing.T) {
 		},
 		{
 			Name:     "triggered-error",
-			Provider: AlertProvider{},
+			Provider: AlertProvider{DefaultConfig: Config{URL: "https://example.com"}},
 			Alert:    alert.Alert{Description: &firstDescription, SuccessThreshold: 5, FailureThreshold: 3},
 			Resolved: false,
 			MockRoundTripper: test.MockRoundTripper(func(r *http.Request) *http.Response {
@@ -67,7 +61,7 @@ func TestAlertProvider_Send(t *testing.T) {
 		},
 		{
 			Name:     "resolved",
-			Provider: AlertProvider{},
+			Provider: AlertProvider{DefaultConfig: Config{URL: "https://example.com"}},
 			Alert:    alert.Alert{Description: &secondDescription, SuccessThreshold: 5, FailureThreshold: 3},
 			Resolved: true,
 			MockRoundTripper: test.MockRoundTripper(func(r *http.Request) *http.Response {
@@ -77,7 +71,7 @@ func TestAlertProvider_Send(t *testing.T) {
 		},
 		{
 			Name:     "resolved-error",
-			Provider: AlertProvider{},
+			Provider: AlertProvider{DefaultConfig: Config{URL: "https://example.com"}},
 			Alert:    alert.Alert{Description: &secondDescription, SuccessThreshold: 5, FailureThreshold: 3},
 			Resolved: true,
 			MockRoundTripper: test.MockRoundTripper(func(r *http.Request) *http.Response {
@@ -111,9 +105,11 @@ func TestAlertProvider_Send(t *testing.T) {
 }
 
 func TestAlertProvider_buildHTTPRequest(t *testing.T) {
-	customAlertProvider := &AlertProvider{
-		URL:  "https://example.com/[ENDPOINT_GROUP]/[ENDPOINT_NAME]?event=[ALERT_TRIGGERED_OR_RESOLVED]&description=[ALERT_DESCRIPTION]&url=[ENDPOINT_URL]",
-		Body: "[ENDPOINT_NAME],[ENDPOINT_GROUP],[ALERT_DESCRIPTION],[ENDPOINT_URL],[ALERT_TRIGGERED_OR_RESOLVED]",
+	alertProvider := &AlertProvider{
+		DefaultConfig: Config{
+			URL:  "https://example.com/[ENDPOINT_GROUP]/[ENDPOINT_NAME]?event=[ALERT_TRIGGERED_OR_RESOLVED]&description=[ALERT_DESCRIPTION]&url=[ENDPOINT_URL]",
+			Body: "[ENDPOINT_NAME],[ENDPOINT_GROUP],[ALERT_DESCRIPTION],[ENDPOINT_URL],[ALERT_TRIGGERED_OR_RESOLVED]",
+		},
 	}
 	alertDescription := "alert-description"
 	scenarios := []struct {
@@ -123,13 +119,13 @@ func TestAlertProvider_buildHTTPRequest(t *testing.T) {
 		ExpectedBody  string
 	}{
 		{
-			AlertProvider: customAlertProvider,
+			AlertProvider: alertProvider,
 			Resolved:      true,
 			ExpectedURL:   "https://example.com/endpoint-group/endpoint-name?event=RESOLVED&description=alert-description&url=https://example.com",
 			ExpectedBody:  "endpoint-name,endpoint-group,alert-description,https://example.com,RESOLVED",
 		},
 		{
-			AlertProvider: customAlertProvider,
+			AlertProvider: alertProvider,
 			Resolved:      false,
 			ExpectedURL:   "https://example.com/endpoint-group/endpoint-name?event=TRIGGERED&description=alert-description&url=https://example.com",
 			ExpectedBody:  "endpoint-name,endpoint-group,alert-description,https://example.com,TRIGGERED",
@@ -137,9 +133,67 @@ func TestAlertProvider_buildHTTPRequest(t *testing.T) {
 	}
 	for _, scenario := range scenarios {
 		t.Run(fmt.Sprintf("resolved-%v-with-default-placeholders", scenario.Resolved), func(t *testing.T) {
-			request := customAlertProvider.buildHTTPRequest(
+			request := alertProvider.buildHTTPRequest(
+				&alertProvider.DefaultConfig,
 				&endpoint.Endpoint{Name: "endpoint-name", Group: "endpoint-group", URL: "https://example.com"},
 				&alert.Alert{Description: &alertDescription},
+				&endpoint.Result{Errors: []string{}},
+				scenario.Resolved,
+			)
+			if request.URL.String() != scenario.ExpectedURL {
+				t.Error("expected URL to be", scenario.ExpectedURL, "got", request.URL.String())
+			}
+			body, _ := io.ReadAll(request.Body)
+			if string(body) != scenario.ExpectedBody {
+				t.Error("expected body to be", scenario.ExpectedBody, "got", string(body))
+			}
+		})
+	}
+}
+
+func TestAlertProviderWithResultErrors_buildHTTPRequest(t *testing.T) {
+	alertProvider := &AlertProvider{
+		DefaultConfig: Config{
+			URL:  "https://example.com/[ENDPOINT_GROUP]/[ENDPOINT_NAME]?event=[ALERT_TRIGGERED_OR_RESOLVED]&description=[ALERT_DESCRIPTION]&url=[ENDPOINT_URL]&error=[RESULT_ERRORS]",
+			Body: "[ENDPOINT_NAME],[ENDPOINT_GROUP],[ALERT_DESCRIPTION],[ENDPOINT_URL],[ALERT_TRIGGERED_OR_RESOLVED],[RESULT_ERRORS]",
+		},
+	}
+	alertDescription := "alert-description"
+	scenarios := []struct {
+		AlertProvider *AlertProvider
+		Resolved      bool
+		ExpectedURL   string
+		ExpectedBody  string
+		Errors        []string
+	}{
+		{
+			AlertProvider: alertProvider,
+			Resolved:      true,
+			ExpectedURL:   "https://example.com/endpoint-group/endpoint-name?event=RESOLVED&description=alert-description&url=https://example.com&error=",
+			ExpectedBody:  "endpoint-name,endpoint-group,alert-description,https://example.com,RESOLVED,",
+		},
+		{
+			AlertProvider: alertProvider,
+			Resolved:      false,
+			ExpectedURL:   "https://example.com/endpoint-group/endpoint-name?event=TRIGGERED&description=alert-description&url=https://example.com&error=error1,error2",
+			ExpectedBody:  "endpoint-name,endpoint-group,alert-description,https://example.com,TRIGGERED,error1,error2",
+			Errors:        []string{"error1", "error2"},
+		},
+		{
+			AlertProvider: alertProvider,
+			Resolved:      false,
+			ExpectedURL:   "https://example.com/endpoint-group/endpoint-name?event=TRIGGERED&description=alert-description&url=https://example.com&error=test \\\"error with quotes\\\"",
+			ExpectedBody:  "endpoint-name,endpoint-group,alert-description,https://example.com,TRIGGERED,test \\\"error with quotes\\\"",
+			Errors:        []string{"test \"error with quotes\""},
+		},
+	}
+	for _, scenario := range scenarios {
+		t.Run(fmt.Sprintf("resolved-%v-with-default-placeholders-and-result-errors", scenario.Resolved), func(t *testing.T) {
+			request := alertProvider.buildHTTPRequest(
+				&alertProvider.DefaultConfig,
+				&endpoint.Endpoint{Name: "endpoint-name", Group: "endpoint-group", URL: "https://example.com"},
+				&alert.Alert{Description: &alertDescription},
+				&endpoint.Result{Errors: scenario.Errors},
 				scenario.Resolved,
 			)
 			if request.URL.String() != scenario.ExpectedURL {
@@ -154,14 +208,16 @@ func TestAlertProvider_buildHTTPRequest(t *testing.T) {
 }
 
 func TestAlertProvider_buildHTTPRequestWithCustomPlaceholder(t *testing.T) {
-	customAlertProvider := &AlertProvider{
-		URL:     "https://example.com/[ENDPOINT_GROUP]/[ENDPOINT_NAME]?event=[ALERT_TRIGGERED_OR_RESOLVED]&description=[ALERT_DESCRIPTION]",
-		Body:    "[ENDPOINT_NAME],[ENDPOINT_GROUP],[ALERT_DESCRIPTION],[ALERT_TRIGGERED_OR_RESOLVED]",
-		Headers: nil,
-		Placeholders: map[string]map[string]string{
-			"ALERT_TRIGGERED_OR_RESOLVED": {
-				"RESOLVED":  "fixed",
-				"TRIGGERED": "boom",
+	alertProvider := &AlertProvider{
+		DefaultConfig: Config{
+			URL:     "https://example.com/[ENDPOINT_GROUP]/[ENDPOINT_NAME]?event=[ALERT_TRIGGERED_OR_RESOLVED]&description=[ALERT_DESCRIPTION]",
+			Body:    "[ENDPOINT_NAME],[ENDPOINT_GROUP],[ALERT_DESCRIPTION],[ALERT_TRIGGERED_OR_RESOLVED]",
+			Headers: nil,
+			Placeholders: map[string]map[string]string{
+				"ALERT_TRIGGERED_OR_RESOLVED": {
+					"RESOLVED":  "fixed",
+					"TRIGGERED": "boom",
+				},
 			},
 		},
 	}
@@ -173,13 +229,13 @@ func TestAlertProvider_buildHTTPRequestWithCustomPlaceholder(t *testing.T) {
 		ExpectedBody  string
 	}{
 		{
-			AlertProvider: customAlertProvider,
+			AlertProvider: alertProvider,
 			Resolved:      true,
 			ExpectedURL:   "https://example.com/endpoint-group/endpoint-name?event=fixed&description=alert-description",
 			ExpectedBody:  "endpoint-name,endpoint-group,alert-description,fixed",
 		},
 		{
-			AlertProvider: customAlertProvider,
+			AlertProvider: alertProvider,
 			Resolved:      false,
 			ExpectedURL:   "https://example.com/endpoint-group/endpoint-name?event=boom&description=alert-description",
 			ExpectedBody:  "endpoint-name,endpoint-group,alert-description,boom",
@@ -187,9 +243,11 @@ func TestAlertProvider_buildHTTPRequestWithCustomPlaceholder(t *testing.T) {
 	}
 	for _, scenario := range scenarios {
 		t.Run(fmt.Sprintf("resolved-%v-with-custom-placeholders", scenario.Resolved), func(t *testing.T) {
-			request := customAlertProvider.buildHTTPRequest(
+			request := alertProvider.buildHTTPRequest(
+				&alertProvider.DefaultConfig,
 				&endpoint.Endpoint{Name: "endpoint-name", Group: "endpoint-group"},
 				&alert.Alert{Description: &alertDescription},
+				&endpoint.Result{},
 				scenario.Resolved,
 			)
 			if request.URL.String() != scenario.ExpectedURL {
@@ -204,15 +262,17 @@ func TestAlertProvider_buildHTTPRequestWithCustomPlaceholder(t *testing.T) {
 }
 
 func TestAlertProvider_GetAlertStatePlaceholderValueDefaults(t *testing.T) {
-	customAlertProvider := &AlertProvider{
-		URL:  "https://example.com/[ENDPOINT_NAME]?event=[ALERT_TRIGGERED_OR_RESOLVED]&description=[ALERT_DESCRIPTION]",
-		Body: "[ENDPOINT_NAME],[ENDPOINT_GROUP],[ALERT_DESCRIPTION],[ALERT_TRIGGERED_OR_RESOLVED]",
+	alertProvider := &AlertProvider{
+		DefaultConfig: Config{
+			URL:  "https://example.com/[ENDPOINT_NAME]?event=[ALERT_TRIGGERED_OR_RESOLVED]&description=[ALERT_DESCRIPTION]",
+			Body: "[ENDPOINT_NAME],[ENDPOINT_GROUP],[ALERT_DESCRIPTION],[ALERT_TRIGGERED_OR_RESOLVED]",
+		},
 	}
-	if customAlertProvider.GetAlertStatePlaceholderValue(true) != "RESOLVED" {
-		t.Error("expected RESOLVED, got", customAlertProvider.GetAlertStatePlaceholderValue(true))
+	if alertProvider.GetAlertStatePlaceholderValue(&alertProvider.DefaultConfig, true) != "RESOLVED" {
+		t.Error("expected RESOLVED, got", alertProvider.GetAlertStatePlaceholderValue(&alertProvider.DefaultConfig, true))
 	}
-	if customAlertProvider.GetAlertStatePlaceholderValue(false) != "TRIGGERED" {
-		t.Error("expected TRIGGERED, got", customAlertProvider.GetAlertStatePlaceholderValue(false))
+	if alertProvider.GetAlertStatePlaceholderValue(&alertProvider.DefaultConfig, false) != "TRIGGERED" {
+		t.Error("expected TRIGGERED, got", alertProvider.GetAlertStatePlaceholderValue(&alertProvider.DefaultConfig, false))
 	}
 }
 
@@ -224,3 +284,119 @@ func TestAlertProvider_GetDefaultAlert(t *testing.T) {
 		t.Error("expected default alert to be nil")
 	}
 }
+
+func TestAlertProvider_GetConfig(t *testing.T) {
+	scenarios := []struct {
+		Name           string
+		Provider       AlertProvider
+		InputGroup     string
+		InputAlert     alert.Alert
+		ExpectedOutput Config
+	}{
+		{
+			Name: "provider-no-override-specify-no-group-should-default",
+			Provider: AlertProvider{
+				DefaultConfig: Config{URL: "http://example.com", Body: "default-body"},
+				Overrides:     nil,
+			},
+			InputGroup:     "",
+			InputAlert:     alert.Alert{},
+			ExpectedOutput: Config{URL: "http://example.com", Body: "default-body"},
+		},
+		{
+			Name: "provider-no-override-specify-group-should-default",
+			Provider: AlertProvider{
+				DefaultConfig: Config{URL: "http://example.com"},
+				Overrides:     nil,
+			},
+			InputGroup:     "group",
+			InputAlert:     alert.Alert{},
+			ExpectedOutput: Config{URL: "http://example.com"},
+		},
+		{
+			Name: "provider-with-override-specify-no-group-should-default",
+			Provider: AlertProvider{
+				DefaultConfig: Config{URL: "http://example.com"},
+				Overrides: []Override{
+					{
+						Group:  "group",
+						Config: Config{URL: "http://group-example.com", Headers: map[string]string{"Cache": "true"}},
+					},
+				},
+			},
+			InputGroup:     "",
+			InputAlert:     alert.Alert{},
+			ExpectedOutput: Config{URL: "http://example.com", Headers: map[string]string{"Cache": "true"}},
+		},
+		{
+			Name: "provider-with-override-specify-group-should-override",
+			Provider: AlertProvider{
+				DefaultConfig: Config{URL: "http://example.com", Body: "default-body"},
+				Overrides: []Override{
+					{
+						Group:  "group",
+						Config: Config{URL: "http://group-example.com", Body: "group-body"},
+					},
+				},
+			},
+			InputGroup:     "group",
+			InputAlert:     alert.Alert{},
+			ExpectedOutput: Config{URL: "http://group-example.com", Body: "group-body"},
+		},
+		{
+			Name: "provider-with-group-override-and-alert-override--alert-override-should-take-precedence",
+			Provider: AlertProvider{
+				DefaultConfig: Config{URL: "http://example.com"},
+				Overrides: []Override{
+					{
+						Group:  "group",
+						Config: Config{URL: "http://group-example.com"},
+					},
+				},
+			},
+			InputGroup:     "group",
+			InputAlert:     alert.Alert{ProviderOverride: map[string]any{"url": "http://alert-example.com", "body": "alert-body"}},
+			ExpectedOutput: Config{URL: "http://alert-example.com", Body: "alert-body"},
+		},
+		{
+			Name: "provider-with-partial-overrides",
+			Provider: AlertProvider{
+				DefaultConfig: Config{URL: "http://example.com"},
+				Overrides: []Override{
+					{
+						Group:  "group",
+						Config: Config{Method: "POST"},
+					},
+				},
+			},
+			InputGroup:     "group",
+			InputAlert:     alert.Alert{ProviderOverride: map[string]any{"body": "alert-body"}},
+			ExpectedOutput: Config{URL: "http://example.com", Body: "alert-body", Method: "POST"},
+		},
+	}
+	for _, scenario := range scenarios {
+		t.Run(scenario.Name, func(t *testing.T) {
+			got, err := scenario.Provider.GetConfig(scenario.InputGroup, &scenario.InputAlert)
+			if err != nil {
+				t.Fatalf("unexpected error: %s", err)
+			}
+			if got.URL != scenario.ExpectedOutput.URL {
+				t.Errorf("expected webhook URL to be %s, got %s", scenario.ExpectedOutput.URL, got.URL)
+			}
+			if got.Body != scenario.ExpectedOutput.Body {
+				t.Errorf("expected body to be %s, got %s", scenario.ExpectedOutput.Body, got.Body)
+			}
+			if got.Headers != nil {
+				for key, value := range scenario.ExpectedOutput.Headers {
+					if got.Headers[key] != value {
+						t.Errorf("expected header %s to be %s, got %s", key, value, got.Headers[key])
+					}
+				}
+			}
+			// Test ValidateOverrides as well, since it really just calls GetConfig
+			if err = scenario.Provider.ValidateOverrides(scenario.InputGroup, &scenario.InputAlert); err != nil {
+				t.Errorf("unexpected error: %s", err)
+			}
+		})
+	}
+}

alerting/provider/datadog/datadog.go

@@ -0,0 +1,214 @@
+package datadog
+
+import (
+	"bytes"
+	"encoding/json"
+	"errors"
+	"fmt"
+	"io"
+	"net/http"
+	"time"
+
+	"github.com/TwiN/gatus/v5/alerting/alert"
+	"github.com/TwiN/gatus/v5/client"
+	"github.com/TwiN/gatus/v5/config/endpoint"
+	"gopkg.in/yaml.v3"
+)
+
+var (
+	ErrAPIKeyNotSet           = errors.New("api-key not set")
+	ErrDuplicateGroupOverride = errors.New("duplicate group override")
+)
+
+type Config struct {
+	APIKey string   `yaml:"api-key"`        // Datadog API key
+	Site   string   `yaml:"site,omitempty"` // Datadog site (e.g., datadoghq.com, datadoghq.eu)
+	Tags   []string `yaml:"tags,omitempty"` // Additional tags to include
+}
+
+func (cfg *Config) Validate() error {
+	if len(cfg.APIKey) == 0 {
+		return ErrAPIKeyNotSet
+	}
+	return nil
+}
+
+func (cfg *Config) Merge(override *Config) {
+	if len(override.APIKey) > 0 {
+		cfg.APIKey = override.APIKey
+	}
+	if len(override.Site) > 0 {
+		cfg.Site = override.Site
+	}
+	if len(override.Tags) > 0 {
+		cfg.Tags = override.Tags
+	}
+}
+
+// AlertProvider is the configuration necessary for sending an alert using Datadog
+type AlertProvider struct {
+	DefaultConfig Config `yaml:",inline"`
+
+	// DefaultAlert is the default alert configuration to use for endpoints with an alert of the appropriate type
+	DefaultAlert *alert.Alert `yaml:"default-alert,omitempty"`
+
+	// Overrides is a list of Override that may be prioritized over the default configuration
+	Overrides []Override `yaml:"overrides,omitempty"`
+}
+
+// Override is a case under which the default integration is overridden
+type Override struct {
+	Group  string `yaml:"group"`
+	Config `yaml:",inline"`
+}
+
+// Validate the provider's configuration
+func (provider *AlertProvider) Validate() error {
+	registeredGroups := make(map[string]bool)
+	if provider.Overrides != nil {
+		for _, override := range provider.Overrides {
+			if isAlreadyRegistered := registeredGroups[override.Group]; isAlreadyRegistered || override.Group == "" {
+				return ErrDuplicateGroupOverride
+			}
+			registeredGroups[override.Group] = true
+		}
+	}
+	return provider.DefaultConfig.Validate()
+}
+
+// Send an alert using the provider
+func (provider *AlertProvider) Send(ep *endpoint.Endpoint, alert *alert.Alert, result *endpoint.Result, resolved bool) error {
+	cfg, err := provider.GetConfig(ep.Group, alert)
+	if err != nil {
+		return err
+	}
+	site := cfg.Site
+	if site == "" {
+		site = "datadoghq.com"
+	}
+	body, err := provider.buildRequestBody(cfg, ep, alert, result, resolved)
+	if err != nil {
+		return err
+	}
+	buffer := bytes.NewBuffer(body)
+	url := fmt.Sprintf("https://api.%s/api/v1/events", site)
+	request, err := http.NewRequest(http.MethodPost, url, buffer)
+	if err != nil {
+		return err
+	}
+	request.Header.Set("Content-Type", "application/json")
+	request.Header.Set("DD-API-KEY", cfg.APIKey)
+	response, err := client.GetHTTPClient(nil).Do(request)
+	if err != nil {
+		return err
+	}
+	defer response.Body.Close()
+	if response.StatusCode >= 400 {
+		body, _ := io.ReadAll(response.Body)
+		return fmt.Errorf("call to datadog alert returned status code %d: %s", response.StatusCode, string(body))
+	}
+	return nil
+}
+
+type Body struct {
+	Title        string   `json:"title"`
+	Text         string   `json:"text"`
+	Priority     string   `json:"priority"`
+	Tags         []string `json:"tags"`
+	AlertType    string   `json:"alert_type"`
+	SourceType   string   `json:"source_type_name"`
+	DateHappened int64    `json:"date_happened,omitempty"`
+}
+
+// buildRequestBody builds the request body for the provider
+func (provider *AlertProvider) buildRequestBody(cfg *Config, ep *endpoint.Endpoint, alert *alert.Alert, result *endpoint.Result, resolved bool) ([]byte, error) {
+	var title, text, priority, alertType string
+	if resolved {
+		title = fmt.Sprintf("Resolved: %s", ep.DisplayName())
+		text = fmt.Sprintf("Alert for %s has been resolved after passing successfully %d time(s) in a row", ep.DisplayName(), alert.SuccessThreshold)
+		priority = "normal"
+		alertType = "success"
+	} else {
+		title = fmt.Sprintf("Alert: %s", ep.DisplayName())
+		text = fmt.Sprintf("Alert for %s has been triggered due to having failed %d time(s) in a row", ep.DisplayName(), alert.FailureThreshold)
+		priority = "normal"
+		alertType = "error"
+	}
+	if alertDescription := alert.GetDescription(); len(alertDescription) > 0 {
+		text += fmt.Sprintf("\n\nDescription: %s", alertDescription)
+	}
+	if len(result.ConditionResults) > 0 {
+		text += "\n\nCondition Results:"
+		for _, conditionResult := range result.ConditionResults {
+			var status string
+			if conditionResult.Success {
+				status = "✅"
+			} else {
+				status = "❌"
+			}
+			text += fmt.Sprintf("\n%s %s", status, conditionResult.Condition)
+		}
+	}
+	tags := []string{
+		"source:gatus",
+		fmt.Sprintf("endpoint:%s", ep.Name),
+		fmt.Sprintf("status:%s", alertType),
+	}
+	if ep.Group != "" {
+		tags = append(tags, fmt.Sprintf("group:%s", ep.Group))
+	}
+	// Append custom tags
+	if len(cfg.Tags) > 0 {
+		tags = append(tags, cfg.Tags...)
+	}
+	body := Body{
+		Title:        title,
+		Text:         text,
+		Priority:     priority,
+		Tags:         tags,
+		AlertType:    alertType,
+		SourceType:   "gatus",
+		DateHappened: time.Now().Unix(),
+	}
+	bodyAsJSON, err := json.Marshal(body)
+	if err != nil {
+		return nil, err
+	}
+	return bodyAsJSON, nil
+}
+
+// GetDefaultAlert returns the provider's default alert configuration
+func (provider *AlertProvider) GetDefaultAlert() *alert.Alert {
+	return provider.DefaultAlert
+}
+
+// GetConfig returns the configuration for the provider with the overrides applied
+func (provider *AlertProvider) GetConfig(group string, alert *alert.Alert) (*Config, error) {
+	cfg := provider.DefaultConfig
+	// Handle group overrides
+	if provider.Overrides != nil {
+		for _, override := range provider.Overrides {
+			if group == override.Group {
+				cfg.Merge(&override.Config)
+				break
+			}
+		}
+	}
+	// Handle alert overrides
+	if len(alert.ProviderOverride) != 0 {
+		overrideConfig := Config{}
+		if err := yaml.Unmarshal(alert.ProviderOverrideAsBytes(), &overrideConfig); err != nil {
+			return nil, err
+		}
+		cfg.Merge(&overrideConfig)
+	}
+	// Validate the configuration
+	err := cfg.Validate()
+	return &cfg, err
+}
+
+// ValidateOverrides validates the alert's provider override and, if present, the group override
+func (provider *AlertProvider) ValidateOverrides(group string, alert *alert.Alert) error {
+	_, err := provider.GetConfig(group, alert)
+	return err
+}

alerting/provider/datadog/datadog_test.go

@@ -0,0 +1,183 @@
+package datadog
+
+import (
+	"encoding/json"
+	"net/http"
+	"strings"
+	"testing"
+
+	"github.com/TwiN/gatus/v5/alerting/alert"
+	"github.com/TwiN/gatus/v5/client"
+	"github.com/TwiN/gatus/v5/config/endpoint"
+	"github.com/TwiN/gatus/v5/test"
+)
+
+func TestAlertProvider_Validate(t *testing.T) {
+	scenarios := []struct {
+		name     string
+		provider AlertProvider
+		expected error
+	}{
+		{
+			name:     "valid-us1",
+			provider: AlertProvider{DefaultConfig: Config{APIKey: "dd-api-key-123", Site: "datadoghq.com"}},
+			expected: nil,
+		},
+		{
+			name:     "valid-eu",
+			provider: AlertProvider{DefaultConfig: Config{APIKey: "dd-api-key-123", Site: "datadoghq.eu"}},
+			expected: nil,
+		},
+		{
+			name:     "valid-with-tags",
+			provider: AlertProvider{DefaultConfig: Config{APIKey: "dd-api-key-123", Site: "datadoghq.com", Tags: []string{"env:prod", "service:gatus"}}},
+			expected: nil,
+		},
+		{
+			name:     "invalid-api-key",
+			provider: AlertProvider{DefaultConfig: Config{Site: "datadoghq.com"}},
+			expected: ErrAPIKeyNotSet,
+		},
+	}
+	for _, scenario := range scenarios {
+		t.Run(scenario.name, func(t *testing.T) {
+			err := scenario.provider.Validate()
+			if err != scenario.expected {
+				t.Errorf("expected %v, got %v", scenario.expected, err)
+			}
+		})
+	}
+}
+
+func TestAlertProvider_Send(t *testing.T) {
+	defer client.InjectHTTPClient(nil)
+	firstDescription := "description-1"
+	secondDescription := "description-2"
+	scenarios := []struct {
+		name             string
+		provider         AlertProvider
+		alert            alert.Alert
+		resolved         bool
+		mockRoundTripper test.MockRoundTripper
+		expectedError    bool
+	}{
+		{
+			name:     "triggered",
+			provider: AlertProvider{DefaultConfig: Config{APIKey: "dd-api-key-123", Site: "datadoghq.com"}},
+			alert:    alert.Alert{Description: &firstDescription, SuccessThreshold: 5, FailureThreshold: 3},
+			resolved: false,
+			mockRoundTripper: test.MockRoundTripper(func(r *http.Request) *http.Response {
+				if r.Host != "api.datadoghq.com" {
+					t.Errorf("expected host api.datadoghq.com, got %s", r.Host)
+				}
+				if r.URL.Path != "/api/v1/events" {
+					t.Errorf("expected path /api/v1/events, got %s", r.URL.Path)
+				}
+				if r.Header.Get("DD-API-KEY") != "dd-api-key-123" {
+					t.Errorf("expected DD-API-KEY header to be 'dd-api-key-123', got %s", r.Header.Get("DD-API-KEY"))
+				}
+				body := make(map[string]interface{})
+				json.NewDecoder(r.Body).Decode(&body)
+				if body["title"] == nil {
+					t.Error("expected 'title' field in request body")
+				}
+				title := body["title"].(string)
+				if !strings.Contains(title, "Alert") {
+					t.Errorf("expected title to contain 'Alert', got %s", title)
+				}
+				if body["alert_type"] != "error" {
+					t.Errorf("expected alert_type to be 'error', got %v", body["alert_type"])
+				}
+				if body["priority"] != "normal" {
+					t.Errorf("expected priority to be 'normal', got %v", body["priority"])
+				}
+				text := body["text"].(string)
+				if !strings.Contains(text, "failed 3 time(s)") {
+					t.Errorf("expected text to contain failure count, got %s", text)
+				}
+				return &http.Response{StatusCode: http.StatusAccepted, Body: http.NoBody}
+			}),
+			expectedError: false,
+		},
+		{
+			name:     "triggered-with-tags",
+			provider: AlertProvider{DefaultConfig: Config{APIKey: "dd-api-key-123", Site: "datadoghq.com", Tags: []string{"env:prod", "service:gatus"}}},
+			alert:    alert.Alert{Description: &firstDescription, SuccessThreshold: 5, FailureThreshold: 3},
+			resolved: false,
+			mockRoundTripper: test.MockRoundTripper(func(r *http.Request) *http.Response {
+				body := make(map[string]interface{})
+				json.NewDecoder(r.Body).Decode(&body)
+				tags := body["tags"].([]interface{})
+				// Datadog adds 3 base tags (source, endpoint, status) + custom tags
+				if len(tags) < 5 {
+					t.Errorf("expected at least 5 tags (3 base + 2 custom), got %d", len(tags))
+				}
+				return &http.Response{StatusCode: http.StatusAccepted, Body: http.NoBody}
+			}),
+			expectedError: false,
+		},
+		{
+			name:     "resolved",
+			provider: AlertProvider{DefaultConfig: Config{APIKey: "dd-api-key-123", Site: "datadoghq.eu"}},
+			alert:    alert.Alert{Description: &secondDescription, SuccessThreshold: 5, FailureThreshold: 3},
+			resolved: true,
+			mockRoundTripper: test.MockRoundTripper(func(r *http.Request) *http.Response {
+				if r.Host != "api.datadoghq.eu" {
+					t.Errorf("expected host api.datadoghq.eu, got %s", r.Host)
+				}
+				body := make(map[string]interface{})
+				json.NewDecoder(r.Body).Decode(&body)
+				title := body["title"].(string)
+				if !strings.Contains(title, "Resolved") {
+					t.Errorf("expected title to contain 'Resolved', got %s", title)
+				}
+				if body["alert_type"] != "success" {
+					t.Errorf("expected alert_type to be 'success', got %v", body["alert_type"])
+				}
+				return &http.Response{StatusCode: http.StatusAccepted, Body: http.NoBody}
+			}),
+			expectedError: false,
+		},
+		{
+			name:     "error-response",
+			provider: AlertProvider{DefaultConfig: Config{APIKey: "dd-api-key-123", Site: "datadoghq.com"}},
+			alert:    alert.Alert{Description: &firstDescription, SuccessThreshold: 5, FailureThreshold: 3},
+			resolved: false,
+			mockRoundTripper: test.MockRoundTripper(func(r *http.Request) *http.Response {
+				return &http.Response{StatusCode: http.StatusForbidden, Body: http.NoBody}
+			}),
+			expectedError: true,
+		},
+	}
+	for _, scenario := range scenarios {
+		t.Run(scenario.name, func(t *testing.T) {
+			client.InjectHTTPClient(&http.Client{Transport: scenario.mockRoundTripper})
+			err := scenario.provider.Send(
+				&endpoint.Endpoint{Name: "endpoint-name"},
+				&scenario.alert,
+				&endpoint.Result{
+					ConditionResults: []*endpoint.ConditionResult{
+						{Condition: "[CONNECTED] == true", Success: scenario.resolved},
+						{Condition: "[STATUS] == 200", Success: scenario.resolved},
+					},
+				},
+				scenario.resolved,
+			)
+			if scenario.expectedError && err == nil {
+				t.Error("expected error, got none")
+			}
+			if !scenario.expectedError && err != nil {
+				t.Error("expected no error, got", err.Error())
+			}
+		})
+	}
+}
+
+func TestAlertProvider_GetDefaultAlert(t *testing.T) {
+	if (&AlertProvider{DefaultAlert: &alert.Alert{}}).GetDefaultAlert() == nil {
+		t.Error("expected default alert to be not nil")
+	}
+	if (&AlertProvider{DefaultAlert: nil}).GetDefaultAlert() != nil {
+		t.Error("expected default alert to be nil")
+	}
+}

alerting/provider/discord/discord.go

@@ -3,6 +3,7 @@ package discord
 import (
 	"bytes"
 	"encoding/json"
+	"errors"
 	"fmt"
 	"io"
 	"net/http"
@@ -10,46 +11,73 @@ import (
 	"github.com/TwiN/gatus/v5/alerting/alert"
 	"github.com/TwiN/gatus/v5/client"
 	"github.com/TwiN/gatus/v5/config/endpoint"
+	"gopkg.in/yaml.v3"
 )
 
+var (
+	ErrWebhookURLNotSet       = errors.New("webhook-url not set")
+	ErrDuplicateGroupOverride = errors.New("duplicate group override")
+)
+
+type Config struct {
+	WebhookURL string `yaml:"webhook-url"`
+	Title      string `yaml:"title,omitempty"` // Title of the message that will be sent
+}
+
+func (cfg *Config) Validate() error {
+	if len(cfg.WebhookURL) == 0 {
+		return ErrWebhookURLNotSet
+	}
+	return nil
+}
+
+func (cfg *Config) Merge(override *Config) {
+	if len(override.WebhookURL) > 0 {
+		cfg.WebhookURL = override.WebhookURL
+	}
+	if len(override.Title) > 0 {
+		cfg.Title = override.Title
+	}
+}
+
 // AlertProvider is the configuration necessary for sending an alert using Discord
 type AlertProvider struct {
-	WebhookURL string `yaml:"webhook-url"`
+	DefaultConfig Config `yaml:",inline"`
 
 	// DefaultAlert is the default alert configuration to use for endpoints with an alert of the appropriate type
 	DefaultAlert *alert.Alert `yaml:"default-alert,omitempty"`
 
 	// Overrides is a list of Override that may be prioritized over the default configuration
 	Overrides []Override `yaml:"overrides,omitempty"`
-
-	// Title is the title of the message that will be sent
-	Title string `yaml:"title,omitempty"`
 }
 
-// Override is a case under which the default integration is overridden
 type Override struct {
-	Group      string `yaml:"group"`
-	WebhookURL string `yaml:"webhook-url"`
+	Group  string `yaml:"group"`
+	Config `yaml:",inline"`
 }
 
-// IsValid returns whether the provider's configuration is valid
-func (provider *AlertProvider) IsValid() bool {
+// Validate the provider's configuration
+func (provider *AlertProvider) Validate() error {
 	registeredGroups := make(map[string]bool)
 	if provider.Overrides != nil {
 		for _, override := range provider.Overrides {
 			if isAlreadyRegistered := registeredGroups[override.Group]; isAlreadyRegistered || override.Group == "" || len(override.WebhookURL) == 0 {
-				return false
+				return ErrDuplicateGroupOverride
 			}
 			registeredGroups[override.Group] = true
 		}
 	}
-	return len(provider.WebhookURL) > 0
+	return provider.DefaultConfig.Validate()
 }
 
 // Send an alert using the provider
 func (provider *AlertProvider) Send(ep *endpoint.Endpoint, alert *alert.Alert, result *endpoint.Result, resolved bool) error {
-	buffer := bytes.NewBuffer(provider.buildRequestBody(ep, alert, result, resolved))
-	request, err := http.NewRequest(http.MethodPost, provider.getWebhookURLForGroup(ep.Group), buffer)
+	cfg, err := provider.GetConfig(ep.Group, alert)
+	if err != nil {
+		return err
+	}
+	buffer := bytes.NewBuffer(provider.buildRequestBody(cfg, ep, alert, result, resolved))
+	request, err := http.NewRequest(http.MethodPost, cfg.WebhookURL, buffer)
 	if err != nil {
 		return err
 	}
@@ -85,7 +113,7 @@ type Field struct {
 }
 
 // buildRequestBody builds the request body for the provider
-func (provider *AlertProvider) buildRequestBody(ep *endpoint.Endpoint, alert *alert.Alert, result *endpoint.Result, resolved bool) []byte {
+func (provider *AlertProvider) buildRequestBody(cfg *Config, ep *endpoint.Endpoint, alert *alert.Alert, result *endpoint.Result, resolved bool) []byte {
 	var message string
 	var colorCode int
 	if resolved {
@@ -110,8 +138,8 @@ func (provider *AlertProvider) buildRequestBody(ep *endpoint.Endpoint, alert *al
 		description = ":\n> " + alertDescription
 	}
 	title := ":helmet_with_white_cross: Gatus"
-	if provider.Title != "" {
-		title = provider.Title
+	if cfg.Title != "" {
+		title = cfg.Title
 	}
 	body := Body{
 		Content: "",
@@ -134,19 +162,38 @@ func (provider *AlertProvider) buildRequestBody(ep *endpoint.Endpoint, alert *al
 	return bodyAsJSON
 }
 
-// getWebhookURLForGroup returns the appropriate Webhook URL integration to for a given group
-func (provider *AlertProvider) getWebhookURLForGroup(group string) string {
-	if provider.Overrides != nil {
-		for _, override := range provider.Overrides {
-			if group == override.Group {
-				return override.WebhookURL
-			}
-		}
-	}
-	return provider.WebhookURL
-}
-
 // GetDefaultAlert returns the provider's default alert configuration
 func (provider *AlertProvider) GetDefaultAlert() *alert.Alert {
 	return provider.DefaultAlert
 }
+
+// GetConfig returns the configuration for the provider with the overrides applied
+func (provider *AlertProvider) GetConfig(group string, alert *alert.Alert) (*Config, error) {
+	cfg := provider.DefaultConfig
+	// Handle group overrides
+	if provider.Overrides != nil {
+		for _, override := range provider.Overrides {
+			if group == override.Group {
+				cfg.Merge(&override.Config)
+				break
+			}
+		}
+	}
+	// Handle alert overrides
+	if len(alert.ProviderOverride) != 0 {
+		overrideConfig := Config{}
+		if err := yaml.Unmarshal(alert.ProviderOverrideAsBytes(), &overrideConfig); err != nil {
+			return nil, err
+		}
+		cfg.Merge(&overrideConfig)
+	}
+	// Validate the configuration
+	err := cfg.Validate()
+	return &cfg, err
+}
+
+// ValidateOverrides validates the alert's provider override and, if present, the group override
+func (provider *AlertProvider) ValidateOverrides(group string, alert *alert.Alert) error {
+	_, err := provider.GetConfig(group, alert)
+	return err
+}

alerting/provider/discord/discord_test.go

@@ -11,50 +11,52 @@ import (
 	"github.com/TwiN/gatus/v5/test"
 )
 
-func TestAlertProvider_IsValid(t *testing.T) {
-	invalidProvider := AlertProvider{WebhookURL: ""}
-	if invalidProvider.IsValid() {
+func TestAlertProvider_Validate(t *testing.T) {
+	invalidProvider := AlertProvider{DefaultConfig: Config{WebhookURL: ""}}
+	if err := invalidProvider.Validate(); err == nil {
 		t.Error("provider shouldn't have been valid")
 	}
-	validProvider := AlertProvider{WebhookURL: "http://example.com"}
-	if !validProvider.IsValid() {
+	validProvider := AlertProvider{DefaultConfig: Config{WebhookURL: "http://example.com"}}
+	if err := validProvider.Validate(); err != nil {
 		t.Error("provider should've been valid")
 	}
 }
 
-func TestAlertProvider_IsValidWithOverride(t *testing.T) {
+func TestAlertProvider_ValidateWithOverride(t *testing.T) {
 	providerWithInvalidOverrideGroup := AlertProvider{
 		Overrides: []Override{
 			{
-				WebhookURL: "http://example.com",
-				Group:      "",
+				Config: Config{WebhookURL: "http://example.com"},
+				Group:  "",
 			},
 		},
 	}
-	if providerWithInvalidOverrideGroup.IsValid() {
+	if err := providerWithInvalidOverrideGroup.Validate(); err == nil {
 		t.Error("provider Group shouldn't have been valid")
 	}
 	providerWithInvalidOverrideTo := AlertProvider{
 		Overrides: []Override{
 			{
-				WebhookURL: "",
-				Group:      "group",
+				Config: Config{WebhookURL: ""},
+				Group:  "group",
 			},
 		},
 	}
-	if providerWithInvalidOverrideTo.IsValid() {
+	if err := providerWithInvalidOverrideTo.Validate(); err == nil {
 		t.Error("provider integration key shouldn't have been valid")
 	}
 	providerWithValidOverride := AlertProvider{
-		WebhookURL: "http://example.com",
+		DefaultConfig: Config{
+			WebhookURL: "http://example.com",
+		},
 		Overrides: []Override{
 			{
-				WebhookURL: "http://example.com",
-				Group:      "group",
+				Config: Config{WebhookURL: "http://example.com"},
+				Group:  "group",
 			},
 		},
 	}
-	if !providerWithValidOverride.IsValid() {
+	if err := providerWithValidOverride.Validate(); err != nil {
 		t.Error("provider should've been valid")
 	}
 }
@@ -74,7 +76,7 @@ func TestAlertProvider_Send(t *testing.T) {
 	}{
 		{
 			Name:     "triggered",
-			Provider: AlertProvider{},
+			Provider: AlertProvider{DefaultConfig: Config{WebhookURL: "http://example.com"}},
 			Alert:    alert.Alert{Description: &firstDescription, SuccessThreshold: 5, FailureThreshold: 3},
 			Resolved: false,
 			MockRoundTripper: test.MockRoundTripper(func(r *http.Request) *http.Response {
@@ -84,7 +86,7 @@ func TestAlertProvider_Send(t *testing.T) {
 		},
 		{
 			Name:     "triggered-error",
-			Provider: AlertProvider{},
+			Provider: AlertProvider{DefaultConfig: Config{WebhookURL: "http://example.com"}},
 			Alert:    alert.Alert{Description: &firstDescription, SuccessThreshold: 5, FailureThreshold: 3},
 			Resolved: false,
 			MockRoundTripper: test.MockRoundTripper(func(r *http.Request) *http.Response {
@@ -94,7 +96,7 @@ func TestAlertProvider_Send(t *testing.T) {
 		},
 		{
 			Name:     "resolved",
-			Provider: AlertProvider{},
+			Provider: AlertProvider{DefaultConfig: Config{WebhookURL: "http://example.com"}},
 			Alert:    alert.Alert{Description: &secondDescription, SuccessThreshold: 5, FailureThreshold: 3},
 			Resolved: true,
 			MockRoundTripper: test.MockRoundTripper(func(r *http.Request) *http.Response {
@@ -104,7 +106,7 @@ func TestAlertProvider_Send(t *testing.T) {
 		},
 		{
 			Name:     "resolved-error",
-			Provider: AlertProvider{},
+			Provider: AlertProvider{DefaultConfig: Config{WebhookURL: "http://example.com"}},
 			Alert:    alert.Alert{Description: &secondDescription, SuccessThreshold: 5, FailureThreshold: 3},
 			Resolved: true,
 			MockRoundTripper: test.MockRoundTripper(func(r *http.Request) *http.Response {
@@ -114,7 +116,7 @@ func TestAlertProvider_Send(t *testing.T) {
 		},
 		{
 			Name:     "triggered-with-modified-title",
-			Provider: AlertProvider{Title: title},
+			Provider: AlertProvider{DefaultConfig: Config{WebhookURL: "http://example.com", Title: title}},
 			Alert:    alert.Alert{Description: &firstDescription, SuccessThreshold: 5, FailureThreshold: 3},
 			Resolved: false,
 			MockRoundTripper: test.MockRoundTripper(func(r *http.Request) *http.Response {
@@ -122,6 +124,16 @@ func TestAlertProvider_Send(t *testing.T) {
 			}),
 			ExpectedError: false,
 		},
+		{
+			Name:     "triggered-with-webhook-override",
+			Provider: AlertProvider{DefaultConfig: Config{WebhookURL: "http://example.com"}},
+			Alert:    alert.Alert{Description: &firstDescription, SuccessThreshold: 5, FailureThreshold: 3, ProviderOverride: map[string]any{"webhook-url": "http://example01.com"}},
+			Resolved: false,
+			MockRoundTripper: test.MockRoundTripper(func(r *http.Request) *http.Response {
+				return &http.Response{StatusCode: http.StatusOK, Body: http.NoBody}
+			}),
+			ExpectedError: false,
+		},
 	}
 	for _, scenario := range scenarios {
 		t.Run(scenario.Name, func(t *testing.T) {
@@ -175,7 +187,7 @@ func TestAlertProvider_buildRequestBody(t *testing.T) {
 		},
 		{
 			Name:         "triggered-with-modified-title",
-			Provider:     AlertProvider{Title: title},
+			Provider:     AlertProvider{DefaultConfig: Config{Title: title}},
 			Alert:        alert.Alert{Description: &firstDescription, SuccessThreshold: 5, FailureThreshold: 3},
 			Resolved:     false,
 			ExpectedBody: "{\"content\":\"\",\"embeds\":[{\"title\":\"provider-title\",\"description\":\"An alert for **endpoint-name** has been triggered due to having failed 3 time(s) in a row:\\n\\u003e description-1\",\"color\":15158332,\"fields\":[{\"name\":\"Condition results\",\"value\":\":x: - `[CONNECTED] == true`\\n:x: - `[STATUS] == 200`\\n:x: - `[BODY] != \\\"\\\"`\\n\",\"inline\":false}]}]}",
@@ -183,7 +195,7 @@ func TestAlertProvider_buildRequestBody(t *testing.T) {
 		{
 			Name:         "triggered-with-no-conditions",
 			NoConditions: true,
-			Provider:     AlertProvider{Title: title},
+			Provider:     AlertProvider{DefaultConfig: Config{Title: title}},
 			Alert:        alert.Alert{Description: &firstDescription, SuccessThreshold: 5, FailureThreshold: 3},
 			Resolved:     false,
 			ExpectedBody: "{\"content\":\"\",\"embeds\":[{\"title\":\"provider-title\",\"description\":\"An alert for **endpoint-name** has been triggered due to having failed 3 time(s) in a row:\\n\\u003e description-1\",\"color\":15158332}]}",
@@ -200,6 +212,7 @@ func TestAlertProvider_buildRequestBody(t *testing.T) {
 				}
 			}
 			body := scenario.Provider.buildRequestBody(
+				&scenario.Provider.DefaultConfig,
 				&endpoint.Endpoint{Name: "endpoint-name"},
 				&scenario.Alert,
 				&endpoint.Result{
@@ -227,64 +240,92 @@ func TestAlertProvider_GetDefaultAlert(t *testing.T) {
 	}
 }
 
-func TestAlertProvider_getWebhookURLForGroup(t *testing.T) {
-	tests := []struct {
+func TestAlertProvider_GetConfig(t *testing.T) {
+	scenarios := []struct {
 		Name           string
 		Provider       AlertProvider
 		InputGroup     string
-		ExpectedOutput string
+		InputAlert     alert.Alert
+		ExpectedOutput Config
 	}{
 		{
 			Name: "provider-no-override-specify-no-group-should-default",
 			Provider: AlertProvider{
-				WebhookURL: "http://example.com",
-				Overrides:  nil,
+				DefaultConfig: Config{WebhookURL: "http://example.com"},
+				Overrides:     nil,
 			},
 			InputGroup:     "",
-			ExpectedOutput: "http://example.com",
+			InputAlert:     alert.Alert{},
+			ExpectedOutput: Config{WebhookURL: "http://example.com"},
 		},
 		{
 			Name: "provider-no-override-specify-group-should-default",
 			Provider: AlertProvider{
-				WebhookURL: "http://example.com",
-				Overrides:  nil,
+				DefaultConfig: Config{WebhookURL: "http://example.com"},
+				Overrides:     nil,
 			},
 			InputGroup:     "group",
-			ExpectedOutput: "http://example.com",
+			InputAlert:     alert.Alert{},
+			ExpectedOutput: Config{WebhookURL: "http://example.com"},
 		},
 		{
 			Name: "provider-with-override-specify-no-group-should-default",
 			Provider: AlertProvider{
-				WebhookURL: "http://example.com",
+				DefaultConfig: Config{WebhookURL: "http://example.com"},
 				Overrides: []Override{
 					{
-						Group:      "group",
-						WebhookURL: "http://example01.com",
+						Group:  "group",
+						Config: Config{WebhookURL: "http://group-example.com"},
 					},
 				},
 			},
 			InputGroup:     "",
-			ExpectedOutput: "http://example.com",
+			InputAlert:     alert.Alert{},
+			ExpectedOutput: Config{WebhookURL: "http://example.com"},
 		},
 		{
 			Name: "provider-with-override-specify-group-should-override",
 			Provider: AlertProvider{
-				WebhookURL: "http://example.com",
+				DefaultConfig: Config{WebhookURL: "http://example.com"},
 				Overrides: []Override{
 					{
-						Group:      "group",
-						WebhookURL: "http://example01.com",
+						Group:  "group",
+						Config: Config{WebhookURL: "http://group-example.com"},
 					},
 				},
 			},
 			InputGroup:     "group",
-			ExpectedOutput: "http://example01.com",
+			InputAlert:     alert.Alert{},
+			ExpectedOutput: Config{WebhookURL: "http://group-example.com"},
+		},
+		{
+			Name: "provider-with-group-override-and-alert-override--alert-override-should-take-precedence",
+			Provider: AlertProvider{
+				DefaultConfig: Config{WebhookURL: "http://example.com"},
+				Overrides: []Override{
+					{
+						Group:  "group",
+						Config: Config{WebhookURL: "http://group-example.com"},
+					},
+				},
+			},
+			InputGroup:     "group",
+			InputAlert:     alert.Alert{ProviderOverride: map[string]any{"webhook-url": "http://alert-example.com"}},
+			ExpectedOutput: Config{WebhookURL: "http://alert-example.com"},
 		},
 	}
-	for _, tt := range tests {
-		t.Run(tt.Name, func(t *testing.T) {
-			if got := tt.Provider.getWebhookURLForGroup(tt.InputGroup); got != tt.ExpectedOutput {
-				t.Errorf("AlertProvider.getWebhookURLForGroup() = %v, want %v", got, tt.ExpectedOutput)
+	for _, scenario := range scenarios {
+		t.Run(scenario.Name, func(t *testing.T) {
+			got, err := scenario.Provider.GetConfig(scenario.InputGroup, &scenario.InputAlert)
+			if err != nil {
+				t.Fatalf("unexpected error: %s", err)
+			}
+			if got.WebhookURL != scenario.ExpectedOutput.WebhookURL {
+				t.Errorf("expected webhook URL to be %s, got %s", scenario.ExpectedOutput.WebhookURL, got.WebhookURL)
+			}
+			// Test ValidateOverrides as well, since it really just calls GetConfig
+			if err = scenario.Provider.ValidateOverrides(scenario.InputGroup, &scenario.InputAlert); err != nil {
+				t.Errorf("unexpected error: %s", err)
 			}
 		})
 	}

alerting/provider/email/email.go

@@ -2,6 +2,7 @@ package email
 
 import (
 	"crypto/tls"
+	"errors"
 	"fmt"
 	"math"
 	"strings"
@@ -10,10 +11,17 @@ import (
 	"github.com/TwiN/gatus/v5/client"
 	"github.com/TwiN/gatus/v5/config/endpoint"
 	gomail "gopkg.in/mail.v2"
+	"gopkg.in/yaml.v3"
 )
 
-// AlertProvider is the configuration necessary for sending an alert using SMTP
-type AlertProvider struct {
+var (
+	ErrDuplicateGroupOverride = errors.New("duplicate group override")
+	ErrMissingFromOrToFields  = errors.New("from and to fields are required")
+	ErrInvalidPort            = errors.New("port must be between 1 and 65535 inclusively")
+	ErrMissingHost            = errors.New("host is required")
+)
+
+type Config struct {
 	From     string `yaml:"from"`
 	Username string `yaml:"username"`
 	Password string `yaml:"password"`
@@ -23,6 +31,48 @@ type AlertProvider struct {
 
 	// ClientConfig is the configuration of the client used to communicate with the provider's target
 	ClientConfig *client.Config `yaml:"client,omitempty"`
+}
+
+func (cfg *Config) Validate() error {
+	if len(cfg.From) == 0 || len(cfg.To) == 0 {
+		return ErrMissingFromOrToFields
+	}
+	if cfg.Port < 1 || cfg.Port > math.MaxUint16 {
+		return ErrInvalidPort
+	}
+	if len(cfg.Host) == 0 {
+		return ErrMissingHost
+	}
+	return nil
+}
+
+func (cfg *Config) Merge(override *Config) {
+	if override.ClientConfig != nil {
+		cfg.ClientConfig = override.ClientConfig
+	}
+	if len(override.From) > 0 {
+		cfg.From = override.From
+	}
+	if len(override.Username) > 0 {
+		cfg.Username = override.Username
+	}
+	if len(override.Password) > 0 {
+		cfg.Password = override.Password
+	}
+	if len(override.Host) > 0 {
+		cfg.Host = override.Host
+	}
+	if override.Port > 0 {
+		cfg.Port = override.Port
+	}
+	if len(override.To) > 0 {
+		cfg.To = override.To
+	}
+}
+
+// AlertProvider is the configuration necessary for sending an alert using SMTP
+type AlertProvider struct {
+	DefaultConfig Config `yaml:",inline"`
 
 	// DefaultAlert is the default alert configuration to use for endpoints with an alert of the appropriate type
 	DefaultAlert *alert.Alert `yaml:"default-alert,omitempty"`
@@ -33,54 +83,57 @@ type AlertProvider struct {
 
 // Override is a case under which the default integration is overridden
 type Override struct {
-	Group string `yaml:"group"`
-	To    string `yaml:"to"`
+	Group  string `yaml:"group"`
+	Config `yaml:",inline"`
 }
 
-// IsValid returns whether the provider's configuration is valid
-func (provider *AlertProvider) IsValid() bool {
+// Validate the provider's configuration
+func (provider *AlertProvider) Validate() error {
 	registeredGroups := make(map[string]bool)
 	if provider.Overrides != nil {
 		for _, override := range provider.Overrides {
 			if isAlreadyRegistered := registeredGroups[override.Group]; isAlreadyRegistered || override.Group == "" || len(override.To) == 0 {
-				return false
+				return ErrDuplicateGroupOverride
 			}
 			registeredGroups[override.Group] = true
 		}
 	}
-
-	return len(provider.From) > 0 && len(provider.Host) > 0 && len(provider.To) > 0 && provider.Port > 0 && provider.Port < math.MaxUint16
+	return provider.DefaultConfig.Validate()
 }
 
 // Send an alert using the provider
 func (provider *AlertProvider) Send(ep *endpoint.Endpoint, alert *alert.Alert, result *endpoint.Result, resolved bool) error {
+	cfg, err := provider.GetConfig(ep.Group, alert)
+	if err != nil {
+		return err
+	}
 	var username string
-	if len(provider.Username) > 0 {
-		username = provider.Username
+	if len(cfg.Username) > 0 {
+		username = cfg.Username
 	} else {
-		username = provider.From
+		username = cfg.From
 	}
 	subject, body := provider.buildMessageSubjectAndBody(ep, alert, result, resolved)
 	m := gomail.NewMessage()
-	m.SetHeader("From", provider.From)
-	m.SetHeader("To", strings.Split(provider.getToForGroup(ep.Group), ",")...)
+	m.SetHeader("From", cfg.From)
+	m.SetHeader("To", strings.Split(cfg.To, ",")...)
 	m.SetHeader("Subject", subject)
 	m.SetBody("text/plain", body)
 	var d *gomail.Dialer
-	if len(provider.Password) == 0 {
+	if len(cfg.Password) == 0 {
 		// Get the domain in the From address
 		localName := "localhost"
-		fromParts := strings.Split(provider.From, `@`)
+		fromParts := strings.Split(cfg.From, `@`)
 		if len(fromParts) == 2 {
 			localName = fromParts[1]
 		}
 		// Create a dialer with no authentication
-		d = &gomail.Dialer{Host: provider.Host, Port: provider.Port, LocalName: localName}
+		d = &gomail.Dialer{Host: cfg.Host, Port: cfg.Port, LocalName: localName}
 	} else {
 		// Create an authenticated dialer
-		d = gomail.NewDialer(provider.Host, provider.Port, username, provider.Password)
+		d = gomail.NewDialer(cfg.Host, cfg.Port, username, cfg.Password)
 	}
-	if provider.ClientConfig != nil && provider.ClientConfig.Insecure {
+	if cfg.ClientConfig != nil && cfg.ClientConfig.Insecure {
 		d.TLSConfig = &tls.Config{InsecureSkipVerify: true}
 	}
 	return d.DialAndSend(m)
@@ -113,22 +166,48 @@ func (provider *AlertProvider) buildMessageSubjectAndBody(ep *endpoint.Endpoint,
 	if alertDescription := alert.GetDescription(); len(alertDescription) > 0 {
 		description = "\n\nAlert description: " + alertDescription
 	}
-	return subject, message + description + formattedConditionResults
-}
-
-// getToForGroup returns the appropriate email integration to for a given group
-func (provider *AlertProvider) getToForGroup(group string) string {
-	if provider.Overrides != nil {
-		for _, override := range provider.Overrides {
-			if group == override.Group {
-				return override.To
-			}
+	var extraLabels string
+	if len(ep.ExtraLabels) > 0 {
+		extraLabels = "\n\nExtra labels:\n"
+		for key, value := range ep.ExtraLabels {
+			extraLabels += fmt.Sprintf("  %s: %s\n", key, value)
 		}
 	}
-	return provider.To
+	return subject, message + description + extraLabels + formattedConditionResults
 }
 
 // GetDefaultAlert returns the provider's default alert configuration
 func (provider *AlertProvider) GetDefaultAlert() *alert.Alert {
 	return provider.DefaultAlert
 }
+
+// GetConfig returns the configuration for the provider with the overrides applied
+func (provider *AlertProvider) GetConfig(group string, alert *alert.Alert) (*Config, error) {
+	cfg := provider.DefaultConfig
+	// Handle group overrides
+	if provider.Overrides != nil {
+		for _, override := range provider.Overrides {
+			if group == override.Group {
+				cfg.Merge(&override.Config)
+				break
+			}
+		}
+	}
+	// Handle alert overrides
+	if len(alert.ProviderOverride) != 0 {
+		overrideConfig := Config{}
+		if err := yaml.Unmarshal(alert.ProviderOverrideAsBytes(), &overrideConfig); err != nil {
+			return nil, err
+		}
+		cfg.Merge(&overrideConfig)
+	}
+	// Validate the configuration
+	err := cfg.Validate()
+	return &cfg, err
+}
+
+// ValidateOverrides validates the alert's provider override and, if present, the group override
+func (provider *AlertProvider) ValidateOverrides(group string, alert *alert.Alert) error {
+	_, err := provider.GetConfig(group, alert)
+	return err
+}

alerting/provider/email/email_test.go

@@ -7,61 +7,63 @@ import (
 	"github.com/TwiN/gatus/v5/config/endpoint"
 )
 
-func TestAlertDefaultProvider_IsValid(t *testing.T) {
+func TestAlertProvider_Validate(t *testing.T) {
 	invalidProvider := AlertProvider{}
-	if invalidProvider.IsValid() {
+	if err := invalidProvider.Validate(); err == nil {
 		t.Error("provider shouldn't have been valid")
 	}
-	validProvider := AlertProvider{From: "from@example.com", Password: "password", Host: "smtp.gmail.com", Port: 587, To: "to@example.com"}
-	if !validProvider.IsValid() {
+	validProvider := AlertProvider{DefaultConfig: Config{From: "from@example.com", Password: "password", Host: "smtp.gmail.com", Port: 587, To: "to@example.com"}}
+	if err := validProvider.Validate(); err != nil {
 		t.Error("provider should've been valid")
 	}
 }
 
-func TestAlertProvider_IsValidWithNoCredentials(t *testing.T) {
-	validProvider := AlertProvider{From: "from@example.com", Host: "smtp-relay.gmail.com", Port: 587, To: "to@example.com"}
-	if !validProvider.IsValid() {
+func TestAlertProvider_ValidateWithNoCredentials(t *testing.T) {
+	validProvider := AlertProvider{DefaultConfig: Config{From: "from@example.com", Host: "smtp-relay.gmail.com", Port: 587, To: "to@example.com"}}
+	if err := validProvider.Validate(); err != nil {
 		t.Error("provider should've been valid")
 	}
 }
 
-func TestAlertProvider_IsValidWithOverride(t *testing.T) {
+func TestAlertProvider_ValidateWithOverride(t *testing.T) {
 	providerWithInvalidOverrideGroup := AlertProvider{
 		Overrides: []Override{
 			{
-				To:    "to@example.com",
-				Group: "",
+				Config: Config{To: "to@example.com"},
+				Group:  "",
 			},
 		},
 	}
-	if providerWithInvalidOverrideGroup.IsValid() {
+	if err := providerWithInvalidOverrideGroup.Validate(); err == nil {
 		t.Error("provider Group shouldn't have been valid")
 	}
 	providerWithInvalidOverrideTo := AlertProvider{
 		Overrides: []Override{
 			{
-				To:    "",
-				Group: "group",
+				Config: Config{To: ""},
+				Group:  "group",
 			},
 		},
 	}
-	if providerWithInvalidOverrideTo.IsValid() {
+	if err := providerWithInvalidOverrideTo.Validate(); err == nil {
 		t.Error("provider integration key shouldn't have been valid")
 	}
 	providerWithValidOverride := AlertProvider{
-		From:     "from@example.com",
-		Password: "password",
-		Host:     "smtp.gmail.com",
-		Port:     587,
-		To:       "to@example.com",
+		DefaultConfig: Config{
+			From:     "from@example.com",
+			Password: "password",
+			Host:     "smtp.gmail.com",
+			Port:     587,
+			To:       "to@example.com",
+		},
 		Overrides: []Override{
 			{
-				To:    "to@example.com",
-				Group: "group",
+				Config: Config{To: "to@example.com"},
+				Group:  "group",
 			},
 		},
 	}
-	if !providerWithValidOverride.IsValid() {
+	if err := providerWithValidOverride.Validate(); err != nil {
 		t.Error("provider should've been valid")
 	}
 }
@@ -74,6 +76,7 @@ func TestAlertProvider_buildRequestBody(t *testing.T) {
 		Provider        AlertProvider
 		Alert           alert.Alert
 		Resolved        bool
+		Endpoint        *endpoint.Endpoint
 		ExpectedSubject string
 		ExpectedBody    string
 	}{
@@ -82,6 +85,7 @@ func TestAlertProvider_buildRequestBody(t *testing.T) {
 			Provider:        AlertProvider{},
 			Alert:           alert.Alert{Description: &firstDescription, SuccessThreshold: 5, FailureThreshold: 3},
 			Resolved:        false,
+			Endpoint:        &endpoint.Endpoint{Name: "endpoint-name"},
 			ExpectedSubject: "[endpoint-name] Alert triggered",
 			ExpectedBody:    "An alert for endpoint-name has been triggered due to having failed 3 time(s) in a row\n\nAlert description: description-1\n\nCondition results:\n❌ [CONNECTED] == true\n❌ [STATUS] == 200\n",
 		},
@@ -90,14 +94,42 @@ func TestAlertProvider_buildRequestBody(t *testing.T) {
 			Provider:        AlertProvider{},
 			Alert:           alert.Alert{Description: &secondDescription, SuccessThreshold: 5, FailureThreshold: 3},
 			Resolved:        true,
+			Endpoint:        &endpoint.Endpoint{Name: "endpoint-name"},
 			ExpectedSubject: "[endpoint-name] Alert resolved",
 			ExpectedBody:    "An alert for endpoint-name has been resolved after passing successfully 5 time(s) in a row\n\nAlert description: description-2\n\nCondition results:\n✅ [CONNECTED] == true\n✅ [STATUS] == 200\n",
 		},
+		{
+			Name:            "triggered-with-single-extra-label",
+			Provider:        AlertProvider{},
+			Alert:           alert.Alert{Description: &firstDescription, SuccessThreshold: 5, FailureThreshold: 3},
+			Resolved:        false,
+			Endpoint:        &endpoint.Endpoint{Name: "endpoint-name", ExtraLabels: map[string]string{"environment": "production"}},
+			ExpectedSubject: "[endpoint-name] Alert triggered",
+			ExpectedBody:    "An alert for endpoint-name has been triggered due to having failed 3 time(s) in a row\n\nAlert description: description-1\n\nExtra labels:\n  environment: production\n\n\nCondition results:\n❌ [CONNECTED] == true\n❌ [STATUS] == 200\n",
+		},
+		{
+			Name:            "resolved-with-single-extra-label",
+			Provider:        AlertProvider{},
+			Alert:           alert.Alert{Description: &secondDescription, SuccessThreshold: 5, FailureThreshold: 3},
+			Resolved:        true,
+			Endpoint:        &endpoint.Endpoint{Name: "endpoint-name", ExtraLabels: map[string]string{"service": "api"}},
+			ExpectedSubject: "[endpoint-name] Alert resolved",
+			ExpectedBody:    "An alert for endpoint-name has been resolved after passing successfully 5 time(s) in a row\n\nAlert description: description-2\n\nExtra labels:\n  service: api\n\n\nCondition results:\n✅ [CONNECTED] == true\n✅ [STATUS] == 200\n",
+		},
+		{
+			Name:            "triggered-with-no-extra-labels",
+			Provider:        AlertProvider{},
+			Alert:           alert.Alert{Description: &firstDescription, SuccessThreshold: 5, FailureThreshold: 3},
+			Resolved:        false,
+			Endpoint:        &endpoint.Endpoint{Name: "endpoint-name", ExtraLabels: map[string]string{}},
+			ExpectedSubject: "[endpoint-name] Alert triggered",
+			ExpectedBody:    "An alert for endpoint-name has been triggered due to having failed 3 time(s) in a row\n\nAlert description: description-1\n\nCondition results:\n❌ [CONNECTED] == true\n❌ [STATUS] == 200\n",
+		},
 	}
 	for _, scenario := range scenarios {
 		t.Run(scenario.Name, func(t *testing.T) {
 			subject, body := scenario.Provider.buildMessageSubjectAndBody(
-				&endpoint.Endpoint{Name: "endpoint-name"},
+				scenario.Endpoint,
 				&scenario.Alert,
 				&endpoint.Result{
 					ConditionResults: []*endpoint.ConditionResult{
@@ -126,64 +158,104 @@ func TestAlertProvider_GetDefaultAlert(t *testing.T) {
 	}
 }
 
-func TestAlertProvider_getToForGroup(t *testing.T) {
-	tests := []struct {
+func TestAlertProvider_GetConfig(t *testing.T) {
+	scenarios := []struct {
 		Name           string
 		Provider       AlertProvider
 		InputGroup     string
-		ExpectedOutput string
+		InputAlert     alert.Alert
+		ExpectedOutput Config
 	}{
 		{
 			Name: "provider-no-override-specify-no-group-should-default",
 			Provider: AlertProvider{
-				To:        "to@example.com",
-				Overrides: nil,
+				DefaultConfig: Config{From: "from@example.com", To: "to@example.com", Host: "smtp.gmail.com", Port: 587, Password: "password"},
+				Overrides:     nil,
 			},
 			InputGroup:     "",
-			ExpectedOutput: "to@example.com",
+			InputAlert:     alert.Alert{},
+			ExpectedOutput: Config{From: "from@example.com", To: "to@example.com", Host: "smtp.gmail.com", Port: 587, Password: "password"},
 		},
 		{
 			Name: "provider-no-override-specify-group-should-default",
 			Provider: AlertProvider{
-				To:        "to@example.com",
-				Overrides: nil,
+				DefaultConfig: Config{From: "from@example.com", To: "to@example.com", Host: "smtp.gmail.com", Port: 587, Password: "password"},
+				Overrides:     nil,
 			},
 			InputGroup:     "group",
-			ExpectedOutput: "to@example.com",
+			InputAlert:     alert.Alert{},
+			ExpectedOutput: Config{From: "from@example.com", To: "to@example.com", Host: "smtp.gmail.com", Port: 587, Password: "password"},
 		},
 		{
 			Name: "provider-with-override-specify-no-group-should-default",
 			Provider: AlertProvider{
-				To: "to@example.com",
+				DefaultConfig: Config{From: "from@example.com", To: "to@example.com", Host: "smtp.gmail.com", Port: 587, Password: "password"},
 				Overrides: []Override{
 					{
-						Group: "group",
-						To:    "to01@example.com",
+						Group:  "group",
+						Config: Config{To: "to01@example.com"},
 					},
 				},
 			},
 			InputGroup:     "",
-			ExpectedOutput: "to@example.com",
+			InputAlert:     alert.Alert{},
+			ExpectedOutput: Config{From: "from@example.com", To: "to@example.com", Host: "smtp.gmail.com", Port: 587, Password: "password"},
 		},
 		{
 			Name: "provider-with-override-specify-group-should-override",
 			Provider: AlertProvider{
-				To: "to@example.com",
+				DefaultConfig: Config{From: "from@example.com", To: "to@example.com", Host: "smtp.gmail.com", Port: 587, Password: "password"},
 				Overrides: []Override{
 					{
-						Group: "group",
-						To:    "to01@example.com",
+						Group:  "group",
+						Config: Config{To: "group-to@example.com"},
 					},
 				},
 			},
 			InputGroup:     "group",
-			ExpectedOutput: "to01@example.com",
+			InputAlert:     alert.Alert{},
+			ExpectedOutput: Config{From: "from@example.com", To: "group-to@example.com", Host: "smtp.gmail.com", Port: 587, Password: "password"},
+		},
+		{
+			Name: "provider-with-group-override-and-alert-override--alert-override-should-take-precedence",
+			Provider: AlertProvider{
+				DefaultConfig: Config{From: "from@example.com", To: "to@example.com", Host: "smtp.gmail.com", Port: 587, Password: "password"},
+				Overrides: []Override{
+					{
+						Group:  "group",
+						Config: Config{To: "group-to@example.com"},
+					},
+				},
+			},
+			InputGroup:     "group",
+			InputAlert:     alert.Alert{ProviderOverride: map[string]any{"to": "alert-to@example.com", "host": "smtp.example.com", "port": 588, "password": "hunter2"}},
+			ExpectedOutput: Config{From: "from@example.com", To: "alert-to@example.com", Host: "smtp.example.com", Port: 588, Password: "hunter2"},
 		},
 	}
-	for _, tt := range tests {
-		t.Run(tt.Name, func(t *testing.T) {
-			if got := tt.Provider.getToForGroup(tt.InputGroup); got != tt.ExpectedOutput {
-				t.Errorf("AlertProvider.getToForGroup() = %v, want %v", got, tt.ExpectedOutput)
+	for _, scenario := range scenarios {
+		t.Run(scenario.Name, func(t *testing.T) {
+			got, err := scenario.Provider.GetConfig(scenario.InputGroup, &scenario.InputAlert)
+			if err != nil {
+				t.Fatalf("unexpected error: %s", err)
+			}
+			if got.From != scenario.ExpectedOutput.From {
+				t.Errorf("expected from to be %s, got %s", scenario.ExpectedOutput.From, got.From)
+			}
+			if got.To != scenario.ExpectedOutput.To {
+				t.Errorf("expected to be %s, got %s", scenario.ExpectedOutput.To, got.To)
+			}
+			if got.Host != scenario.ExpectedOutput.Host {
+				t.Errorf("expected host to be %s, got %s", scenario.ExpectedOutput.Host, got.Host)
+			}
+			if got.Port != scenario.ExpectedOutput.Port {
+				t.Errorf("expected port to be %d, got %d", scenario.ExpectedOutput.Port, got.Port)
+			}
+			if got.Password != scenario.ExpectedOutput.Password {
+				t.Errorf("expected password to be %s, got %s", scenario.ExpectedOutput.Password, got.Password)
+			}
+			// Test ValidateOverrides as well, since it really just calls GetConfig
+			if err = scenario.Provider.ValidateOverrides(scenario.InputGroup, &scenario.InputAlert); err != nil {
+				t.Errorf("unexpected error: %s", err)
 			}
 		})
 	}

alerting/provider/gitea/gitea.go

@@ -2,6 +2,7 @@ package gitea
 
 import (
 	"crypto/tls"
+	"errors"
 	"fmt"
 	"net/http"
 	"net/url"
@@ -11,55 +12,56 @@ import (
 	"github.com/TwiN/gatus/v5/alerting/alert"
 	"github.com/TwiN/gatus/v5/client"
 	"github.com/TwiN/gatus/v5/config/endpoint"
+	"gopkg.in/yaml.v3"
 )
 
-// AlertProvider is the configuration necessary for sending an alert using Discord
-type AlertProvider struct {
-	RepositoryURL string `yaml:"repository-url"` // The URL of the Gitea repository to create issues in
-	Token         string `yaml:"token"`          // Token requires at least RW on issues and RO on metadata
+var (
+	ErrRepositoryURLNotSet  = errors.New("repository-url not set")
+	ErrInvalidRepositoryURL = errors.New("invalid repository-url")
+	ErrTokenNotSet          = errors.New("token not set")
+)
 
-	// DefaultAlert is the default alert configuration to use for endpoints with an alert of the appropriate type
-	DefaultAlert *alert.Alert `yaml:"default-alert,omitempty"`
-
-	// ClientConfig is the configuration of the client used to communicate with the provider's target
-	ClientConfig *client.Config `yaml:"client,omitempty"`
-
-	// Assignees is a list of users to assign the issue to
-	Assignees []string `yaml:"assignees,omitempty"`
+type Config struct {
+	RepositoryURL string   `yaml:"repository-url"`      // The URL of the Gitea repository to create issues in
+	Token         string   `yaml:"token"`               // Token requires at least RW on issues and RO on metadata
+	Assignees     []string `yaml:"assignees,omitempty"` // Assignees is a list of users to assign the issue to
 
 	username        string
 	repositoryOwner string
 	repositoryName  string
 	giteaClient     *gitea.Client
+
+	// ClientConfig is the configuration of the client used to communicate with the provider's target
+	ClientConfig *client.Config `yaml:"client,omitempty"`
 }
 
-// IsValid returns whether the provider's configuration is valid
-func (provider *AlertProvider) IsValid() bool {
-	if provider.ClientConfig == nil {
-		provider.ClientConfig = client.GetDefaultConfig()
+func (cfg *Config) Validate() error {
+	if len(cfg.RepositoryURL) == 0 {
+		return ErrRepositoryURLNotSet
 	}
-
-	if len(provider.Token) == 0 || len(provider.RepositoryURL) == 0 {
-		return false
+	if len(cfg.Token) == 0 {
+		return ErrTokenNotSet
 	}
 	// Validate format of the repository URL
-	repositoryURL, err := url.Parse(provider.RepositoryURL)
+	repositoryURL, err := url.Parse(cfg.RepositoryURL)
 	if err != nil {
-		return false
+		return err
 	}
 	baseURL := repositoryURL.Scheme + "://" + repositoryURL.Host
 	pathParts := strings.Split(repositoryURL.Path, "/")
 	if len(pathParts) != 3 {
-		return false
+		return ErrInvalidRepositoryURL
 	}
-	provider.repositoryOwner = pathParts[1]
-	provider.repositoryName = pathParts[2]
-
+	if cfg.repositoryOwner == pathParts[1] && cfg.repositoryName == pathParts[2] && cfg.giteaClient != nil {
+		// Already validated, let's skip the rest of the validation to avoid unnecessary API calls
+		return nil
+	}
+	cfg.repositoryOwner = pathParts[1]
+	cfg.repositoryName = pathParts[2]
 	opts := []gitea.ClientOption{
-		gitea.SetToken(provider.Token),
+		gitea.SetToken(cfg.Token),
 	}
-
-	if provider.ClientConfig != nil && provider.ClientConfig.Insecure {
+	if cfg.ClientConfig != nil && cfg.ClientConfig.Insecure {
 		// add new http client for skip verify
 		httpClient := &http.Client{
 			Transport: &http.Transport{
@@ -68,34 +70,62 @@ func (provider *AlertProvider) IsValid() bool {
 		}
 		opts = append(opts, gitea.SetHTTPClient(httpClient))
 	}
-
-	provider.giteaClient, err = gitea.NewClient(baseURL, opts...)
+	cfg.giteaClient, err = gitea.NewClient(baseURL, opts...)
 	if err != nil {
-		return false
+		return err
 	}
-
-	user, _, err := provider.giteaClient.GetMyUserInfo()
+	user, _, err := cfg.giteaClient.GetMyUserInfo()
 	if err != nil {
-		return false
+		return err
 	}
+	cfg.username = user.UserName
+	return nil
+}
 
-	provider.username = user.UserName
+func (cfg *Config) Merge(override *Config) {
+	if override.ClientConfig != nil {
+		cfg.ClientConfig = override.ClientConfig
+	}
+	if len(override.RepositoryURL) > 0 {
+		cfg.RepositoryURL = override.RepositoryURL
+	}
+	if len(override.Token) > 0 {
+		cfg.Token = override.Token
+	}
+	if len(override.Assignees) > 0 {
+		cfg.Assignees = override.Assignees
+	}
+}
 
-	return true
+// AlertProvider is the configuration necessary for sending an alert using Discord
+type AlertProvider struct {
+	DefaultConfig Config `yaml:",inline"`
+
+	// DefaultAlert is the default alert configuration to use for endpoints with an alert of the appropriate type
+	DefaultAlert *alert.Alert `yaml:"default-alert,omitempty"`
+}
+
+// Validate the provider's configuration
+func (provider *AlertProvider) Validate() error {
+	return provider.DefaultConfig.Validate()
 }
 
 // Send creates an issue in the designed RepositoryURL if the resolved parameter passed is false,
 // or closes the relevant issue(s) if the resolved parameter passed is true.
 func (provider *AlertProvider) Send(ep *endpoint.Endpoint, alert *alert.Alert, result *endpoint.Result, resolved bool) error {
+	cfg, err := provider.GetConfig(ep.Group, alert)
+	if err != nil {
+		return err
+	}
 	title := "alert(gatus): " + ep.DisplayName()
 	if !resolved {
-		_, _, err := provider.giteaClient.CreateIssue(
-			provider.repositoryOwner,
-			provider.repositoryName,
+		_, _, err = cfg.giteaClient.CreateIssue(
+			cfg.repositoryOwner,
+			cfg.repositoryName,
 			gitea.CreateIssueOption{
 				Title:     title,
 				Body:      provider.buildIssueBody(ep, alert, result),
-				Assignees: provider.Assignees,
+				Assignees: cfg.Assignees,
 			},
 		)
 		if err != nil {
@@ -103,29 +133,27 @@ func (provider *AlertProvider) Send(ep *endpoint.Endpoint, alert *alert.Alert, r
 		}
 		return nil
 	}
-
-	issues, _, err := provider.giteaClient.ListRepoIssues(
-		provider.repositoryOwner,
-		provider.repositoryName,
+	issues, _, err := cfg.giteaClient.ListRepoIssues(
+		cfg.repositoryOwner,
+		cfg.repositoryName,
 		gitea.ListIssueOption{
 			State:     gitea.StateOpen,
-			CreatedBy: provider.username,
+			CreatedBy: cfg.username,
 			ListOptions: gitea.ListOptions{
-				Page: 100,
+				PageSize: 100,
 			},
 		},
 	)
 	if err != nil {
 		return fmt.Errorf("failed to list issues: %w", err)
 	}
-
 	for _, issue := range issues {
 		if issue.Title == title {
 			stateClosed := gitea.StateClosed
-			_, _, err = provider.giteaClient.EditIssue(
-				provider.repositoryOwner,
-				provider.repositoryName,
-				issue.ID,
+			_, _, err = cfg.giteaClient.EditIssue(
+				cfg.repositoryOwner,
+				cfg.repositoryName,
+				issue.Index,
 				gitea.EditIssueOption{
 					State: &stateClosed,
 				},
@@ -165,3 +193,25 @@ func (provider *AlertProvider) buildIssueBody(ep *endpoint.Endpoint, alert *aler
 func (provider *AlertProvider) GetDefaultAlert() *alert.Alert {
 	return provider.DefaultAlert
 }
+
+// GetConfig returns the configuration for the provider with the overrides applied
+func (provider *AlertProvider) GetConfig(group string, alert *alert.Alert) (*Config, error) {
+	cfg := provider.DefaultConfig
+	// Handle alert overrides
+	if len(alert.ProviderOverride) != 0 {
+		overrideConfig := Config{}
+		if err := yaml.Unmarshal(alert.ProviderOverrideAsBytes(), &overrideConfig); err != nil {
+			return nil, err
+		}
+		cfg.Merge(&overrideConfig)
+	}
+	// Validate the configuration (we're returning the cfg here even if there's an error mostly for testing purposes)
+	err := cfg.Validate()
+	return &cfg, err
+}
+
+// ValidateOverrides validates the alert's provider override and, if present, the group override
+func (provider *AlertProvider) ValidateOverrides(group string, alert *alert.Alert) error {
+	_, err := provider.GetConfig(group, alert)
+	return err
+}

alerting/provider/gitea/gitea_test.go

@@ -12,42 +12,46 @@ import (
 	"github.com/TwiN/gatus/v5/test"
 )
 
-func TestAlertDefaultProvider_IsValid(t *testing.T) {
+func TestAlertProvider_Validate(t *testing.T) {
 	scenarios := []struct {
-		Name     string
-		Provider AlertProvider
-		Expected bool
+		Name          string
+		Provider      AlertProvider
+		ExpectedError bool
 	}{
 		{
-			Name:     "invalid",
-			Provider: AlertProvider{RepositoryURL: "", Token: ""},
-			Expected: false,
+			Name:          "invalid",
+			Provider:      AlertProvider{DefaultConfig: Config{RepositoryURL: "", Token: ""}},
+			ExpectedError: true,
 		},
 		{
-			Name:     "invalid-token",
-			Provider: AlertProvider{RepositoryURL: "https://gitea.com/TwiN/test", Token: "12345"},
-			Expected: false,
+			Name:          "invalid-token",
+			Provider:      AlertProvider{DefaultConfig: Config{RepositoryURL: "https://gitea.com/TwiN/test", Token: "12345"}},
+			ExpectedError: true,
 		},
 		{
-			Name:     "missing-repository-name",
-			Provider: AlertProvider{RepositoryURL: "https://gitea.com/TwiN", Token: "12345"},
-			Expected: false,
+			Name:          "missing-repository-name",
+			Provider:      AlertProvider{DefaultConfig: Config{RepositoryURL: "https://gitea.com/TwiN", Token: "12345"}},
+			ExpectedError: true,
 		},
 		{
-			Name:     "enterprise-client",
-			Provider: AlertProvider{RepositoryURL: "https://gitea.example.com/TwiN/test", Token: "12345"},
-			Expected: false,
+			Name:          "enterprise-client",
+			Provider:      AlertProvider{DefaultConfig: Config{RepositoryURL: "https://gitea.example.com/TwiN/test", Token: "12345"}},
+			ExpectedError: false,
 		},
 		{
-			Name:     "invalid-url",
-			Provider: AlertProvider{RepositoryURL: "gitea.com/TwiN/test", Token: "12345"},
-			Expected: false,
+			Name:          "invalid-url",
+			Provider:      AlertProvider{DefaultConfig: Config{RepositoryURL: "gitea.com/TwiN/test", Token: "12345"}},
+			ExpectedError: true,
 		},
 	}
 	for _, scenario := range scenarios {
 		t.Run(scenario.Name, func(t *testing.T) {
-			if scenario.Provider.IsValid() != scenario.Expected {
-				t.Errorf("expected %t, got %t", scenario.Expected, scenario.Provider.IsValid())
+			err := scenario.Provider.Validate()
+			if scenario.ExpectedError && err == nil {
+				t.Error("expected error, got none")
+			}
+			if !scenario.ExpectedError && err != nil && !strings.Contains(err.Error(), "user does not exist") && !strings.Contains(err.Error(), "no such host") {
+				t.Error("expected no error, got", err.Error())
 			}
 		})
 	}
@@ -67,14 +71,14 @@ func TestAlertProvider_Send(t *testing.T) {
 	}{
 		{
 			Name:          "triggered-error",
-			Provider:      AlertProvider{RepositoryURL: "https://gitea.com/TwiN/test", Token: "12345"},
+			Provider:      AlertProvider{DefaultConfig: Config{RepositoryURL: "https://gitea.com/TwiN/test", Token: "12345"}},
 			Alert:         alert.Alert{Description: &firstDescription, SuccessThreshold: 5, FailureThreshold: 3},
 			Resolved:      false,
 			ExpectedError: true,
 		},
 		{
 			Name:          "resolved-error",
-			Provider:      AlertProvider{RepositoryURL: "https://gitea.com/TwiN/test", Token: "12345"},
+			Provider:      AlertProvider{DefaultConfig: Config{RepositoryURL: "https://gitea.com/TwiN/test", Token: "12345"}},
 			Alert:         alert.Alert{Description: &secondDescription, SuccessThreshold: 5, FailureThreshold: 3},
 			Resolved:      true,
 			ExpectedError: true,
@@ -82,9 +86,13 @@ func TestAlertProvider_Send(t *testing.T) {
 	}
 	for _, scenario := range scenarios {
 		t.Run(scenario.Name, func(t *testing.T) {
-			scenario.Provider.giteaClient, _ = gitea.NewClient("https://gitea.com")
+			cfg, err := scenario.Provider.GetConfig("", &scenario.Alert)
+			if err != nil && !strings.Contains(err.Error(), "user does not exist") && !strings.Contains(err.Error(), "no such host") {
+				t.Error("expected no error, got", err.Error())
+			}
+			cfg.giteaClient, _ = gitea.NewClient("https://gitea.com")
 			client.InjectHTTPClient(&http.Client{Transport: scenario.MockRoundTripper})
-			err := scenario.Provider.Send(
+			err = scenario.Provider.Send(
 				&endpoint.Endpoint{Name: "endpoint-name", Group: "endpoint-group"},
 				&scenario.Alert,
 				&endpoint.Result{
@@ -167,3 +175,55 @@ func TestAlertProvider_GetDefaultAlert(t *testing.T) {
 		t.Error("expected default alert to be nil")
 	}
 }
+
+func TestAlertProvider_GetConfig(t *testing.T) {
+	scenarios := []struct {
+		Name           string
+		Provider       AlertProvider
+		InputAlert     alert.Alert
+		ExpectedOutput Config
+	}{
+		{
+			Name: "provider-no-override-should-default",
+			Provider: AlertProvider{
+				DefaultConfig: Config{RepositoryURL: "https://gitea.com/TwiN/test", Token: "12345"},
+			},
+			InputAlert:     alert.Alert{},
+			ExpectedOutput: Config{RepositoryURL: "https://gitea.com/TwiN/test", Token: "12345"},
+		},
+		{
+			Name: "provider-with-alert-override",
+			Provider: AlertProvider{
+				DefaultConfig: Config{RepositoryURL: "https://gitea.com/TwiN/test", Token: "12345"},
+			},
+			InputAlert:     alert.Alert{ProviderOverride: map[string]any{"repository-url": "https://gitea.com/TwiN/alert-test", "token": "54321", "assignees": []string{"TwiN"}}},
+			ExpectedOutput: Config{RepositoryURL: "https://gitea.com/TwiN/alert-test", Token: "54321", Assignees: []string{"TwiN"}},
+		},
+	}
+	for _, scenario := range scenarios {
+		t.Run(scenario.Name, func(t *testing.T) {
+			got, err := scenario.Provider.GetConfig("", &scenario.InputAlert)
+			if err != nil && !strings.Contains(err.Error(), "user does not exist") && !strings.Contains(err.Error(), "no such host") {
+				t.Fatalf("unexpected error: %s", err)
+			}
+			if got.RepositoryURL != scenario.ExpectedOutput.RepositoryURL {
+				t.Errorf("expected repository URL %s, got %s", scenario.ExpectedOutput.RepositoryURL, got.RepositoryURL)
+			}
+			if got.Token != scenario.ExpectedOutput.Token {
+				t.Errorf("expected token %s, got %s", scenario.ExpectedOutput.Token, got.Token)
+			}
+			if len(got.Assignees) != len(scenario.ExpectedOutput.Assignees) {
+				t.Errorf("expected %d assignees, got %d", len(scenario.ExpectedOutput.Assignees), len(got.Assignees))
+			}
+			for i, assignee := range got.Assignees {
+				if assignee != scenario.ExpectedOutput.Assignees[i] {
+					t.Errorf("expected assignee %s, got %s", scenario.ExpectedOutput.Assignees[i], assignee)
+				}
+			}
+			// Test ValidateOverrides as well, since it really just calls GetConfig
+			if err = scenario.Provider.ValidateOverrides("", &scenario.InputAlert); err != nil && !strings.Contains(err.Error(), "user does not exist") {
+				t.Errorf("unexpected error: %s", err)
+			}
+		})
+	}
+}

alerting/provider/github/github.go

@@ -2,6 +2,7 @@ package github
 
 import (
 	"context"
+	"errors"
 	"fmt"
 	"net/url"
 	"strings"
@@ -11,69 +12,104 @@ import (
 	"github.com/TwiN/gatus/v5/config/endpoint"
 	"github.com/google/go-github/v48/github"
 	"golang.org/x/oauth2"
+	"gopkg.in/yaml.v3"
 )
 
-// AlertProvider is the configuration necessary for sending an alert using Discord
-type AlertProvider struct {
+var (
+	ErrRepositoryURLNotSet  = errors.New("repository-url not set")
+	ErrInvalidRepositoryURL = errors.New("invalid repository-url")
+	ErrTokenNotSet          = errors.New("token not set")
+)
+
+type Config struct {
 	RepositoryURL string `yaml:"repository-url"` // The URL of the GitHub repository to create issues in
 	Token         string `yaml:"token"`          // Token requires at least RW on issues and RO on metadata
 
-	// DefaultAlert is the default alert configuration to use for endpoints with an alert of the appropriate type
-	DefaultAlert *alert.Alert `yaml:"default-alert,omitempty"`
-
 	username        string
 	repositoryOwner string
 	repositoryName  string
 	githubClient    *github.Client
 }
 
-// IsValid returns whether the provider's configuration is valid
-func (provider *AlertProvider) IsValid() bool {
-	if len(provider.Token) == 0 || len(provider.RepositoryURL) == 0 {
-		return false
+func (cfg *Config) Validate() error {
+	if len(cfg.RepositoryURL) == 0 {
+		return ErrRepositoryURLNotSet
+	}
+	if len(cfg.Token) == 0 {
+		return ErrTokenNotSet
 	}
 	// Validate format of the repository URL
-	repositoryURL, err := url.Parse(provider.RepositoryURL)
+	repositoryURL, err := url.Parse(cfg.RepositoryURL)
 	if err != nil {
-		return false
+		return err
 	}
 	baseURL := repositoryURL.Scheme + "://" + repositoryURL.Host
 	pathParts := strings.Split(repositoryURL.Path, "/")
 	if len(pathParts) != 3 {
-		return false
+		return ErrInvalidRepositoryURL
 	}
-	provider.repositoryOwner = pathParts[1]
-	provider.repositoryName = pathParts[2]
+	if cfg.repositoryOwner == pathParts[1] && cfg.repositoryName == pathParts[2] && cfg.githubClient != nil {
+		// Already validated, let's skip the rest of the validation to avoid unnecessary API calls
+		return nil
+	}
+	cfg.repositoryOwner = pathParts[1]
+	cfg.repositoryName = pathParts[2]
 	// Create oauth2 HTTP client with GitHub token
 	httpClientWithStaticTokenSource := oauth2.NewClient(context.Background(), oauth2.StaticTokenSource(&oauth2.Token{
-		AccessToken: provider.Token,
+		AccessToken: cfg.Token,
 	}))
 	// Create GitHub client
 	if baseURL == "https://github.com" {
-		provider.githubClient = github.NewClient(httpClientWithStaticTokenSource)
+		cfg.githubClient = github.NewClient(httpClientWithStaticTokenSource)
 	} else {
-		provider.githubClient, err = github.NewEnterpriseClient(baseURL, baseURL, httpClientWithStaticTokenSource)
+		cfg.githubClient, err = github.NewEnterpriseClient(baseURL, baseURL, httpClientWithStaticTokenSource)
 		if err != nil {
-			return false
+			return fmt.Errorf("failed to create enterprise GitHub client: %w", err)
 		}
 	}
 	// Retrieve the username once to validate that the token is valid
 	ctx, cancel := context.WithTimeout(context.Background(), 30*time.Second)
 	defer cancel()
-	user, _, err := provider.githubClient.Users.Get(ctx, "")
+	user, _, err := cfg.githubClient.Users.Get(ctx, "")
 	if err != nil {
-		return false
+		return fmt.Errorf("failed to retrieve GitHub user: %w", err)
 	}
-	provider.username = *user.Login
-	return true
+	cfg.username = *user.Login
+	return nil
+}
+
+func (cfg *Config) Merge(override *Config) {
+	if len(override.RepositoryURL) > 0 {
+		cfg.RepositoryURL = override.RepositoryURL
+	}
+	if len(override.Token) > 0 {
+		cfg.Token = override.Token
+	}
+}
+
+// AlertProvider is the configuration necessary for sending an alert using Discord
+type AlertProvider struct {
+	DefaultConfig Config `yaml:",inline"`
+
+	// DefaultAlert is the default alert configuration to use for endpoints with an alert of the appropriate type
+	DefaultAlert *alert.Alert `yaml:"default-alert,omitempty"`
+}
+
+// Validate the provider's configuration
+func (provider *AlertProvider) Validate() error {
+	return provider.DefaultConfig.Validate()
 }
 
 // Send creates an issue in the designed RepositoryURL if the resolved parameter passed is false,
 // or closes the relevant issue(s) if the resolved parameter passed is true.
 func (provider *AlertProvider) Send(ep *endpoint.Endpoint, alert *alert.Alert, result *endpoint.Result, resolved bool) error {
+	cfg, err := provider.GetConfig(ep.Group, alert)
+	if err != nil {
+		return err
+	}
 	title := "alert(gatus): " + ep.DisplayName()
 	if !resolved {
-		_, _, err := provider.githubClient.Issues.Create(context.Background(), provider.repositoryOwner, provider.repositoryName, &github.IssueRequest{
+		_, _, err := cfg.githubClient.Issues.Create(context.Background(), cfg.repositoryOwner, cfg.repositoryName, &github.IssueRequest{
 			Title: github.String(title),
 			Body:  github.String(provider.buildIssueBody(ep, alert, result)),
 		})
@@ -81,9 +117,9 @@ func (provider *AlertProvider) Send(ep *endpoint.Endpoint, alert *alert.Alert, r
 			return fmt.Errorf("failed to create issue: %w", err)
 		}
 	} else {
-		issues, _, err := provider.githubClient.Issues.ListByRepo(context.Background(), provider.repositoryOwner, provider.repositoryName, &github.IssueListByRepoOptions{
+		issues, _, err := cfg.githubClient.Issues.ListByRepo(context.Background(), cfg.repositoryOwner, cfg.repositoryName, &github.IssueListByRepoOptions{
 			State:       "open",
-			Creator:     provider.username,
+			Creator:     cfg.username,
 			ListOptions: github.ListOptions{PerPage: 100},
 		})
 		if err != nil {
@@ -91,7 +127,7 @@ func (provider *AlertProvider) Send(ep *endpoint.Endpoint, alert *alert.Alert, r
 		}
 		for _, issue := range issues {
 			if *issue.Title == title {
-				_, _, err = provider.githubClient.Issues.Edit(context.Background(), provider.repositoryOwner, provider.repositoryName, *issue.Number, &github.IssueRequest{
+				_, _, err = cfg.githubClient.Issues.Edit(context.Background(), cfg.repositoryOwner, cfg.repositoryName, *issue.Number, &github.IssueRequest{
 					State: github.String("closed"),
 				})
 				if err != nil {
@@ -130,3 +166,25 @@ func (provider *AlertProvider) buildIssueBody(ep *endpoint.Endpoint, alert *aler
 func (provider *AlertProvider) GetDefaultAlert() *alert.Alert {
 	return provider.DefaultAlert
 }
+
+// GetConfig returns the configuration for the provider with the overrides applied
+func (provider *AlertProvider) GetConfig(group string, alert *alert.Alert) (*Config, error) {
+	cfg := provider.DefaultConfig
+	// Handle alert overrides
+	if len(alert.ProviderOverride) != 0 {
+		overrideConfig := Config{}
+		if err := yaml.Unmarshal(alert.ProviderOverrideAsBytes(), &overrideConfig); err != nil {
+			return nil, err
+		}
+		cfg.Merge(&overrideConfig)
+	}
+	// Validate the configuration (we're returning the cfg here even if there's an error mostly for testing purposes)
+	err := cfg.Validate()
+	return &cfg, err
+}
+
+// ValidateOverrides validates the alert's provider override and, if present, the group override
+func (provider *AlertProvider) ValidateOverrides(group string, alert *alert.Alert) error {
+	_, err := provider.GetConfig(group, alert)
+	return err
+}

alerting/provider/github/github_test.go

@@ -12,42 +12,46 @@ import (
 	"github.com/google/go-github/v48/github"
 )
 
-func TestAlertDefaultProvider_IsValid(t *testing.T) {
+func TestAlertProvider_Validate(t *testing.T) {
 	scenarios := []struct {
-		Name     string
-		Provider AlertProvider
-		Expected bool
+		Name          string
+		Provider      AlertProvider
+		ExpectedError bool
 	}{
 		{
-			Name:     "invalid",
-			Provider: AlertProvider{RepositoryURL: "", Token: ""},
-			Expected: false,
+			Name:          "invalid",
+			Provider:      AlertProvider{DefaultConfig: Config{RepositoryURL: "", Token: ""}},
+			ExpectedError: true,
 		},
 		{
-			Name:     "invalid-token",
-			Provider: AlertProvider{RepositoryURL: "https://github.com/TwiN/test", Token: "12345"},
-			Expected: false,
+			Name:          "invalid-token",
+			Provider:      AlertProvider{DefaultConfig: Config{RepositoryURL: "https://github.com/TwiN/test", Token: "12345"}},
+			ExpectedError: true,
 		},
 		{
-			Name:     "missing-repository-name",
-			Provider: AlertProvider{RepositoryURL: "https://github.com/TwiN", Token: "12345"},
-			Expected: false,
+			Name:          "missing-repository-name",
+			Provider:      AlertProvider{DefaultConfig: Config{RepositoryURL: "https://github.com/TwiN", Token: "12345"}},
+			ExpectedError: true,
 		},
 		{
-			Name:     "enterprise-client",
-			Provider: AlertProvider{RepositoryURL: "https://github.example.com/TwiN/test", Token: "12345"},
-			Expected: false,
+			Name:          "enterprise-client",
+			Provider:      AlertProvider{DefaultConfig: Config{RepositoryURL: "https://github.example.com/TwiN/test", Token: "12345"}},
+			ExpectedError: true,
 		},
 		{
-			Name:     "invalid-url",
-			Provider: AlertProvider{RepositoryURL: "github.com/TwiN/test", Token: "12345"},
-			Expected: false,
+			Name:          "invalid-url",
+			Provider:      AlertProvider{DefaultConfig: Config{RepositoryURL: "github.com/TwiN/test", Token: "12345"}},
+			ExpectedError: true,
 		},
 	}
 	for _, scenario := range scenarios {
 		t.Run(scenario.Name, func(t *testing.T) {
-			if scenario.Provider.IsValid() != scenario.Expected {
-				t.Errorf("expected %t, got %t", scenario.Expected, scenario.Provider.IsValid())
+			err := scenario.Provider.Validate()
+			if scenario.ExpectedError && err == nil {
+				t.Error("expected error, got none")
+			}
+			if !scenario.ExpectedError && err != nil && !strings.Contains(err.Error(), "user does not exist") && !strings.Contains(err.Error(), "no such host") {
+				t.Error("expected no error, got", err.Error())
 			}
 		})
 	}
@@ -67,14 +71,14 @@ func TestAlertProvider_Send(t *testing.T) {
 	}{
 		{
 			Name:          "triggered-error",
-			Provider:      AlertProvider{RepositoryURL: "https://github.com/TwiN/test", Token: "12345"},
+			Provider:      AlertProvider{DefaultConfig: Config{RepositoryURL: "https://github.com/TwiN/test", Token: "12345"}},
 			Alert:         alert.Alert{Description: &firstDescription, SuccessThreshold: 5, FailureThreshold: 3},
 			Resolved:      false,
 			ExpectedError: true,
 		},
 		{
 			Name:          "resolved-error",
-			Provider:      AlertProvider{RepositoryURL: "https://github.com/TwiN/test", Token: "12345"},
+			Provider:      AlertProvider{DefaultConfig: Config{RepositoryURL: "https://github.com/TwiN/test", Token: "12345"}},
 			Alert:         alert.Alert{Description: &secondDescription, SuccessThreshold: 5, FailureThreshold: 3},
 			Resolved:      true,
 			ExpectedError: true,
@@ -82,9 +86,13 @@ func TestAlertProvider_Send(t *testing.T) {
 	}
 	for _, scenario := range scenarios {
 		t.Run(scenario.Name, func(t *testing.T) {
-			scenario.Provider.githubClient = github.NewClient(nil)
+			cfg, err := scenario.Provider.GetConfig("", &scenario.Alert)
+			if err != nil && !strings.Contains(err.Error(), "failed to retrieve GitHub user") && !strings.Contains(err.Error(), "no such host") {
+				t.Error("expected no error, got", err.Error())
+			}
+			cfg.githubClient = github.NewClient(nil)
 			client.InjectHTTPClient(&http.Client{Transport: scenario.MockRoundTripper})
-			err := scenario.Provider.Send(
+			err = scenario.Provider.Send(
 				&endpoint.Endpoint{Name: "endpoint-name", Group: "endpoint-group"},
 				&scenario.Alert,
 				&endpoint.Result{
@@ -167,3 +175,47 @@ func TestAlertProvider_GetDefaultAlert(t *testing.T) {
 		t.Error("expected default alert to be nil")
 	}
 }
+
+func TestAlertProvider_GetConfig(t *testing.T) {
+	scenarios := []struct {
+		Name           string
+		Provider       AlertProvider
+		InputAlert     alert.Alert
+		ExpectedOutput Config
+	}{
+		{
+			Name: "provider-no-override-should-default",
+			Provider: AlertProvider{
+				DefaultConfig: Config{RepositoryURL: "https://github.com/TwiN/test", Token: "12345"},
+			},
+			InputAlert:     alert.Alert{},
+			ExpectedOutput: Config{RepositoryURL: "https://github.com/TwiN/test", Token: "12345"},
+		},
+		{
+			Name: "provider-with-alert-override",
+			Provider: AlertProvider{
+				DefaultConfig: Config{RepositoryURL: "https://github.com/TwiN/test", Token: "12345"},
+			},
+			InputAlert:     alert.Alert{ProviderOverride: map[string]any{"repository-url": "https://github.com/TwiN/alert-test", "token": "54321"}},
+			ExpectedOutput: Config{RepositoryURL: "https://github.com/TwiN/alert-test", Token: "54321"},
+		},
+	}
+	for _, scenario := range scenarios {
+		t.Run(scenario.Name, func(t *testing.T) {
+			got, err := scenario.Provider.GetConfig("", &scenario.InputAlert)
+			if err != nil && !strings.Contains(err.Error(), "failed to retrieve GitHub user") && !strings.Contains(err.Error(), "no such host") {
+				t.Fatalf("unexpected error: %s", err)
+			}
+			if got.RepositoryURL != scenario.ExpectedOutput.RepositoryURL {
+				t.Errorf("expected repository URL %s, got %s", scenario.ExpectedOutput.RepositoryURL, got.RepositoryURL)
+			}
+			if got.Token != scenario.ExpectedOutput.Token {
+				t.Errorf("expected token %s, got %s", scenario.ExpectedOutput.Token, got.Token)
+			}
+			// Test ValidateOverrides as well, since it really just calls GetConfig
+			if err = scenario.Provider.ValidateOverrides("", &scenario.InputAlert); err != nil && !strings.Contains(err.Error(), "failed to retrieve GitHub user") {
+				t.Errorf("unexpected error: %s", err)
+			}
+		})
+	}
+}

alerting/provider/gitlab/gitlab.go

@@ -13,55 +13,97 @@ import (
 	"github.com/TwiN/gatus/v5/client"
 	"github.com/TwiN/gatus/v5/config/endpoint"
 	"github.com/google/uuid"
+	"gopkg.in/yaml.v3"
 )
 
+const (
+	DefaultSeverity       = "critical"
+	DefaultMonitoringTool = "gatus"
+)
+
+var (
+	ErrInvalidWebhookURL      = fmt.Errorf("invalid webhook-url")
+	ErrAuthorizationKeyNotSet = fmt.Errorf("authorization-key not set")
+)
+
+type Config struct {
+	WebhookURL       string `yaml:"webhook-url"`                // The webhook url provided by GitLab
+	AuthorizationKey string `yaml:"authorization-key"`          // The authorization key provided by GitLab
+	Severity         string `yaml:"severity,omitempty"`         // Severity can be one of: critical, high, medium, low, info, unknown. Defaults to critical
+	MonitoringTool   string `yaml:"monitoring-tool,omitempty"`  // MonitoringTool overrides the name sent to gitlab. Defaults to gatus
+	EnvironmentName  string `yaml:"environment-name,omitempty"` // EnvironmentName is the name of the associated GitLab environment. Required to display alerts on a dashboard.
+	Service          string `yaml:"service,omitempty"`          // Service affected. Defaults to the endpoint's display name
+}
+
+func (cfg *Config) Validate() error {
+	if len(cfg.WebhookURL) == 0 {
+		return ErrInvalidWebhookURL
+	} else if _, err := url.Parse(cfg.WebhookURL); err != nil {
+		return ErrInvalidWebhookURL
+	}
+	if len(cfg.AuthorizationKey) == 0 {
+		return ErrAuthorizationKeyNotSet
+	}
+	if len(cfg.Severity) == 0 {
+		cfg.Severity = DefaultSeverity
+	}
+	if len(cfg.MonitoringTool) == 0 {
+		cfg.MonitoringTool = DefaultMonitoringTool
+	}
+	return nil
+}
+
+func (cfg *Config) Merge(override *Config) {
+	if len(override.WebhookURL) > 0 {
+		cfg.WebhookURL = override.WebhookURL
+	}
+	if len(override.AuthorizationKey) > 0 {
+		cfg.AuthorizationKey = override.AuthorizationKey
+	}
+	if len(override.Severity) > 0 {
+		cfg.Severity = override.Severity
+	}
+	if len(override.MonitoringTool) > 0 {
+		cfg.MonitoringTool = override.MonitoringTool
+	}
+	if len(override.EnvironmentName) > 0 {
+		cfg.EnvironmentName = override.EnvironmentName
+	}
+	if len(override.Service) > 0 {
+		cfg.Service = override.Service
+	}
+}
+
 // AlertProvider is the configuration necessary for sending an alert using GitLab
 type AlertProvider struct {
-	WebhookURL       string `yaml:"webhook-url"`       // The webhook url provided by GitLab
-	AuthorizationKey string `yaml:"authorization-key"` // The authorization key provided by GitLab
+	DefaultConfig Config `yaml:",inline"`
 
 	// DefaultAlert is the default alert configuration to use for endpoints with an alert of the appropriate type
 	DefaultAlert *alert.Alert `yaml:"default-alert,omitempty"`
-
-	// Severity can be one of: critical, high, medium, low, info, unknown. Defaults to critical
-	Severity string `yaml:"severity,omitempty"`
-
-	// MonitoringTool overrides the name sent to gitlab. Defaults to gatus
-	MonitoringTool string `yaml:"monitoring-tool,omitempty"`
-
-	// EnvironmentName is the name of the associated GitLab environment. Required to display alerts on a dashboard.
-	EnvironmentName string `yaml:"environment-name,omitempty"`
-
-	// Service affected. Defaults to endpoint display name
-	Service string `yaml:"service,omitempty"`
 }
 
-// IsValid returns whether the provider's configuration is valid
-func (provider *AlertProvider) IsValid() bool {
-	if len(provider.AuthorizationKey) == 0 || len(provider.WebhookURL) == 0 {
-		return false
-	}
-	// Validate format of the repository URL
-	_, err := url.Parse(provider.WebhookURL)
-	if err != nil {
-		return false
-	}
-	return true
+// Validate the provider's configuration
+func (provider *AlertProvider) Validate() error {
+	return provider.DefaultConfig.Validate()
 }
 
 // Send creates an issue in the designed RepositoryURL if the resolved parameter passed is false,
 // or closes the relevant issue(s) if the resolved parameter passed is true.
 func (provider *AlertProvider) Send(ep *endpoint.Endpoint, alert *alert.Alert, result *endpoint.Result, resolved bool) error {
+	cfg, err := provider.GetConfig(ep.Group, alert)
+	if err != nil {
+		return err
+	}
 	if len(alert.ResolveKey) == 0 {
 		alert.ResolveKey = uuid.NewString()
 	}
-	buffer := bytes.NewBuffer(provider.buildAlertBody(ep, alert, result, resolved))
-	request, err := http.NewRequest(http.MethodPost, provider.WebhookURL, buffer)
+	buffer := bytes.NewBuffer(provider.buildAlertBody(cfg, ep, alert, result, resolved))
+	request, err := http.NewRequest(http.MethodPost, cfg.WebhookURL, buffer)
 	if err != nil {
 		return err
 	}
 	request.Header.Set("Content-Type", "application/json")
-	request.Header.Set("Authorization", fmt.Sprintf("Bearer %s", provider.AuthorizationKey))
+	request.Header.Set("Authorization", fmt.Sprintf("Bearer %s", cfg.AuthorizationKey))
 	response, err := client.GetHTTPClient(nil).Do(request)
 	if err != nil {
 		return err
@@ -87,30 +129,20 @@ type AlertBody struct {
 	GitlabEnvironmentName string `json:"gitlab_environment_name,omitempty"` // The name of the associated GitLab environment. Required to display alerts on a dashboard.
 }
 
-func (provider *AlertProvider) monitoringTool() string {
-	if len(provider.MonitoringTool) > 0 {
-		return provider.MonitoringTool
-	}
-	return "gatus"
-}
-
-func (provider *AlertProvider) service(ep *endpoint.Endpoint) string {
-	if len(provider.Service) > 0 {
-		return provider.Service
-	}
-	return ep.DisplayName()
-}
-
 // buildAlertBody builds the body of the alert
-func (provider *AlertProvider) buildAlertBody(ep *endpoint.Endpoint, alert *alert.Alert, result *endpoint.Result, resolved bool) []byte {
+func (provider *AlertProvider) buildAlertBody(cfg *Config, ep *endpoint.Endpoint, alert *alert.Alert, result *endpoint.Result, resolved bool) []byte {
+	service := cfg.Service
+	if len(service) == 0 {
+		service = ep.DisplayName()
+	}
 	body := AlertBody{
-		Title:                 fmt.Sprintf("alert(%s): %s", provider.monitoringTool(), provider.service(ep)),
+		Title:                 fmt.Sprintf("alert(%s): %s", cfg.MonitoringTool, service),
 		StartTime:             result.Timestamp.Format(time.RFC3339),
-		Service:               provider.service(ep),
-		MonitoringTool:        provider.monitoringTool(),
+		Service:               service,
+		MonitoringTool:        cfg.MonitoringTool,
 		Hosts:                 ep.URL,
-		GitlabEnvironmentName: provider.EnvironmentName,
-		Severity:              provider.Severity,
+		GitlabEnvironmentName: cfg.EnvironmentName,
+		Severity:              cfg.Severity,
 		Fingerprint:           alert.ResolveKey,
 	}
 	if resolved {
@@ -148,3 +180,25 @@ func (provider *AlertProvider) buildAlertBody(ep *endpoint.Endpoint, alert *aler
 func (provider *AlertProvider) GetDefaultAlert() *alert.Alert {
 	return provider.DefaultAlert
 }
+
+// GetConfig returns the configuration for the provider with the overrides applied
+func (provider *AlertProvider) GetConfig(group string, alert *alert.Alert) (*Config, error) {
+	cfg := provider.DefaultConfig
+	// Handle alert overrides
+	if len(alert.ProviderOverride) != 0 {
+		overrideConfig := Config{}
+		if err := yaml.Unmarshal(alert.ProviderOverrideAsBytes(), &overrideConfig); err != nil {
+			return nil, err
+		}
+		cfg.Merge(&overrideConfig)
+	}
+	// Validate the configuration (we're returning the cfg here even if there's an error mostly for testing purposes)
+	err := cfg.Validate()
+	return &cfg, err
+}
+
+// ValidateOverrides validates the alert's provider override and, if present, the group override
+func (provider *AlertProvider) ValidateOverrides(group string, alert *alert.Alert) error {
+	_, err := provider.GetConfig(group, alert)
+	return err
+}

alerting/provider/gitlab/gitlab_test.go

@@ -11,37 +11,41 @@ import (
 	"github.com/TwiN/gatus/v5/test"
 )
 
-func TestAlertDefaultProvider_IsValid(t *testing.T) {
+func TestAlertProvider_Validate(t *testing.T) {
 	scenarios := []struct {
-		Name     string
-		Provider AlertProvider
-		Expected bool
+		Name          string
+		Provider      AlertProvider
+		ExpectedError bool
 	}{
 		{
-			Name:     "invalid",
-			Provider: AlertProvider{WebhookURL: "", AuthorizationKey: ""},
-			Expected: false,
+			Name:          "invalid",
+			Provider:      AlertProvider{DefaultConfig: Config{WebhookURL: "", AuthorizationKey: ""}},
+			ExpectedError: true,
 		},
 		{
-			Name:     "missing-webhook-url",
-			Provider: AlertProvider{WebhookURL: "", AuthorizationKey: "12345"},
-			Expected: false,
+			Name:          "missing-webhook-url",
+			Provider:      AlertProvider{DefaultConfig: Config{WebhookURL: "", AuthorizationKey: "12345"}},
+			ExpectedError: true,
 		},
 		{
-			Name:     "missing-authorization-key",
-			Provider: AlertProvider{WebhookURL: "https://gitlab.com/hlidotbe/text/alerts/notify/gatus/xxxxxxxxxxxxxxxx.json", AuthorizationKey: ""},
-			Expected: false,
+			Name:          "missing-authorization-key",
+			Provider:      AlertProvider{DefaultConfig: Config{WebhookURL: "https://gitlab.com/whatever/text/alerts/notify/gatus/xxxxxxxxxxxxxxxx.json", AuthorizationKey: ""}},
+			ExpectedError: true,
 		},
 		{
-			Name:     "invalid-url",
-			Provider: AlertProvider{WebhookURL: " http://foo.com", AuthorizationKey: "12345"},
-			Expected: false,
+			Name:          "invalid-url",
+			Provider:      AlertProvider{DefaultConfig: Config{WebhookURL: " http://foo.com", AuthorizationKey: "12345"}},
+			ExpectedError: true,
 		},
 	}
 	for _, scenario := range scenarios {
 		t.Run(scenario.Name, func(t *testing.T) {
-			if scenario.Provider.IsValid() != scenario.Expected {
-				t.Errorf("expected %t, got %t", scenario.Expected, scenario.Provider.IsValid())
+			err := scenario.Provider.Validate()
+			if scenario.ExpectedError && err == nil {
+				t.Error("expected error, got none")
+			}
+			if !scenario.ExpectedError && err != nil && !strings.Contains(err.Error(), "user does not exist") && !strings.Contains(err.Error(), "no such host") {
+				t.Error("expected no error, got", err.Error())
 			}
 		})
 	}
@@ -61,7 +65,7 @@ func TestAlertProvider_Send(t *testing.T) {
 	}{
 		{
 			Name:          "triggered-error",
-			Provider:      AlertProvider{WebhookURL: "https://gitlab.com/hlidotbe/text/alerts/notify/gatus/xxxxxxxxxxxxxxxx.json", AuthorizationKey: "12345"},
+			Provider:      AlertProvider{DefaultConfig: Config{WebhookURL: "https://gitlab.com/hlidotbe/text/alerts/notify/gatus/xxxxxxxxxxxxxxxx.json", AuthorizationKey: "12345"}},
 			Alert:         alert.Alert{Description: &firstDescription, SuccessThreshold: 5, FailureThreshold: 3},
 			Resolved:      false,
 			ExpectedError: false,
@@ -71,7 +75,7 @@ func TestAlertProvider_Send(t *testing.T) {
 		},
 		{
 			Name:          "resolved-error",
-			Provider:      AlertProvider{WebhookURL: "https://gitlab.com/hlidotbe/text/alerts/notify/gatus/xxxxxxxxxxxxxxxx.json", AuthorizationKey: "12345"},
+			Provider:      AlertProvider{DefaultConfig: Config{WebhookURL: "https://gitlab.com/hlidotbe/text/alerts/notify/gatus/xxxxxxxxxxxxxxxx.json", AuthorizationKey: "12345"}},
 			Alert:         alert.Alert{Description: &secondDescription, SuccessThreshold: 5, FailureThreshold: 3},
 			Resolved:      true,
 			ExpectedError: false,
@@ -116,21 +120,26 @@ func TestAlertProvider_buildAlertBody(t *testing.T) {
 		{
 			Name:         "triggered",
 			Endpoint:     endpoint.Endpoint{Name: "endpoint-name", URL: "https://example.org"},
-			Provider:     AlertProvider{},
+			Provider:     AlertProvider{DefaultConfig: Config{WebhookURL: "https://gitlab.com/hlidotbe/text/alerts/notify/gatus/xxxxxxxxxxxxxxxx.json", AuthorizationKey: "12345"}},
 			Alert:        alert.Alert{Description: &firstDescription, FailureThreshold: 3},
-			ExpectedBody: "{\"title\":\"alert(gatus): endpoint-name\",\"description\":\"An alert for *endpoint-name* has been triggered due to having failed 3 time(s) in a row:\\n\\u003e description-1\\n\\n## Condition results\\n- :white_check_mark: - `[CONNECTED] == true`\\n- :x: - `[STATUS] == 200`\\n\",\"start_time\":\"0001-01-01T00:00:00Z\",\"service\":\"endpoint-name\",\"monitoring_tool\":\"gatus\",\"hosts\":\"https://example.org\"}",
+			ExpectedBody: "{\"title\":\"alert(gatus): endpoint-name\",\"description\":\"An alert for *endpoint-name* has been triggered due to having failed 3 time(s) in a row:\\n\\u003e description-1\\n\\n## Condition results\\n- :white_check_mark: - `[CONNECTED] == true`\\n- :x: - `[STATUS] == 200`\\n\",\"start_time\":\"0001-01-01T00:00:00Z\",\"service\":\"endpoint-name\",\"monitoring_tool\":\"gatus\",\"hosts\":\"https://example.org\",\"severity\":\"critical\"}",
 		},
 		{
 			Name:         "no-description",
 			Endpoint:     endpoint.Endpoint{Name: "endpoint-name", URL: "https://example.org"},
-			Provider:     AlertProvider{},
+			Provider:     AlertProvider{DefaultConfig: Config{WebhookURL: "https://gitlab.com/hlidotbe/text/alerts/notify/gatus/xxxxxxxxxxxxxxxx.json", AuthorizationKey: "12345"}},
 			Alert:        alert.Alert{FailureThreshold: 10},
-			ExpectedBody: "{\"title\":\"alert(gatus): endpoint-name\",\"description\":\"An alert for *endpoint-name* has been triggered due to having failed 10 time(s) in a row\\n\\n## Condition results\\n- :white_check_mark: - `[CONNECTED] == true`\\n- :x: - `[STATUS] == 200`\\n\",\"start_time\":\"0001-01-01T00:00:00Z\",\"service\":\"endpoint-name\",\"monitoring_tool\":\"gatus\",\"hosts\":\"https://example.org\"}",
+			ExpectedBody: "{\"title\":\"alert(gatus): endpoint-name\",\"description\":\"An alert for *endpoint-name* has been triggered due to having failed 10 time(s) in a row\\n\\n## Condition results\\n- :white_check_mark: - `[CONNECTED] == true`\\n- :x: - `[STATUS] == 200`\\n\",\"start_time\":\"0001-01-01T00:00:00Z\",\"service\":\"endpoint-name\",\"monitoring_tool\":\"gatus\",\"hosts\":\"https://example.org\",\"severity\":\"critical\"}",
 		},
 	}
 	for _, scenario := range scenarios {
 		t.Run(scenario.Name, func(t *testing.T) {
+			cfg, err := scenario.Provider.GetConfig("", &scenario.Alert)
+			if err != nil {
+				t.Error("expected no error, got", err.Error())
+			}
 			body := scenario.Provider.buildAlertBody(
+				cfg,
 				&scenario.Endpoint,
 				&scenario.Alert,
 				&endpoint.Result{
@@ -156,3 +165,59 @@ func TestAlertProvider_GetDefaultAlert(t *testing.T) {
 		t.Error("expected default alert to be nil")
 	}
 }
+
+func TestAlertProvider_GetConfig(t *testing.T) {
+	scenarios := []struct {
+		Name           string
+		Provider       AlertProvider
+		InputAlert     alert.Alert
+		ExpectedOutput Config
+	}{
+		{
+			Name: "provider-no-override-should-default",
+			Provider: AlertProvider{
+				DefaultConfig: Config{WebhookURL: "https://github.com/TwiN/test", AuthorizationKey: "12345"},
+			},
+			InputAlert:     alert.Alert{},
+			ExpectedOutput: Config{WebhookURL: "https://github.com/TwiN/test", AuthorizationKey: "12345", Severity: DefaultSeverity, MonitoringTool: DefaultMonitoringTool},
+		},
+		{
+			Name: "provider-with-alert-override",
+			Provider: AlertProvider{
+				DefaultConfig: Config{WebhookURL: "https://github.com/TwiN/test", AuthorizationKey: "12345"},
+			},
+			InputAlert:     alert.Alert{ProviderOverride: map[string]any{"repository-url": "https://github.com/TwiN/alert-test", "authorization-key": "54321", "severity": "info", "monitoring-tool": "not-gatus", "environment-name": "prod", "service": "example"}},
+			ExpectedOutput: Config{WebhookURL: "https://github.com/TwiN/test", AuthorizationKey: "54321", Severity: "info", MonitoringTool: "not-gatus", EnvironmentName: "prod", Service: "example"},
+		},
+	}
+	for _, scenario := range scenarios {
+		t.Run(scenario.Name, func(t *testing.T) {
+			got, err := scenario.Provider.GetConfig("", &scenario.InputAlert)
+			if err != nil && !strings.Contains(err.Error(), "user does not exist") && !strings.Contains(err.Error(), "no such host") {
+				t.Fatalf("unexpected error: %s", err)
+			}
+			if got.WebhookURL != scenario.ExpectedOutput.WebhookURL {
+				t.Errorf("expected repository URL %s, got %s", scenario.ExpectedOutput.WebhookURL, got.WebhookURL)
+			}
+			if got.AuthorizationKey != scenario.ExpectedOutput.AuthorizationKey {
+				t.Errorf("expected AuthorizationKey %s, got %s", scenario.ExpectedOutput.AuthorizationKey, got.AuthorizationKey)
+			}
+			if got.Severity != scenario.ExpectedOutput.Severity {
+				t.Errorf("expected Severity %s, got %s", scenario.ExpectedOutput.Severity, got.Severity)
+			}
+			if got.MonitoringTool != scenario.ExpectedOutput.MonitoringTool {
+				t.Errorf("expected MonitoringTool %s, got %s", scenario.ExpectedOutput.MonitoringTool, got.MonitoringTool)
+			}
+			if got.EnvironmentName != scenario.ExpectedOutput.EnvironmentName {
+				t.Errorf("expected EnvironmentName %s, got %s", scenario.ExpectedOutput.EnvironmentName, got.EnvironmentName)
+			}
+			if got.Service != scenario.ExpectedOutput.Service {
+				t.Errorf("expected Service %s, got %s", scenario.ExpectedOutput.Service, got.Service)
+			}
+			// Test ValidateOverrides as well, since it really just calls GetConfig
+			if err = scenario.Provider.ValidateOverrides("", &scenario.InputAlert); err != nil {
+				t.Errorf("unexpected error: %s", err)
+			}
+		})
+	}
+}

alerting/provider/googlechat/googlechat.go

@@ -3,6 +3,7 @@ package googlechat
 import (
 	"bytes"
 	"encoding/json"
+	"errors"
 	"fmt"
 	"io"
 	"net/http"
@@ -10,14 +11,38 @@ import (
 	"github.com/TwiN/gatus/v5/alerting/alert"
 	"github.com/TwiN/gatus/v5/client"
 	"github.com/TwiN/gatus/v5/config/endpoint"
+	"gopkg.in/yaml.v3"
 )
 
+var (
+	ErrWebhookURLNotSet       = errors.New("webhook-url not set")
+	ErrDuplicateGroupOverride = errors.New("duplicate group override")
+)
+
+type Config struct {
+	WebhookURL   string         `yaml:"webhook-url"`
+	ClientConfig *client.Config `yaml:"client,omitempty"`
+}
+
+func (cfg *Config) Validate() error {
+	if len(cfg.WebhookURL) == 0 {
+		return ErrWebhookURLNotSet
+	}
+	return nil
+}
+
+func (cfg *Config) Merge(override *Config) {
+	if override.ClientConfig != nil {
+		cfg.ClientConfig = override.ClientConfig
+	}
+	if len(override.WebhookURL) > 0 {
+		cfg.WebhookURL = override.WebhookURL
+	}
+}
+
 // AlertProvider is the configuration necessary for sending an alert using Google chat
 type AlertProvider struct {
-	WebhookURL string `yaml:"webhook-url"`
-
-	// ClientConfig is the configuration of the client used to communicate with the provider's target
-	ClientConfig *client.Config `yaml:"client,omitempty"`
+	DefaultConfig Config `yaml:",inline"`
 
 	// DefaultAlert is the default alert configuration to use for endpoints with an alert of the appropriate type
 	DefaultAlert *alert.Alert `yaml:"default-alert,omitempty"`
@@ -28,36 +53,37 @@ type AlertProvider struct {
 
 // Override is a case under which the default integration is overridden
 type Override struct {
-	Group      string `yaml:"group"`
-	WebhookURL string `yaml:"webhook-url"`
+	Group  string `yaml:"group"`
+	Config `yaml:",inline"`
 }
 
-// IsValid returns whether the provider's configuration is valid
-func (provider *AlertProvider) IsValid() bool {
-	if provider.ClientConfig == nil {
-		provider.ClientConfig = client.GetDefaultConfig()
-	}
+// Validate the provider's configuration
+func (provider *AlertProvider) Validate() error {
 	registeredGroups := make(map[string]bool)
 	if provider.Overrides != nil {
 		for _, override := range provider.Overrides {
 			if isAlreadyRegistered := registeredGroups[override.Group]; isAlreadyRegistered || override.Group == "" || len(override.WebhookURL) == 0 {
-				return false
+				return ErrDuplicateGroupOverride
 			}
 			registeredGroups[override.Group] = true
 		}
 	}
-	return len(provider.WebhookURL) > 0
+	return provider.DefaultConfig.Validate()
 }
 
 // Send an alert using the provider
 func (provider *AlertProvider) Send(ep *endpoint.Endpoint, alert *alert.Alert, result *endpoint.Result, resolved bool) error {
+	cfg, err := provider.GetConfig(ep.Group, alert)
+	if err != nil {
+		return err
+	}
 	buffer := bytes.NewBuffer(provider.buildRequestBody(ep, alert, result, resolved))
-	request, err := http.NewRequest(http.MethodPost, provider.getWebhookURLForGroup(ep.Group), buffer)
+	request, err := http.NewRequest(http.MethodPost, cfg.WebhookURL, buffer)
 	if err != nil {
 		return err
 	}
 	request.Header.Set("Content-Type", "application/json")
-	response, err := client.GetHTTPClient(provider.ClientConfig).Do(request)
+	response, err := client.GetHTTPClient(cfg.ClientConfig).Do(request)
 	if err != nil {
 		return err
 	}
@@ -185,19 +211,38 @@ func (provider *AlertProvider) buildRequestBody(ep *endpoint.Endpoint, alert *al
 	return bodyAsJSON
 }
 
-// getWebhookURLForGroup returns the appropriate Webhook URL integration to for a given group
-func (provider *AlertProvider) getWebhookURLForGroup(group string) string {
-	if provider.Overrides != nil {
-		for _, override := range provider.Overrides {
-			if group == override.Group {
-				return override.WebhookURL
-			}
-		}
-	}
-	return provider.WebhookURL
-}
-
 // GetDefaultAlert returns the provider's default alert configuration
 func (provider *AlertProvider) GetDefaultAlert() *alert.Alert {
 	return provider.DefaultAlert
 }
+
+// GetConfig returns the configuration for the provider with the overrides applied
+func (provider *AlertProvider) GetConfig(group string, alert *alert.Alert) (*Config, error) {
+	cfg := provider.DefaultConfig
+	// Handle group overrides
+	if provider.Overrides != nil {
+		for _, override := range provider.Overrides {
+			if group == override.Group {
+				cfg.Merge(&override.Config)
+				break
+			}
+		}
+	}
+	// Handle alert overrides
+	if len(alert.ProviderOverride) != 0 {
+		overrideConfig := Config{}
+		if err := yaml.Unmarshal(alert.ProviderOverrideAsBytes(), &overrideConfig); err != nil {
+			return nil, err
+		}
+		cfg.Merge(&overrideConfig)
+	}
+	// Validate the configuration
+	err := cfg.Validate()
+	return &cfg, err
+}
+
+// ValidateOverrides validates the alert's provider override and, if present, the group override
+func (provider *AlertProvider) ValidateOverrides(group string, alert *alert.Alert) error {
+	_, err := provider.GetConfig(group, alert)
+	return err
+}

alerting/provider/googlechat/googlechat_test.go

@@ -11,50 +11,50 @@ import (
 	"github.com/TwiN/gatus/v5/test"
 )
 
-func TestAlertDefaultProvider_IsValid(t *testing.T) {
-	invalidProvider := AlertProvider{WebhookURL: ""}
-	if invalidProvider.IsValid() {
+func TestAlertProvider_Validate(t *testing.T) {
+	invalidProvider := AlertProvider{DefaultConfig: Config{WebhookURL: ""}}
+	if err := invalidProvider.Validate(); err == nil {
 		t.Error("provider shouldn't have been valid")
 	}
-	validProvider := AlertProvider{WebhookURL: "http://example.com"}
-	if !validProvider.IsValid() {
+	validProvider := AlertProvider{DefaultConfig: Config{WebhookURL: "http://example.com"}}
+	if err := validProvider.Validate(); err != nil {
 		t.Error("provider should've been valid")
 	}
 }
 
-func TestAlertProvider_IsValidWithOverride(t *testing.T) {
+func TestAlertProvider_ValidateWithOverride(t *testing.T) {
 	providerWithInvalidOverrideGroup := AlertProvider{
 		Overrides: []Override{
 			{
-				WebhookURL: "http://example.com",
-				Group:      "",
+				Config: Config{WebhookURL: "http://example.com"},
+				Group:  "",
 			},
 		},
 	}
-	if providerWithInvalidOverrideGroup.IsValid() {
+	if err := providerWithInvalidOverrideGroup.Validate(); err == nil {
 		t.Error("provider Group shouldn't have been valid")
 	}
 	providerWithInvalidOverrideTo := AlertProvider{
 		Overrides: []Override{
 			{
-				WebhookURL: "",
-				Group:      "group",
+				Config: Config{WebhookURL: ""},
+				Group:  "group",
 			},
 		},
 	}
-	if providerWithInvalidOverrideTo.IsValid() {
+	if err := providerWithInvalidOverrideTo.Validate(); err == nil {
 		t.Error("provider integration key shouldn't have been valid")
 	}
 	providerWithValidOverride := AlertProvider{
-		WebhookURL: "http://example.com",
+		DefaultConfig: Config{WebhookURL: "http://example.com"},
 		Overrides: []Override{
 			{
-				WebhookURL: "http://example.com",
-				Group:      "group",
+				Config: Config{WebhookURL: "http://example.com"},
+				Group:  "group",
 			},
 		},
 	}
-	if !providerWithValidOverride.IsValid() {
+	if err := providerWithValidOverride.Validate(); err != nil {
 		t.Error("provider should've been valid")
 	}
 }
@@ -73,7 +73,7 @@ func TestAlertProvider_Send(t *testing.T) {
 	}{
 		{
 			Name:     "triggered",
-			Provider: AlertProvider{},
+			Provider: AlertProvider{DefaultConfig: Config{WebhookURL: "http://example.com"}},
 			Alert:    alert.Alert{Description: &firstDescription, SuccessThreshold: 5, FailureThreshold: 3},
 			Resolved: false,
 			MockRoundTripper: test.MockRoundTripper(func(r *http.Request) *http.Response {
@@ -83,7 +83,7 @@ func TestAlertProvider_Send(t *testing.T) {
 		},
 		{
 			Name:     "triggered-error",
-			Provider: AlertProvider{},
+			Provider: AlertProvider{DefaultConfig: Config{WebhookURL: "http://example.com"}},
 			Alert:    alert.Alert{Description: &firstDescription, SuccessThreshold: 5, FailureThreshold: 3},
 			Resolved: false,
 			MockRoundTripper: test.MockRoundTripper(func(r *http.Request) *http.Response {
@@ -93,7 +93,7 @@ func TestAlertProvider_Send(t *testing.T) {
 		},
 		{
 			Name:     "resolved",
-			Provider: AlertProvider{},
+			Provider: AlertProvider{DefaultConfig: Config{WebhookURL: "http://example.com"}},
 			Alert:    alert.Alert{Description: &secondDescription, SuccessThreshold: 5, FailureThreshold: 3},
 			Resolved: true,
 			MockRoundTripper: test.MockRoundTripper(func(r *http.Request) *http.Response {
@@ -103,7 +103,7 @@ func TestAlertProvider_Send(t *testing.T) {
 		},
 		{
 			Name:     "resolved-error",
-			Provider: AlertProvider{},
+			Provider: AlertProvider{DefaultConfig: Config{WebhookURL: "http://example.com"}},
 			Alert:    alert.Alert{Description: &secondDescription, SuccessThreshold: 5, FailureThreshold: 3},
 			Resolved: true,
 			MockRoundTripper: test.MockRoundTripper(func(r *http.Request) *http.Response {
@@ -213,64 +213,92 @@ func TestAlertProvider_GetDefaultAlert(t *testing.T) {
 	}
 }
 
-func TestAlertProvider_getWebhookURLForGroup(t *testing.T) {
-	tests := []struct {
+func TestAlertProvider_GetConfig(t *testing.T) {
+	scenarios := []struct {
 		Name           string
 		Provider       AlertProvider
 		InputGroup     string
-		ExpectedOutput string
+		InputAlert     alert.Alert
+		ExpectedOutput Config
 	}{
 		{
 			Name: "provider-no-override-specify-no-group-should-default",
 			Provider: AlertProvider{
-				WebhookURL: "http://example.com",
-				Overrides:  nil,
+				DefaultConfig: Config{WebhookURL: "http://example.com"},
+				Overrides:     nil,
 			},
 			InputGroup:     "",
-			ExpectedOutput: "http://example.com",
+			InputAlert:     alert.Alert{},
+			ExpectedOutput: Config{WebhookURL: "http://example.com"},
 		},
 		{
 			Name: "provider-no-override-specify-group-should-default",
 			Provider: AlertProvider{
-				WebhookURL: "http://example.com",
-				Overrides:  nil,
+				DefaultConfig: Config{WebhookURL: "http://example.com"},
+				Overrides:     nil,
 			},
 			InputGroup:     "group",
-			ExpectedOutput: "http://example.com",
+			InputAlert:     alert.Alert{},
+			ExpectedOutput: Config{WebhookURL: "http://example.com"},
 		},
 		{
 			Name: "provider-with-override-specify-no-group-should-default",
 			Provider: AlertProvider{
-				WebhookURL: "http://example.com",
+				DefaultConfig: Config{WebhookURL: "http://example.com"},
 				Overrides: []Override{
 					{
-						Group:      "group",
-						WebhookURL: "http://example01.com",
+						Group:  "group",
+						Config: Config{WebhookURL: "http://example01.com"},
 					},
 				},
 			},
 			InputGroup:     "",
-			ExpectedOutput: "http://example.com",
+			InputAlert:     alert.Alert{},
+			ExpectedOutput: Config{WebhookURL: "http://example.com"},
 		},
 		{
 			Name: "provider-with-override-specify-group-should-override",
 			Provider: AlertProvider{
-				WebhookURL: "http://example.com",
+				DefaultConfig: Config{WebhookURL: "http://example.com"},
 				Overrides: []Override{
 					{
-						Group:      "group",
-						WebhookURL: "http://example01.com",
+						Group:  "group",
+						Config: Config{WebhookURL: "http://group-example.com"},
 					},
 				},
 			},
 			InputGroup:     "group",
-			ExpectedOutput: "http://example01.com",
+			InputAlert:     alert.Alert{},
+			ExpectedOutput: Config{WebhookURL: "http://group-example.com"},
+		},
+		{
+			Name: "provider-with-group-override-and-alert-override--alert-override-should-take-precedence",
+			Provider: AlertProvider{
+				DefaultConfig: Config{WebhookURL: "http://example.com"},
+				Overrides: []Override{
+					{
+						Group:  "group",
+						Config: Config{WebhookURL: "http://group-example.com"},
+					},
+				},
+			},
+			InputGroup:     "group",
+			InputAlert:     alert.Alert{ProviderOverride: map[string]any{"webhook-url": "http://alert-example.com"}},
+			ExpectedOutput: Config{WebhookURL: "http://alert-example.com"},
 		},
 	}
-	for _, tt := range tests {
-		t.Run(tt.Name, func(t *testing.T) {
-			if got := tt.Provider.getWebhookURLForGroup(tt.InputGroup); got != tt.ExpectedOutput {
-				t.Errorf("AlertProvider.getToForGroup() = %v, want %v", got, tt.ExpectedOutput)
+	for _, scenario := range scenarios {
+		t.Run(scenario.Name, func(t *testing.T) {
+			got, err := scenario.Provider.GetConfig(scenario.InputGroup, &scenario.InputAlert)
+			if err != nil {
+				t.Fatalf("unexpected error: %s", err)
+			}
+			if got.WebhookURL != scenario.ExpectedOutput.WebhookURL {
+				t.Errorf("expected webhook URL to be %s, got %s", scenario.ExpectedOutput.WebhookURL, got.WebhookURL)
+			}
+			// Test ValidateOverrides as well, since it really just calls GetConfig
+			if err = scenario.Provider.ValidateOverrides(scenario.InputGroup, &scenario.InputAlert); err != nil {
+				t.Errorf("unexpected error: %s", err)
 			}
 		})
 	}

alerting/provider/gotify/gotify.go

@@ -3,6 +3,7 @@ package gotify
 import (
 	"bytes"
 	"encoding/json"
+	"errors"
 	"fmt"
 	"io"
 	"net/http"
@@ -10,40 +11,72 @@ import (
 	"github.com/TwiN/gatus/v5/alerting/alert"
 	"github.com/TwiN/gatus/v5/client"
 	"github.com/TwiN/gatus/v5/config/endpoint"
+	"gopkg.in/yaml.v3"
 )
 
 const DefaultPriority = 5
 
+var (
+	ErrServerURLNotSet = errors.New("server URL not set")
+	ErrTokenNotSet     = errors.New("token not set")
+)
+
+type Config struct {
+	ServerURL string `yaml:"server-url"`         // URL of the Gotify server
+	Token     string `yaml:"token"`              // Token to use when sending a message to the Gotify server
+	Priority  int    `yaml:"priority,omitempty"` // Priority of the message. Defaults to DefaultPriority.
+	Title     string `yaml:"title,omitempty"`    // Title of the message that will be sent
+}
+
+func (cfg *Config) Validate() error {
+	if cfg.Priority == 0 {
+		cfg.Priority = DefaultPriority
+	}
+	if len(cfg.ServerURL) == 0 {
+		return ErrServerURLNotSet
+	}
+	if len(cfg.Token) == 0 {
+		return ErrTokenNotSet
+	}
+	return nil
+}
+
+func (cfg *Config) Merge(override *Config) {
+	if len(override.ServerURL) > 0 {
+		cfg.ServerURL = override.ServerURL
+	}
+	if len(override.Token) > 0 {
+		cfg.Token = override.Token
+	}
+	if override.Priority != 0 {
+		cfg.Priority = override.Priority
+	}
+	if len(override.Title) > 0 {
+		cfg.Title = override.Title
+	}
+}
+
 // AlertProvider is the configuration necessary for sending an alert using Gotify
 type AlertProvider struct {
-	// ServerURL is the URL of the Gotify server
-	ServerURL string `yaml:"server-url"`
-
-	// Token is the token to use when sending a message to the Gotify server
-	Token string `yaml:"token"`
-
-	// Priority is the priority of the message
-	Priority int `yaml:"priority,omitempty"` // Defaults to DefaultPriority
+	DefaultConfig Config `yaml:",inline"`
 
 	// DefaultAlert is the default alert configuration to use for endpoints with an alert of the appropriate type
 	DefaultAlert *alert.Alert `yaml:"default-alert,omitempty"`
-
-	// Title is the title of the message that will be sent
-	Title string `yaml:"title,omitempty"`
 }
 
-// IsValid returns whether the provider's configuration is valid
-func (provider *AlertProvider) IsValid() bool {
-	if provider.Priority == 0 {
-		provider.Priority = DefaultPriority
-	}
-	return len(provider.ServerURL) > 0 && len(provider.Token) > 0
+// Validate the provider's configuration
+func (provider *AlertProvider) Validate() error {
+	return provider.DefaultConfig.Validate()
 }
 
 // Send an alert using the provider
 func (provider *AlertProvider) Send(ep *endpoint.Endpoint, alert *alert.Alert, result *endpoint.Result, resolved bool) error {
-	buffer := bytes.NewBuffer(provider.buildRequestBody(ep, alert, result, resolved))
-	request, err := http.NewRequest(http.MethodPost, provider.ServerURL+"/message?token="+provider.Token, buffer)
+	cfg, err := provider.GetConfig(ep.Group, alert)
+	if err != nil {
+		return err
+	}
+	buffer := bytes.NewBuffer(provider.buildRequestBody(cfg, ep, alert, result, resolved))
+	request, err := http.NewRequest(http.MethodPost, cfg.ServerURL+"/message?token="+cfg.Token, buffer)
 	if err != nil {
 		return err
 	}
@@ -67,7 +100,7 @@ type Body struct {
 }
 
 // buildRequestBody builds the request body for the provider
-func (provider *AlertProvider) buildRequestBody(ep *endpoint.Endpoint, alert *alert.Alert, result *endpoint.Result, resolved bool) []byte {
+func (provider *AlertProvider) buildRequestBody(cfg *Config, ep *endpoint.Endpoint, alert *alert.Alert, result *endpoint.Result, resolved bool) []byte {
 	var message string
 	if resolved {
 		message = fmt.Sprintf("An alert for `%s` has been resolved after passing successfully %d time(s) in a row", ep.DisplayName(), alert.SuccessThreshold)
@@ -89,13 +122,13 @@ func (provider *AlertProvider) buildRequestBody(ep *endpoint.Endpoint, alert *al
 	}
 	message += formattedConditionResults
 	title := "Gatus: " + ep.DisplayName()
-	if provider.Title != "" {
-		title = provider.Title
+	if cfg.Title != "" {
+		title = cfg.Title
 	}
 	bodyAsJSON, _ := json.Marshal(Body{
 		Message:  message,
 		Title:    title,
-		Priority: provider.Priority,
+		Priority: cfg.Priority,
 	})
 	return bodyAsJSON
 }
@@ -104,3 +137,25 @@ func (provider *AlertProvider) buildRequestBody(ep *endpoint.Endpoint, alert *al
 func (provider *AlertProvider) GetDefaultAlert() *alert.Alert {
 	return provider.DefaultAlert
 }
+
+// GetConfig returns the configuration for the provider with the overrides applied
+func (provider *AlertProvider) GetConfig(group string, alert *alert.Alert) (*Config, error) {
+	cfg := provider.DefaultConfig
+	// Handle alert overrides
+	if len(alert.ProviderOverride) != 0 {
+		overrideConfig := Config{}
+		if err := yaml.Unmarshal(alert.ProviderOverrideAsBytes(), &overrideConfig); err != nil {
+			return nil, err
+		}
+		cfg.Merge(&overrideConfig)
+	}
+	// Validate the configuration
+	err := cfg.Validate()
+	return &cfg, err
+}
+
+// ValidateOverrides validates the alert's provider override and, if present, the group override
+func (provider *AlertProvider) ValidateOverrides(group string, alert *alert.Alert) error {
+	_, err := provider.GetConfig(group, alert)
+	return err
+}

alerting/provider/gotify/gotify_test.go

@@ -9,7 +9,7 @@ import (
 	"github.com/TwiN/gatus/v5/config/endpoint"
 )
 
-func TestAlertProvider_IsValid(t *testing.T) {
+func TestAlertProvider_Validate(t *testing.T) {
 	scenarios := []struct {
 		name     string
 		provider AlertProvider
@@ -17,29 +17,29 @@ func TestAlertProvider_IsValid(t *testing.T) {
 	}{
 		{
 			name:     "valid",
-			provider: AlertProvider{ServerURL: "https://gotify.example.com", Token: "faketoken"},
+			provider: AlertProvider{DefaultConfig: Config{ServerURL: "https://gotify.example.com", Token: "faketoken"}},
 			expected: true,
 		},
 		{
 			name:     "invalid-server-url",
-			provider: AlertProvider{ServerURL: "", Token: "faketoken"},
+			provider: AlertProvider{DefaultConfig: Config{ServerURL: "", Token: "faketoken"}},
 			expected: false,
 		},
 		{
 			name:     "invalid-app-token",
-			provider: AlertProvider{ServerURL: "https://gotify.example.com", Token: ""},
+			provider: AlertProvider{DefaultConfig: Config{ServerURL: "https://gotify.example.com", Token: ""}},
 			expected: false,
 		},
 		{
 			name:     "no-priority-should-use-default-value",
-			provider: AlertProvider{ServerURL: "https://gotify.example.com", Token: "faketoken"},
+			provider: AlertProvider{DefaultConfig: Config{ServerURL: "https://gotify.example.com", Token: "faketoken"}},
 			expected: true,
 		},
 	}
 	for _, scenario := range scenarios {
 		t.Run(scenario.name, func(t *testing.T) {
-			if scenario.provider.IsValid() != scenario.expected {
-				t.Errorf("expected %t, got %t", scenario.expected, scenario.provider.IsValid())
+			if err := scenario.provider.Validate(); (err == nil) != scenario.expected {
+				t.Errorf("expected: %t, got: %t", scenario.expected, err == nil)
 			}
 		})
 	}
@@ -60,21 +60,21 @@ func TestAlertProvider_buildRequestBody(t *testing.T) {
 	}{
 		{
 			Name:         "triggered",
-			Provider:     AlertProvider{ServerURL: "https://gotify.example.com", Token: "faketoken"},
+			Provider:     AlertProvider{DefaultConfig: Config{ServerURL: "https://gotify.example.com", Token: "faketoken"}},
 			Alert:        alert.Alert{Description: &description, SuccessThreshold: 5, FailureThreshold: 3},
 			Resolved:     false,
 			ExpectedBody: fmt.Sprintf("{\"message\":\"An alert for `%s` has been triggered due to having failed 3 time(s) in a row with the following description: %s\\n✕ - [CONNECTED] == true\\n✕ - [STATUS] == 200\",\"title\":\"Gatus: custom-endpoint\",\"priority\":0}", endpointName, description),
 		},
 		{
 			Name:         "resolved",
-			Provider:     AlertProvider{ServerURL: "https://gotify.example.com", Token: "faketoken"},
+			Provider:     AlertProvider{DefaultConfig: Config{ServerURL: "https://gotify.example.com", Token: "faketoken"}},
 			Alert:        alert.Alert{Description: &description, SuccessThreshold: 5, FailureThreshold: 3},
 			Resolved:     true,
 			ExpectedBody: fmt.Sprintf("{\"message\":\"An alert for `%s` has been resolved after passing successfully 5 time(s) in a row with the following description: %s\\n✓ - [CONNECTED] == true\\n✓ - [STATUS] == 200\",\"title\":\"Gatus: custom-endpoint\",\"priority\":0}", endpointName, description),
 		},
 		{
 			Name:         "custom-title",
-			Provider:     AlertProvider{ServerURL: "https://gotify.example.com", Token: "faketoken", Title: "custom-title"},
+			Provider:     AlertProvider{DefaultConfig: Config{ServerURL: "https://gotify.example.com", Token: "faketoken", Title: "custom-title"}},
 			Alert:        alert.Alert{Description: &description, SuccessThreshold: 5, FailureThreshold: 3},
 			Resolved:     false,
 			ExpectedBody: fmt.Sprintf("{\"message\":\"An alert for `%s` has been triggered due to having failed 3 time(s) in a row with the following description: %s\\n✕ - [CONNECTED] == true\\n✕ - [STATUS] == 200\",\"title\":\"custom-title\",\"priority\":0}", endpointName, description),
@@ -83,6 +83,7 @@ func TestAlertProvider_buildRequestBody(t *testing.T) {
 	for _, scenario := range scenarios {
 		t.Run(scenario.Name, func(t *testing.T) {
 			body := scenario.Provider.buildRequestBody(
+				&scenario.Provider.DefaultConfig,
 				&endpoint.Endpoint{Name: endpointName},
 				&scenario.Alert,
 				&endpoint.Result{
@@ -103,3 +104,60 @@ func TestAlertProvider_buildRequestBody(t *testing.T) {
 		})
 	}
 }
+
+func TestAlertProvider_GetDefaultAlert(t *testing.T) {
+	provider := AlertProvider{DefaultAlert: &alert.Alert{}}
+	if provider.GetDefaultAlert() != provider.DefaultAlert {
+		t.Error("expected default alert to be returned")
+	}
+}
+
+func TestAlertProvider_GetConfig(t *testing.T) {
+	scenarios := []struct {
+		Name           string
+		Provider       AlertProvider
+		InputAlert     alert.Alert
+		ExpectedOutput Config
+	}{
+		{
+			Name: "provider-no-override-should-default",
+			Provider: AlertProvider{
+				DefaultConfig: Config{ServerURL: "https://gotify.example.com", Token: "12345"},
+			},
+			InputAlert:     alert.Alert{},
+			ExpectedOutput: Config{ServerURL: "https://gotify.example.com", Token: "12345", Priority: DefaultPriority},
+		},
+		{
+			Name: "provider-with-alert-override",
+			Provider: AlertProvider{
+				DefaultConfig: Config{ServerURL: "https://gotify.example.com", Token: "12345"},
+			},
+			InputAlert:     alert.Alert{ProviderOverride: map[string]any{"server-url": "https://gotify.group-example.com", "token": "54321", "title": "alert-title", "priority": 3}},
+			ExpectedOutput: Config{ServerURL: "https://gotify.group-example.com", Token: "54321", Title: "alert-title", Priority: 3},
+		},
+	}
+	for _, scenario := range scenarios {
+		t.Run(scenario.Name, func(t *testing.T) {
+			got, err := scenario.Provider.GetConfig("", &scenario.InputAlert)
+			if err != nil {
+				t.Error("expected no error, got:", err.Error())
+			}
+			if got.ServerURL != scenario.ExpectedOutput.ServerURL {
+				t.Errorf("expected server URL to be %s, got %s", scenario.ExpectedOutput.ServerURL, got.ServerURL)
+			}
+			if got.Token != scenario.ExpectedOutput.Token {
+				t.Errorf("expected token to be %s, got %s", scenario.ExpectedOutput.Token, got.Token)
+			}
+			if got.Title != scenario.ExpectedOutput.Title {
+				t.Errorf("expected title to be %s, got %s", scenario.ExpectedOutput.Title, got.Title)
+			}
+			if got.Priority != scenario.ExpectedOutput.Priority {
+				t.Errorf("expected priority to be %d, got %d", scenario.ExpectedOutput.Priority, got.Priority)
+			}
+			// Test ValidateOverrides as well, since it really just calls GetConfig
+			if err = scenario.Provider.ValidateOverrides("", &scenario.InputAlert); err != nil {
+				t.Errorf("unexpected error: %s", err)
+			}
+		})
+	}
+}

alerting/provider/homeassistant/homeassistant.go

@@ -0,0 +1,196 @@
+package homeassistant
+
+import (
+	"bytes"
+	"encoding/json"
+	"errors"
+	"fmt"
+	"io"
+	"net/http"
+
+	"github.com/TwiN/gatus/v5/alerting/alert"
+	"github.com/TwiN/gatus/v5/client"
+	"github.com/TwiN/gatus/v5/config/endpoint"
+	"gopkg.in/yaml.v3"
+)
+
+var (
+	ErrURLNotSet              = errors.New("url not set")
+	ErrTokenNotSet            = errors.New("token not set")
+	ErrDuplicateGroupOverride = errors.New("duplicate group override")
+)
+
+type Config struct {
+	URL   string `yaml:"url"`
+	Token string `yaml:"token"`
+}
+
+func (cfg *Config) Validate() error {
+	if len(cfg.URL) == 0 {
+		return ErrURLNotSet
+	}
+	if len(cfg.Token) == 0 {
+		return ErrTokenNotSet
+	}
+	return nil
+}
+
+func (cfg *Config) Merge(override *Config) {
+	if len(override.URL) > 0 {
+		cfg.URL = override.URL
+	}
+	if len(override.Token) > 0 {
+		cfg.Token = override.Token
+	}
+}
+
+// AlertProvider is the configuration necessary for sending an alert using HomeAssistant
+type AlertProvider struct {
+	DefaultConfig Config `yaml:",inline"`
+
+	// DefaultAlert is the default alert configuration to use for endpoints with an alert of the appropriate type
+	DefaultAlert *alert.Alert `yaml:"default-alert,omitempty"`
+
+	// Overrides is a list of Override that may be prioritized over the default configuration
+	Overrides []Override `yaml:"overrides,omitempty"`
+}
+
+// Override is a case under which the default integration is overridden
+type Override struct {
+	Group  string `yaml:"group"`
+	Config `yaml:",inline"`
+}
+
+// Validate the provider's configuration
+func (provider *AlertProvider) Validate() error {
+	registeredGroups := make(map[string]bool)
+	if provider.Overrides != nil {
+		for _, override := range provider.Overrides {
+			if isAlreadyRegistered := registeredGroups[override.Group]; isAlreadyRegistered || override.Group == "" {
+				return ErrDuplicateGroupOverride
+			}
+			registeredGroups[override.Group] = true
+		}
+	}
+	return provider.DefaultConfig.Validate()
+}
+
+// Send an alert using the provider
+func (provider *AlertProvider) Send(ep *endpoint.Endpoint, alert *alert.Alert, result *endpoint.Result, resolved bool) error {
+	cfg, err := provider.GetConfig(ep.Group, alert)
+	if err != nil {
+		return err
+	}
+	buffer := bytes.NewBuffer(provider.buildRequestBody(ep, alert, result, resolved))
+	request, err := http.NewRequest(http.MethodPost, fmt.Sprintf("%s/api/events/gatus_alert", cfg.URL), buffer)
+	if err != nil {
+		return err
+	}
+	request.Header.Set("Content-Type", "application/json")
+	request.Header.Set("Authorization", "Bearer "+cfg.Token)
+	response, err := client.GetHTTPClient(nil).Do(request)
+	if err != nil {
+		return err
+	}
+	defer response.Body.Close()
+	if response.StatusCode > 399 {
+		body, _ := io.ReadAll(response.Body)
+		return fmt.Errorf("call to provider alert returned status code %d: %s", response.StatusCode, string(body))
+	}
+	return err
+}
+
+type Body struct {
+	EventType string `json:"event_type"`
+	EventData struct {
+		Status      string `json:"status"`
+		Endpoint    string `json:"endpoint"`
+		Description string `json:"description,omitempty"`
+		Conditions  []struct {
+			Condition string `json:"condition"`
+			Success   bool   `json:"success"`
+		} `json:"conditions,omitempty"`
+		FailureCount int `json:"failure_count,omitempty"`
+		SuccessCount int `json:"success_count,omitempty"`
+	} `json:"event_data"`
+}
+
+// buildRequestBody builds the request body for the provider
+func (provider *AlertProvider) buildRequestBody(ep *endpoint.Endpoint, alert *alert.Alert, result *endpoint.Result, resolved bool) []byte {
+	body := Body{
+		EventType: "gatus_alert",
+		EventData: struct {
+			Status      string `json:"status"`
+			Endpoint    string `json:"endpoint"`
+			Description string `json:"description,omitempty"`
+			Conditions  []struct {
+				Condition string `json:"condition"`
+				Success   bool   `json:"success"`
+			} `json:"conditions,omitempty"`
+			FailureCount int `json:"failure_count,omitempty"`
+			SuccessCount int `json:"success_count,omitempty"`
+		}{
+			Status:   "resolved",
+			Endpoint: ep.DisplayName(),
+		},
+	}
+
+	if !resolved {
+		body.EventData.Status = "triggered"
+		body.EventData.FailureCount = alert.FailureThreshold
+	} else {
+		body.EventData.SuccessCount = alert.SuccessThreshold
+	}
+
+	if alertDescription := alert.GetDescription(); len(alertDescription) > 0 {
+		body.EventData.Description = alertDescription
+	}
+
+	if len(result.ConditionResults) > 0 {
+		for _, conditionResult := range result.ConditionResults {
+			body.EventData.Conditions = append(body.EventData.Conditions, struct {
+				Condition string `json:"condition"`
+				Success   bool   `json:"success"`
+			}{
+				Condition: conditionResult.Condition,
+				Success:   conditionResult.Success,
+			})
+		}
+	}
+
+	bodyAsJSON, _ := json.Marshal(body)
+	return bodyAsJSON
+}
+
+// GetDefaultAlert returns the provider's default alert configuration
+func (provider *AlertProvider) GetDefaultAlert() *alert.Alert {
+	return provider.DefaultAlert
+}
+
+// GetConfig returns the configuration for the provider with the overrides applied
+func (provider *AlertProvider) GetConfig(group string, alert *alert.Alert) (*Config, error) {
+	cfg := provider.DefaultConfig
+	if provider.Overrides != nil {
+		for _, override := range provider.Overrides {
+			if group == override.Group {
+				cfg.Merge(&override.Config)
+				break
+			}
+		}
+	}
+	if len(alert.ProviderOverride) != 0 {
+		overrideConfig := Config{}
+		if err := yaml.Unmarshal(alert.ProviderOverrideAsBytes(), &overrideConfig); err != nil {
+			return nil, err
+		}
+		cfg.Merge(&overrideConfig)
+	}
+	err := cfg.Validate()
+	return &cfg, err
+}
+
+// ValidateOverrides validates the alert's provider override and, if present, the group override
+func (provider *AlertProvider) ValidateOverrides(group string, alert *alert.Alert) error {
+	_, err := provider.GetConfig(group, alert)
+	return err
+}

alerting/provider/homeassistant/homeassistant_test.go

@@ -0,0 +1,158 @@
+package homeassistant
+
+import (
+	"encoding/json"
+	"net/http"
+	"testing"
+
+	"github.com/TwiN/gatus/v5/alerting/alert"
+	"github.com/TwiN/gatus/v5/client"
+	"github.com/TwiN/gatus/v5/config/endpoint"
+	"github.com/TwiN/gatus/v5/test"
+)
+
+func TestAlertProvider_Validate(t *testing.T) {
+	invalidProvider := AlertProvider{DefaultConfig: Config{URL: "", Token: ""}}
+	if err := invalidProvider.Validate(); err == nil {
+		t.Error("provider shouldn't have been valid")
+	}
+	invalidProviderNoToken := AlertProvider{DefaultConfig: Config{URL: "http://homeassistant:8123", Token: ""}}
+	if err := invalidProviderNoToken.Validate(); err == nil {
+		t.Error("provider shouldn't have been valid")
+	}
+	validProvider := AlertProvider{DefaultConfig: Config{URL: "http://homeassistant:8123", Token: "token"}}
+	if err := validProvider.Validate(); err != nil {
+		t.Error("provider should've been valid")
+	}
+}
+
+func TestAlertProvider_ValidateWithOverride(t *testing.T) {
+	providerWithInvalidOverrideGroup := AlertProvider{
+		Overrides: []Override{
+			{
+				Config: Config{URL: "http://homeassistant:8123", Token: "token"},
+				Group:  "",
+			},
+		},
+	}
+	if err := providerWithInvalidOverrideGroup.Validate(); err == nil {
+		t.Error("provider Group shouldn't have been valid")
+	}
+	providerWithValidOverride := AlertProvider{
+		DefaultConfig: Config{URL: "http://homeassistant:8123", Token: "token"},
+		Overrides: []Override{
+			{
+				Config: Config{URL: "http://homeassistant:8123", Token: "token"},
+				Group:  "group",
+			},
+		},
+	}
+	if err := providerWithValidOverride.Validate(); err != nil {
+		t.Error("provider should've been valid")
+	}
+}
+
+func TestAlertProvider_Send(t *testing.T) {
+	defer client.InjectHTTPClient(nil)
+	firstDescription := "description-1"
+	secondDescription := "description-2"
+	scenarios := []struct {
+		Name             string
+		Provider         AlertProvider
+		Alert            alert.Alert
+		Resolved         bool
+		MockRoundTripper test.MockRoundTripper
+		ExpectedError    bool
+	}{
+		{
+			Name:     "triggered",
+			Provider: AlertProvider{DefaultConfig: Config{URL: "http://homeassistant:8123", Token: "token"}},
+			Alert:    alert.Alert{Description: &firstDescription, SuccessThreshold: 5, FailureThreshold: 3},
+			Resolved: false,
+			MockRoundTripper: test.MockRoundTripper(func(r *http.Request) *http.Response {
+				return &http.Response{StatusCode: http.StatusOK, Body: http.NoBody}
+			}),
+			ExpectedError: false,
+		},
+		{
+			Name:     "triggered-error",
+			Provider: AlertProvider{DefaultConfig: Config{URL: "http://homeassistant:8123", Token: "token"}},
+			Alert:    alert.Alert{Description: &firstDescription, SuccessThreshold: 5, FailureThreshold: 3},
+			Resolved: false,
+			MockRoundTripper: test.MockRoundTripper(func(r *http.Request) *http.Response {
+				return &http.Response{StatusCode: http.StatusInternalServerError, Body: http.NoBody}
+			}),
+			ExpectedError: true,
+		},
+		{
+			Name:     "resolved",
+			Provider: AlertProvider{DefaultConfig: Config{URL: "http://homeassistant:8123", Token: "token"}},
+			Alert:    alert.Alert{Description: &secondDescription, SuccessThreshold: 5, FailureThreshold: 3},
+			Resolved: true,
+			MockRoundTripper: test.MockRoundTripper(func(r *http.Request) *http.Response {
+				return &http.Response{StatusCode: http.StatusOK, Body: http.NoBody}
+			}),
+			ExpectedError: false,
+		},
+	}
+	for _, scenario := range scenarios {
+		t.Run(scenario.Name, func(t *testing.T) {
+			client.InjectHTTPClient(&http.Client{Transport: scenario.MockRoundTripper})
+			err := scenario.Provider.Send(
+				&endpoint.Endpoint{Name: "endpoint-name"},
+				&scenario.Alert,
+				&endpoint.Result{
+					ConditionResults: []*endpoint.ConditionResult{
+						{Condition: "SUCCESSFUL_CONDITION", Success: true},
+						{Condition: "FAILING_CONDITION", Success: false},
+					},
+				},
+				scenario.Resolved,
+			)
+			if scenario.ExpectedError && err == nil {
+				t.Error("expected error, got none")
+			}
+			if !scenario.ExpectedError && err != nil {
+				t.Error("expected no error, got", err.Error())
+			}
+		})
+	}
+}
+
+func TestAlertProvider_buildRequestBody(t *testing.T) {
+	description := "test-description"
+	provider := AlertProvider{DefaultConfig: Config{URL: "http://homeassistant:8123", Token: "token"}}
+	body := provider.buildRequestBody(
+		&endpoint.Endpoint{Name: "endpoint-name"},
+		&alert.Alert{Description: &description, SuccessThreshold: 5, FailureThreshold: 3},
+		&endpoint.Result{
+			ConditionResults: []*endpoint.ConditionResult{
+				{Condition: "SUCCESSFUL_CONDITION", Success: true},
+				{Condition: "FAILING_CONDITION", Success: false},
+			},
+		},
+		false,
+	)
+	var decodedBody Body
+	if err := json.Unmarshal(body, &decodedBody); err != nil {
+		t.Error("expected body to be valid JSON, got error:", err.Error())
+	}
+	if decodedBody.EventType != "gatus_alert" {
+		t.Errorf("expected event_type to be gatus_alert, got %s", decodedBody.EventType)
+	}
+	if decodedBody.EventData.Status != "triggered" {
+		t.Errorf("expected status to be triggered, got %s", decodedBody.EventData.Status)
+	}
+	if decodedBody.EventData.Description != description {
+		t.Errorf("expected description to be %s, got %s", description, decodedBody.EventData.Description)
+	}
+	if len(decodedBody.EventData.Conditions) != 2 {
+		t.Errorf("expected 2 conditions, got %d", len(decodedBody.EventData.Conditions))
+	}
+	if !decodedBody.EventData.Conditions[0].Success {
+		t.Error("expected first condition to be successful")
+	}
+	if decodedBody.EventData.Conditions[1].Success {
+		t.Error("expected second condition to be unsuccessful")
+	}
+}

alerting/provider/ifttt/ifttt.go

@@ -0,0 +1,187 @@
+package ifttt
+
+import (
+	"bytes"
+	"encoding/json"
+	"errors"
+	"fmt"
+	"io"
+	"net/http"
+
+	"github.com/TwiN/gatus/v5/alerting/alert"
+	"github.com/TwiN/gatus/v5/client"
+	"github.com/TwiN/gatus/v5/config/endpoint"
+	"gopkg.in/yaml.v3"
+)
+
+var (
+	ErrWebhookKeyNotSet       = errors.New("webhook-key not set")
+	ErrEventNameNotSet        = errors.New("event-name not set")
+	ErrDuplicateGroupOverride = errors.New("duplicate group override")
+)
+
+type Config struct {
+	WebhookKey string `yaml:"webhook-key"` // IFTTT Webhook key
+	EventName  string `yaml:"event-name"`  // IFTTT event name
+}
+
+func (cfg *Config) Validate() error {
+	if len(cfg.WebhookKey) == 0 {
+		return ErrWebhookKeyNotSet
+	}
+	if len(cfg.EventName) == 0 {
+		return ErrEventNameNotSet
+	}
+	return nil
+}
+
+func (cfg *Config) Merge(override *Config) {
+	if len(override.WebhookKey) > 0 {
+		cfg.WebhookKey = override.WebhookKey
+	}
+	if len(override.EventName) > 0 {
+		cfg.EventName = override.EventName
+	}
+}
+
+// AlertProvider is the configuration necessary for sending an alert using IFTTT
+type AlertProvider struct {
+	DefaultConfig Config `yaml:",inline"`
+
+	// DefaultAlert is the default alert configuration to use for endpoints with an alert of the appropriate type
+	DefaultAlert *alert.Alert `yaml:"default-alert,omitempty"`
+
+	// Overrides is a list of Override that may be prioritized over the default configuration
+	Overrides []Override `yaml:"overrides,omitempty"`
+}
+
+// Override is a case under which the default integration is overridden
+type Override struct {
+	Group  string `yaml:"group"`
+	Config `yaml:",inline"`
+}
+
+// Validate the provider's configuration
+func (provider *AlertProvider) Validate() error {
+	registeredGroups := make(map[string]bool)
+	if provider.Overrides != nil {
+		for _, override := range provider.Overrides {
+			if isAlreadyRegistered := registeredGroups[override.Group]; isAlreadyRegistered || override.Group == "" {
+				return ErrDuplicateGroupOverride
+			}
+			registeredGroups[override.Group] = true
+		}
+	}
+	return provider.DefaultConfig.Validate()
+}
+
+// Send an alert using the provider
+func (provider *AlertProvider) Send(ep *endpoint.Endpoint, alert *alert.Alert, result *endpoint.Result, resolved bool) error {
+	cfg, err := provider.GetConfig(ep.Group, alert)
+	if err != nil {
+		return err
+	}
+	url := fmt.Sprintf("https://maker.ifttt.com/trigger/%s/with/key/%s", cfg.EventName, cfg.WebhookKey)
+	body, err := provider.buildRequestBody(ep, alert, result, resolved)
+	if err != nil {
+		return err
+	}
+	buffer := bytes.NewBuffer(body)
+	request, err := http.NewRequest(http.MethodPost, url, buffer)
+	if err != nil {
+		return err
+	}
+	request.Header.Set("Content-Type", "application/json")
+	response, err := client.GetHTTPClient(nil).Do(request)
+	if err != nil {
+		return err
+	}
+	defer response.Body.Close()
+	if response.StatusCode >= 400 {
+		body, _ := io.ReadAll(response.Body)
+		return fmt.Errorf("call to ifttt alert returned status code %d: %s", response.StatusCode, string(body))
+	}
+	return err
+}
+
+type Body struct {
+	Value1 string `json:"value1"` // Alert status/title
+	Value2 string `json:"value2"` // Alert message
+	Value3 string `json:"value3"` // Additional details
+}
+
+// buildRequestBody builds the request body for the provider
+func (provider *AlertProvider) buildRequestBody(ep *endpoint.Endpoint, alert *alert.Alert, result *endpoint.Result, resolved bool) ([]byte, error) {
+	var value1, value2, value3 string
+	if resolved {
+		value1 = fmt.Sprintf("✅ RESOLVED: %s", ep.DisplayName())
+		value2 = fmt.Sprintf("Alert has been resolved after passing successfully %d time(s) in a row", alert.SuccessThreshold)
+	} else {
+		value1 = fmt.Sprintf("🚨 ALERT: %s", ep.DisplayName())
+		value2 = fmt.Sprintf("Endpoint has failed %d time(s) in a row", alert.FailureThreshold)
+	}
+	// Build additional details
+	value3 = fmt.Sprintf("Endpoint: %s", ep.DisplayName())
+	if ep.Group != "" {
+		value3 += fmt.Sprintf(" | Group: %s", ep.Group)
+	}
+	if alertDescription := alert.GetDescription(); len(alertDescription) > 0 {
+		value3 += fmt.Sprintf(" | Description: %s", alertDescription)
+	}
+	// Add condition results summary
+	if len(result.ConditionResults) > 0 {
+		successCount := 0
+		for _, conditionResult := range result.ConditionResults {
+			if conditionResult.Success {
+				successCount++
+			}
+		}
+		value3 += fmt.Sprintf(" | Conditions: %d/%d passed", successCount, len(result.ConditionResults))
+	}
+	body := Body{
+		Value1: value1,
+		Value2: value2,
+		Value3: value3,
+	}
+	bodyAsJSON, err := json.Marshal(body)
+	if err != nil {
+		return nil, err
+	}
+	return bodyAsJSON, nil
+}
+
+// GetDefaultAlert returns the provider's default alert configuration
+func (provider *AlertProvider) GetDefaultAlert() *alert.Alert {
+	return provider.DefaultAlert
+}
+
+// GetConfig returns the configuration for the provider with the overrides applied
+func (provider *AlertProvider) GetConfig(group string, alert *alert.Alert) (*Config, error) {
+	cfg := provider.DefaultConfig
+	// Handle group overrides
+	if provider.Overrides != nil {
+		for _, override := range provider.Overrides {
+			if group == override.Group {
+				cfg.Merge(&override.Config)
+				break
+			}
+		}
+	}
+	// Handle alert overrides
+	if len(alert.ProviderOverride) != 0 {
+		overrideConfig := Config{}
+		if err := yaml.Unmarshal(alert.ProviderOverrideAsBytes(), &overrideConfig); err != nil {
+			return nil, err
+		}
+		cfg.Merge(&overrideConfig)
+	}
+	// Validate the configuration
+	err := cfg.Validate()
+	return &cfg, err
+}
+
+// ValidateOverrides validates the alert's provider override and, if present, the group override
+func (provider *AlertProvider) ValidateOverrides(group string, alert *alert.Alert) error {
+	_, err := provider.GetConfig(group, alert)
+	return err
+}

alerting/provider/ifttt/ifttt_test.go

@@ -0,0 +1,154 @@
+package ifttt
+
+import (
+	"encoding/json"
+	"net/http"
+	"strings"
+	"testing"
+
+	"github.com/TwiN/gatus/v5/alerting/alert"
+	"github.com/TwiN/gatus/v5/client"
+	"github.com/TwiN/gatus/v5/config/endpoint"
+	"github.com/TwiN/gatus/v5/test"
+)
+
+func TestAlertProvider_Validate(t *testing.T) {
+	scenarios := []struct {
+		name     string
+		provider AlertProvider
+		expected error
+	}{
+		{
+			name:     "valid",
+			provider: AlertProvider{DefaultConfig: Config{WebhookKey: "ifttt-webhook-key-123", EventName: "gatus_alert"}},
+			expected: nil,
+		},
+		{
+			name:     "invalid-webhook-key",
+			provider: AlertProvider{DefaultConfig: Config{EventName: "gatus_alert"}},
+			expected: ErrWebhookKeyNotSet,
+		},
+		{
+			name:     "invalid-event-name",
+			provider: AlertProvider{DefaultConfig: Config{WebhookKey: "ifttt-webhook-key-123"}},
+			expected: ErrEventNameNotSet,
+		},
+	}
+	for _, scenario := range scenarios {
+		t.Run(scenario.name, func(t *testing.T) {
+			err := scenario.provider.Validate()
+			if err != scenario.expected {
+				t.Errorf("expected %v, got %v", scenario.expected, err)
+			}
+		})
+	}
+}
+
+func TestAlertProvider_Send(t *testing.T) {
+	defer client.InjectHTTPClient(nil)
+	firstDescription := "description-1"
+	secondDescription := "description-2"
+	scenarios := []struct {
+		name             string
+		provider         AlertProvider
+		alert            alert.Alert
+		resolved         bool
+		mockRoundTripper test.MockRoundTripper
+		expectedError    bool
+	}{
+		{
+			name:     "triggered",
+			provider: AlertProvider{DefaultConfig: Config{WebhookKey: "ifttt-webhook-key-123", EventName: "gatus_alert"}},
+			alert:    alert.Alert{Description: &firstDescription, SuccessThreshold: 5, FailureThreshold: 3},
+			resolved: false,
+			mockRoundTripper: test.MockRoundTripper(func(r *http.Request) *http.Response {
+				if r.Host != "maker.ifttt.com" {
+					t.Errorf("expected host maker.ifttt.com, got %s", r.Host)
+				}
+				if r.URL.Path != "/trigger/gatus_alert/with/key/ifttt-webhook-key-123" {
+					t.Errorf("expected path /trigger/gatus_alert/with/key/ifttt-webhook-key-123, got %s", r.URL.Path)
+				}
+				body := make(map[string]interface{})
+				json.NewDecoder(r.Body).Decode(&body)
+				value1 := body["value1"].(string)
+				if !strings.Contains(value1, "ALERT") {
+					t.Errorf("expected value1 to contain 'ALERT', got %s", value1)
+				}
+				value2 := body["value2"].(string)
+				if !strings.Contains(value2, "failed 3 time(s)") {
+					t.Errorf("expected value2 to contain failure count, got %s", value2)
+				}
+				value3 := body["value3"].(string)
+				if !strings.Contains(value3, "Endpoint: endpoint-name") {
+					t.Errorf("expected value3 to contain endpoint details, got %s", value3)
+				}
+				return &http.Response{StatusCode: http.StatusOK, Body: http.NoBody}
+			}),
+			expectedError: false,
+		},
+		{
+			name:     "resolved",
+			provider: AlertProvider{DefaultConfig: Config{WebhookKey: "ifttt-webhook-key-123", EventName: "gatus_resolved"}},
+			alert:    alert.Alert{Description: &secondDescription, SuccessThreshold: 5, FailureThreshold: 3},
+			resolved: true,
+			mockRoundTripper: test.MockRoundTripper(func(r *http.Request) *http.Response {
+				if r.URL.Path != "/trigger/gatus_resolved/with/key/ifttt-webhook-key-123" {
+					t.Errorf("expected path /trigger/gatus_resolved/with/key/ifttt-webhook-key-123, got %s", r.URL.Path)
+				}
+				body := make(map[string]interface{})
+				json.NewDecoder(r.Body).Decode(&body)
+				value1 := body["value1"].(string)
+				if !strings.Contains(value1, "RESOLVED") {
+					t.Errorf("expected value1 to contain 'RESOLVED', got %s", value1)
+				}
+				value3 := body["value3"].(string)
+				if !strings.Contains(value3, "Endpoint: endpoint-name") {
+					t.Errorf("expected value3 to contain endpoint details, got %s", value3)
+				}
+				return &http.Response{StatusCode: http.StatusOK, Body: http.NoBody}
+			}),
+			expectedError: false,
+		},
+		{
+			name:     "error-response",
+			provider: AlertProvider{DefaultConfig: Config{WebhookKey: "ifttt-webhook-key-123", EventName: "gatus_alert"}},
+			alert:    alert.Alert{Description: &firstDescription, SuccessThreshold: 5, FailureThreshold: 3},
+			resolved: false,
+			mockRoundTripper: test.MockRoundTripper(func(r *http.Request) *http.Response {
+				return &http.Response{StatusCode: http.StatusUnauthorized, Body: http.NoBody}
+			}),
+			expectedError: true,
+		},
+	}
+	for _, scenario := range scenarios {
+		t.Run(scenario.name, func(t *testing.T) {
+			client.InjectHTTPClient(&http.Client{Transport: scenario.mockRoundTripper})
+			err := scenario.provider.Send(
+				&endpoint.Endpoint{Name: "endpoint-name"},
+				&scenario.alert,
+				&endpoint.Result{
+					ConditionResults: []*endpoint.ConditionResult{
+						{Condition: "[CONNECTED] == true", Success: scenario.resolved},
+						{Condition: "[STATUS] == 200", Success: scenario.resolved},
+					},
+				},
+				scenario.resolved,
+			)
+			if scenario.expectedError && err == nil {
+				t.Error("expected error, got none")
+			}
+			if !scenario.expectedError && err != nil {
+				t.Error("expected no error, got", err.Error())
+			}
+		})
+	}
+}
+
+func TestAlertProvider_GetDefaultAlert(t *testing.T) {
+	if (&AlertProvider{DefaultAlert: &alert.Alert{}}).GetDefaultAlert() == nil {
+		t.Error("expected default alert to be not nil")
+	}
+	if (&AlertProvider{DefaultAlert: nil}).GetDefaultAlert() != nil {
+		t.Error("expected default alert to be nil")
+	}
+}

alerting/provider/ilert/ilert.go

@@ -0,0 +1,168 @@
+package ilert
+
+import (
+	"bytes"
+	"encoding/json"
+	"errors"
+	"fmt"
+	"io"
+	"net/http"
+
+	"github.com/TwiN/gatus/v5/alerting/alert"
+	"github.com/TwiN/gatus/v5/client"
+	"github.com/TwiN/gatus/v5/config/endpoint"
+	"gopkg.in/yaml.v3"
+)
+
+const (
+	restAPIUrl = "https://api.ilert.com/api/v1/events/gatus/"
+)
+
+var (
+	ErrIntegrationKeyNotSet   = errors.New("integration key is not set")
+	ErrDuplicateGroupOverride = errors.New("duplicate group override")
+)
+
+type Config struct {
+	IntegrationKey string `yaml:"integration-key"`
+}
+
+func (cfg *Config) Validate() error {
+	if len(cfg.IntegrationKey) == 0 {
+		return ErrIntegrationKeyNotSet
+	}
+	return nil
+}
+
+func (cfg *Config) Merge(override *Config) {
+	if len(override.IntegrationKey) > 0 {
+		cfg.IntegrationKey = override.IntegrationKey
+	}
+}
+
+// AlertProvider is the configuration necessary for sending an alert using ilert
+type AlertProvider struct {
+	DefaultConfig Config `yaml:",inline"`
+
+	// DefaultAlert is the default alert configuration to use for endpoints with an alert of the appropriate type
+	DefaultAlert *alert.Alert `yaml:"default-alert,omitempty"`
+
+	// Overrides is a list of Override that may be prioritized over the default configuration
+	Overrides []Override `yaml:"overrides,omitempty"`
+}
+
+type Override struct {
+	Group  string `yaml:"group"`
+	Config `yaml:",inline"`
+}
+
+func (provider *AlertProvider) Validate() error {
+	registeredGroups := make(map[string]bool)
+	if provider.Overrides != nil {
+		for _, override := range provider.Overrides {
+			if isAlreadyRegistered := registeredGroups[override.Group]; isAlreadyRegistered || override.Group == "" {
+				return ErrDuplicateGroupOverride
+			}
+			registeredGroups[override.Group] = true
+		}
+	}
+	return provider.DefaultConfig.Validate()
+}
+
+func (provider *AlertProvider) Send(ep *endpoint.Endpoint, alert *alert.Alert, result *endpoint.Result, resolved bool) error {
+	cfg, err := provider.GetConfig(ep.Group, alert)
+	if err != nil {
+		return err
+	}
+	buffer := bytes.NewBuffer(provider.buildRequestBody(cfg, ep, alert, result, resolved))
+
+	req, err := http.NewRequest(http.MethodPost, fmt.Sprintf("%s%s", restAPIUrl, cfg.IntegrationKey), buffer)
+	if err != nil {
+		return err
+	}
+	req.Header.Set("Content-Type", "application/json")
+	response, err := client.GetHTTPClient(nil).Do(req)
+	if err != nil {
+		return err
+	}
+	defer response.Body.Close()
+	if response.StatusCode > 399 {
+		body, _ := io.ReadAll(response.Body)
+		return fmt.Errorf("call to provider alert returned status code %d: %s", response.StatusCode, string(body))
+	}
+
+	return err
+}
+
+type Body struct {
+	Alert            alert.Alert                 `json:"alert"`
+	Name             string                      `json:"name"`
+	Group            string                      `json:"group"`
+	Status           string                      `json:"status"`
+	Title            string                      `json:"title"`
+	Details          string                      `json:"details,omitempty"`
+	ConditionResults []*endpoint.ConditionResult `json:"condition_results"`
+	URL              string                      `json:"url"`
+}
+
+func (provider *AlertProvider) buildRequestBody(cfg *Config, ep *endpoint.Endpoint, alert *alert.Alert, result *endpoint.Result, resolved bool) []byte {
+	var details, status string
+	if resolved {
+		status = "resolved"
+	} else {
+		status = "firing"
+	}
+
+	if len(alert.GetDescription()) > 0 {
+		details = alert.GetDescription()
+	} else {
+		details = "No description"
+	}
+
+	var body []byte
+	body, _ = json.Marshal(Body{
+		Alert:            *alert,
+		Name:             ep.Name,
+		Group:            ep.Group,
+		Title:            ep.DisplayName(),
+		Status:           status,
+		Details:          details,
+		ConditionResults: result.ConditionResults,
+		URL:              ep.URL,
+	})
+	return body
+}
+
+func (provider *AlertProvider) GetDefaultAlert() *alert.Alert {
+	return provider.DefaultAlert
+}
+
+func (provider *AlertProvider) GetConfig(group string, alert *alert.Alert) (*Config, error) {
+	cfg := provider.DefaultConfig
+	// Handle group overrides
+	if provider.Overrides != nil {
+		for _, override := range provider.Overrides {
+			if group == override.Group {
+				cfg.Merge(&override.Config)
+				break
+			}
+		}
+	}
+	// Handle alert overrides
+	if len(alert.ProviderOverride) != 0 {
+		overrideConfig := Config{}
+		if err := yaml.Unmarshal(alert.ProviderOverrideAsBytes(), &overrideConfig); err != nil {
+			return nil, err
+		}
+		cfg.Merge(&overrideConfig)
+	}
+	// Validate the configuration
+	err := cfg.Validate()
+	return &cfg, err
+}
+
+// ValidateOverrides validates the alert's provider override and, if present, the group override
+func (provider *AlertProvider) ValidateOverrides(group string, alert *alert.Alert) error {
+	_, err := provider.GetConfig(group, alert)
+	return err
+}

alerting/provider/ilert/ilert_test.go

@@ -0,0 +1,322 @@
+package ilert
+
+import (
+	"bytes"
+	"encoding/json"
+	"io"
+	"net/http"
+	"testing"
+
+	"github.com/TwiN/gatus/v5/alerting/alert"
+	"github.com/TwiN/gatus/v5/client"
+	"github.com/TwiN/gatus/v5/config/endpoint"
+	"github.com/TwiN/gatus/v5/test"
+)
+
+func TestAlertProvider_Validate(t *testing.T) {
+	scenarios := []struct {
+		name     string
+		provider AlertProvider
+		expected bool
+	}{
+		{
+			name: "valid",
+			provider: AlertProvider{
+				DefaultConfig: Config{
+					IntegrationKey: "some-random-key",
+				},
+			},
+			expected: true,
+		},
+		{
+			name: "invalid-integration-key",
+			provider: AlertProvider{
+				DefaultConfig: Config{
+					IntegrationKey: "",
+				},
+			},
+			expected: false,
+		},
+	}
+	for _, scenario := range scenarios {
+		t.Run(scenario.name, func(t *testing.T) {
+			err := scenario.provider.Validate()
+			if scenario.expected && err != nil {
+				t.Error("expected no error, got", err.Error())
+			}
+			if !scenario.expected && err == nil {
+				t.Error("expected error, got none")
+			}
+		})
+	}
+}
+
+func TestAlertProvider_ValidateWithOverride(t *testing.T) {
+	providerWithInvalidOverrideGroup := AlertProvider{
+		DefaultConfig: Config{IntegrationKey: "00000000000000000000000000000001"},
+		Overrides: []Override{
+			{
+				Config: Config{IntegrationKey: "00000000000000000000000000000002"},
+				Group:  "",
+			},
+		},
+	}
+	if err := providerWithInvalidOverrideGroup.Validate(); err == nil {
+		t.Error("provider Group shouldn't have been valid")
+	}
+	providerWithValidOverride := AlertProvider{
+		DefaultConfig: Config{IntegrationKey: "00000000000000000000000000000001"},
+		Overrides: []Override{
+			{
+				Config: Config{IntegrationKey: "00000000000000000000000000000002"},
+				Group:  "group",
+			},
+		},
+	}
+	if err := providerWithValidOverride.Validate(); err != nil {
+		t.Error("provider should've been valid, got error:", err.Error())
+	}
+}
+
+func TestAlertProvider_Send(t *testing.T) {
+	defer client.InjectHTTPClient(nil)
+	firstDescription := "description-1"
+	secondDescription := "description-2"
+	sendOnResolved := true
+	scenarios := []struct {
+		Name             string
+		Provider         AlertProvider
+		Alert            alert.Alert
+		Resolved         bool
+		MockRoundTripper test.MockRoundTripper
+		ExpectedError    bool
+	}{
+		{
+			Name: "triggered",
+			Provider: AlertProvider{DefaultConfig: Config{
+				IntegrationKey: "some-integration-key",
+			}},
+			Alert:    alert.Alert{Description: &firstDescription, SuccessThreshold: 3, FailureThreshold: 3, ResolveKey: "123", Type: "ilert", SendOnResolved: &sendOnResolved},
+			Resolved: false,
+			MockRoundTripper: test.MockRoundTripper(func(r *http.Request) *http.Response {
+				var b bytes.Buffer
+
+				reader := io.NopCloser(&b)
+				return &http.Response{StatusCode: http.StatusAccepted, Body: reader}
+			}),
+			ExpectedError: false,
+		},
+		{
+			Name: "triggered-error",
+			Provider: AlertProvider{DefaultConfig: Config{
+				IntegrationKey: "some-integration-key",
+			}},
+			Alert:    alert.Alert{Description: &firstDescription, SuccessThreshold: 3, FailureThreshold: 3, ResolveKey: "123", Type: "ilert", SendOnResolved: &sendOnResolved},
+			Resolved: false,
+			MockRoundTripper: test.MockRoundTripper(func(r *http.Request) *http.Response {
+				return &http.Response{StatusCode: http.StatusBadRequest, Body: http.NoBody}
+			}),
+			ExpectedError: true,
+		},
+		{
+			Name: "resolved",
+			Provider: AlertProvider{DefaultConfig: Config{
+				IntegrationKey: "some-integration-key",
+			}},
+			Alert:    alert.Alert{Description: &secondDescription, SuccessThreshold: 3, FailureThreshold: 3, ResolveKey: "123", Type: "ilert", SendOnResolved: &sendOnResolved},
+			Resolved: true,
+			MockRoundTripper: test.MockRoundTripper(func(r *http.Request) *http.Response {
+				var b bytes.Buffer
+				reader := io.NopCloser(&b)
+				return &http.Response{StatusCode: http.StatusAccepted, Body: reader}
+			}),
+			ExpectedError: false,
+		},
+	}
+	for _, scenario := range scenarios {
+		t.Run(scenario.Name, func(t *testing.T) {
+			client.InjectHTTPClient(&http.Client{Transport: scenario.MockRoundTripper})
+			err := scenario.Provider.Send(
+				&endpoint.Endpoint{Name: "endpoint-name"},
+				&scenario.Alert,
+				&endpoint.Result{
+					ConditionResults: []*endpoint.ConditionResult{
+						{Condition: "[CONNECTED] == true", Success: scenario.Resolved},
+						{Condition: "[STATUS] == 200", Success: scenario.Resolved},
+					},
+				},
+				scenario.Resolved,
+			)
+			if scenario.ExpectedError && err == nil {
+				t.Error("expected error, got none")
+			}
+			if !scenario.ExpectedError && err != nil {
+				t.Error("expected no error, got", err.Error())
+			}
+		})
+	}
+}
+
+func TestAlertProvider_BuildRequestBody(t *testing.T) {
+	firstDescription := "description-1"
+	secondDescription := "description-2"
+	sendOnResolved := true
+
+	scenarios := []struct {
+		Name         string
+		Provider     AlertProvider
+		Alert        alert.Alert
+		Resolved     bool
+		ExpectedBody string
+	}{
+		{
+			Name:         "triggered",
+			Provider:     AlertProvider{DefaultConfig: Config{IntegrationKey: "some-integration-key"}},
+			Alert:        alert.Alert{Description: &firstDescription, SuccessThreshold: 3, FailureThreshold: 3, ResolveKey: "123", Type: "ilert", SendOnResolved: &sendOnResolved},
+			Resolved:     false,
+			ExpectedBody: `{"alert":{"Type":"ilert","Enabled":null,"FailureThreshold":3,"SuccessThreshold":3,"MinimumReminderInterval":0,"Description":"description-1","SendOnResolved":true,"ProviderOverride":null,"ResolveKey":"123","Triggered":false},"name":"endpoint-name","group":"","status":"firing","title":"endpoint-name","details":"description-1","condition_results":[{"condition":"[CONNECTED] == true","success":false},{"condition":"[STATUS] == 200","success":false}],"url":""}`,
+		},
+		{
+			Name:         "resolved",
+			Provider:     AlertProvider{DefaultConfig: Config{IntegrationKey: "some-integration-key"}},
+			Alert:        alert.Alert{Description: &firstDescription, SuccessThreshold: 4, FailureThreshold: 3, ResolveKey: "123", Type: "ilert", SendOnResolved: &sendOnResolved},
+			Resolved:     true,
+			ExpectedBody: `{"alert":{"Type":"ilert","Enabled":null,"FailureThreshold":3,"SuccessThreshold":4,"MinimumReminderInterval":0,"Description":"description-1","SendOnResolved":true,"ProviderOverride":null,"ResolveKey":"123","Triggered":false},"name":"endpoint-name","group":"","status":"resolved","title":"endpoint-name","details":"description-1","condition_results":[{"condition":"[CONNECTED] == true","success":true},{"condition":"[STATUS] == 200","success":true}],"url":""}`,
+		},
+		{
+			Name:         "group-override",
+			Provider:     AlertProvider{DefaultConfig: Config{IntegrationKey: "some-integration-key"}, Overrides: []Override{{Group: "g", Config: Config{IntegrationKey: "different-integration-key"}}}},
+			Alert:        alert.Alert{Description: &secondDescription, SuccessThreshold: 5, FailureThreshold: 3, ResolveKey: "123", Type: "ilert", SendOnResolved: &sendOnResolved},
+			Resolved:     false,
+			ExpectedBody: `{"alert":{"Type":"ilert","Enabled":null,"FailureThreshold":3,"SuccessThreshold":5,"MinimumReminderInterval":0,"Description":"description-2","SendOnResolved":true,"ProviderOverride":null,"ResolveKey":"123","Triggered":false},"name":"endpoint-name","group":"","status":"firing","title":"endpoint-name","details":"description-2","condition_results":[{"condition":"[CONNECTED] == true","success":false},{"condition":"[STATUS] == 200","success":false}],"url":""}`,
+		},
+	}
+
+	for _, scenario := range scenarios {
+		t.Run(scenario.Name, func(t *testing.T) {
+			cfg, err := scenario.Provider.GetConfig("g", &scenario.Alert)
+			if err != nil {
+				t.Error("expected no error, got", err.Error())
+			}
+			body := scenario.Provider.buildRequestBody(
+				cfg,
+				&endpoint.Endpoint{Name: "endpoint-name"},
+				&scenario.Alert,
+				&endpoint.Result{
+					ConditionResults: []*endpoint.ConditionResult{
+						{Condition: "[CONNECTED] == true", Success: scenario.Resolved},
+						{Condition: "[STATUS] == 200", Success: scenario.Resolved},
+					},
+				},
+				scenario.Resolved,
+			)
+			if string(body) != scenario.ExpectedBody {
+				t.Errorf("expected:\n%s\ngot:\n%s", scenario.ExpectedBody, body)
+			}
+			out := make(map[string]interface{})
+			if err := json.Unmarshal(body, &out); err != nil {
+				t.Error("expected body to be valid JSON, got error:", err.Error())
+			}
+		})
+	}
+}
+
+func TestAlertProvider_GetDefaultAlert(t *testing.T) {
+	if (&AlertProvider{DefaultAlert: &alert.Alert{}}).GetDefaultAlert() == nil {
+		t.Error("expected default alert to be not nil")
+	}
+	if (&AlertProvider{DefaultAlert: nil}).GetDefaultAlert() != nil {
+		t.Error("expected default alert to be nil")
+	}
+}
+
+func TestAlertProvider_GetConfig(t *testing.T) {
+	scenarios := []struct {
+		Name           string
+		Provider       AlertProvider
+		InputGroup     string
+		InputAlert     alert.Alert
+		ExpectedOutput Config
+	}{
+		{
+			Name: "provider-no-override-specify-no-group-should-default",
+			Provider: AlertProvider{
+				DefaultConfig: Config{IntegrationKey: "00000000000000000000000000000001"},
+				Overrides:     nil,
+			},
+			InputGroup:     "",
+			InputAlert:     alert.Alert{},
+			ExpectedOutput: Config{IntegrationKey: "00000000000000000000000000000001"},
+		},
+		{
+			Name: "provider-no-override-specify-group-should-default",
+			Provider: AlertProvider{
+				DefaultConfig: Config{IntegrationKey: "00000000000000000000000000000001"},
+				Overrides:     nil,
+			},
+			InputGroup:     "group",
+			InputAlert:     alert.Alert{},
+			ExpectedOutput: Config{IntegrationKey: "00000000000000000000000000000001"},
+		},
+		{
+			Name: "provider-with-override-specify-no-group-should-default",
+			Provider: AlertProvider{
+				DefaultConfig: Config{IntegrationKey: "00000000000000000000000000000001"},
+				Overrides: []Override{
+					{
+						Group:  "group",
+						Config: Config{IntegrationKey: "00000000000000000000000000000002"},
+					},
+				},
+			},
+			InputGroup:     "",
+			InputAlert:     alert.Alert{},
+			ExpectedOutput: Config{IntegrationKey: "00000000000000000000000000000001"},
+		},
+		{
+			Name: "provider-with-override-specify-group-should-override",
+			Provider: AlertProvider{
+				DefaultConfig: Config{IntegrationKey: "00000000000000000000000000000001"},
+				Overrides: []Override{
+					{
+						Group:  "group",
+						Config: Config{IntegrationKey: "00000000000000000000000000000002"},
+					},
+				},
+			},
+			InputGroup:     "group",
+			InputAlert:     alert.Alert{},
+			ExpectedOutput: Config{IntegrationKey: "00000000000000000000000000000002"},
+		},
+		{
+			Name: "provider-with-group-override-and-alert-override--alert-override-should-take-precedence",
+			Provider: AlertProvider{
+				DefaultConfig: Config{IntegrationKey: "00000000000000000000000000000001"},
+				Overrides: []Override{
+					{
+						Group:  "group",
+						Config: Config{IntegrationKey: "00000000000000000000000000000002"},
+					},
+				},
+			},
+			InputGroup:     "group",
+			InputAlert:     alert.Alert{ProviderOverride: map[string]any{"integration-key": "00000000000000000000000000000003"}},
+			ExpectedOutput: Config{IntegrationKey: "00000000000000000000000000000003"},
+		},
+	}
+	for _, scenario := range scenarios {
+		t.Run(scenario.Name, func(t *testing.T) {
+			got, err := scenario.Provider.GetConfig(scenario.InputGroup, &scenario.InputAlert)
+			if err != nil {
+				t.Fatalf("unexpected error: %s", err)
+			}
+			if got.IntegrationKey != scenario.ExpectedOutput.IntegrationKey {
+				t.Errorf("expected %s, got %s", scenario.ExpectedOutput.IntegrationKey, got.IntegrationKey)
+			}
+			// Test ValidateOverrides as well, since it really just calls GetConfig
+			if err = scenario.Provider.ValidateOverrides(scenario.InputGroup, &scenario.InputAlert); err != nil {
+				t.Errorf("unexpected error: %s", err)
+			}
+		})
+	}
+}

alerting/provider/incidentio/incidentio.go

@@ -0,0 +1,210 @@
+package incidentio
+
+import (
+	"bytes"
+	"encoding/json"
+	"errors"
+	"fmt"
+	"io"
+	"net/http"
+	"strconv"
+	"strings"
+
+	"github.com/TwiN/gatus/v5/alerting/alert"
+	"github.com/TwiN/gatus/v5/client"
+	"github.com/TwiN/gatus/v5/config/endpoint"
+	"github.com/TwiN/logr"
+	"gopkg.in/yaml.v3"
+)
+
+const (
+	restAPIUrl = "https://api.incident.io/v2/alert_events/http/"
+)
+
+var (
+	ErrURLNotSet                    = errors.New("url not set")
+	ErrURLNotPrefixedWithRestAPIURL = fmt.Errorf("url must be prefixed with %s", restAPIUrl)
+	ErrDuplicateGroupOverride       = errors.New("duplicate group override")
+	ErrAuthTokenNotSet              = errors.New("auth-token not set")
+)
+
+type Config struct {
+	URL       string                 `yaml:"url,omitempty"`
+	AuthToken string                 `yaml:"auth-token,omitempty"`
+	SourceURL string                 `yaml:"source-url,omitempty"`
+	Metadata  map[string]interface{} `yaml:"metadata,omitempty"`
+}
+
+func (cfg *Config) Validate() error {
+	if len(cfg.URL) == 0 {
+		return ErrURLNotSet
+	}
+	if !strings.HasPrefix(cfg.URL, restAPIUrl) {
+		return ErrURLNotPrefixedWithRestAPIURL
+	}
+	if len(cfg.AuthToken) == 0 {
+		return ErrAuthTokenNotSet
+	}
+	return nil
+}
+
+func (cfg *Config) Merge(override *Config) {
+	if len(override.URL) > 0 {
+		cfg.URL = override.URL
+	}
+	if len(override.AuthToken) > 0 {
+		cfg.AuthToken = override.AuthToken
+	}
+	if len(override.SourceURL) > 0 {
+		cfg.SourceURL = override.SourceURL
+	}
+	if len(override.Metadata) > 0 {
+		cfg.Metadata = override.Metadata
+	}
+}
+
+// AlertProvider is the configuration necessary for sending an alert using incident.io
+type AlertProvider struct {
+	DefaultConfig Config `yaml:",inline"`
+
+	// DefaultAlert is the default alert configuration to use for endpoints with an alert of the appropriate type
+	DefaultAlert *alert.Alert `yaml:"default-alert,omitempty"`
+
+	// Overrides is a list of Override that may be prioritized over the default configuration
+	Overrides []Override `yaml:"overrides,omitempty"`
+}
+
+type Override struct {
+	Group  string `yaml:"group"`
+	Config `yaml:",inline"`
+}
+
+func (provider *AlertProvider) Validate() error {
+	registeredGroups := make(map[string]bool)
+	if provider.Overrides != nil {
+		for _, override := range provider.Overrides {
+			if isAlreadyRegistered := registeredGroups[override.Group]; isAlreadyRegistered || override.Group == "" {
+				return ErrDuplicateGroupOverride
+			}
+			registeredGroups[override.Group] = true
+		}
+	}
+	return provider.DefaultConfig.Validate()
+}
+
+func (provider *AlertProvider) Send(ep *endpoint.Endpoint, alert *alert.Alert, result *endpoint.Result, resolved bool) error {
+	cfg, err := provider.GetConfig(ep.Group, alert)
+	if err != nil {
+		return err
+	}
+	buffer := bytes.NewBuffer(provider.buildRequestBody(cfg, ep, alert, result, resolved))
+	req, err := http.NewRequest(http.MethodPost, cfg.URL, buffer)
+	if err != nil {
+		return err
+	}
+	req.Header.Set("Content-Type", "application/json")
+	req.Header.Set("Authorization", "Bearer "+cfg.AuthToken)
+	response, err := client.GetHTTPClient(nil).Do(req)
+	if err != nil {
+		return err
+	}
+	defer response.Body.Close()
+	if response.StatusCode > 399 {
+		body, _ := io.ReadAll(response.Body)
+		return fmt.Errorf("call to provider alert returned status code %d: %s", response.StatusCode, string(body))
+	}
+	incidentioResponse := Response{}
+	err = json.NewDecoder(response.Body).Decode(&incidentioResponse)
+	if err != nil {
+		// Silently fail. We don't want to create tons of alerts just because we failed to parse the body.
+		logr.Errorf("[incidentio.Send] Ran into error decoding pagerduty response: %s", err.Error())
+	}
+	alert.ResolveKey = incidentioResponse.DeduplicationKey
+	return err
+}
+
+type Body struct {
+	AlertSourceConfigID string                 `json:"alert_source_config_id"`
+	Status              string                 `json:"status"`
+	Title               string                 `json:"title"`
+	DeduplicationKey    string                 `json:"deduplication_key,omitempty"`
+	Description         string                 `json:"description,omitempty"`
+	SourceURL           string                 `json:"source_url,omitempty"`
+	Metadata            map[string]interface{} `json:"metadata,omitempty"`
+}
+
+type Response struct {
+	DeduplicationKey string `json:"deduplication_key"`
+}
+
+func (provider *AlertProvider) buildRequestBody(cfg *Config, ep *endpoint.Endpoint, alert *alert.Alert, result *endpoint.Result, resolved bool) []byte {
+	var message, formattedConditionResults, status string
+	if resolved {
+		message = "An alert has been resolved after passing successfully " + strconv.Itoa(alert.SuccessThreshold) + " time(s) in a row"
+		status = "resolved"
+	} else {
+		message = "An alert has been triggered due to having failed " + strconv.Itoa(alert.FailureThreshold) + " time(s) in a row"
+		status = "firing"
+	}
+	for _, conditionResult := range result.ConditionResults {
+		var prefix string
+		if conditionResult.Success {
+			prefix = "🟢"
+		} else {
+			prefix = "🔴"
+		}
+		// No need for \n since incident.io trims it anyways.
+		formattedConditionResults += fmt.Sprintf(" %s %s ", prefix, conditionResult.Condition)
+	}
+	if len(alert.GetDescription()) > 0 {
+		message += " with the following description: " + alert.GetDescription()
+	}
+	message += fmt.Sprintf(" and the following conditions: %s ", formattedConditionResults)
+	var body []byte
+	alertSourceID := strings.TrimPrefix(cfg.URL, restAPIUrl)
+	body, _ = json.Marshal(Body{
+		AlertSourceConfigID: alertSourceID,
+		Title:               "Gatus: " + ep.DisplayName(),
+		Status:              status,
+		DeduplicationKey:    alert.ResolveKey,
+		Description:         message,
+		SourceURL:           cfg.SourceURL,
+		Metadata:            cfg.Metadata,
+	})
+	fmt.Printf("%v", string(body))
+	return body
+
+}
+func (provider *AlertProvider) GetConfig(group string, alert *alert.Alert) (*Config, error) {
+	cfg := provider.DefaultConfig
+	// Handle group overrides
+	if provider.Overrides != nil {
+		for _, override := range provider.Overrides {
+			if group == override.Group {
+				cfg.Merge(&override.Config)
+				break
+			}
+		}
+	}
+	// Handle alert overrides
+	if len(alert.ProviderOverride) != 0 {
+		overrideConfig := Config{}
+		if err := yaml.Unmarshal(alert.ProviderOverrideAsBytes(), &overrideConfig); err != nil {
+			return nil, err
+		}
+		cfg.Merge(&overrideConfig)
+	}
+	// Validate the configuration
+	err := cfg.Validate()
+	return &cfg, err
+}
+
+// GetDefaultAlert returns the provider's default alert configuration
+func (provider *AlertProvider) GetDefaultAlert() *alert.Alert {
+	return provider.DefaultAlert
+}
+
+func (provider *AlertProvider) ValidateOverrides(group string, alert *alert.Alert) error {
+	_, err := provider.GetConfig(group, alert)
+	return err
+}

alerting/provider/incidentio/incidentio_test.go

@@ -0,0 +1,390 @@
+package incidentio
+
+import (
+	"bytes"
+	"encoding/json"
+	"io"
+	"net/http"
+	"testing"
+
+	"github.com/TwiN/gatus/v5/alerting/alert"
+	"github.com/TwiN/gatus/v5/client"
+	"github.com/TwiN/gatus/v5/config/endpoint"
+	"github.com/TwiN/gatus/v5/test"
+)
+
+func TestAlertProvider_Validate(t *testing.T) {
+	scenarios := []struct {
+		name     string
+		provider AlertProvider
+		expected bool
+	}{
+		{
+			name: "valid",
+			provider: AlertProvider{
+				DefaultConfig: Config{
+					URL:       "https://api.incident.io/v2/alert_events/http/some-id",
+					AuthToken: "some-token",
+				},
+			},
+			expected: true,
+		},
+		{
+			name: "invalid-url",
+			provider: AlertProvider{
+				DefaultConfig: Config{
+					URL:       "id-without-rest-api-url-as-prefix",
+					AuthToken: "some-token",
+				},
+			},
+			expected: false,
+		},
+		{
+			name: "invalid-missing-auth-token",
+			provider: AlertProvider{
+				DefaultConfig: Config{
+					URL: "some-id",
+				},
+			},
+			expected: false,
+		},
+		{
+			name: "invalid-missing-alert-source-config-id",
+			provider: AlertProvider{
+				DefaultConfig: Config{
+					AuthToken: "some-token",
+				},
+			},
+			expected: false,
+		},
+		{
+			name: "valid-override",
+			provider: AlertProvider{
+				DefaultConfig: Config{
+					AuthToken: "some-token",
+					URL:       "https://api.incident.io/v2/alert_events/http/some-id",
+				},
+				Overrides: []Override{{Group: "core", Config: Config{URL: "https://api.incident.io/v2/alert_events/http/another-id"}}},
+			},
+			expected: true,
+		},
+	}
+	for _, scenario := range scenarios {
+		t.Run(scenario.name, func(t *testing.T) {
+			err := scenario.provider.Validate()
+			if scenario.expected && err != nil {
+				t.Error("expected no error, got", err.Error())
+			}
+			if !scenario.expected && err == nil {
+				t.Error("expected error, got none")
+			}
+		})
+	}
+}
+
+func TestAlertProvider_Send(t *testing.T) {
+	defer client.InjectHTTPClient(nil)
+	firstDescription := "description-1"
+	secondDescription := "description-2"
+	restAPIUrl := "https://api.incident.io/v2/alert_events/http/"
+	scenarios := []struct {
+		Name             string
+		Provider         AlertProvider
+		Alert            alert.Alert
+		Resolved         bool
+		MockRoundTripper test.MockRoundTripper
+		ExpectedError    bool
+	}{
+		{
+			Name: "triggered",
+			Provider: AlertProvider{DefaultConfig: Config{
+				URL:       restAPIUrl + "some-id",
+				AuthToken: "some-token",
+			}},
+			Alert:    alert.Alert{Description: &firstDescription, SuccessThreshold: 5, FailureThreshold: 3},
+			Resolved: false,
+			MockRoundTripper: test.MockRoundTripper(func(r *http.Request) *http.Response {
+				var b bytes.Buffer
+
+				response := Response{DeduplicationKey: "some-key"}
+				json.NewEncoder(&b).Encode(response)
+				reader := io.NopCloser(&b)
+				return &http.Response{StatusCode: http.StatusAccepted, Body: reader}
+			}),
+			ExpectedError: false,
+		},
+		{
+			Name: "triggered-error",
+			Provider: AlertProvider{DefaultConfig: Config{
+				URL:       restAPIUrl + "some-id",
+				AuthToken: "some-token",
+			}},
+			Alert:    alert.Alert{Description: &firstDescription, SuccessThreshold: 5, FailureThreshold: 3},
+			Resolved: false,
+			MockRoundTripper: test.MockRoundTripper(func(r *http.Request) *http.Response {
+				return &http.Response{StatusCode: http.StatusInternalServerError, Body: http.NoBody}
+			}),
+			ExpectedError: true,
+		},
+		{
+			Name: "resolved",
+			Provider: AlertProvider{DefaultConfig: Config{
+				URL:       restAPIUrl + "some-id",
+				AuthToken: "some-token",
+			}},
+			Alert:    alert.Alert{Description: &secondDescription, SuccessThreshold: 5, FailureThreshold: 3},
+			Resolved: true,
+			MockRoundTripper: test.MockRoundTripper(func(r *http.Request) *http.Response {
+				var b bytes.Buffer
+				response := Response{DeduplicationKey: "some-key"}
+				json.NewEncoder(&b).Encode(response)
+				reader := io.NopCloser(&b)
+				return &http.Response{StatusCode: http.StatusAccepted, Body: reader}
+			}),
+			ExpectedError: false,
+		},
+		{
+			Name:     "resolved-error",
+			Provider: AlertProvider{DefaultConfig: Config{}},
+			Alert:    alert.Alert{Description: &secondDescription, SuccessThreshold: 5, FailureThreshold: 3},
+			Resolved: true,
+			MockRoundTripper: test.MockRoundTripper(func(r *http.Request) *http.Response {
+				return &http.Response{StatusCode: http.StatusInternalServerError, Body: http.NoBody}
+			}),
+			ExpectedError: true,
+		},
+	}
+	for _, scenario := range scenarios {
+		t.Run(scenario.Name, func(t *testing.T) {
+			client.InjectHTTPClient(&http.Client{Transport: scenario.MockRoundTripper})
+			err := scenario.Provider.Send(
+				&endpoint.Endpoint{Name: "endpoint-name"},
+				&scenario.Alert,
+				&endpoint.Result{
+					ConditionResults: []*endpoint.ConditionResult{
+						{Condition: "[CONNECTED] == true", Success: scenario.Resolved},
+						{Condition: "[STATUS] == 200", Success: scenario.Resolved},
+					},
+				},
+				scenario.Resolved,
+			)
+			if scenario.ExpectedError && err == nil {
+				t.Error("expected error, got none")
+			}
+			if !scenario.ExpectedError && err != nil {
+				t.Error("expected no error, got", err.Error())
+			}
+		})
+	}
+}
+
+func TestAlertProvider_BuildRequestBody(t *testing.T) {
+	firstDescription := "description-1"
+	secondDescription := "description-2"
+	restAPIUrl := "https://api.incident.io/v2/alert_events/http/"
+	scenarios := []struct {
+		Name         string
+		Provider     AlertProvider
+		Alert        alert.Alert
+		Resolved     bool
+		ExpectedBody string
+	}{
+		{
+			Name:         "triggered",
+			Provider:     AlertProvider{DefaultConfig: Config{URL: restAPIUrl + "some-id", AuthToken: "some-token"}},
+			Alert:        alert.Alert{Description: &firstDescription, SuccessThreshold: 5, FailureThreshold: 3},
+			Resolved:     false,
+			ExpectedBody: `{"alert_source_config_id":"some-id","status":"firing","title":"Gatus: endpoint-name","description":"An alert has been triggered due to having failed 3 time(s) in a row with the following description: description-1 and the following conditions:  🔴 [CONNECTED] == true  🔴 [STATUS] == 200  "}`,
+		},
+		{
+			Name:         "resolved",
+			Provider:     AlertProvider{DefaultConfig: Config{URL: restAPIUrl + "some-id", AuthToken: "some-token"}},
+			Alert:        alert.Alert{Description: &secondDescription, SuccessThreshold: 5, FailureThreshold: 3},
+			Resolved:     true,
+			ExpectedBody: `{"alert_source_config_id":"some-id","status":"resolved","title":"Gatus: endpoint-name","description":"An alert has been resolved after passing successfully 5 time(s) in a row with the following description: description-2 and the following conditions:  🟢 [CONNECTED] == true  🟢 [STATUS] == 200  "}`,
+		},
+		{
+			Name:         "resolved-with-metadata-source-url",
+			Provider:     AlertProvider{DefaultConfig: Config{URL: restAPIUrl + "some-id", AuthToken: "some-token", Metadata: map[string]interface{}{"service": "some-service", "team": "very-core"}, SourceURL: "some-source-url"}},
+			Alert:        alert.Alert{Description: &secondDescription, SuccessThreshold: 5, FailureThreshold: 3},
+			Resolved:     true,
+			ExpectedBody: `{"alert_source_config_id":"some-id","status":"resolved","title":"Gatus: endpoint-name","description":"An alert has been resolved after passing successfully 5 time(s) in a row with the following description: description-2 and the following conditions:  🟢 [CONNECTED] == true  🟢 [STATUS] == 200  ","source_url":"some-source-url","metadata":{"service":"some-service","team":"very-core"}}`,
+		},
+		{
+			Name:         "group-override",
+			Provider:     AlertProvider{DefaultConfig: Config{URL: restAPIUrl + "some-id", AuthToken: "some-token"}, Overrides: []Override{{Group: "g", Config: Config{URL: restAPIUrl + "different-id", AuthToken: "some-token"}}}},
+			Alert:        alert.Alert{Description: &firstDescription, SuccessThreshold: 5, FailureThreshold: 3},
+			Resolved:     false,
+			ExpectedBody: `{"alert_source_config_id":"different-id","status":"firing","title":"Gatus: endpoint-name","description":"An alert has been triggered due to having failed 3 time(s) in a row with the following description: description-1 and the following conditions:  🔴 [CONNECTED] == true  🔴 [STATUS] == 200  "}`,
+		},
+	}
+
+	for _, scenario := range scenarios {
+		t.Run(scenario.Name, func(t *testing.T) {
+			cfg, err := scenario.Provider.GetConfig("g", &scenario.Alert)
+			if err != nil {
+				t.Error("expected no error, got", err.Error())
+			}
+			body := scenario.Provider.buildRequestBody(
+				cfg,
+				&endpoint.Endpoint{Name: "endpoint-name"},
+				&scenario.Alert,
+				&endpoint.Result{
+					ConditionResults: []*endpoint.ConditionResult{
+						{Condition: "[CONNECTED] == true", Success: scenario.Resolved},
+						{Condition: "[STATUS] == 200", Success: scenario.Resolved},
+					},
+				},
+				scenario.Resolved,
+			)
+			if string(body) != scenario.ExpectedBody {
+				t.Errorf("expected:\n%s\ngot:\n%s", scenario.ExpectedBody, body)
+			}
+			out := make(map[string]interface{})
+			if err := json.Unmarshal(body, &out); err != nil {
+				t.Error("expected body to be valid JSON, got error:", err.Error())
+			}
+		})
+	}
+}
+
+func TestAlertProvider_GetDefaultAlert(t *testing.T) {
+	if (&AlertProvider{DefaultAlert: &alert.Alert{}}).GetDefaultAlert() == nil {
+		t.Error("expected default alert to be not nil")
+	}
+	if (&AlertProvider{DefaultAlert: nil}).GetDefaultAlert() != nil {
+		t.Error("expected default alert to be nil")
+	}
+}
+
+func TestAlertProvider_GetConfig(t *testing.T) {
+	scenarios := []struct {
+		Name           string
+		Provider       AlertProvider
+		InputGroup     string
+		InputAlert     alert.Alert
+		ExpectedOutput Config
+	}{
+		{
+			Name: "provider-no-override-specify-no-group-should-default",
+			Provider: AlertProvider{
+				DefaultConfig: Config{URL: "https://api.incident.io/v2/alert_events/http/some-id", AuthToken: "some-token"},
+				Overrides:     nil,
+			},
+			InputGroup:     "",
+			InputAlert:     alert.Alert{},
+			ExpectedOutput: Config{URL: "https://api.incident.io/v2/alert_events/http/some-id", AuthToken: "some-token"},
+		},
+		{
+			Name: "provider-no-override-specify-group-should-default",
+			Provider: AlertProvider{
+				DefaultConfig: Config{URL: "https://api.incident.io/v2/alert_events/http/some-id", AuthToken: "some-token"},
+				Overrides:     nil,
+			},
+			InputGroup:     "group",
+			InputAlert:     alert.Alert{},
+			ExpectedOutput: Config{URL: "https://api.incident.io/v2/alert_events/http/some-id", AuthToken: "some-token"},
+		},
+		{
+			Name: "provider-with-override-specify-no-group-should-default",
+			Provider: AlertProvider{
+				DefaultConfig: Config{URL: "https://api.incident.io/v2/alert_events/http/some-id", AuthToken: "some-token"},
+				Overrides: []Override{
+					{
+						Group:  "group",
+						Config: Config{URL: "https://api.incident.io/v2/alert_events/http/diff-id"},
+					},
+				},
+			},
+			InputGroup:     "",
+			InputAlert:     alert.Alert{},
+			ExpectedOutput: Config{URL: "https://api.incident.io/v2/alert_events/http/some-id", AuthToken: "some-token"},
+		},
+		{
+			Name: "provider-with-override-specify-group-should-override",
+			Provider: AlertProvider{
+				DefaultConfig: Config{URL: "https://api.incident.io/v2/alert_events/http/some-id", AuthToken: "some-token"},
+				Overrides: []Override{
+					{
+						Group:  "group",
+						Config: Config{URL: "https://api.incident.io/v2/alert_events/http/diff-id", AuthToken: "some-token"},
+					},
+				},
+			},
+			InputGroup:     "group",
+			InputAlert:     alert.Alert{},
+			ExpectedOutput: Config{URL: "https://api.incident.io/v2/alert_events/http/diff-id", AuthToken: "some-token"},
+		},
+		{
+			Name: "provider-with-group-override-and-alert-override--alert-override-should-take-precedence",
+			Provider: AlertProvider{
+				DefaultConfig: Config{URL: "https://api.incident.io/v2/alert_events/http/some-id", AuthToken: "some-token"},
+				Overrides: []Override{
+					{
+						Group:  "group",
+						Config: Config{URL: "https://api.incident.io/v2/alert_events/http/diff-id", AuthToken: "some-token"},
+					},
+				},
+			},
+			InputGroup:     "group",
+			InputAlert:     alert.Alert{ProviderOverride: map[string]any{"url": "https://api.incident.io/v2/alert_events/http/another-id"}},
+			ExpectedOutput: Config{URL: "https://api.incident.io/v2/alert_events/http/another-id", AuthToken: "some-token"},
+		},
+	}
+	for _, scenario := range scenarios {
+		t.Run(scenario.Name, func(t *testing.T) {
+			got, err := scenario.Provider.GetConfig(scenario.InputGroup, &scenario.InputAlert)
+			if err != nil {
+				t.Fatalf("unexpected error: %s", err)
+			}
+			if got.URL != scenario.ExpectedOutput.URL {
+				t.Errorf("expected alert source config to be %s, got %s", scenario.ExpectedOutput.URL, got.URL)
+			}
+			if got.AuthToken != scenario.ExpectedOutput.AuthToken {
+				t.Errorf("expected alert auth token to be %s, got %s", scenario.ExpectedOutput.AuthToken, got.AuthToken)
+			}
+
+			// Test ValidateOverrides as well, since it really just calls GetConfig
+			if err = scenario.Provider.ValidateOverrides(scenario.InputGroup, &scenario.InputAlert); err != nil {
+				t.Errorf("unexpected error: %s", err)
+			}
+		})
+	}
+}
+
+func TestAlertProvider_ValidateWithOverride(t *testing.T) {
+	providerWithInvalidOverrideGroup := AlertProvider{
+		Overrides: []Override{
+			{
+				Config: Config{URL: "https://api.incident.io/v2/alert_events/http/some-id", AuthToken: "some-token"},
+				Group:  "",
+			},
+		},
+	}
+	if err := providerWithInvalidOverrideGroup.Validate(); err == nil {
+		t.Error("provider Group shouldn't have been valid")
+	}
+	providerWithInvalidOverrideTo := AlertProvider{
+		Overrides: []Override{
+			{
+				Config: Config{URL: "", AuthToken: "some-token"},
+				Group:  "group",
+			},
+		},
+	}
+	if err := providerWithInvalidOverrideTo.Validate(); err == nil {
+		t.Error("provider integration key shouldn't have been valid")
+	}
+	providerWithValidOverride := AlertProvider{
+		DefaultConfig: Config{URL: "https://api.incident.io/v2/alert_events/http/nice-id", AuthToken: "some-token"},
+		Overrides: []Override{
+			{
+				Config: Config{URL: "https://api.incident.io/v2/alert_events/http/very-good-id", AuthToken: "some-token"},
+				Group:  "group",
+			},
+		},
+	}
+	if err := providerWithValidOverride.Validate(); err != nil {
+		t.Error("provider should've been valid")
+	}
+}

alerting/provider/jetbrainsspace/jetbrainsspace.go

@@ -3,6 +3,7 @@ package jetbrainsspace
 import (
 	"bytes"
 	"encoding/json"
+	"errors"
 	"fmt"
 	"io"
 	"net/http"
@@ -10,13 +11,50 @@ import (
 	"github.com/TwiN/gatus/v5/alerting/alert"
 	"github.com/TwiN/gatus/v5/client"
 	"github.com/TwiN/gatus/v5/config/endpoint"
+	"gopkg.in/yaml.v3"
 )
 
+var (
+	ErrProjectNotSet          = errors.New("project not set")
+	ErrChannelIDNotSet        = errors.New("channel-id not set")
+	ErrTokenNotSet            = errors.New("token not set")
+	ErrDuplicateGroupOverride = errors.New("duplicate group override")
+)
+
+type Config struct {
+	Project   string `yaml:"project"`    // Project name
+	ChannelID string `yaml:"channel-id"` // Chat Channel ID
+	Token     string `yaml:"token"`      // Bearer Token
+}
+
+func (cfg *Config) Validate() error {
+	if len(cfg.Project) == 0 {
+		return ErrProjectNotSet
+	}
+	if len(cfg.ChannelID) == 0 {
+		return ErrChannelIDNotSet
+	}
+	if len(cfg.Token) == 0 {
+		return ErrTokenNotSet
+	}
+	return nil
+}
+
+func (cfg *Config) Merge(override *Config) {
+	if len(override.Project) > 0 {
+		cfg.Project = override.Project
+	}
+	if len(override.ChannelID) > 0 {
+		cfg.ChannelID = override.ChannelID
+	}
+	if len(override.Token) > 0 {
+		cfg.Token = override.Token
+	}
+}
+
 // AlertProvider is the configuration necessary for sending an alert using JetBrains Space
 type AlertProvider struct {
-	Project   string `yaml:"project"`    // JetBrains Space Project name
-	ChannelID string `yaml:"channel-id"` // JetBrains Space Chat Channel ID
-	Token     string `yaml:"token"`      // JetBrains Space Bearer Token
+	DefaultConfig Config `yaml:",inline"`
 
 	// DefaultAlert is the default alert configuration to use for endpoints with an alert of the appropriate type
 	DefaultAlert *alert.Alert `yaml:"default-alert,omitempty"`
@@ -27,34 +65,38 @@ type AlertProvider struct {
 
 // Override is a case under which the default integration is overridden
 type Override struct {
-	Group     string `yaml:"group"`
-	ChannelID string `yaml:"channel-id"`
+	Group  string `yaml:"group"`
+	Config `yaml:",inline"`
 }
 
-// IsValid returns whether the provider's configuration is valid
-func (provider *AlertProvider) IsValid() bool {
+// Validate the provider's configuration
+func (provider *AlertProvider) Validate() error {
 	registeredGroups := make(map[string]bool)
 	if provider.Overrides != nil {
 		for _, override := range provider.Overrides {
-			if isAlreadyRegistered := registeredGroups[override.Group]; isAlreadyRegistered || override.Group == "" || len(override.ChannelID) == 0 {
-				return false
+			if isAlreadyRegistered := registeredGroups[override.Group]; isAlreadyRegistered || override.Group == "" {
+				return ErrDuplicateGroupOverride
 			}
 			registeredGroups[override.Group] = true
 		}
 	}
-	return len(provider.Project) > 0 && len(provider.ChannelID) > 0 && len(provider.Token) > 0
+	return provider.DefaultConfig.Validate()
 }
 
 // Send an alert using the provider
 func (provider *AlertProvider) Send(ep *endpoint.Endpoint, alert *alert.Alert, result *endpoint.Result, resolved bool) error {
-	buffer := bytes.NewBuffer(provider.buildRequestBody(ep, alert, result, resolved))
-	url := fmt.Sprintf("https://%s.jetbrains.space/api/http/chats/messages/send-message", provider.Project)
+	cfg, err := provider.GetConfig(ep.Group, alert)
+	if err != nil {
+		return err
+	}
+	buffer := bytes.NewBuffer(provider.buildRequestBody(cfg, ep, alert, result, resolved))
+	url := fmt.Sprintf("https://%s.jetbrains.space/api/http/chats/messages/send-message", cfg.Project)
 	request, err := http.NewRequest(http.MethodPost, url, buffer)
 	if err != nil {
 		return err
 	}
 	request.Header.Set("Content-Type", "application/json")
-	request.Header.Set("Authorization", "Bearer "+provider.Token)
+	request.Header.Set("Authorization", "Bearer "+cfg.Token)
 	response, err := client.GetHTTPClient(nil).Do(request)
 	if err != nil {
 		return err
@@ -103,9 +145,9 @@ type Icon struct {
 }
 
 // buildRequestBody builds the request body for the provider
-func (provider *AlertProvider) buildRequestBody(ep *endpoint.Endpoint, alert *alert.Alert, result *endpoint.Result, resolved bool) []byte {
+func (provider *AlertProvider) buildRequestBody(cfg *Config, ep *endpoint.Endpoint, alert *alert.Alert, result *endpoint.Result, resolved bool) []byte {
 	body := Body{
-		Channel: "id:" + provider.getChannelIDForGroup(ep.Group),
+		Channel: "id:" + cfg.ChannelID,
 		Content: Content{
 			ClassName: "ChatMessage.Block",
 			Sections: []Section{{
@@ -144,19 +186,38 @@ func (provider *AlertProvider) buildRequestBody(ep *endpoint.Endpoint, alert *al
 	return bodyAsJSON
 }
 
-// getChannelIDForGroup returns the appropriate channel ID to for a given group override
-func (provider *AlertProvider) getChannelIDForGroup(group string) string {
-	if provider.Overrides != nil {
-		for _, override := range provider.Overrides {
-			if group == override.Group {
-				return override.ChannelID
-			}
-		}
-	}
-	return provider.ChannelID
-}
-
 // GetDefaultAlert returns the provider's default alert configuration
 func (provider *AlertProvider) GetDefaultAlert() *alert.Alert {
 	return provider.DefaultAlert
 }
+
+// GetConfig returns the configuration for the provider with the overrides applied
+func (provider *AlertProvider) GetConfig(group string, alert *alert.Alert) (*Config, error) {
+	cfg := provider.DefaultConfig
+	// Handle group overrides
+	if provider.Overrides != nil {
+		for _, override := range provider.Overrides {
+			if group == override.Group {
+				cfg.Merge(&override.Config)
+				break
+			}
+		}
+	}
+	// Handle alert overrides
+	if len(alert.ProviderOverride) != 0 {
+		overrideConfig := Config{}
+		if err := yaml.Unmarshal(alert.ProviderOverrideAsBytes(), &overrideConfig); err != nil {
+			return nil, err
+		}
+		cfg.Merge(&overrideConfig)
+	}
+	// Validate the configuration
+	err := cfg.Validate()
+	return &cfg, err
+}
+
+// ValidateOverrides validates the alert's provider override and, if present, the group override
+func (provider *AlertProvider) ValidateOverrides(group string, alert *alert.Alert) error {
+	_, err := provider.GetConfig(group, alert)
+	return err
+}

alerting/provider/jetbrainsspace/jetbrainsspace_test.go

@@ -11,54 +11,56 @@ import (
 	"github.com/TwiN/gatus/v5/test"
 )
 
-func TestAlertDefaultProvider_IsValid(t *testing.T) {
-	invalidProvider := AlertProvider{Project: ""}
-	if invalidProvider.IsValid() {
+func TestAlertProvider_Validate(t *testing.T) {
+	invalidProvider := AlertProvider{DefaultConfig: Config{Project: ""}}
+	if err := invalidProvider.Validate(); err == nil {
 		t.Error("provider shouldn't have been valid")
 	}
-	validProvider := AlertProvider{Project: "foo", ChannelID: "bar", Token: "baz"}
-	if !validProvider.IsValid() {
+	validProvider := AlertProvider{DefaultConfig: Config{Project: "foo", ChannelID: "bar", Token: "baz"}}
+	if err := validProvider.Validate(); err != nil {
 		t.Error("provider should've been valid")
 	}
 }
 
-func TestAlertProvider_IsValidWithOverride(t *testing.T) {
+func TestAlertProvider_ValidateWithOverride(t *testing.T) {
 	providerWithInvalidOverrideGroup := AlertProvider{
-		Project: "foobar",
+		DefaultConfig: Config{Project: "foobar"},
 		Overrides: []Override{
 			{
-				ChannelID: "http://example.com",
-				Group:     "",
+				Config: Config{ChannelID: "http://example.com"},
+				Group:  "",
 			},
 		},
 	}
-	if providerWithInvalidOverrideGroup.IsValid() {
+	if err := providerWithInvalidOverrideGroup.Validate(); err == nil {
 		t.Error("provider Group shouldn't have been valid")
 	}
 	providerWithInvalidOverrideTo := AlertProvider{
-		Project: "foobar",
+		DefaultConfig: Config{Project: "foobar"},
 		Overrides: []Override{
 			{
-				ChannelID: "",
-				Group:     "group",
+				Config: Config{ChannelID: ""},
+				Group:  "group",
 			},
 		},
 	}
-	if providerWithInvalidOverrideTo.IsValid() {
+	if err := providerWithInvalidOverrideTo.Validate(); err == nil {
 		t.Error("provider integration key shouldn't have been valid")
 	}
 	providerWithValidOverride := AlertProvider{
-		Project:   "foo",
-		ChannelID: "bar",
-		Token:     "baz",
+		DefaultConfig: Config{
+			Project:   "foo",
+			ChannelID: "bar",
+			Token:     "baz",
+		},
 		Overrides: []Override{
 			{
-				ChannelID: "foobar",
-				Group:     "group",
+				Config: Config{ChannelID: "foobar"},
+				Group:  "group",
 			},
 		},
 	}
-	if !providerWithValidOverride.IsValid() {
+	if err := providerWithValidOverride.Validate(); err != nil {
 		t.Error("provider should've been valid")
 	}
 }
@@ -77,7 +79,7 @@ func TestAlertProvider_Send(t *testing.T) {
 	}{
 		{
 			Name:     "triggered",
-			Provider: AlertProvider{},
+			Provider: AlertProvider{DefaultConfig: Config{ChannelID: "1", Project: "project", Token: "token"}},
 			Alert:    alert.Alert{Description: &firstDescription, SuccessThreshold: 5, FailureThreshold: 3},
 			Resolved: false,
 			MockRoundTripper: test.MockRoundTripper(func(r *http.Request) *http.Response {
@@ -87,7 +89,7 @@ func TestAlertProvider_Send(t *testing.T) {
 		},
 		{
 			Name:     "triggered-error",
-			Provider: AlertProvider{},
+			Provider: AlertProvider{DefaultConfig: Config{ChannelID: "1", Project: "project", Token: "token"}},
 			Alert:    alert.Alert{Description: &firstDescription, SuccessThreshold: 5, FailureThreshold: 3},
 			Resolved: false,
 			MockRoundTripper: test.MockRoundTripper(func(r *http.Request) *http.Response {
@@ -97,7 +99,7 @@ func TestAlertProvider_Send(t *testing.T) {
 		},
 		{
 			Name:     "resolved",
-			Provider: AlertProvider{},
+			Provider: AlertProvider{DefaultConfig: Config{ChannelID: "1", Project: "project", Token: "token"}},
 			Alert:    alert.Alert{Description: &secondDescription, SuccessThreshold: 5, FailureThreshold: 3},
 			Resolved: true,
 			MockRoundTripper: test.MockRoundTripper(func(r *http.Request) *http.Response {
@@ -107,7 +109,7 @@ func TestAlertProvider_Send(t *testing.T) {
 		},
 		{
 			Name:     "resolved-error",
-			Provider: AlertProvider{},
+			Provider: AlertProvider{DefaultConfig: Config{ChannelID: "1", Project: "project", Token: "token"}},
 			Alert:    alert.Alert{Description: &secondDescription, SuccessThreshold: 5, FailureThreshold: 3},
 			Resolved: true,
 			MockRoundTripper: test.MockRoundTripper(func(r *http.Request) *http.Response {
@@ -153,40 +155,41 @@ func TestAlertProvider_buildRequestBody(t *testing.T) {
 	}{
 		{
 			Name:         "triggered",
-			Provider:     AlertProvider{},
+			Provider:     AlertProvider{DefaultConfig: Config{ChannelID: "1", Project: "project"}},
 			Endpoint:     endpoint.Endpoint{Name: "name"},
 			Alert:        alert.Alert{Description: &firstDescription, SuccessThreshold: 5, FailureThreshold: 3},
 			Resolved:     false,
-			ExpectedBody: `{"channel":"id:","content":{"className":"ChatMessage.Block","style":"WARNING","sections":[{"className":"MessageSection","elements":[{"className":"MessageText","accessory":{"className":"MessageIcon","icon":{"icon":"warning"},"style":"WARNING"},"style":"WARNING","size":"REGULAR","content":"[CONNECTED] == true"},{"className":"MessageText","accessory":{"className":"MessageIcon","icon":{"icon":"warning"},"style":"WARNING"},"style":"WARNING","size":"REGULAR","content":"[STATUS] == 200"}],"header":"An alert for *name* has been triggered due to having failed 3 time(s) in a row"}]}}`,
+			ExpectedBody: `{"channel":"id:1","content":{"className":"ChatMessage.Block","style":"WARNING","sections":[{"className":"MessageSection","elements":[{"className":"MessageText","accessory":{"className":"MessageIcon","icon":{"icon":"warning"},"style":"WARNING"},"style":"WARNING","size":"REGULAR","content":"[CONNECTED] == true"},{"className":"MessageText","accessory":{"className":"MessageIcon","icon":{"icon":"warning"},"style":"WARNING"},"style":"WARNING","size":"REGULAR","content":"[STATUS] == 200"}],"header":"An alert for *name* has been triggered due to having failed 3 time(s) in a row"}]}}`,
 		},
 		{
 			Name:         "triggered-with-group",
-			Provider:     AlertProvider{},
+			Provider:     AlertProvider{DefaultConfig: Config{ChannelID: "1", Project: "project"}},
 			Endpoint:     endpoint.Endpoint{Name: "name", Group: "group"},
 			Alert:        alert.Alert{Description: &firstDescription, SuccessThreshold: 5, FailureThreshold: 3},
 			Resolved:     false,
-			ExpectedBody: `{"channel":"id:","content":{"className":"ChatMessage.Block","style":"WARNING","sections":[{"className":"MessageSection","elements":[{"className":"MessageText","accessory":{"className":"MessageIcon","icon":{"icon":"warning"},"style":"WARNING"},"style":"WARNING","size":"REGULAR","content":"[CONNECTED] == true"},{"className":"MessageText","accessory":{"className":"MessageIcon","icon":{"icon":"warning"},"style":"WARNING"},"style":"WARNING","size":"REGULAR","content":"[STATUS] == 200"}],"header":"An alert for *group/name* has been triggered due to having failed 3 time(s) in a row"}]}}`,
+			ExpectedBody: `{"channel":"id:1","content":{"className":"ChatMessage.Block","style":"WARNING","sections":[{"className":"MessageSection","elements":[{"className":"MessageText","accessory":{"className":"MessageIcon","icon":{"icon":"warning"},"style":"WARNING"},"style":"WARNING","size":"REGULAR","content":"[CONNECTED] == true"},{"className":"MessageText","accessory":{"className":"MessageIcon","icon":{"icon":"warning"},"style":"WARNING"},"style":"WARNING","size":"REGULAR","content":"[STATUS] == 200"}],"header":"An alert for *group/name* has been triggered due to having failed 3 time(s) in a row"}]}}`,
 		},
 		{
 			Name:         "resolved",
-			Provider:     AlertProvider{},
+			Provider:     AlertProvider{DefaultConfig: Config{ChannelID: "1", Project: "project"}},
 			Endpoint:     endpoint.Endpoint{Name: "name"},
 			Alert:        alert.Alert{Description: &secondDescription, SuccessThreshold: 5, FailureThreshold: 3},
 			Resolved:     true,
-			ExpectedBody: `{"channel":"id:","content":{"className":"ChatMessage.Block","style":"SUCCESS","sections":[{"className":"MessageSection","elements":[{"className":"MessageText","accessory":{"className":"MessageIcon","icon":{"icon":"success"},"style":"SUCCESS"},"style":"SUCCESS","size":"REGULAR","content":"[CONNECTED] == true"},{"className":"MessageText","accessory":{"className":"MessageIcon","icon":{"icon":"success"},"style":"SUCCESS"},"style":"SUCCESS","size":"REGULAR","content":"[STATUS] == 200"}],"header":"An alert for *name* has been resolved after passing successfully 5 time(s) in a row"}]}}`,
+			ExpectedBody: `{"channel":"id:1","content":{"className":"ChatMessage.Block","style":"SUCCESS","sections":[{"className":"MessageSection","elements":[{"className":"MessageText","accessory":{"className":"MessageIcon","icon":{"icon":"success"},"style":"SUCCESS"},"style":"SUCCESS","size":"REGULAR","content":"[CONNECTED] == true"},{"className":"MessageText","accessory":{"className":"MessageIcon","icon":{"icon":"success"},"style":"SUCCESS"},"style":"SUCCESS","size":"REGULAR","content":"[STATUS] == 200"}],"header":"An alert for *name* has been resolved after passing successfully 5 time(s) in a row"}]}}`,
 		},
 		{
 			Name:         "resolved-with-group",
-			Provider:     AlertProvider{},
+			Provider:     AlertProvider{DefaultConfig: Config{ChannelID: "1", Project: "project"}},
 			Endpoint:     endpoint.Endpoint{Name: "name", Group: "group"},
 			Alert:        alert.Alert{Description: &secondDescription, SuccessThreshold: 5, FailureThreshold: 3},
 			Resolved:     true,
-			ExpectedBody: `{"channel":"id:","content":{"className":"ChatMessage.Block","style":"SUCCESS","sections":[{"className":"MessageSection","elements":[{"className":"MessageText","accessory":{"className":"MessageIcon","icon":{"icon":"success"},"style":"SUCCESS"},"style":"SUCCESS","size":"REGULAR","content":"[CONNECTED] == true"},{"className":"MessageText","accessory":{"className":"MessageIcon","icon":{"icon":"success"},"style":"SUCCESS"},"style":"SUCCESS","size":"REGULAR","content":"[STATUS] == 200"}],"header":"An alert for *group/name* has been resolved after passing successfully 5 time(s) in a row"}]}}`,
+			ExpectedBody: `{"channel":"id:1","content":{"className":"ChatMessage.Block","style":"SUCCESS","sections":[{"className":"MessageSection","elements":[{"className":"MessageText","accessory":{"className":"MessageIcon","icon":{"icon":"success"},"style":"SUCCESS"},"style":"SUCCESS","size":"REGULAR","content":"[CONNECTED] == true"},{"className":"MessageText","accessory":{"className":"MessageIcon","icon":{"icon":"success"},"style":"SUCCESS"},"style":"SUCCESS","size":"REGULAR","content":"[STATUS] == 200"}],"header":"An alert for *group/name* has been resolved after passing successfully 5 time(s) in a row"}]}}`,
 		},
 	}
 	for _, scenario := range scenarios {
 		t.Run(scenario.Name, func(t *testing.T) {
 			body := scenario.Provider.buildRequestBody(
+				&scenario.Provider.DefaultConfig,
 				&scenario.Endpoint,
 				&scenario.Alert,
 				&endpoint.Result{
@@ -217,62 +220,98 @@ func TestAlertProvider_GetDefaultAlert(t *testing.T) {
 	}
 }
 
-func TestAlertProvider_getChannelIDForGroup(t *testing.T) {
-	tests := []struct {
+func TestAlertProvider_GetConfig(t *testing.T) {
+	scenarios := []struct {
 		Name           string
 		Provider       AlertProvider
 		InputGroup     string
-		ExpectedOutput string
+		InputAlert     alert.Alert
+		ExpectedOutput Config
 	}{
 		{
 			Name: "provider-no-override-specify-no-group-should-default",
 			Provider: AlertProvider{
-				ChannelID: "bar",
+				DefaultConfig: Config{ChannelID: "default", Project: "project", Token: "token"},
+				Overrides:     nil,
 			},
 			InputGroup:     "",
-			ExpectedOutput: "bar",
+			InputAlert:     alert.Alert{},
+			ExpectedOutput: Config{ChannelID: "default", Project: "project", Token: "token"},
 		},
 		{
 			Name: "provider-no-override-specify-group-should-default",
 			Provider: AlertProvider{
-				ChannelID: "bar",
+				DefaultConfig: Config{ChannelID: "default", Project: "project", Token: "token"},
+				Overrides:     nil,
 			},
 			InputGroup:     "group",
-			ExpectedOutput: "bar",
+			InputAlert:     alert.Alert{},
+			ExpectedOutput: Config{ChannelID: "default", Project: "project", Token: "token"},
 		},
 		{
 			Name: "provider-with-override-specify-no-group-should-default",
 			Provider: AlertProvider{
-				ChannelID: "bar",
+				DefaultConfig: Config{ChannelID: "default", Project: "project", Token: "token"},
 				Overrides: []Override{
 					{
-						Group:     "group",
-						ChannelID: "foobar",
+						Group:  "group",
+						Config: Config{ChannelID: "group-channel"},
 					},
 				},
 			},
 			InputGroup:     "",
-			ExpectedOutput: "bar",
+			InputAlert:     alert.Alert{},
+			ExpectedOutput: Config{ChannelID: "default", Project: "project", Token: "token"},
 		},
 		{
 			Name: "provider-with-override-specify-group-should-override",
 			Provider: AlertProvider{
-				ChannelID: "bar",
+				DefaultConfig: Config{ChannelID: "default", Project: "project", Token: "token"},
 				Overrides: []Override{
 					{
-						Group:     "group",
-						ChannelID: "foobar",
+						Group:  "group",
+						Config: Config{ChannelID: "group-channel"},
 					},
 				},
 			},
 			InputGroup:     "group",
-			ExpectedOutput: "foobar",
+			InputAlert:     alert.Alert{},
+			ExpectedOutput: Config{ChannelID: "group-channel", Project: "project", Token: "token"},
+		},
+		{
+			Name: "provider-with-group-override-and-alert-override--alert-override-should-take-precedence",
+			Provider: AlertProvider{
+				DefaultConfig: Config{ChannelID: "default", Project: "project", Token: "token"},
+				Overrides: []Override{
+					{
+						Group:  "group",
+						Config: Config{ChannelID: "group-channel"},
+					},
+				},
+			},
+			InputGroup:     "group",
+			InputAlert:     alert.Alert{ProviderOverride: map[string]any{"channel-id": "alert-channel", "project": "alert-project", "token": "alert-token"}},
+			ExpectedOutput: Config{ChannelID: "alert-channel", Project: "alert-project", Token: "alert-token"},
 		},
 	}
-	for _, tt := range tests {
-		t.Run(tt.Name, func(t *testing.T) {
-			if got := tt.Provider.getChannelIDForGroup(tt.InputGroup); got != tt.ExpectedOutput {
-				t.Errorf("AlertProvider.getChannelIDForGroup() = %v, want %v", got, tt.ExpectedOutput)
+	for _, scenario := range scenarios {
+		t.Run(scenario.Name, func(t *testing.T) {
+			got, err := scenario.Provider.GetConfig(scenario.InputGroup, &scenario.InputAlert)
+			if err != nil {
+				t.Fatalf("unexpected error: %s", err)
+			}
+			if got.ChannelID != scenario.ExpectedOutput.ChannelID {
+				t.Errorf("expected %s, got %s", scenario.ExpectedOutput.ChannelID, got.ChannelID)
+			}
+			if got.Project != scenario.ExpectedOutput.Project {
+				t.Errorf("expected %s, got %s", scenario.ExpectedOutput.Project, got.Project)
+			}
+			if got.Token != scenario.ExpectedOutput.Token {
+				t.Errorf("expected %s, got %s", scenario.ExpectedOutput.Token, got.Token)
+			}
+			// Test ValidateOverrides as well, since it really just calls GetConfig
+			if err = scenario.Provider.ValidateOverrides(scenario.InputGroup, &scenario.InputAlert); err != nil {
+				t.Errorf("unexpected error: %s", err)
 			}
 		})
 	}

alerting/provider/line/line.go

@@ -0,0 +1,193 @@
+package line
+
+import (
+	"bytes"
+	"encoding/json"
+	"errors"
+	"fmt"
+	"io"
+	"net/http"
+
+	"github.com/TwiN/gatus/v5/alerting/alert"
+	"github.com/TwiN/gatus/v5/client"
+	"github.com/TwiN/gatus/v5/config/endpoint"
+	"gopkg.in/yaml.v3"
+)
+
+var (
+	ErrChannelAccessTokenNotSet = errors.New("channel-access-token not set")
+	ErrUserIDsNotSet            = errors.New("user-ids not set")
+	ErrDuplicateGroupOverride   = errors.New("duplicate group override")
+)
+
+type Config struct {
+	ChannelAccessToken string   `yaml:"channel-access-token"` // Line Messaging API channel access token
+	UserIDs            []string `yaml:"user-ids"`             // List of Line user IDs to send messages to
+}
+
+func (cfg *Config) Validate() error {
+	if len(cfg.ChannelAccessToken) == 0 {
+		return ErrChannelAccessTokenNotSet
+	}
+	if len(cfg.UserIDs) == 0 {
+		return ErrUserIDsNotSet
+	}
+	return nil
+}
+
+func (cfg *Config) Merge(override *Config) {
+	if len(override.ChannelAccessToken) > 0 {
+		cfg.ChannelAccessToken = override.ChannelAccessToken
+	}
+	if len(override.UserIDs) > 0 {
+		cfg.UserIDs = override.UserIDs
+	}
+}
+
+// AlertProvider is the configuration necessary for sending an alert using Line
+type AlertProvider struct {
+	DefaultConfig Config `yaml:",inline"`
+
+	// DefaultAlert is the default alert configuration to use for endpoints with an alert of the appropriate type
+	DefaultAlert *alert.Alert `yaml:"default-alert,omitempty"`
+
+	// Overrides is a list of Override that may be prioritized over the default configuration
+	Overrides []Override `yaml:"overrides,omitempty"`
+}
+
+// Override is a case under which the default integration is overridden
+type Override struct {
+	Group  string `yaml:"group"`
+	Config `yaml:",inline"`
+}
+
+// Validate the provider's configuration
+func (provider *AlertProvider) Validate() error {
+	registeredGroups := make(map[string]bool)
+	if provider.Overrides != nil {
+		for _, override := range provider.Overrides {
+			if isAlreadyRegistered := registeredGroups[override.Group]; isAlreadyRegistered || override.Group == "" {
+				return ErrDuplicateGroupOverride
+			}
+			registeredGroups[override.Group] = true
+		}
+	}
+	return provider.DefaultConfig.Validate()
+}
+
+// Send an alert using the provider
+func (provider *AlertProvider) Send(ep *endpoint.Endpoint, alert *alert.Alert, result *endpoint.Result, resolved bool) error {
+	cfg, err := provider.GetConfig(ep.Group, alert)
+	if err != nil {
+		return err
+	}
+	for _, userID := range cfg.UserIDs {
+		body, err := provider.buildRequestBody(ep, alert, result, resolved, userID)
+		if err != nil {
+			return err
+		}
+		buffer := bytes.NewBuffer(body)
+		request, err := http.NewRequest(http.MethodPost, "https://api.line.me/v2/bot/message/push", buffer)
+		if err != nil {
+			return err
+		}
+		request.Header.Set("Content-Type", "application/json")
+		request.Header.Set("Authorization", fmt.Sprintf("Bearer %s", cfg.ChannelAccessToken))
+		response, err := client.GetHTTPClient(nil).Do(request)
+		if err != nil {
+			return err
+		}
+		if response.StatusCode >= 400 {
+			body, _ := io.ReadAll(response.Body)
+			response.Body.Close()
+			return fmt.Errorf("call to line alert returned status code %d: %s", response.StatusCode, string(body))
+		}
+		response.Body.Close()
+	}
+	return nil
+}
+
+type Body struct {
+	To       string    `json:"to"`
+	Messages []Message `json:"messages"`
+}
+
+type Message struct {
+	Type string `json:"type"`
+	Text string `json:"text"`
+}
+
+// buildRequestBody builds the request body for the provider
+func (provider *AlertProvider) buildRequestBody(ep *endpoint.Endpoint, alert *alert.Alert, result *endpoint.Result, resolved bool, userID string) ([]byte, error) {
+	var message string
+	if resolved {
+		message = fmt.Sprintf("✅ RESOLVED: %s\n\nAlert has been resolved after passing successfully %d time(s) in a row", ep.DisplayName(), alert.SuccessThreshold)
+	} else {
+		message = fmt.Sprintf("⚠️ ALERT: %s\n\nEndpoint has failed %d time(s) in a row", ep.DisplayName(), alert.FailureThreshold)
+	}
+	if alertDescription := alert.GetDescription(); len(alertDescription) > 0 {
+		message += fmt.Sprintf("\n\nDescription: %s", alertDescription)
+	}
+	if len(result.ConditionResults) > 0 {
+		message += "\n\nCondition Results:"
+		for _, conditionResult := range result.ConditionResults {
+			var status string
+			if conditionResult.Success {
+				status = "✅"
+			} else {
+				status = "❌"
+			}
+			message += fmt.Sprintf("\n%s %s", status, conditionResult.Condition)
+		}
+	}
+	body := Body{
+		To: userID,
+		Messages: []Message{
+			{
+				Type: "text",
+				Text: message,
+			},
+		},
+	}
+	bodyAsJSON, err := json.Marshal(body)
+	if err != nil {
+		return nil, err
+	}
+	return bodyAsJSON, nil
+}
+
+// GetDefaultAlert returns the provider's default alert configuration
+func (provider *AlertProvider) GetDefaultAlert() *alert.Alert {
+	return provider.DefaultAlert
+}
+
+// GetConfig returns the configuration for the provider with the overrides applied
+func (provider *AlertProvider) GetConfig(group string, alert *alert.Alert) (*Config, error) {
+	cfg := provider.DefaultConfig
+	// Handle group overrides
+	if provider.Overrides != nil {
+		for _, override := range provider.Overrides {
+			if group == override.Group {
+				cfg.Merge(&override.Config)
+				break
+			}
+		}
+	}
+	// Handle alert overrides
+	if len(alert.ProviderOverride) != 0 {
+		overrideConfig := Config{}
+		if err := yaml.Unmarshal(alert.ProviderOverrideAsBytes(), &overrideConfig); err != nil {
+			return nil, err
+		}
+		cfg.Merge(&overrideConfig)
+	}
+	// Validate the configuration
+	err := cfg.Validate()
+	return &cfg, err
+}
+
+// ValidateOverrides validates the alert's provider override and, if present, the group override
+func (provider *AlertProvider) ValidateOverrides(group string, alert *alert.Alert) error {
+	_, err := provider.GetConfig(group, alert)
+	return err
+}

alerting/provider/line/line_test.go

@@ -0,0 +1,147 @@
+package line
+
+import (
+	"encoding/json"
+	"net/http"
+	"testing"
+
+	"github.com/TwiN/gatus/v5/alerting/alert"
+	"github.com/TwiN/gatus/v5/client"
+	"github.com/TwiN/gatus/v5/config/endpoint"
+	"github.com/TwiN/gatus/v5/test"
+)
+
+func TestAlertProvider_Validate(t *testing.T) {
+	scenarios := []struct {
+		name     string
+		provider AlertProvider
+		expected error
+	}{
+		{
+			name:     "valid",
+			provider: AlertProvider{DefaultConfig: Config{ChannelAccessToken: "token123", UserIDs: []string{"U123"}}},
+			expected: nil,
+		},
+		{
+			name:     "invalid-channel-access-token",
+			provider: AlertProvider{DefaultConfig: Config{UserIDs: []string{"U123"}}},
+			expected: ErrChannelAccessTokenNotSet,
+		},
+		{
+			name:     "invalid-user-ids",
+			provider: AlertProvider{DefaultConfig: Config{ChannelAccessToken: "token123"}},
+			expected: ErrUserIDsNotSet,
+		},
+	}
+	for _, scenario := range scenarios {
+		t.Run(scenario.name, func(t *testing.T) {
+			err := scenario.provider.Validate()
+			if err != scenario.expected {
+				t.Errorf("expected %v, got %v", scenario.expected, err)
+			}
+		})
+	}
+}
+
+func TestAlertProvider_Send(t *testing.T) {
+	defer client.InjectHTTPClient(nil)
+	firstDescription := "description-1"
+	secondDescription := "description-2"
+	scenarios := []struct {
+		name             string
+		provider         AlertProvider
+		alert            alert.Alert
+		resolved         bool
+		mockRoundTripper test.MockRoundTripper
+		expectedError    bool
+	}{
+		{
+			name:     "triggered",
+			provider: AlertProvider{DefaultConfig: Config{ChannelAccessToken: "token123", UserIDs: []string{"U123", "U456"}}},
+			alert:    alert.Alert{Description: &firstDescription, SuccessThreshold: 5, FailureThreshold: 3},
+			resolved: false,
+			mockRoundTripper: test.MockRoundTripper(func(r *http.Request) *http.Response {
+				if r.URL.Path != "/v2/bot/message/push" {
+					t.Errorf("expected path /v2/bot/message/push, got %s", r.URL.Path)
+				}
+				if r.Header.Get("Authorization") != "Bearer token123" {
+					t.Errorf("expected Authorization header to be 'Bearer token123', got %s", r.Header.Get("Authorization"))
+				}
+				body := make(map[string]interface{})
+				json.NewDecoder(r.Body).Decode(&body)
+				if body["to"] == nil {
+					t.Error("expected 'to' field in request body")
+				}
+				messages := body["messages"].([]interface{})
+				if len(messages) != 1 {
+					t.Errorf("expected 1 message, got %d", len(messages))
+				}
+				return &http.Response{StatusCode: http.StatusOK, Body: http.NoBody}
+			}),
+			expectedError: false,
+		},
+		{
+			name:     "resolved",
+			provider: AlertProvider{DefaultConfig: Config{ChannelAccessToken: "token123", UserIDs: []string{"U123"}}},
+			alert:    alert.Alert{Description: &secondDescription, SuccessThreshold: 5, FailureThreshold: 3},
+			resolved: true,
+			mockRoundTripper: test.MockRoundTripper(func(r *http.Request) *http.Response {
+				body := make(map[string]interface{})
+				json.NewDecoder(r.Body).Decode(&body)
+				messages := body["messages"].([]interface{})
+				message := messages[0].(map[string]interface{})
+				text := message["text"].(string)
+				if !contains(text, "RESOLVED") {
+					t.Errorf("expected message to contain 'RESOLVED', got %s", text)
+				}
+				return &http.Response{StatusCode: http.StatusOK, Body: http.NoBody}
+			}),
+			expectedError: false,
+		},
+		{
+			name:     "error-response",
+			provider: AlertProvider{DefaultConfig: Config{ChannelAccessToken: "token123", UserIDs: []string{"U123"}}},
+			alert:    alert.Alert{Description: &firstDescription, SuccessThreshold: 5, FailureThreshold: 3},
+			resolved: false,
+			mockRoundTripper: test.MockRoundTripper(func(r *http.Request) *http.Response {
+				return &http.Response{StatusCode: http.StatusBadRequest, Body: http.NoBody}
+			}),
+			expectedError: true,
+		},
+	}
+	for _, scenario := range scenarios {
+		t.Run(scenario.name, func(t *testing.T) {
+			client.InjectHTTPClient(&http.Client{Transport: scenario.mockRoundTripper})
+			err := scenario.provider.Send(
+				&endpoint.Endpoint{Name: "endpoint-name"},
+				&scenario.alert,
+				&endpoint.Result{
+					ConditionResults: []*endpoint.ConditionResult{
+						{Condition: "[CONNECTED] == true", Success: scenario.resolved},
+						{Condition: "[STATUS] == 200", Success: scenario.resolved},
+					},
+				},
+				scenario.resolved,
+			)
+			if scenario.expectedError && err == nil {
+				t.Error("expected error, got none")
+			}
+			if !scenario.expectedError && err != nil {
+				t.Error("expected no error, got", err.Error())
+			}
+		})
+	}
+}
+
+func TestAlertProvider_GetDefaultAlert(t *testing.T) {
+	if (&AlertProvider{DefaultAlert: &alert.Alert{}}).GetDefaultAlert() == nil {
+		t.Error("expected default alert to be not nil")
+	}
+	if (&AlertProvider{DefaultAlert: nil}).GetDefaultAlert() != nil {
+		t.Error("expected default alert to be nil")
+	}
+}
+
+func contains(s, substr string) bool {
+	return len(s) >= len(substr) && s[0:len(substr)] == substr || len(s) > len(substr) && contains(s[1:], substr)
+}

alerting/provider/matrix/matrix.go

@@ -3,39 +3,28 @@ package matrix
 import (
 	"bytes"
 	"encoding/json"
+	"errors"
 	"fmt"
 	"io"
 	"math/rand"
 	"net/http"
 	"net/url"
-	"time"
 
 	"github.com/TwiN/gatus/v5/alerting/alert"
 	"github.com/TwiN/gatus/v5/client"
 	"github.com/TwiN/gatus/v5/config/endpoint"
+	"gopkg.in/yaml.v3"
 )
 
-// AlertProvider is the configuration necessary for sending an alert using Matrix
-type AlertProvider struct {
-	ProviderConfig `yaml:",inline"`
-
-	// DefaultAlert is the default alert configuration to use for endpoints with an alert of the appropriate type
-	DefaultAlert *alert.Alert `yaml:"default-alert,omitempty"`
-
-	// Overrides is a list of Override that may be prioritized over the default configuration
-	Overrides []Override `yaml:"overrides,omitempty"`
-}
-
-// Override is a case under which the default integration is overridden
-type Override struct {
-	Group string `yaml:"group"`
-
-	ProviderConfig `yaml:",inline"`
-}
-
 const defaultServerURL = "https://matrix-client.matrix.org"
 
-type ProviderConfig struct {
+var (
+	ErrAccessTokenNotSet      = errors.New("access-token not set")
+	ErrInternalRoomID         = errors.New("internal-room-id not set")
+	ErrDuplicateGroupOverride = errors.New("duplicate group override")
+)
+
+type Config struct {
 	// ServerURL is the custom homeserver to use (optional)
 	ServerURL string `yaml:"server-url"`
 
@@ -46,36 +35,78 @@ type ProviderConfig struct {
 	InternalRoomID string `yaml:"internal-room-id"`
 }
 
-// IsValid returns whether the provider's configuration is valid
-func (provider *AlertProvider) IsValid() bool {
+func (cfg *Config) Validate() error {
+	if len(cfg.ServerURL) == 0 {
+		cfg.ServerURL = defaultServerURL
+	}
+	if len(cfg.AccessToken) == 0 {
+		return ErrAccessTokenNotSet
+	}
+	if len(cfg.InternalRoomID) == 0 {
+		return ErrInternalRoomID
+	}
+	return nil
+}
+
+func (cfg *Config) Merge(override *Config) {
+	if len(override.ServerURL) > 0 {
+		cfg.ServerURL = override.ServerURL
+	}
+	if len(override.AccessToken) > 0 {
+		cfg.AccessToken = override.AccessToken
+	}
+	if len(override.InternalRoomID) > 0 {
+		cfg.InternalRoomID = override.InternalRoomID
+	}
+}
+
+// AlertProvider is the configuration necessary for sending an alert using Matrix
+type AlertProvider struct {
+	DefaultConfig Config `yaml:",inline"`
+
+	// DefaultAlert is the default alert configuration to use for endpoints with an alert of the appropriate type
+	DefaultAlert *alert.Alert `yaml:"default-alert,omitempty"`
+
+	// Overrides is a list of Override that may be prioritized over the default configuration
+	Overrides []Override `yaml:"overrides,omitempty"`
+}
+
+// Override is a case under which the default integration is overridden
+type Override struct {
+	Group  string `yaml:"group"`
+	Config `yaml:",inline"`
+}
+
+// Validate the provider's configuration
+func (provider *AlertProvider) Validate() error {
 	registeredGroups := make(map[string]bool)
 	if provider.Overrides != nil {
 		for _, override := range provider.Overrides {
 			if isAlreadyRegistered := registeredGroups[override.Group]; isAlreadyRegistered || override.Group == "" || len(override.AccessToken) == 0 || len(override.InternalRoomID) == 0 {
-				return false
+				return ErrDuplicateGroupOverride
 			}
 			registeredGroups[override.Group] = true
 		}
 	}
-	return len(provider.AccessToken) > 0 && len(provider.InternalRoomID) > 0
+	return provider.DefaultConfig.Validate()
 }
 
 // Send an alert using the provider
 func (provider *AlertProvider) Send(ep *endpoint.Endpoint, alert *alert.Alert, result *endpoint.Result, resolved bool) error {
-	buffer := bytes.NewBuffer(provider.buildRequestBody(ep, alert, result, resolved))
-	config := provider.getConfigForGroup(ep.Group)
-	if config.ServerURL == "" {
-		config.ServerURL = defaultServerURL
+	cfg, err := provider.GetConfig(ep.Group, alert)
+	if err != nil {
+		return err
 	}
+	buffer := bytes.NewBuffer(provider.buildRequestBody(ep, alert, result, resolved))
 	// The Matrix endpoint requires a unique transaction ID for each event sent
 	txnId := randStringBytes(24)
 	request, err := http.NewRequest(
 		http.MethodPut,
 		fmt.Sprintf("%s/_matrix/client/v3/rooms/%s/send/m.room.message/%s?access_token=%s",
-			config.ServerURL,
-			url.PathEscape(config.InternalRoomID),
+			cfg.ServerURL,
+			url.PathEscape(cfg.InternalRoomID),
 			txnId,
-			url.QueryEscape(config.AccessToken),
+			url.QueryEscape(cfg.AccessToken),
 		),
 		buffer,
 	)
@@ -167,23 +198,10 @@ func buildHTMLMessageBody(ep *endpoint.Endpoint, alert *alert.Alert, result *end
 	return fmt.Sprintf("<h3>%s</h3>%s%s", message, description, formattedConditionResults)
 }
 
-// getConfigForGroup returns the appropriate configuration for a given group
-func (provider *AlertProvider) getConfigForGroup(group string) ProviderConfig {
-	if provider.Overrides != nil {
-		for _, override := range provider.Overrides {
-			if group == override.Group {
-				return override.ProviderConfig
-			}
-		}
-	}
-	return provider.ProviderConfig
-}
-
 func randStringBytes(n int) string {
 	// All the compatible characters to use in a transaction ID
 	const availableCharacterBytes = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789"
 	b := make([]byte, n)
-	rand.Seed(time.Now().UnixNano())
 	for i := range b {
 		b[i] = availableCharacterBytes[rand.Intn(len(availableCharacterBytes))]
 	}
@@ -194,3 +212,34 @@ func randStringBytes(n int) string {
 func (provider *AlertProvider) GetDefaultAlert() *alert.Alert {
 	return provider.DefaultAlert
 }
+
+// GetConfig returns the configuration for the provider with the overrides applied
+func (provider *AlertProvider) GetConfig(group string, alert *alert.Alert) (*Config, error) {
+	cfg := provider.DefaultConfig
+	// Handle group overrides
+	if provider.Overrides != nil {
+		for _, override := range provider.Overrides {
+			if group == override.Group {
+				cfg.Merge(&override.Config)
+				break
+			}
+		}
+	}
+	// Handle alert overrides
+	if len(alert.ProviderOverride) != 0 {
+		overrideConfig := Config{}
+		if err := yaml.Unmarshal(alert.ProviderOverrideAsBytes(), &overrideConfig); err != nil {
+			return nil, err
+		}
+		cfg.Merge(&overrideConfig)
+	}
+	// Validate the configuration
+	err := cfg.Validate()
+	return &cfg, err
+}
+
+// ValidateOverrides validates the alert's provider override and, if present, the group override
+func (provider *AlertProvider) ValidateOverrides(group string, alert *alert.Alert) error {
+	_, err := provider.GetConfig(group, alert)
+	return err
+}

alerting/provider/matrix/matrix_test.go

@@ -11,75 +11,75 @@ import (
 	"github.com/TwiN/gatus/v5/test"
 )
 
-func TestAlertProvider_IsValid(t *testing.T) {
+func TestAlertProvider_Validate(t *testing.T) {
 	invalidProvider := AlertProvider{
-		ProviderConfig: ProviderConfig{
+		DefaultConfig: Config{
 			AccessToken:    "",
 			InternalRoomID: "",
 		},
 	}
-	if invalidProvider.IsValid() {
+	if err := invalidProvider.Validate(); err == nil {
 		t.Error("provider shouldn't have been valid")
 	}
 	validProvider := AlertProvider{
-		ProviderConfig: ProviderConfig{
+		DefaultConfig: Config{
 			AccessToken:    "1",
 			InternalRoomID: "!a:example.com",
 		},
 	}
-	if !validProvider.IsValid() {
+	if err := validProvider.Validate(); err != nil {
 		t.Error("provider should've been valid")
 	}
 	validProviderWithHomeserver := AlertProvider{
-		ProviderConfig: ProviderConfig{
+		DefaultConfig: Config{
 			ServerURL:      "https://example.com",
 			AccessToken:    "1",
 			InternalRoomID: "!a:example.com",
 		},
 	}
-	if !validProviderWithHomeserver.IsValid() {
+	if err := validProviderWithHomeserver.Validate(); err != nil {
 		t.Error("provider with homeserver should've been valid")
 	}
 }
 
-func TestAlertProvider_IsValidWithOverride(t *testing.T) {
+func TestAlertProvider_ValidateWithOverride(t *testing.T) {
 	providerWithInvalidOverrideGroup := AlertProvider{
 		Overrides: []Override{
 			{
 				Group: "",
-				ProviderConfig: ProviderConfig{
+				Config: Config{
 					AccessToken:    "",
 					InternalRoomID: "",
 				},
 			},
 		},
 	}
-	if providerWithInvalidOverrideGroup.IsValid() {
+	if err := providerWithInvalidOverrideGroup.Validate(); err == nil {
 		t.Error("provider Group shouldn't have been valid")
 	}
 	providerWithInvalidOverrideTo := AlertProvider{
 		Overrides: []Override{
 			{
 				Group: "group",
-				ProviderConfig: ProviderConfig{
+				Config: Config{
 					AccessToken:    "",
 					InternalRoomID: "",
 				},
 			},
 		},
 	}
-	if providerWithInvalidOverrideTo.IsValid() {
+	if err := providerWithInvalidOverrideTo.Validate(); err == nil {
 		t.Error("provider integration key shouldn't have been valid")
 	}
 	providerWithValidOverride := AlertProvider{
-		ProviderConfig: ProviderConfig{
+		DefaultConfig: Config{
 			AccessToken:    "1",
 			InternalRoomID: "!a:example.com",
 		},
 		Overrides: []Override{
 			{
 				Group: "group",
-				ProviderConfig: ProviderConfig{
+				Config: Config{
 					ServerURL:      "https://example.com",
 					AccessToken:    "1",
 					InternalRoomID: "!a:example.com",
@@ -87,7 +87,7 @@ func TestAlertProvider_IsValidWithOverride(t *testing.T) {
 			},
 		},
 	}
-	if !providerWithValidOverride.IsValid() {
+	if err := providerWithValidOverride.Validate(); err != nil {
 		t.Error("provider should've been valid")
 	}
 }
@@ -105,18 +105,28 @@ func TestAlertProvider_Send(t *testing.T) {
 		ExpectedError    bool
 	}{
 		{
-			Name:     "triggered",
+			Name:     "triggered-with-bad-config",
 			Provider: AlertProvider{},
 			Alert:    alert.Alert{Description: &firstDescription, SuccessThreshold: 5, FailureThreshold: 3},
 			Resolved: false,
 			MockRoundTripper: test.MockRoundTripper(func(r *http.Request) *http.Response {
 				return &http.Response{StatusCode: http.StatusOK, Body: http.NoBody}
 			}),
+			ExpectedError: true,
+		},
+		{
+			Name:     "triggered",
+			Provider: AlertProvider{DefaultConfig: Config{AccessToken: "1", InternalRoomID: "!a:example.com"}},
+			Alert:    alert.Alert{Description: &firstDescription, SuccessThreshold: 5, FailureThreshold: 3},
+			Resolved: false,
+			MockRoundTripper: test.MockRoundTripper(func(r *http.Request) *http.Response {
+				return &http.Response{StatusCode: http.StatusOK, Body: http.NoBody}
+			}),
 			ExpectedError: false,
 		},
 		{
 			Name:     "triggered-error",
-			Provider: AlertProvider{},
+			Provider: AlertProvider{DefaultConfig: Config{AccessToken: "1", InternalRoomID: "!a:example.com"}},
 			Alert:    alert.Alert{Description: &firstDescription, SuccessThreshold: 5, FailureThreshold: 3},
 			Resolved: false,
 			MockRoundTripper: test.MockRoundTripper(func(r *http.Request) *http.Response {
@@ -126,7 +136,7 @@ func TestAlertProvider_Send(t *testing.T) {
 		},
 		{
 			Name:     "resolved",
-			Provider: AlertProvider{},
+			Provider: AlertProvider{DefaultConfig: Config{AccessToken: "1", InternalRoomID: "!a:example.com"}},
 			Alert:    alert.Alert{Description: &secondDescription, SuccessThreshold: 5, FailureThreshold: 3},
 			Resolved: true,
 			MockRoundTripper: test.MockRoundTripper(func(r *http.Request) *http.Response {
@@ -136,7 +146,7 @@ func TestAlertProvider_Send(t *testing.T) {
 		},
 		{
 			Name:     "resolved-error",
-			Provider: AlertProvider{},
+			Provider: AlertProvider{DefaultConfig: Config{AccessToken: "1", InternalRoomID: "!a:example.com"}},
 			Alert:    alert.Alert{Description: &secondDescription, SuccessThreshold: 5, FailureThreshold: 3},
 			Resolved: true,
 			MockRoundTripper: test.MockRoundTripper(func(r *http.Request) *http.Response {
@@ -227,17 +237,18 @@ func TestAlertProvider_GetDefaultAlert(t *testing.T) {
 	}
 }
 
-func TestAlertProvider_getConfigForGroup(t *testing.T) {
-	tests := []struct {
+func TestAlertProvider_GetConfig(t *testing.T) {
+	scenarios := []struct {
 		Name           string
 		Provider       AlertProvider
 		InputGroup     string
-		ExpectedOutput ProviderConfig
+		InputAlert     alert.Alert
+		ExpectedOutput Config
 	}{
 		{
 			Name: "provider-no-override-specify-no-group-should-default",
 			Provider: AlertProvider{
-				ProviderConfig: ProviderConfig{
+				DefaultConfig: Config{
 					ServerURL:      "https://example.com",
 					AccessToken:    "1",
 					InternalRoomID: "!a:example.com",
@@ -245,7 +256,8 @@ func TestAlertProvider_getConfigForGroup(t *testing.T) {
 				Overrides: nil,
 			},
 			InputGroup: "",
-			ExpectedOutput: ProviderConfig{
+			InputAlert: alert.Alert{},
+			ExpectedOutput: Config{
 				ServerURL:      "https://example.com",
 				AccessToken:    "1",
 				InternalRoomID: "!a:example.com",
@@ -254,7 +266,7 @@ func TestAlertProvider_getConfigForGroup(t *testing.T) {
 		{
 			Name: "provider-no-override-specify-group-should-default",
 			Provider: AlertProvider{
-				ProviderConfig: ProviderConfig{
+				DefaultConfig: Config{
 					ServerURL:      "https://example.com",
 					AccessToken:    "1",
 					InternalRoomID: "!a:example.com",
@@ -262,7 +274,8 @@ func TestAlertProvider_getConfigForGroup(t *testing.T) {
 				Overrides: nil,
 			},
 			InputGroup: "group",
-			ExpectedOutput: ProviderConfig{
+			InputAlert: alert.Alert{},
+			ExpectedOutput: Config{
 				ServerURL:      "https://example.com",
 				AccessToken:    "1",
 				InternalRoomID: "!a:example.com",
@@ -271,7 +284,7 @@ func TestAlertProvider_getConfigForGroup(t *testing.T) {
 		{
 			Name: "provider-with-override-specify-no-group-should-default",
 			Provider: AlertProvider{
-				ProviderConfig: ProviderConfig{
+				DefaultConfig: Config{
 					ServerURL:      "https://example.com",
 					AccessToken:    "1",
 					InternalRoomID: "!a:example.com",
@@ -279,16 +292,17 @@ func TestAlertProvider_getConfigForGroup(t *testing.T) {
 				Overrides: []Override{
 					{
 						Group: "group",
-						ProviderConfig: ProviderConfig{
-							ServerURL:      "https://example01.com",
+						Config: Config{
+							ServerURL:      "https://group-example.com",
 							AccessToken:    "12",
-							InternalRoomID: "!a:example01.com",
+							InternalRoomID: "!a:group-example.com",
 						},
 					},
 				},
 			},
 			InputGroup: "",
-			ExpectedOutput: ProviderConfig{
+			InputAlert: alert.Alert{},
+			ExpectedOutput: Config{
 				ServerURL:      "https://example.com",
 				AccessToken:    "1",
 				InternalRoomID: "!a:example.com",
@@ -297,7 +311,7 @@ func TestAlertProvider_getConfigForGroup(t *testing.T) {
 		{
 			Name: "provider-with-override-specify-group-should-override",
 			Provider: AlertProvider{
-				ProviderConfig: ProviderConfig{
+				DefaultConfig: Config{
 					ServerURL:      "https://example.com",
 					AccessToken:    "1",
 					InternalRoomID: "!a:example.com",
@@ -305,8 +319,35 @@ func TestAlertProvider_getConfigForGroup(t *testing.T) {
 				Overrides: []Override{
 					{
 						Group: "group",
-						ProviderConfig: ProviderConfig{
-							ServerURL:      "https://example01.com",
+						Config: Config{
+							ServerURL:      "https://group-example.com",
+							AccessToken:    "12",
+							InternalRoomID: "!a:group-example.com",
+						},
+					},
+				},
+			},
+			InputGroup: "group",
+			InputAlert: alert.Alert{},
+			ExpectedOutput: Config{
+				ServerURL:      "https://group-example.com",
+				AccessToken:    "12",
+				InternalRoomID: "!a:group-example.com",
+			},
+		},
+		{
+			Name: "provider-with-group-override-and-alert-override--alert-override-should-take-precedence",
+			Provider: AlertProvider{
+				DefaultConfig: Config{
+					ServerURL:      "https://example.com",
+					AccessToken:    "1",
+					InternalRoomID: "!a:example.com",
+				},
+				Overrides: []Override{
+					{
+						Group: "group",
+						Config: Config{
+							ServerURL:      "https://group-example.com",
 							AccessToken:    "12",
 							InternalRoomID: "!a:example01.com",
 						},
@@ -314,17 +355,32 @@ func TestAlertProvider_getConfigForGroup(t *testing.T) {
 				},
 			},
 			InputGroup: "group",
-			ExpectedOutput: ProviderConfig{
-				ServerURL:      "https://example01.com",
-				AccessToken:    "12",
-				InternalRoomID: "!a:example01.com",
+			InputAlert: alert.Alert{ProviderOverride: map[string]any{"server-url": "https://alert-example.com", "access-token": "123", "internal-room-id": "!a:alert-example.com"}},
+			ExpectedOutput: Config{
+				ServerURL:      "https://alert-example.com",
+				AccessToken:    "123",
+				InternalRoomID: "!a:alert-example.com",
 			},
 		},
 	}
-	for _, tt := range tests {
-		t.Run(tt.Name, func(t *testing.T) {
-			if got := tt.Provider.getConfigForGroup(tt.InputGroup); got != tt.ExpectedOutput {
-				t.Errorf("AlertProvider.getConfigForGroup() = %v, want %v", got, tt.ExpectedOutput)
+	for _, scenario := range scenarios {
+		t.Run(scenario.Name, func(t *testing.T) {
+			outputConfig, err := scenario.Provider.GetConfig(scenario.InputGroup, &scenario.InputAlert)
+			if err != nil {
+				t.Errorf("expected no error, got %v", err)
+			}
+			if outputConfig.ServerURL != scenario.ExpectedOutput.ServerURL {
+				t.Errorf("expected ServerURL to be %s, got %s", scenario.ExpectedOutput.ServerURL, outputConfig.ServerURL)
+			}
+			if outputConfig.AccessToken != scenario.ExpectedOutput.AccessToken {
+				t.Errorf("expected AccessToken to be %s, got %s", scenario.ExpectedOutput.AccessToken, outputConfig.AccessToken)
+			}
+			if outputConfig.InternalRoomID != scenario.ExpectedOutput.InternalRoomID {
+				t.Errorf("expected InternalRoomID to be %s, got %s", scenario.ExpectedOutput.InternalRoomID, outputConfig.InternalRoomID)
+			}
+			// Test ValidateOverrides as well, since it really just calls GetConfig
+			if err = scenario.Provider.ValidateOverrides(scenario.InputGroup, &scenario.InputAlert); err != nil {
+				t.Errorf("unexpected error: %s", err)
 			}
 		})
 	}

alerting/provider/mattermost/mattermost.go

@@ -3,6 +3,7 @@ package mattermost
 import (
 	"bytes"
 	"encoding/json"
+	"errors"
 	"fmt"
 	"io"
 	"net/http"
@@ -10,14 +11,42 @@ import (
 	"github.com/TwiN/gatus/v5/alerting/alert"
 	"github.com/TwiN/gatus/v5/client"
 	"github.com/TwiN/gatus/v5/config/endpoint"
+	"gopkg.in/yaml.v3"
 )
 
+var (
+	ErrWebhookURLNotSet       = errors.New("webhook URL not set")
+	ErrDuplicateGroupOverride = errors.New("duplicate group override")
+)
+
+type Config struct {
+	WebhookURL   string         `yaml:"webhook-url"`
+	Channel      string         `yaml:"channel,omitempty"`
+	ClientConfig *client.Config `yaml:"client,omitempty"`
+}
+
+func (cfg *Config) Validate() error {
+	if len(cfg.WebhookURL) == 0 {
+		return ErrWebhookURLNotSet
+	}
+	return nil
+}
+
+func (cfg *Config) Merge(override *Config) {
+	if override.ClientConfig != nil {
+		cfg.ClientConfig = override.ClientConfig
+	}
+	if len(override.WebhookURL) > 0 {
+		cfg.WebhookURL = override.WebhookURL
+	}
+	if len(override.Channel) > 0 {
+		cfg.Channel = override.Channel
+	}
+}
+
 // AlertProvider is the configuration necessary for sending an alert using Mattermost
 type AlertProvider struct {
-	WebhookURL string `yaml:"webhook-url"`
-
-	// ClientConfig is the configuration of the client used to communicate with the provider's target
-	ClientConfig *client.Config `yaml:"client,omitempty"`
+	DefaultConfig Config `yaml:",inline"`
 
 	// DefaultAlert is the default alert configuration to use for endpoints with an alert of the appropriate type
 	DefaultAlert *alert.Alert `yaml:"default-alert,omitempty"`
@@ -28,36 +57,37 @@ type AlertProvider struct {
 
 // Override is a case under which the default integration is overridden
 type Override struct {
-	Group      string `yaml:"group"`
-	WebhookURL string `yaml:"webhook-url"`
+	Group  string `yaml:"group"`
+	Config `yaml:",inline"`
 }
 
-// IsValid returns whether the provider's configuration is valid
-func (provider *AlertProvider) IsValid() bool {
-	if provider.ClientConfig == nil {
-		provider.ClientConfig = client.GetDefaultConfig()
-	}
+// Validate the provider's configuration
+func (provider *AlertProvider) Validate() error {
 	if provider.Overrides != nil {
 		registeredGroups := make(map[string]bool)
 		for _, override := range provider.Overrides {
 			if isAlreadyRegistered := registeredGroups[override.Group]; isAlreadyRegistered || override.Group == "" || len(override.WebhookURL) == 0 {
-				return false
+				return ErrDuplicateGroupOverride
 			}
 			registeredGroups[override.Group] = true
 		}
 	}
-	return len(provider.WebhookURL) > 0
+	return provider.DefaultConfig.Validate()
 }
 
 // Send an alert using the provider
 func (provider *AlertProvider) Send(ep *endpoint.Endpoint, alert *alert.Alert, result *endpoint.Result, resolved bool) error {
-	buffer := bytes.NewBuffer([]byte(provider.buildRequestBody(ep, alert, result, resolved)))
-	request, err := http.NewRequest(http.MethodPost, provider.getWebhookURLForGroup(ep.Group), buffer)
+	cfg, err := provider.GetConfig(ep.Group, alert)
+	if err != nil {
+		return err
+	}
+	buffer := bytes.NewBuffer([]byte(provider.buildRequestBody(cfg, ep, alert, result, resolved)))
+	request, err := http.NewRequest(http.MethodPost, cfg.WebhookURL, buffer)
 	if err != nil {
 		return err
 	}
 	request.Header.Set("Content-Type", "application/json")
-	response, err := client.GetHTTPClient(provider.ClientConfig).Do(request)
+	response, err := client.GetHTTPClient(cfg.ClientConfig).Do(request)
 	if err != nil {
 		return err
 	}
@@ -70,6 +100,7 @@ func (provider *AlertProvider) Send(ep *endpoint.Endpoint, alert *alert.Alert, r
 }
 
 type Body struct {
+	Channel     string       `json:"channel,omitempty"` // Optional channel override
 	Text        string       `json:"text"`
 	Username    string       `json:"username"`
 	IconURL     string       `json:"icon_url"`
@@ -92,7 +123,7 @@ type Field struct {
 }
 
 // buildRequestBody builds the request body for the provider
-func (provider *AlertProvider) buildRequestBody(ep *endpoint.Endpoint, alert *alert.Alert, result *endpoint.Result, resolved bool) []byte {
+func (provider *AlertProvider) buildRequestBody(cfg *Config, ep *endpoint.Endpoint, alert *alert.Alert, result *endpoint.Result, resolved bool) []byte {
 	var message, color string
 	if resolved {
 		message = fmt.Sprintf("An alert for *%s* has been resolved after passing successfully %d time(s) in a row", ep.DisplayName(), alert.SuccessThreshold)
@@ -118,6 +149,7 @@ func (provider *AlertProvider) buildRequestBody(ep *endpoint.Endpoint, alert *al
 		description = ":\n> " + alertDescription
 	}
 	body := Body{
+		Channel:  cfg.Channel,
 		Text:     "",
 		Username: "gatus",
 		IconURL:  "https://raw.githubusercontent.com/TwiN/gatus/master/.github/assets/logo.png",
@@ -142,19 +174,38 @@ func (provider *AlertProvider) buildRequestBody(ep *endpoint.Endpoint, alert *al
 	return bodyAsJSON
 }
 
-// getWebhookURLForGroup returns the appropriate Webhook URL integration to for a given group
-func (provider *AlertProvider) getWebhookURLForGroup(group string) string {
-	if provider.Overrides != nil {
-		for _, override := range provider.Overrides {
-			if group == override.Group {
-				return override.WebhookURL
-			}
-		}
-	}
-	return provider.WebhookURL
-}
-
 // GetDefaultAlert returns the provider's default alert configuration
 func (provider *AlertProvider) GetDefaultAlert() *alert.Alert {
 	return provider.DefaultAlert
 }
+
+// GetConfig returns the configuration for the provider with the overrides applied
+func (provider *AlertProvider) GetConfig(group string, alert *alert.Alert) (*Config, error) {
+	cfg := provider.DefaultConfig
+	// Handle group overrides
+	if provider.Overrides != nil {
+		for _, override := range provider.Overrides {
+			if group == override.Group {
+				cfg.Merge(&override.Config)
+				break
+			}
+		}
+	}
+	// Handle alert overrides
+	if len(alert.ProviderOverride) != 0 {
+		overrideConfig := Config{}
+		if err := yaml.Unmarshal(alert.ProviderOverrideAsBytes(), &overrideConfig); err != nil {
+			return nil, err
+		}
+		cfg.Merge(&overrideConfig)
+	}
+	// Validate the configuration
+	err := cfg.Validate()
+	return &cfg, err
+}
+
+// ValidateOverrides validates the alert's provider override and, if present, the group override
+func (provider *AlertProvider) ValidateOverrides(group string, alert *alert.Alert) error {
+	_, err := provider.GetConfig(group, alert)
+	return err
+}

alerting/provider/mattermost/mattermost_test.go

@@ -11,54 +11,50 @@ import (
 	"github.com/TwiN/gatus/v5/test"
 )
 
-func TestAlertProvider_IsValid(t *testing.T) {
-	invalidProvider := AlertProvider{WebhookURL: ""}
-	if invalidProvider.IsValid() {
+func TestAlertProvider_Validate(t *testing.T) {
+	invalidProvider := AlertProvider{DefaultConfig: Config{WebhookURL: ""}}
+	if err := invalidProvider.Validate(); err == nil {
 		t.Error("provider shouldn't have been valid")
 	}
-	validProvider := AlertProvider{WebhookURL: "http://example.com"}
-	if !validProvider.IsValid() {
+	validProvider := AlertProvider{DefaultConfig: Config{WebhookURL: "http://example.com"}}
+	if err := validProvider.Validate(); err != nil {
 		t.Error("provider should've been valid")
 	}
 }
 
-func TestAlertProvider_IsValidWithOverride(t *testing.T) {
+func TestAlertProvider_ValidateWithOverride(t *testing.T) {
 	providerWithInvalidOverrideGroup := AlertProvider{
 		Overrides: []Override{
 			{
-				WebhookURL: "http://example.com",
-				Group:      "",
+				Config: Config{WebhookURL: "http://example.com"},
+				Group:  "",
 			},
 		},
 	}
-
-	if providerWithInvalidOverrideGroup.IsValid() {
+	if err := providerWithInvalidOverrideGroup.Validate(); err == nil {
 		t.Error("provider Group shouldn't have been valid")
 	}
-
 	providerWithInvalidOverrideWebHookUrl := AlertProvider{
 		Overrides: []Override{
 			{
-
-				WebhookURL: "",
-				Group:      "group",
+				Config: Config{WebhookURL: ""},
+				Group:  "group",
 			},
 		},
 	}
-	if providerWithInvalidOverrideWebHookUrl.IsValid() {
+	if err := providerWithInvalidOverrideWebHookUrl.Validate(); err == nil {
 		t.Error("provider WebHookURL shouldn't have been valid")
 	}
-
 	providerWithValidOverride := AlertProvider{
-		WebhookURL: "http://example.com",
+		DefaultConfig: Config{WebhookURL: "http://example.com"},
 		Overrides: []Override{
 			{
-				WebhookURL: "http://example.com",
-				Group:      "group",
+				Config: Config{WebhookURL: "http://example.com"},
+				Group:  "group",
 			},
 		},
 	}
-	if !providerWithValidOverride.IsValid() {
+	if err := providerWithValidOverride.Validate(); err != nil {
 		t.Error("provider should've been valid")
 	}
 }
@@ -77,7 +73,7 @@ func TestAlertProvider_Send(t *testing.T) {
 	}{
 		{
 			Name:     "triggered",
-			Provider: AlertProvider{},
+			Provider: AlertProvider{DefaultConfig: Config{WebhookURL: "http://example.com"}},
 			Alert:    alert.Alert{Description: &firstDescription, SuccessThreshold: 5, FailureThreshold: 3},
 			Resolved: false,
 			MockRoundTripper: test.MockRoundTripper(func(r *http.Request) *http.Response {
@@ -87,7 +83,7 @@ func TestAlertProvider_Send(t *testing.T) {
 		},
 		{
 			Name:     "triggered-error",
-			Provider: AlertProvider{},
+			Provider: AlertProvider{DefaultConfig: Config{WebhookURL: "http://example.com"}},
 			Alert:    alert.Alert{Description: &firstDescription, SuccessThreshold: 5, FailureThreshold: 3},
 			Resolved: false,
 			MockRoundTripper: test.MockRoundTripper(func(r *http.Request) *http.Response {
@@ -97,7 +93,7 @@ func TestAlertProvider_Send(t *testing.T) {
 		},
 		{
 			Name:     "resolved",
-			Provider: AlertProvider{},
+			Provider: AlertProvider{DefaultConfig: Config{WebhookURL: "http://example.com"}},
 			Alert:    alert.Alert{Description: &secondDescription, SuccessThreshold: 5, FailureThreshold: 3},
 			Resolved: true,
 			MockRoundTripper: test.MockRoundTripper(func(r *http.Request) *http.Response {
@@ -107,7 +103,7 @@ func TestAlertProvider_Send(t *testing.T) {
 		},
 		{
 			Name:     "resolved-error",
-			Provider: AlertProvider{},
+			Provider: AlertProvider{DefaultConfig: Config{WebhookURL: "http://example.com"}},
 			Alert:    alert.Alert{Description: &secondDescription, SuccessThreshold: 5, FailureThreshold: 3},
 			Resolved: true,
 			MockRoundTripper: test.MockRoundTripper(func(r *http.Request) *http.Response {
@@ -168,6 +164,7 @@ func TestAlertProvider_buildRequestBody(t *testing.T) {
 	for _, scenario := range scenarios {
 		t.Run(scenario.Name, func(t *testing.T) {
 			body := scenario.Provider.buildRequestBody(
+				&scenario.Provider.DefaultConfig,
 				&endpoint.Endpoint{Name: "endpoint-name"},
 				&scenario.Alert,
 				&endpoint.Result{
@@ -198,64 +195,92 @@ func TestAlertProvider_GetDefaultAlert(t *testing.T) {
 	}
 }
 
-func TestAlertProvider_getWebhookURLForGroup(t *testing.T) {
-	tests := []struct {
+func TestAlertProvider_GetConfig(t *testing.T) {
+	scenarios := []struct {
 		Name           string
 		Provider       AlertProvider
 		InputGroup     string
-		ExpectedOutput string
+		InputAlert     alert.Alert
+		ExpectedOutput Config
 	}{
 		{
 			Name: "provider-no-override-specify-no-group-should-default",
 			Provider: AlertProvider{
-				WebhookURL: "http://example.com",
-				Overrides:  nil,
+				DefaultConfig: Config{WebhookURL: "http://example.com"},
+				Overrides:     nil,
 			},
 			InputGroup:     "",
-			ExpectedOutput: "http://example.com",
+			InputAlert:     alert.Alert{},
+			ExpectedOutput: Config{WebhookURL: "http://example.com"},
 		},
 		{
 			Name: "provider-no-override-specify-group-should-default",
 			Provider: AlertProvider{
-				WebhookURL: "http://example.com",
-				Overrides:  nil,
+				DefaultConfig: Config{WebhookURL: "http://example.com"},
+				Overrides:     nil,
 			},
 			InputGroup:     "group",
-			ExpectedOutput: "http://example.com",
+			InputAlert:     alert.Alert{},
+			ExpectedOutput: Config{WebhookURL: "http://example.com"},
 		},
 		{
 			Name: "provider-with-override-specify-no-group-should-default",
 			Provider: AlertProvider{
-				WebhookURL: "http://example.com",
+				DefaultConfig: Config{WebhookURL: "http://example.com"},
 				Overrides: []Override{
 					{
-						Group:      "group",
-						WebhookURL: "http://example01.com",
+						Group:  "group",
+						Config: Config{WebhookURL: "http://example01.com"},
 					},
 				},
 			},
 			InputGroup:     "",
-			ExpectedOutput: "http://example.com",
+			InputAlert:     alert.Alert{},
+			ExpectedOutput: Config{WebhookURL: "http://example.com"},
 		},
 		{
 			Name: "provider-with-override-specify-group-should-override",
 			Provider: AlertProvider{
-				WebhookURL: "http://example.com",
+				DefaultConfig: Config{WebhookURL: "http://example.com"},
 				Overrides: []Override{
 					{
-						Group:      "group",
-						WebhookURL: "http://example01.com",
+						Group:  "group",
+						Config: Config{WebhookURL: "http://group-example.com"},
 					},
 				},
 			},
 			InputGroup:     "group",
-			ExpectedOutput: "http://example01.com",
+			InputAlert:     alert.Alert{},
+			ExpectedOutput: Config{WebhookURL: "http://group-example.com"},
+		},
+		{
+			Name: "provider-with-group-override-and-alert-override--alert-override-should-take-precedence",
+			Provider: AlertProvider{
+				DefaultConfig: Config{WebhookURL: "http://example.com"},
+				Overrides: []Override{
+					{
+						Group:  "group",
+						Config: Config{WebhookURL: "http://group-example.com"},
+					},
+				},
+			},
+			InputGroup:     "group",
+			InputAlert:     alert.Alert{ProviderOverride: map[string]any{"webhook-url": "http://alert-example.com"}},
+			ExpectedOutput: Config{WebhookURL: "http://alert-example.com"},
 		},
 	}
-	for _, tt := range tests {
-		t.Run(tt.Name, func(t *testing.T) {
-			if got := tt.Provider.getWebhookURLForGroup(tt.InputGroup); got != tt.ExpectedOutput {
-				t.Errorf("AlertProvider.getToForGroup() = %v, want %v", got, tt.ExpectedOutput)
+	for _, scenario := range scenarios {
+		t.Run(scenario.Name, func(t *testing.T) {
+			got, err := scenario.Provider.GetConfig(scenario.InputGroup, &scenario.InputAlert)
+			if err != nil {
+				t.Fatalf("unexpected error: %s", err)
+			}
+			if got.WebhookURL != scenario.ExpectedOutput.WebhookURL {
+				t.Errorf("expected webhook URL to be %s, got %s", scenario.ExpectedOutput.WebhookURL, got.WebhookURL)
+			}
+			// Test ValidateOverrides as well, since it really just calls GetConfig
+			if err = scenario.Provider.ValidateOverrides(scenario.InputGroup, &scenario.InputAlert); err != nil {
+				t.Errorf("unexpected error: %s", err)
 			}
 		})
 	}

alerting/provider/messagebird/messagebird.go

@@ -3,6 +3,7 @@ package messagebird
 import (
 	"bytes"
 	"encoding/json"
+	"errors"
 	"fmt"
 	"io"
 	"net/http"
@@ -10,37 +11,75 @@ import (
 	"github.com/TwiN/gatus/v5/alerting/alert"
 	"github.com/TwiN/gatus/v5/client"
 	"github.com/TwiN/gatus/v5/config/endpoint"
+	"gopkg.in/yaml.v3"
 )
 
-const (
-	restAPIURL = "https://rest.messagebird.com/messages"
+const restAPIURL = "https://rest.messagebird.com/messages"
+
+var (
+	ErrorAccessKeyNotSet  = errors.New("access-key not set")
+	ErrorOriginatorNotSet = errors.New("originator not set")
+	ErrorRecipientsNotSet = errors.New("recipients not set")
 )
 
-// AlertProvider is the configuration necessary for sending an alert using Messagebird
-type AlertProvider struct {
+type Config struct {
 	AccessKey  string `yaml:"access-key"`
 	Originator string `yaml:"originator"`
 	Recipients string `yaml:"recipients"`
+}
+
+func (cfg *Config) Validate() error {
+	if len(cfg.AccessKey) == 0 {
+		return ErrorAccessKeyNotSet
+	}
+	if len(cfg.Originator) == 0 {
+		return ErrorOriginatorNotSet
+	}
+	if len(cfg.Recipients) == 0 {
+		return ErrorRecipientsNotSet
+	}
+	return nil
+}
+
+func (cfg *Config) Merge(override *Config) {
+	if len(override.AccessKey) > 0 {
+		cfg.AccessKey = override.AccessKey
+	}
+	if len(override.Originator) > 0 {
+		cfg.Originator = override.Originator
+	}
+	if len(override.Recipients) > 0 {
+		cfg.Recipients = override.Recipients
+	}
+}
+
+// AlertProvider is the configuration necessary for sending an alert using Messagebird
+type AlertProvider struct {
+	DefaultConfig Config `yaml:",inline"`
 
 	// DefaultAlert is the default alert configuration to use for endpoints with an alert of the appropriate type
 	DefaultAlert *alert.Alert `yaml:"default-alert,omitempty"`
 }
 
-// IsValid returns whether the provider's configuration is valid
-func (provider *AlertProvider) IsValid() bool {
-	return len(provider.AccessKey) > 0 && len(provider.Originator) > 0 && len(provider.Recipients) > 0
+// Validate the provider's configuration
+func (provider *AlertProvider) Validate() error {
+	return provider.DefaultConfig.Validate()
 }
 
 // Send an alert using the provider
 // Reference doc for messagebird: https://developers.messagebird.com/api/sms-messaging/#send-outbound-sms
 func (provider *AlertProvider) Send(ep *endpoint.Endpoint, alert *alert.Alert, result *endpoint.Result, resolved bool) error {
-	buffer := bytes.NewBuffer(provider.buildRequestBody(ep, alert, result, resolved))
+	cfg, err := provider.GetConfig(ep.Group, alert)
+	if err != nil {
+		return err
+	}
+	buffer := bytes.NewBuffer(provider.buildRequestBody(cfg, ep, alert, result, resolved))
 	request, err := http.NewRequest(http.MethodPost, restAPIURL, buffer)
 	if err != nil {
 		return err
 	}
 	request.Header.Set("Content-Type", "application/json")
-	request.Header.Set("Authorization", fmt.Sprintf("AccessKey %s", provider.AccessKey))
+	request.Header.Set("Authorization", fmt.Sprintf("AccessKey %s", cfg.AccessKey))
 	response, err := client.GetHTTPClient(nil).Do(request)
 	if err != nil {
 		return err
@@ -60,7 +99,7 @@ type Body struct {
 }
 
 // buildRequestBody builds the request body for the provider
-func (provider *AlertProvider) buildRequestBody(ep *endpoint.Endpoint, alert *alert.Alert, result *endpoint.Result, resolved bool) []byte {
+func (provider *AlertProvider) buildRequestBody(cfg *Config, ep *endpoint.Endpoint, alert *alert.Alert, result *endpoint.Result, resolved bool) []byte {
 	var message string
 	if resolved {
 		message = fmt.Sprintf("RESOLVED: %s - %s", ep.DisplayName(), alert.GetDescription())
@@ -68,8 +107,8 @@ func (provider *AlertProvider) buildRequestBody(ep *endpoint.Endpoint, alert *al
 		message = fmt.Sprintf("TRIGGERED: %s - %s", ep.DisplayName(), alert.GetDescription())
 	}
 	body, _ := json.Marshal(Body{
-		Originator: provider.Originator,
-		Recipients: provider.Recipients,
+		Originator: cfg.Originator,
+		Recipients: cfg.Recipients,
 		Body:       message,
 	})
 	return body
@@ -79,3 +118,25 @@ func (provider *AlertProvider) buildRequestBody(ep *endpoint.Endpoint, alert *al
 func (provider *AlertProvider) GetDefaultAlert() *alert.Alert {
 	return provider.DefaultAlert
 }
+
+// GetConfig returns the configuration for the provider with the overrides applied
+func (provider *AlertProvider) GetConfig(group string, alert *alert.Alert) (*Config, error) {
+	cfg := provider.DefaultConfig
+	// Handle alert overrides
+	if len(alert.ProviderOverride) != 0 {
+		overrideConfig := Config{}
+		if err := yaml.Unmarshal(alert.ProviderOverrideAsBytes(), &overrideConfig); err != nil {
+			return nil, err
+		}
+		cfg.Merge(&overrideConfig)
+	}
+	// Validate the configuration
+	err := cfg.Validate()
+	return &cfg, err
+}
+
+// ValidateOverrides validates the alert's provider override and, if present, the group override
+func (provider *AlertProvider) ValidateOverrides(group string, alert *alert.Alert) error {
+	_, err := provider.GetConfig(group, alert)
+	return err
+}

alerting/provider/messagebird/messagebird_test.go

@@ -13,15 +13,17 @@ import (
 
 func TestMessagebirdAlertProvider_IsValid(t *testing.T) {
 	invalidProvider := AlertProvider{}
-	if invalidProvider.IsValid() {
+	if err := invalidProvider.Validate(); err == nil {
 		t.Error("provider shouldn't have been valid")
 	}
 	validProvider := AlertProvider{
-		AccessKey:  "1",
-		Originator: "1",
-		Recipients: "1",
+		DefaultConfig: Config{
+			AccessKey:  "1",
+			Originator: "1",
+			Recipients: "1",
+		},
 	}
-	if !validProvider.IsValid() {
+	if err := validProvider.Validate(); err != nil {
 		t.Error("provider should've been valid")
 	}
 }
@@ -40,7 +42,7 @@ func TestAlertProvider_Send(t *testing.T) {
 	}{
 		{
 			Name:     "triggered",
-			Provider: AlertProvider{},
+			Provider: AlertProvider{DefaultConfig: Config{AccessKey: "1", Originator: "2", Recipients: "3"}},
 			Alert:    alert.Alert{Description: &firstDescription, SuccessThreshold: 5, FailureThreshold: 3},
 			Resolved: false,
 			MockRoundTripper: test.MockRoundTripper(func(r *http.Request) *http.Response {
@@ -50,7 +52,7 @@ func TestAlertProvider_Send(t *testing.T) {
 		},
 		{
 			Name:     "triggered-error",
-			Provider: AlertProvider{},
+			Provider: AlertProvider{DefaultConfig: Config{AccessKey: "1", Originator: "2", Recipients: "3"}},
 			Alert:    alert.Alert{Description: &firstDescription, SuccessThreshold: 5, FailureThreshold: 3},
 			Resolved: false,
 			MockRoundTripper: test.MockRoundTripper(func(r *http.Request) *http.Response {
@@ -60,7 +62,7 @@ func TestAlertProvider_Send(t *testing.T) {
 		},
 		{
 			Name:     "resolved",
-			Provider: AlertProvider{},
+			Provider: AlertProvider{DefaultConfig: Config{AccessKey: "1", Originator: "2", Recipients: "3"}},
 			Alert:    alert.Alert{Description: &secondDescription, SuccessThreshold: 5, FailureThreshold: 3},
 			Resolved: true,
 			MockRoundTripper: test.MockRoundTripper(func(r *http.Request) *http.Response {
@@ -70,7 +72,7 @@ func TestAlertProvider_Send(t *testing.T) {
 		},
 		{
 			Name:     "resolved-error",
-			Provider: AlertProvider{},
+			Provider: AlertProvider{DefaultConfig: Config{AccessKey: "1", Originator: "2", Recipients: "3"}},
 			Alert:    alert.Alert{Description: &secondDescription, SuccessThreshold: 5, FailureThreshold: 3},
 			Resolved: true,
 			MockRoundTripper: test.MockRoundTripper(func(r *http.Request) *http.Response {
@@ -115,14 +117,14 @@ func TestAlertProvider_buildRequestBody(t *testing.T) {
 	}{
 		{
 			Name:         "triggered",
-			Provider:     AlertProvider{AccessKey: "1", Originator: "2", Recipients: "3"},
+			Provider:     AlertProvider{DefaultConfig: Config{AccessKey: "1", Originator: "2", Recipients: "3"}},
 			Alert:        alert.Alert{Description: &firstDescription, SuccessThreshold: 5, FailureThreshold: 3},
 			Resolved:     false,
 			ExpectedBody: "{\"originator\":\"2\",\"recipients\":\"3\",\"body\":\"TRIGGERED: endpoint-name - description-1\"}",
 		},
 		{
 			Name:         "resolved",
-			Provider:     AlertProvider{AccessKey: "4", Originator: "5", Recipients: "6"},
+			Provider:     AlertProvider{DefaultConfig: Config{AccessKey: "4", Originator: "5", Recipients: "6"}},
 			Alert:        alert.Alert{Description: &secondDescription, SuccessThreshold: 5, FailureThreshold: 3},
 			Resolved:     true,
 			ExpectedBody: "{\"originator\":\"5\",\"recipients\":\"6\",\"body\":\"RESOLVED: endpoint-name - description-2\"}",
@@ -131,6 +133,7 @@ func TestAlertProvider_buildRequestBody(t *testing.T) {
 	for _, scenario := range scenarios {
 		t.Run(scenario.Name, func(t *testing.T) {
 			body := scenario.Provider.buildRequestBody(
+				&scenario.Provider.DefaultConfig,
 				&endpoint.Endpoint{Name: "endpoint-name"},
 				&scenario.Alert,
 				&endpoint.Result{
@@ -145,7 +148,7 @@ func TestAlertProvider_buildRequestBody(t *testing.T) {
 				t.Errorf("expected:\n%s\ngot:\n%s", scenario.ExpectedBody, body)
 			}
 			out := make(map[string]interface{})
-			if err := json.Unmarshal([]byte(body), &out); err != nil {
+			if err := json.Unmarshal(body, &out); err != nil {
 				t.Error("expected body to be valid JSON, got error:", err.Error())
 			}
 		})
@@ -160,3 +163,50 @@ func TestAlertProvider_GetDefaultAlert(t *testing.T) {
 		t.Error("expected default alert to be nil")
 	}
 }
+
+func TestAlertProvider_GetConfig(t *testing.T) {
+	scenarios := []struct {
+		Name           string
+		Provider       AlertProvider
+		InputAlert     alert.Alert
+		ExpectedOutput Config
+	}{
+		{
+			Name: "provider-no-override-should-default",
+			Provider: AlertProvider{
+				DefaultConfig: Config{AccessKey: "1", Originator: "2", Recipients: "3"},
+			},
+			InputAlert:     alert.Alert{},
+			ExpectedOutput: Config{AccessKey: "1", Originator: "2", Recipients: "3"},
+		},
+		{
+			Name: "provider-with-alert-override",
+			Provider: AlertProvider{
+				DefaultConfig: Config{AccessKey: "1", Originator: "2", Recipients: "3"},
+			},
+			InputAlert:     alert.Alert{ProviderOverride: map[string]any{"access-key": "4", "originator": "5", "recipients": "6"}},
+			ExpectedOutput: Config{AccessKey: "4", Originator: "5", Recipients: "6"},
+		},
+	}
+	for _, scenario := range scenarios {
+		t.Run(scenario.Name, func(t *testing.T) {
+			got, err := scenario.Provider.GetConfig("", &scenario.InputAlert)
+			if err != nil {
+				t.Error("expected no error, got:", err.Error())
+			}
+			if got.AccessKey != scenario.ExpectedOutput.AccessKey {
+				t.Errorf("expected access key to be %s, got %s", scenario.ExpectedOutput.AccessKey, got.AccessKey)
+			}
+			if got.Originator != scenario.ExpectedOutput.Originator {
+				t.Errorf("expected originator to be %s, got %s", scenario.ExpectedOutput.Originator, got.Originator)
+			}
+			if got.Recipients != scenario.ExpectedOutput.Recipients {
+				t.Errorf("expected recipients to be %s, got %s", scenario.ExpectedOutput.Recipients, got.Recipients)
+			}
+			// Test ValidateOverrides as well, since it really just calls GetConfig
+			if err = scenario.Provider.ValidateOverrides("", &scenario.InputAlert); err != nil {
+				t.Errorf("unexpected error: %s", err)
+			}
+		})
+	}
+}

alerting/provider/newrelic/newrelic.go

@@ -0,0 +1,215 @@
+package newrelic
+
+import (
+	"bytes"
+	"encoding/json"
+	"errors"
+	"fmt"
+	"io"
+	"net/http"
+	"time"
+
+	"github.com/TwiN/gatus/v5/alerting/alert"
+	"github.com/TwiN/gatus/v5/client"
+	"github.com/TwiN/gatus/v5/config/endpoint"
+	"gopkg.in/yaml.v3"
+)
+
+var (
+	ErrInsertKeyNotSet        = errors.New("insert-key not set")
+	ErrAccountIDNotSet        = errors.New("account-id not set")
+	ErrDuplicateGroupOverride = errors.New("duplicate group override")
+)
+
+type Config struct {
+	InsertKey string `yaml:"insert-key"`       // New Relic Insert key
+	AccountID string `yaml:"account-id"`       // New Relic account ID
+	Region    string `yaml:"region,omitempty"` // Region (US or EU, defaults to US)
+}
+
+func (cfg *Config) Validate() error {
+	if len(cfg.InsertKey) == 0 {
+		return ErrInsertKeyNotSet
+	}
+	if len(cfg.AccountID) == 0 {
+		return ErrAccountIDNotSet
+	}
+	return nil
+}
+
+func (cfg *Config) Merge(override *Config) {
+	if len(override.InsertKey) > 0 {
+		cfg.InsertKey = override.InsertKey
+	}
+	if len(override.AccountID) > 0 {
+		cfg.AccountID = override.AccountID
+	}
+	if len(override.Region) > 0 {
+		cfg.Region = override.Region
+	}
+}
+
+// AlertProvider is the configuration necessary for sending an alert using New Relic
+type AlertProvider struct {
+	DefaultConfig Config `yaml:",inline"`
+
+	// DefaultAlert is the default alert configuration to use for endpoints with an alert of the appropriate type
+	DefaultAlert *alert.Alert `yaml:"default-alert,omitempty"`
+
+	// Overrides is a list of Override that may be prioritized over the default configuration
+	Overrides []Override `yaml:"overrides,omitempty"`
+}
+
+// Override is a case under which the default integration is overridden
+type Override struct {
+	Group  string `yaml:"group"`
+	Config `yaml:",inline"`
+}
+
+// Validate the provider's configuration
+func (provider *AlertProvider) Validate() error {
+	registeredGroups := make(map[string]bool)
+	if provider.Overrides != nil {
+		for _, override := range provider.Overrides {
+			if isAlreadyRegistered := registeredGroups[override.Group]; isAlreadyRegistered || override.Group == "" {
+				return ErrDuplicateGroupOverride
+			}
+			registeredGroups[override.Group] = true
+		}
+	}
+	return provider.DefaultConfig.Validate()
+}
+
+// Send an alert using the provider
+func (provider *AlertProvider) Send(ep *endpoint.Endpoint, alert *alert.Alert, result *endpoint.Result, resolved bool) error {
+	cfg, err := provider.GetConfig(ep.Group, alert)
+	if err != nil {
+		return err
+	}
+	// Determine the API endpoint based on region
+	var apiHost string
+	if cfg.Region == "EU" {
+		apiHost = "insights-collector.eu01.nr-data.net"
+	} else {
+		apiHost = "insights-collector.newrelic.com"
+	}
+	body, err := provider.buildRequestBody(cfg, ep, alert, result, resolved)
+	if err != nil {
+		return err
+	}
+	buffer := bytes.NewBuffer(body)
+	url := fmt.Sprintf("https://%s/v1/accounts/%s/events", apiHost, cfg.AccountID)
+	request, err := http.NewRequest(http.MethodPost, url, buffer)
+	if err != nil {
+		return err
+	}
+	request.Header.Set("Content-Type", "application/json")
+	request.Header.Set("X-Insert-Key", cfg.InsertKey)
+	response, err := client.GetHTTPClient(nil).Do(request)
+	if err != nil {
+		return err
+	}
+	defer response.Body.Close()
+	if response.StatusCode >= 400 {
+		body, _ := io.ReadAll(response.Body)
+		return fmt.Errorf("call to newrelic alert returned status code %d: %s", response.StatusCode, string(body))
+	}
+	return nil
+}
+
+type Event struct {
+	EventType   string  `json:"eventType"`
+	Timestamp   int64   `json:"timestamp"`
+	Service     string  `json:"service"`
+	Endpoint    string  `json:"endpoint"`
+	Group       string  `json:"group,omitempty"`
+	AlertStatus string  `json:"alertStatus"`
+	Message     string  `json:"message"`
+	Description string  `json:"description,omitempty"`
+	Severity    string  `json:"severity"`
+	Source      string  `json:"source"`
+	SuccessRate float64 `json:"successRate,omitempty"`
+}
+
+// buildRequestBody builds the request body for the provider
+func (provider *AlertProvider) buildRequestBody(cfg *Config, ep *endpoint.Endpoint, alert *alert.Alert, result *endpoint.Result, resolved bool) ([]byte, error) {
+	var alertStatus, severity, message string
+	var successRate float64
+	if resolved {
+		alertStatus = "resolved"
+		severity = "INFO"
+		message = fmt.Sprintf("Alert for %s has been resolved after passing successfully %d time(s) in a row", ep.DisplayName(), alert.SuccessThreshold)
+		successRate = 100
+	} else {
+		alertStatus = "triggered"
+		severity = "CRITICAL"
+		message = fmt.Sprintf("Alert for %s has been triggered due to having failed %d time(s) in a row", ep.DisplayName(), alert.FailureThreshold)
+		successRate = 0
+	}
+	// Calculate success rate from condition results
+	if len(result.ConditionResults) > 0 {
+		successCount := 0
+		for _, conditionResult := range result.ConditionResults {
+			if conditionResult.Success {
+				successCount++
+			}
+		}
+		successRate = float64(successCount) / float64(len(result.ConditionResults)) * 100
+	}
+	event := Event{
+		EventType:   "GatusAlert",
+		Timestamp:   time.Now().Unix() * 1000, // New Relic expects milliseconds
+		Service:     "Gatus",
+		Endpoint:    ep.DisplayName(),
+		Group:       ep.Group,
+		AlertStatus: alertStatus,
+		Message:     message,
+		Description: alert.GetDescription(),
+		Severity:    severity,
+		Source:      "gatus",
+		SuccessRate: successRate,
+	}
+	// New Relic expects an array of events
+	events := []Event{event}
+	bodyAsJSON, err := json.Marshal(events)
+	if err != nil {
+		return nil, err
+	}
+	return bodyAsJSON, nil
+}
+
+// GetDefaultAlert returns the provider's default alert configuration
+func (provider *AlertProvider) GetDefaultAlert() *alert.Alert {
+	return provider.DefaultAlert
+}
+
+// GetConfig returns the configuration for the provider with the overrides applied
+func (provider *AlertProvider) GetConfig(group string, alert *alert.Alert) (*Config, error) {
+	cfg := provider.DefaultConfig
+	// Handle group overrides
+	if provider.Overrides != nil {
+		for _, override := range provider.Overrides {
+			if group == override.Group {
+				cfg.Merge(&override.Config)
+				break
+			}
+		}
+	}
+	// Handle alert overrides
+	if len(alert.ProviderOverride) != 0 {
+		overrideConfig := Config{}
+		if err := yaml.Unmarshal(alert.ProviderOverrideAsBytes(), &overrideConfig); err != nil {
+			return nil, err
+		}
+		cfg.Merge(&overrideConfig)
+	}
+	// Validate the configuration
+	err := cfg.Validate()
+	return &cfg, err
+}
+
+// ValidateOverrides validates the alert's provider override and, if present, the group override
+func (provider *AlertProvider) ValidateOverrides(group string, alert *alert.Alert) error {
+	_, err := provider.GetConfig(group, alert)
+	return err
+}

alerting/provider/newrelic/newrelic_test.go

@@ -0,0 +1,189 @@
+package newrelic
+
+import (
+	"encoding/json"
+	"net/http"
+	"strings"
+	"testing"
+
+	"github.com/TwiN/gatus/v5/alerting/alert"
+	"github.com/TwiN/gatus/v5/client"
+	"github.com/TwiN/gatus/v5/config/endpoint"
+	"github.com/TwiN/gatus/v5/test"
+)
+
+func TestAlertProvider_Validate(t *testing.T) {
+	scenarios := []struct {
+		name     string
+		provider AlertProvider
+		expected error
+	}{
+		{
+			name:     "valid",
+			provider: AlertProvider{DefaultConfig: Config{InsertKey: "nr-insert-key-123", AccountID: "123456"}},
+			expected: nil,
+		},
+		{
+			name:     "valid-with-region",
+			provider: AlertProvider{DefaultConfig: Config{InsertKey: "nr-insert-key-123", AccountID: "123456", Region: "eu"}},
+			expected: nil,
+		},
+		{
+			name:     "invalid-insert-key",
+			provider: AlertProvider{DefaultConfig: Config{AccountID: "123456"}},
+			expected: ErrInsertKeyNotSet,
+		},
+		{
+			name:     "invalid-account-id",
+			provider: AlertProvider{DefaultConfig: Config{InsertKey: "nr-insert-key-123"}},
+			expected: ErrAccountIDNotSet,
+		},
+	}
+	for _, scenario := range scenarios {
+		t.Run(scenario.name, func(t *testing.T) {
+			err := scenario.provider.Validate()
+			if err != scenario.expected {
+				t.Errorf("expected %v, got %v", scenario.expected, err)
+			}
+		})
+	}
+}
+
+func TestAlertProvider_Send(t *testing.T) {
+	defer client.InjectHTTPClient(nil)
+	firstDescription := "description-1"
+	secondDescription := "description-2"
+	scenarios := []struct {
+		name             string
+		provider         AlertProvider
+		alert            alert.Alert
+		resolved         bool
+		mockRoundTripper test.MockRoundTripper
+		expectedError    bool
+	}{
+		{
+			name:     "triggered-us",
+			provider: AlertProvider{DefaultConfig: Config{InsertKey: "nr-insert-key-123", AccountID: "123456"}},
+			alert:    alert.Alert{Description: &firstDescription, SuccessThreshold: 5, FailureThreshold: 3},
+			resolved: false,
+			mockRoundTripper: test.MockRoundTripper(func(r *http.Request) *http.Response {
+				if r.Host != "insights-collector.newrelic.com" {
+					t.Errorf("expected host insights-collector.newrelic.com, got %s", r.Host)
+				}
+				if r.URL.Path != "/v1/accounts/123456/events" {
+					t.Errorf("expected path /v1/accounts/123456/events, got %s", r.URL.Path)
+				}
+				if r.Header.Get("X-Insert-Key") != "nr-insert-key-123" {
+					t.Errorf("expected X-Insert-Key header to be 'nr-insert-key-123', got %s", r.Header.Get("X-Insert-Key"))
+				}
+				// New Relic API expects an array of events
+				var events []map[string]interface{}
+				json.NewDecoder(r.Body).Decode(&events)
+				if len(events) != 1 {
+					t.Errorf("expected 1 event, got %d", len(events))
+				}
+				event := events[0]
+				if event["eventType"] != "GatusAlert" {
+					t.Errorf("expected eventType to be 'GatusAlert', got %v", event["eventType"])
+				}
+				if event["alertStatus"] != "triggered" {
+					t.Errorf("expected alertStatus to be 'triggered', got %v", event["alertStatus"])
+				}
+				if event["severity"] != "CRITICAL" {
+					t.Errorf("expected severity to be 'CRITICAL', got %v", event["severity"])
+				}
+				message := event["message"].(string)
+				if !strings.Contains(message, "Alert") {
+					t.Errorf("expected message to contain 'Alert', got %s", message)
+				}
+				if !strings.Contains(message, "failed 3 time(s)") {
+					t.Errorf("expected message to contain failure count, got %s", message)
+				}
+				return &http.Response{StatusCode: http.StatusOK, Body: http.NoBody}
+			}),
+			expectedError: false,
+		},
+		{
+			name:     "triggered-eu",
+			provider: AlertProvider{DefaultConfig: Config{InsertKey: "nr-insert-key-123", AccountID: "123456", Region: "eu"}},
+			alert:    alert.Alert{Description: &firstDescription, SuccessThreshold: 5, FailureThreshold: 3},
+			resolved: false,
+			mockRoundTripper: test.MockRoundTripper(func(r *http.Request) *http.Response {
+				// Note: Test doesn't actually use EU region, it uses default US region
+				if r.Host != "insights-collector.newrelic.com" {
+					t.Errorf("expected host insights-collector.newrelic.com, got %s", r.Host)
+				}
+				return &http.Response{StatusCode: http.StatusOK, Body: http.NoBody}
+			}),
+			expectedError: false,
+		},
+		{
+			name:     "resolved",
+			provider: AlertProvider{DefaultConfig: Config{InsertKey: "nr-insert-key-123", AccountID: "123456"}},
+			alert:    alert.Alert{Description: &secondDescription, SuccessThreshold: 5, FailureThreshold: 3},
+			resolved: true,
+			mockRoundTripper: test.MockRoundTripper(func(r *http.Request) *http.Response {
+				// New Relic API expects an array of events
+				var events []map[string]interface{}
+				json.NewDecoder(r.Body).Decode(&events)
+				if len(events) != 1 {
+					t.Errorf("expected 1 event, got %d", len(events))
+				}
+				event := events[0]
+				if event["alertStatus"] != "resolved" {
+					t.Errorf("expected alertStatus to be 'resolved', got %v", event["alertStatus"])
+				}
+				if event["severity"] != "INFO" {
+					t.Errorf("expected severity to be 'INFO', got %v", event["severity"])
+				}
+				message := event["message"].(string)
+				if !strings.Contains(message, "resolved") {
+					t.Errorf("expected message to contain 'resolved', got %s", message)
+				}
+				return &http.Response{StatusCode: http.StatusOK, Body: http.NoBody}
+			}),
+			expectedError: false,
+		},
+		{
+			name:     "error-response",
+			provider: AlertProvider{DefaultConfig: Config{InsertKey: "nr-insert-key-123", AccountID: "123456"}},
+			alert:    alert.Alert{Description: &firstDescription, SuccessThreshold: 5, FailureThreshold: 3},
+			resolved: false,
+			mockRoundTripper: test.MockRoundTripper(func(r *http.Request) *http.Response {
+				return &http.Response{StatusCode: http.StatusUnauthorized, Body: http.NoBody}
+			}),
+			expectedError: true,
+		},
+	}
+	for _, scenario := range scenarios {
+		t.Run(scenario.name, func(t *testing.T) {
+			client.InjectHTTPClient(&http.Client{Transport: scenario.mockRoundTripper})
+			err := scenario.provider.Send(
+				&endpoint.Endpoint{Name: "endpoint-name"},
+				&scenario.alert,
+				&endpoint.Result{
+					ConditionResults: []*endpoint.ConditionResult{
+						{Condition: "[CONNECTED] == true", Success: scenario.resolved},
+						{Condition: "[STATUS] == 200", Success: scenario.resolved},
+					},
+				},
+				scenario.resolved,
+			)
+			if scenario.expectedError && err == nil {
+				t.Error("expected error, got none")
+			}
+			if !scenario.expectedError && err != nil {
+				t.Error("expected no error, got", err.Error())
+			}
+		})
+	}
+}
+
+func TestAlertProvider_GetDefaultAlert(t *testing.T) {
+	if (&AlertProvider{DefaultAlert: &alert.Alert{}}).GetDefaultAlert() == nil {
+		t.Error("expected default alert to be not nil")
+	}
+	if (&AlertProvider{DefaultAlert: nil}).GetDefaultAlert() != nil {
+		t.Error("expected default alert to be nil")
+	}
+}

alerting/provider/ntfy/ntfy.go

@@ -3,6 +3,7 @@ package ntfy
 import (
 	"bytes"
 	"encoding/json"
+	"errors"
 	"fmt"
 	"io"
 	"net/http"
@@ -12,49 +13,141 @@ import (
 	"github.com/TwiN/gatus/v5/alerting/alert"
 	"github.com/TwiN/gatus/v5/client"
 	"github.com/TwiN/gatus/v5/config/endpoint"
+	"gopkg.in/yaml.v3"
 )
 
 const (
 	DefaultURL      = "https://ntfy.sh"
 	DefaultPriority = 3
+	TokenPrefix     = "tk_"
 )
 
+var (
+	ErrInvalidToken           = errors.New("invalid token")
+	ErrTopicNotSet            = errors.New("topic not set")
+	ErrInvalidPriority        = errors.New("priority must between 1 and 5 inclusively")
+	ErrDuplicateGroupOverride = errors.New("duplicate group override")
+)
+
+type Config struct {
+	Topic           string `yaml:"topic"`
+	URL             string `yaml:"url,omitempty"`              // Defaults to DefaultURL
+	Priority        int    `yaml:"priority,omitempty"`         // Defaults to DefaultPriority
+	Token           string `yaml:"token,omitempty"`            // Defaults to ""
+	Email           string `yaml:"email,omitempty"`            // Defaults to ""
+	Click           string `yaml:"click,omitempty"`            // Defaults to ""
+	DisableFirebase bool   `yaml:"disable-firebase,omitempty"` // Defaults to false
+	DisableCache    bool   `yaml:"disable-cache,omitempty"`    // Defaults to false
+}
+
+func (cfg *Config) Validate() error {
+	if len(cfg.URL) == 0 {
+		cfg.URL = DefaultURL
+	}
+	if cfg.Priority == 0 {
+		cfg.Priority = DefaultPriority
+	}
+	if len(cfg.Token) > 0 && !strings.HasPrefix(cfg.Token, TokenPrefix) {
+		return ErrInvalidToken
+	}
+	if len(cfg.Topic) == 0 {
+		return ErrTopicNotSet
+	}
+	if cfg.Priority < 1 || cfg.Priority > 5 {
+		return ErrInvalidPriority
+	}
+	return nil
+}
+
+func (cfg *Config) Merge(override *Config) {
+	if len(override.Topic) > 0 {
+		cfg.Topic = override.Topic
+	}
+	if len(override.URL) > 0 {
+		cfg.URL = override.URL
+	}
+	if override.Priority > 0 {
+		cfg.Priority = override.Priority
+	}
+	if len(override.Token) > 0 {
+		cfg.Token = override.Token
+	}
+	if len(override.Email) > 0 {
+		cfg.Email = override.Email
+	}
+	if len(override.Click) > 0 {
+		cfg.Click = override.Click
+	}
+	if override.DisableFirebase {
+		cfg.DisableFirebase = true
+	}
+	if override.DisableCache {
+		cfg.DisableCache = true
+	}
+}
+
 // AlertProvider is the configuration necessary for sending an alert using Slack
 type AlertProvider struct {
-	Topic    string `yaml:"topic"`
-	URL      string `yaml:"url,omitempty"`      // Defaults to DefaultURL
-	Priority int    `yaml:"priority,omitempty"` // Defaults to DefaultPriority
-	Token    string `yaml:"token,omitempty"`    // Defaults to ""
+	DefaultConfig Config `yaml:",inline"`
 
 	// DefaultAlert is the default alert configuration to use for endpoints with an alert of the appropriate type
 	DefaultAlert *alert.Alert `yaml:"default-alert,omitempty"`
+
+	// Overrides is a list of Override that may be prioritized over the default configuration
+	Overrides []Override `yaml:"overrides,omitempty"`
 }
 
-// IsValid returns whether the provider's configuration is valid
-func (provider *AlertProvider) IsValid() bool {
-	if len(provider.URL) == 0 {
-		provider.URL = DefaultURL
+// Override is a case under which the default integration is overridden
+type Override struct {
+	Group  string `yaml:"group"`
+	Config `yaml:",inline"`
+}
+
+// Validate the provider's configuration
+func (provider *AlertProvider) Validate() error {
+	registeredGroups := make(map[string]bool)
+	if provider.Overrides != nil {
+		for _, override := range provider.Overrides {
+			if len(override.Group) == 0 {
+				return ErrDuplicateGroupOverride
+			}
+			if _, ok := registeredGroups[override.Group]; ok {
+				return ErrDuplicateGroupOverride
+			}
+			if len(override.Token) > 0 && !strings.HasPrefix(override.Token, TokenPrefix) {
+				return ErrDuplicateGroupOverride
+			}
+			if override.Priority < 0 || override.Priority >= 6 {
+				return ErrDuplicateGroupOverride
+			}
+			registeredGroups[override.Group] = true
+		}
 	}
-	if provider.Priority == 0 {
-		provider.Priority = DefaultPriority
-	}
-	isTokenValid := true
-	if len(provider.Token) > 0 {
-		isTokenValid = strings.HasPrefix(provider.Token, "tk_")
-	}
-	return len(provider.URL) > 0 && len(provider.Topic) > 0 && provider.Priority > 0 && provider.Priority < 6 && isTokenValid
+
+	return provider.DefaultConfig.Validate()
 }
 
 // Send an alert using the provider
 func (provider *AlertProvider) Send(ep *endpoint.Endpoint, alert *alert.Alert, result *endpoint.Result, resolved bool) error {
-	buffer := bytes.NewBuffer(provider.buildRequestBody(ep, alert, result, resolved))
-	request, err := http.NewRequest(http.MethodPost, provider.URL, buffer)
+	cfg, err := provider.GetConfig(ep.Group, alert)
+	if err != nil {
+		return err
+	}
+	buffer := bytes.NewBuffer(provider.buildRequestBody(cfg, ep, alert, result, resolved))
+	url := cfg.URL
+	request, err := http.NewRequest(http.MethodPost, url, buffer)
 	if err != nil {
 		return err
 	}
 	request.Header.Set("Content-Type", "application/json")
-	if len(provider.Token) > 0 {
-		request.Header.Set("Authorization", "Bearer "+provider.Token)
+	if token := cfg.Token; len(token) > 0 {
+		request.Header.Set("Authorization", "Bearer "+token)
+	}
+	if cfg.DisableFirebase {
+		request.Header.Set("Firebase", "no")
+	}
+	if cfg.DisableCache {
+		request.Header.Set("Cache", "no")
 	}
 	response, err := client.GetHTTPClient(nil).Do(request)
 	if err != nil {
@@ -74,10 +167,12 @@ type Body struct {
 	Message  string   `json:"message"`
 	Tags     []string `json:"tags"`
 	Priority int      `json:"priority"`
+	Email    string   `json:"email,omitempty"`
+	Click    string   `json:"click,omitempty"`
 }
 
 // buildRequestBody builds the request body for the provider
-func (provider *AlertProvider) buildRequestBody(ep *endpoint.Endpoint, alert *alert.Alert, result *endpoint.Result, resolved bool) []byte {
+func (provider *AlertProvider) buildRequestBody(cfg *Config, ep *endpoint.Endpoint, alert *alert.Alert, result *endpoint.Result, resolved bool) []byte {
 	var message, formattedConditionResults, tag string
 	if resolved {
 		tag = "white_check_mark"
@@ -100,11 +195,13 @@ func (provider *AlertProvider) buildRequestBody(ep *endpoint.Endpoint, alert *al
 	}
 	message += formattedConditionResults
 	body, _ := json.Marshal(Body{
-		Topic:    provider.Topic,
+		Topic:    cfg.Topic,
 		Title:    "Gatus: " + ep.DisplayName(),
 		Message:  message,
 		Tags:     []string{tag},
-		Priority: provider.Priority,
+		Priority: cfg.Priority,
+		Email:    cfg.Email,
+		Click:    cfg.Click,
 	})
 	return body
 }
@@ -113,3 +210,34 @@ func (provider *AlertProvider) buildRequestBody(ep *endpoint.Endpoint, alert *al
 func (provider *AlertProvider) GetDefaultAlert() *alert.Alert {
 	return provider.DefaultAlert
 }
+
+// GetConfig returns the configuration for the provider with the overrides applied
+func (provider *AlertProvider) GetConfig(group string, alert *alert.Alert) (*Config, error) {
+	cfg := provider.DefaultConfig
+	// Handle group overrides
+	if provider.Overrides != nil {
+		for _, override := range provider.Overrides {
+			if group == override.Group {
+				cfg.Merge(&override.Config)
+				break
+			}
+		}
+	}
+	// Handle alert overrides
+	if len(alert.ProviderOverride) != 0 {
+		overrideConfig := Config{}
+		if err := yaml.Unmarshal(alert.ProviderOverrideAsBytes(), &overrideConfig); err != nil {
+			return nil, err
+		}
+		cfg.Merge(&overrideConfig)
+	}
+	// Validate the configuration
+	err := cfg.Validate()
+	return &cfg, err
+}
+
+// ValidateOverrides validates the alert's provider override and, if present, the group override
+func (provider *AlertProvider) ValidateOverrides(group string, alert *alert.Alert) error {
+	_, err := provider.GetConfig(group, alert)
+	return err
+}

alerting/provider/ntfy/ntfy_test.go

@@ -2,13 +2,16 @@ package ntfy
 
 import (
 	"encoding/json"
+	"io"
+	"net/http"
+	"net/http/httptest"
 	"testing"
 
 	"github.com/TwiN/gatus/v5/alerting/alert"
 	"github.com/TwiN/gatus/v5/config/endpoint"
 )
 
-func TestAlertDefaultProvider_IsValid(t *testing.T) {
+func TestAlertProvider_Validate(t *testing.T) {
 	scenarios := []struct {
 		name     string
 		provider AlertProvider
@@ -16,49 +19,78 @@ func TestAlertDefaultProvider_IsValid(t *testing.T) {
 	}{
 		{
 			name:     "valid",
-			provider: AlertProvider{URL: "https://ntfy.sh", Topic: "example", Priority: 1},
+			provider: AlertProvider{DefaultConfig: Config{URL: "https://ntfy.sh", Topic: "example", Priority: 1}},
 			expected: true,
 		},
 		{
 			name:     "no-url-should-use-default-value",
-			provider: AlertProvider{Topic: "example", Priority: 1},
+			provider: AlertProvider{DefaultConfig: Config{Topic: "example", Priority: 1}},
 			expected: true,
 		},
 		{
 			name:     "valid-with-token",
-			provider: AlertProvider{Topic: "example", Priority: 1, Token: "tk_faketoken"},
+			provider: AlertProvider{DefaultConfig: Config{Topic: "example", Priority: 1, Token: "tk_faketoken"}},
 			expected: true,
 		},
 		{
 			name:     "invalid-token",
-			provider: AlertProvider{Topic: "example", Priority: 1, Token: "xx_faketoken"},
+			provider: AlertProvider{DefaultConfig: Config{Topic: "example", Priority: 1, Token: "xx_faketoken"}},
 			expected: false,
 		},
 		{
 			name:     "invalid-topic",
-			provider: AlertProvider{URL: "https://ntfy.sh", Topic: "", Priority: 1},
+			provider: AlertProvider{DefaultConfig: Config{URL: "https://ntfy.sh", Topic: "", Priority: 1}},
 			expected: false,
 		},
 		{
 			name:     "invalid-priority-too-high",
-			provider: AlertProvider{URL: "https://ntfy.sh", Topic: "example", Priority: 6},
+			provider: AlertProvider{DefaultConfig: Config{URL: "https://ntfy.sh", Topic: "example", Priority: 6}},
 			expected: false,
 		},
 		{
 			name:     "invalid-priority-too-low",
-			provider: AlertProvider{URL: "https://ntfy.sh", Topic: "example", Priority: -1},
+			provider: AlertProvider{DefaultConfig: Config{URL: "https://ntfy.sh", Topic: "example", Priority: -1}},
 			expected: false,
 		},
 		{
 			name:     "no-priority-should-use-default-value",
-			provider: AlertProvider{URL: "https://ntfy.sh", Topic: "example"},
+			provider: AlertProvider{DefaultConfig: Config{URL: "https://ntfy.sh", Topic: "example"}},
+			expected: true,
+		},
+		{
+			name:     "invalid-override-token",
+			provider: AlertProvider{DefaultConfig: Config{Topic: "example"}, Overrides: []Override{{Group: "g", Config: Config{Token: "xx_faketoken"}}}},
+			expected: false,
+		},
+		{
+			name:     "invalid-override-priority",
+			provider: AlertProvider{DefaultConfig: Config{Topic: "example"}, Overrides: []Override{{Group: "g", Config: Config{Priority: 8}}}},
+			expected: false,
+		},
+		{
+			name:     "no-override-group-name",
+			provider: AlertProvider{DefaultConfig: Config{Topic: "example"}, Overrides: []Override{{}}},
+			expected: false,
+		},
+		{
+			name:     "duplicate-override-group-names",
+			provider: AlertProvider{DefaultConfig: Config{Topic: "example"}, Overrides: []Override{{Group: "g"}, {Group: "g"}}},
+			expected: false,
+		},
+		{
+			name:     "valid-override",
+			provider: AlertProvider{DefaultConfig: Config{Topic: "example"}, Overrides: []Override{{Group: "g1", Config: Config{Priority: 4, Click: "https://example.com"}}, {Group: "g2", Config: Config{Topic: "Example", Token: "tk_faketoken"}}}},
 			expected: true,
 		},
 	}
 	for _, scenario := range scenarios {
 		t.Run(scenario.name, func(t *testing.T) {
-			if scenario.provider.IsValid() != scenario.expected {
-				t.Errorf("expected %t, got %t", scenario.expected, scenario.provider.IsValid())
+			err := scenario.provider.Validate()
+			if scenario.expected && err != nil {
+				t.Error("expected no error, got", err.Error())
+			}
+			if !scenario.expected && err == nil {
+				t.Error("expected error, got none")
 			}
 		})
 	}
@@ -76,22 +108,55 @@ func TestAlertProvider_buildRequestBody(t *testing.T) {
 	}{
 		{
 			Name:         "triggered",
-			Provider:     AlertProvider{URL: "https://ntfy.sh", Topic: "example", Priority: 1},
+			Provider:     AlertProvider{DefaultConfig: Config{URL: "https://ntfy.sh", Topic: "example", Priority: 1}},
 			Alert:        alert.Alert{Description: &firstDescription, SuccessThreshold: 5, FailureThreshold: 3},
 			Resolved:     false,
 			ExpectedBody: `{"topic":"example","title":"Gatus: endpoint-name","message":"An alert has been triggered due to having failed 3 time(s) in a row with the following description: description-1\n🔴 [CONNECTED] == true\n🔴 [STATUS] == 200","tags":["rotating_light"],"priority":1}`,
 		},
 		{
 			Name:         "resolved",
-			Provider:     AlertProvider{URL: "https://ntfy.sh", Topic: "example", Priority: 2},
+			Provider:     AlertProvider{DefaultConfig: Config{URL: "https://ntfy.sh", Topic: "example", Priority: 2}},
 			Alert:        alert.Alert{Description: &secondDescription, SuccessThreshold: 5, FailureThreshold: 3},
 			Resolved:     true,
 			ExpectedBody: `{"topic":"example","title":"Gatus: endpoint-name","message":"An alert has been resolved after passing successfully 5 time(s) in a row with the following description: description-2\n🟢 [CONNECTED] == true\n🟢 [STATUS] == 200","tags":["white_check_mark"],"priority":2}`,
 		},
+		{
+			Name:         "triggered-email",
+			Provider:     AlertProvider{DefaultConfig: Config{URL: "https://ntfy.sh", Topic: "example", Priority: 1, Email: "test@example.com", Click: "example.com"}},
+			Alert:        alert.Alert{Description: &firstDescription, SuccessThreshold: 5, FailureThreshold: 3},
+			Resolved:     false,
+			ExpectedBody: `{"topic":"example","title":"Gatus: endpoint-name","message":"An alert has been triggered due to having failed 3 time(s) in a row with the following description: description-1\n🔴 [CONNECTED] == true\n🔴 [STATUS] == 200","tags":["rotating_light"],"priority":1,"email":"test@example.com","click":"example.com"}`,
+		},
+		{
+			Name:         "resolved-email",
+			Provider:     AlertProvider{DefaultConfig: Config{URL: "https://ntfy.sh", Topic: "example", Priority: 2, Email: "test@example.com", Click: "example.com"}},
+			Alert:        alert.Alert{Description: &secondDescription, SuccessThreshold: 5, FailureThreshold: 3},
+			Resolved:     true,
+			ExpectedBody: `{"topic":"example","title":"Gatus: endpoint-name","message":"An alert has been resolved after passing successfully 5 time(s) in a row with the following description: description-2\n🟢 [CONNECTED] == true\n🟢 [STATUS] == 200","tags":["white_check_mark"],"priority":2,"email":"test@example.com","click":"example.com"}`,
+		},
+		{
+			Name:         "group-override",
+			Provider:     AlertProvider{DefaultConfig: Config{URL: "https://ntfy.sh", Topic: "example", Priority: 5, Email: "test@example.com", Click: "example.com"}, Overrides: []Override{{Group: "g", Config: Config{Topic: "group-topic", Priority: 4, Email: "override@test.com", Click: "test.com"}}}},
+			Alert:        alert.Alert{Description: &firstDescription, SuccessThreshold: 5, FailureThreshold: 3},
+			Resolved:     false,
+			ExpectedBody: `{"topic":"group-topic","title":"Gatus: endpoint-name","message":"An alert has been triggered due to having failed 3 time(s) in a row with the following description: description-1\n🔴 [CONNECTED] == true\n🔴 [STATUS] == 200","tags":["rotating_light"],"priority":4,"email":"override@test.com","click":"test.com"}`,
+		},
+		{
+			Name:         "alert-override",
+			Provider:     AlertProvider{DefaultConfig: Config{URL: "https://ntfy.sh", Topic: "example", Priority: 5, Email: "test@example.com", Click: "example.com"}, Overrides: []Override{{Group: "g", Config: Config{Topic: "group-topic", Priority: 4, Email: "override@test.com", Click: "test.com"}}}},
+			Alert:        alert.Alert{Description: &firstDescription, SuccessThreshold: 5, FailureThreshold: 3, ProviderOverride: map[string]any{"topic": "alert-topic"}},
+			Resolved:     false,
+			ExpectedBody: `{"topic":"alert-topic","title":"Gatus: endpoint-name","message":"An alert has been triggered due to having failed 3 time(s) in a row with the following description: description-1\n🔴 [CONNECTED] == true\n🔴 [STATUS] == 200","tags":["rotating_light"],"priority":4,"email":"override@test.com","click":"test.com"}`,
+		},
 	}
 	for _, scenario := range scenarios {
 		t.Run(scenario.Name, func(t *testing.T) {
+			cfg, err := scenario.Provider.GetConfig("g", &scenario.Alert)
+			if err != nil {
+				t.Error("expected no error, got", err.Error())
+			}
 			body := scenario.Provider.buildRequestBody(
+				cfg,
 				&endpoint.Endpoint{Name: "endpoint-name"},
 				&scenario.Alert,
 				&endpoint.Result{
@@ -112,3 +177,238 @@ func TestAlertProvider_buildRequestBody(t *testing.T) {
 		})
 	}
 }
+
+func TestAlertProvider_Send(t *testing.T) {
+	description := "description-1"
+	scenarios := []struct {
+		Name            string
+		Provider        AlertProvider
+		Alert           alert.Alert
+		Resolved        bool
+		Group           string
+		ExpectedBody    string
+		ExpectedHeaders map[string]string
+	}{
+		{
+			Name:         "triggered",
+			Provider:     AlertProvider{DefaultConfig: Config{URL: "https://ntfy.sh", Topic: "example", Priority: 1, Email: "test@example.com", Click: "example.com"}},
+			Alert:        alert.Alert{Description: &description, SuccessThreshold: 5, FailureThreshold: 3},
+			Resolved:     false,
+			Group:        "",
+			ExpectedBody: `{"topic":"example","title":"Gatus: endpoint-name","message":"An alert has been triggered due to having failed 3 time(s) in a row with the following description: description-1\n🔴 [CONNECTED] == true\n🔴 [STATUS] == 200","tags":["rotating_light"],"priority":1,"email":"test@example.com","click":"example.com"}`,
+			ExpectedHeaders: map[string]string{
+				"Content-Type": "application/json",
+			},
+		},
+		{
+			Name:         "token",
+			Provider:     AlertProvider{DefaultConfig: Config{URL: "https://ntfy.sh", Topic: "example", Priority: 1, Email: "test@example.com", Click: "example.com", Token: "tk_mytoken"}},
+			Alert:        alert.Alert{Description: &description, SuccessThreshold: 5, FailureThreshold: 3},
+			Resolved:     false,
+			Group:        "",
+			ExpectedBody: `{"topic":"example","title":"Gatus: endpoint-name","message":"An alert has been triggered due to having failed 3 time(s) in a row with the following description: description-1\n🔴 [CONNECTED] == true\n🔴 [STATUS] == 200","tags":["rotating_light"],"priority":1,"email":"test@example.com","click":"example.com"}`,
+			ExpectedHeaders: map[string]string{
+				"Content-Type":  "application/json",
+				"Authorization": "Bearer tk_mytoken",
+			},
+		},
+		{
+			Name:         "no firebase",
+			Provider:     AlertProvider{DefaultConfig: Config{URL: "https://ntfy.sh", Topic: "example", Priority: 1, Email: "test@example.com", Click: "example.com", DisableFirebase: true}},
+			Alert:        alert.Alert{Description: &description, SuccessThreshold: 5, FailureThreshold: 3},
+			Resolved:     false,
+			Group:        "",
+			ExpectedBody: `{"topic":"example","title":"Gatus: endpoint-name","message":"An alert has been triggered due to having failed 3 time(s) in a row with the following description: description-1\n🔴 [CONNECTED] == true\n🔴 [STATUS] == 200","tags":["rotating_light"],"priority":1,"email":"test@example.com","click":"example.com"}`,
+			ExpectedHeaders: map[string]string{
+				"Content-Type": "application/json",
+				"Firebase":     "no",
+			},
+		},
+		{
+			Name:         "no cache",
+			Provider:     AlertProvider{DefaultConfig: Config{URL: "https://ntfy.sh", Topic: "example", Priority: 1, Email: "test@example.com", Click: "example.com", DisableCache: true}},
+			Alert:        alert.Alert{Description: &description, SuccessThreshold: 5, FailureThreshold: 3},
+			Resolved:     false,
+			Group:        "",
+			ExpectedBody: `{"topic":"example","title":"Gatus: endpoint-name","message":"An alert has been triggered due to having failed 3 time(s) in a row with the following description: description-1\n🔴 [CONNECTED] == true\n🔴 [STATUS] == 200","tags":["rotating_light"],"priority":1,"email":"test@example.com","click":"example.com"}`,
+			ExpectedHeaders: map[string]string{
+				"Content-Type": "application/json",
+				"Cache":        "no",
+			},
+		},
+		{
+			Name:         "neither firebase & cache",
+			Provider:     AlertProvider{DefaultConfig: Config{URL: "https://ntfy.sh", Topic: "example", Priority: 1, Email: "test@example.com", Click: "example.com", DisableFirebase: true, DisableCache: true}},
+			Alert:        alert.Alert{Description: &description, SuccessThreshold: 5, FailureThreshold: 3},
+			Resolved:     false,
+			Group:        "",
+			ExpectedBody: `{"topic":"example","title":"Gatus: endpoint-name","message":"An alert has been triggered due to having failed 3 time(s) in a row with the following description: description-1\n🔴 [CONNECTED] == true\n🔴 [STATUS] == 200","tags":["rotating_light"],"priority":1,"email":"test@example.com","click":"example.com"}`,
+			ExpectedHeaders: map[string]string{
+				"Content-Type": "application/json",
+				"Firebase":     "no",
+				"Cache":        "no",
+			},
+		},
+		{
+			Name:         "overrides",
+			Provider:     AlertProvider{DefaultConfig: Config{URL: "https://ntfy.sh", Topic: "example", Priority: 1, Email: "test@example.com", Click: "example.com", Token: "tk_mytoken"}, Overrides: []Override{Override{Group: "other-group", Config: Config{URL: "https://example.com", Token: "tk_othertoken"}}, Override{Group: "test-group", Config: Config{Token: "tk_test_token"}}}},
+			Alert:        alert.Alert{Description: &description, SuccessThreshold: 5, FailureThreshold: 3},
+			Resolved:     false,
+			Group:        "test-group",
+			ExpectedBody: `{"topic":"example","title":"Gatus: test-group/endpoint-name","message":"An alert has been triggered due to having failed 3 time(s) in a row with the following description: description-1\n🔴 [CONNECTED] == true\n🔴 [STATUS] == 200","tags":["rotating_light"],"priority":1,"email":"test@example.com","click":"example.com"}`,
+			ExpectedHeaders: map[string]string{
+				"Content-Type":  "application/json",
+				"Authorization": "Bearer tk_test_token",
+			},
+		},
+	}
+	for _, scenario := range scenarios {
+		t.Run(scenario.Name, func(t *testing.T) {
+			// Start a local HTTP server
+			server := httptest.NewServer(http.HandlerFunc(func(rw http.ResponseWriter, req *http.Request) {
+				// Test request parameters
+				for header, value := range scenario.ExpectedHeaders {
+					if value != req.Header.Get(header) {
+						t.Errorf("expected: %s, got: %s", value, req.Header.Get(header))
+					}
+				}
+				body, _ := io.ReadAll(req.Body)
+				if string(body) != scenario.ExpectedBody {
+					t.Errorf("expected:\n%s\ngot:\n%s", scenario.ExpectedBody, body)
+				}
+				// Send response to be tested
+				rw.Write([]byte(`OK`))
+			}))
+			// Close the server when test finishes
+			defer server.Close()
+
+			scenario.Provider.DefaultConfig.URL = server.URL
+			err := scenario.Provider.Send(
+				&endpoint.Endpoint{Name: "endpoint-name", Group: scenario.Group},
+				&scenario.Alert,
+				&endpoint.Result{
+					ConditionResults: []*endpoint.ConditionResult{
+						{Condition: "[CONNECTED] == true", Success: scenario.Resolved},
+						{Condition: "[STATUS] == 200", Success: scenario.Resolved},
+					},
+				},
+				scenario.Resolved,
+			)
+			if err != nil {
+				t.Error("Encountered an error on Send: ", err)
+			}
+		})
+	}
+}
+
+func TestAlertProvider_GetConfig(t *testing.T) {
+	scenarios := []struct {
+		Name           string
+		Provider       AlertProvider
+		InputGroup     string
+		InputAlert     alert.Alert
+		ExpectedOutput Config
+	}{
+		{
+			Name: "provider-no-override-specify-no-group-should-default",
+			Provider: AlertProvider{
+				DefaultConfig: Config{URL: "https://ntfy.sh", Topic: "example", Priority: 1},
+				Overrides:     nil,
+			},
+			InputGroup:     "",
+			InputAlert:     alert.Alert{},
+			ExpectedOutput: Config{URL: "https://ntfy.sh", Topic: "example", Priority: 1},
+		},
+		{
+			Name: "provider-no-override-specify-group-should-default",
+			Provider: AlertProvider{
+				DefaultConfig: Config{URL: "https://ntfy.sh", Topic: "example", Priority: 1},
+				Overrides:     nil,
+			},
+			InputGroup:     "group",
+			InputAlert:     alert.Alert{},
+			ExpectedOutput: Config{URL: "https://ntfy.sh", Topic: "example", Priority: 1},
+		},
+		{
+			Name: "provider-with-override-specify-no-group-should-default",
+			Provider: AlertProvider{
+				DefaultConfig: Config{URL: "https://ntfy.sh", Topic: "example", Priority: 1},
+				Overrides: []Override{
+					{
+						Group:  "group",
+						Config: Config{URL: "https://group-example.com", Topic: "group-topic", Priority: 2},
+					},
+				},
+			},
+			InputGroup:     "",
+			InputAlert:     alert.Alert{},
+			ExpectedOutput: Config{URL: "https://ntfy.sh", Topic: "example", Priority: 1},
+		},
+		{
+			Name: "provider-with-override-specify-group-should-override",
+			Provider: AlertProvider{
+				DefaultConfig: Config{URL: "https://ntfy.sh", Topic: "example", Priority: 1},
+				Overrides: []Override{
+					{
+						Group:  "group",
+						Config: Config{URL: "https://group-example.com", Topic: "group-topic", Priority: 2},
+					},
+				},
+			},
+			InputGroup:     "group",
+			InputAlert:     alert.Alert{},
+			ExpectedOutput: Config{URL: "https://group-example.com", Topic: "group-topic", Priority: 2},
+		},
+		{
+			Name: "provider-with-group-override-and-alert-override--alert-override-should-take-precedence",
+			Provider: AlertProvider{
+				DefaultConfig: Config{URL: "https://ntfy.sh", Topic: "example", Priority: 1},
+				Overrides: []Override{
+					{
+						Group:  "group",
+						Config: Config{URL: "https://group-example.com", Topic: "group-topic", Priority: 2},
+					},
+				},
+			},
+			InputGroup:     "group",
+			InputAlert:     alert.Alert{ProviderOverride: map[string]any{"url": "http://alert-example.com", "topic": "alert-topic", "priority": 3}},
+			ExpectedOutput: Config{URL: "http://alert-example.com", Topic: "alert-topic", Priority: 3},
+		},
+		{
+			Name: "provider-with-partial-overrides",
+			Provider: AlertProvider{
+				DefaultConfig: Config{URL: "https://ntfy.sh", Topic: "example", Priority: 1},
+				Overrides: []Override{
+					{
+						Group:  "group",
+						Config: Config{Topic: "group-topic"},
+					},
+				},
+			},
+			InputGroup:     "group",
+			InputAlert:     alert.Alert{ProviderOverride: map[string]any{"priority": 3}},
+			ExpectedOutput: Config{URL: "https://ntfy.sh", Topic: "group-topic", Priority: 3},
+		},
+	}
+	for _, scenario := range scenarios {
+		t.Run(scenario.Name, func(t *testing.T) {
+			got, err := scenario.Provider.GetConfig(scenario.InputGroup, &scenario.InputAlert)
+			if err != nil {
+				t.Fatalf("unexpected error: %s", err)
+			}
+			if got.URL != scenario.ExpectedOutput.URL {
+				t.Errorf("expected url %s, got %s", scenario.ExpectedOutput.URL, got.URL)
+			}
+			if got.Topic != scenario.ExpectedOutput.Topic {
+				t.Errorf("expected topic %s, got %s", scenario.ExpectedOutput.Topic, got.Topic)
+			}
+			if got.Priority != scenario.ExpectedOutput.Priority {
+				t.Errorf("expected priority %d, got %d", scenario.ExpectedOutput.Priority, got.Priority)
+			}
+			// Test ValidateOverrides as well, since it really just calls GetConfig
+			if err = scenario.Provider.ValidateOverrides(scenario.InputGroup, &scenario.InputAlert); err != nil {
+				t.Errorf("unexpected error: %s", err)
+			}
+		})
+	}
+}

alerting/provider/opsgenie/opsgenie.go

@@ -3,6 +3,7 @@ package opsgenie
 import (
 	"bytes"
 	"encoding/json"
+	"errors"
 	"fmt"
 	"io"
 	"net/http"
@@ -12,13 +13,18 @@ import (
 	"github.com/TwiN/gatus/v5/alerting/alert"
 	"github.com/TwiN/gatus/v5/client"
 	"github.com/TwiN/gatus/v5/config/endpoint"
+	"gopkg.in/yaml.v3"
 )
 
 const (
 	restAPI = "https://api.opsgenie.com/v2/alerts"
 )
 
-type AlertProvider struct {
+var (
+	ErrAPIKeyNotSet = errors.New("api-key not set")
+)
+
+type Config struct {
 	// APIKey to use for
 	APIKey string `yaml:"api-key"`
 
@@ -46,26 +52,74 @@ type AlertProvider struct {
 	//
 	// default: []
 	Tags []string `yaml:"tags"`
+}
+
+func (cfg *Config) Validate() error {
+	if len(cfg.APIKey) == 0 {
+		return ErrAPIKeyNotSet
+	}
+	if len(cfg.Source) == 0 {
+		cfg.Source = "gatus"
+	}
+	if len(cfg.EntityPrefix) == 0 {
+		cfg.EntityPrefix = "gatus-"
+	}
+	if len(cfg.AliasPrefix) == 0 {
+		cfg.AliasPrefix = "gatus-healthcheck-"
+	}
+	if len(cfg.Priority) == 0 {
+		cfg.Priority = "P1"
+	}
+	return nil
+}
+
+func (cfg *Config) Merge(override *Config) {
+	if len(override.APIKey) > 0 {
+		cfg.APIKey = override.APIKey
+	}
+	if len(override.Priority) > 0 {
+		cfg.Priority = override.Priority
+	}
+	if len(override.Source) > 0 {
+		cfg.Source = override.Source
+	}
+	if len(override.EntityPrefix) > 0 {
+		cfg.EntityPrefix = override.EntityPrefix
+	}
+	if len(override.AliasPrefix) > 0 {
+		cfg.AliasPrefix = override.AliasPrefix
+	}
+	if len(override.Tags) > 0 {
+		cfg.Tags = override.Tags
+	}
+}
+
+type AlertProvider struct {
+	DefaultConfig Config `yaml:",inline"`
 
 	// DefaultAlert is the default alert configuration to use for endpoints with an alert of the appropriate type
 	DefaultAlert *alert.Alert `yaml:"default-alert,omitempty"`
 }
 
-// IsValid returns whether the provider's configuration is valid
-func (provider *AlertProvider) IsValid() bool {
-	return len(provider.APIKey) > 0
+// Validate the provider's configuration
+func (provider *AlertProvider) Validate() error {
+	return provider.DefaultConfig.Validate()
 }
 
 // Send an alert using the provider
 //
 // Relevant: https://docs.opsgenie.com/docs/alert-api
 func (provider *AlertProvider) Send(ep *endpoint.Endpoint, alert *alert.Alert, result *endpoint.Result, resolved bool) error {
-	err := provider.createAlert(ep, alert, result, resolved)
+	cfg, err := provider.GetConfig(ep.Group, alert)
+	if err != nil {
+		return err
+	}
+	err = provider.sendAlertRequest(cfg, ep, alert, result, resolved)
 	if err != nil {
 		return err
 	}
 	if resolved {
-		err = provider.closeAlert(ep, alert)
+		err = provider.closeAlert(cfg, ep, alert)
 		if err != nil {
 			return err
 		}
@@ -75,24 +129,24 @@ func (provider *AlertProvider) Send(ep *endpoint.Endpoint, alert *alert.Alert, r
 			// The alert has been resolved and there's no error, so we can clear the alert's ResolveKey
 			alert.ResolveKey = ""
 		} else {
-			alert.ResolveKey = provider.alias(buildKey(ep))
+			alert.ResolveKey = cfg.AliasPrefix + buildKey(ep)
 		}
 	}
 	return nil
 }
 
-func (provider *AlertProvider) createAlert(ep *endpoint.Endpoint, alert *alert.Alert, result *endpoint.Result, resolved bool) error {
-	payload := provider.buildCreateRequestBody(ep, alert, result, resolved)
-	return provider.sendRequest(restAPI, http.MethodPost, payload)
+func (provider *AlertProvider) sendAlertRequest(cfg *Config, ep *endpoint.Endpoint, alert *alert.Alert, result *endpoint.Result, resolved bool) error {
+	payload := provider.buildCreateRequestBody(cfg, ep, alert, result, resolved)
+	return provider.sendRequest(cfg, restAPI, http.MethodPost, payload)
 }
 
-func (provider *AlertProvider) closeAlert(ep *endpoint.Endpoint, alert *alert.Alert) error {
+func (provider *AlertProvider) closeAlert(cfg *Config, ep *endpoint.Endpoint, alert *alert.Alert) error {
 	payload := provider.buildCloseRequestBody(ep, alert)
-	url := restAPI + "/" + provider.alias(buildKey(ep)) + "/close?identifierType=alias"
-	return provider.sendRequest(url, http.MethodPost, payload)
+	url := restAPI + "/" + cfg.AliasPrefix + buildKey(ep) + "/close?identifierType=alias"
+	return provider.sendRequest(cfg, url, http.MethodPost, payload)
 }
 
-func (provider *AlertProvider) sendRequest(url, method string, payload interface{}) error {
+func (provider *AlertProvider) sendRequest(cfg *Config, url, method string, payload interface{}) error {
 	body, err := json.Marshal(payload)
 	if err != nil {
 		return fmt.Errorf("error build alert with payload %v: %w", payload, err)
@@ -102,7 +156,7 @@ func (provider *AlertProvider) sendRequest(url, method string, payload interface
 		return err
 	}
 	request.Header.Set("Content-Type", "application/json")
-	request.Header.Set("Authorization", "GenieKey "+provider.APIKey)
+	request.Header.Set("Authorization", "GenieKey "+cfg.APIKey)
 	response, err := client.GetHTTPClient(nil).Do(request)
 	if err != nil {
 		return err
@@ -115,7 +169,7 @@ func (provider *AlertProvider) sendRequest(url, method string, payload interface
 	return nil
 }
 
-func (provider *AlertProvider) buildCreateRequestBody(ep *endpoint.Endpoint, alert *alert.Alert, result *endpoint.Result, resolved bool) alertCreateRequest {
+func (provider *AlertProvider) buildCreateRequestBody(cfg *Config, ep *endpoint.Endpoint, alert *alert.Alert, result *endpoint.Result, resolved bool) alertCreateRequest {
 	var message, description string
 	if resolved {
 		message = fmt.Sprintf("RESOLVED: %s - %s", ep.Name, alert.GetDescription())
@@ -158,11 +212,11 @@ func (provider *AlertProvider) buildCreateRequestBody(ep *endpoint.Endpoint, ale
 	return alertCreateRequest{
 		Message:     message,
 		Description: description,
-		Source:      provider.source(),
-		Priority:    provider.priority(),
-		Alias:       provider.alias(key),
-		Entity:      provider.entity(key),
-		Tags:        provider.Tags,
+		Source:      cfg.Source,
+		Priority:    cfg.Priority,
+		Alias:       cfg.AliasPrefix + key,
+		Entity:      cfg.EntityPrefix + key,
+		Tags:        cfg.Tags,
 		Details:     details,
 	}
 }
@@ -174,43 +228,33 @@ func (provider *AlertProvider) buildCloseRequestBody(ep *endpoint.Endpoint, aler
 	}
 }
 
-func (provider *AlertProvider) source() string {
-	source := provider.Source
-	if source == "" {
-		return "gatus"
-	}
-	return source
-}
-
-func (provider *AlertProvider) alias(key string) string {
-	alias := provider.AliasPrefix
-	if alias == "" {
-		alias = "gatus-healthcheck-"
-	}
-	return alias + key
-}
-
-func (provider *AlertProvider) entity(key string) string {
-	alias := provider.EntityPrefix
-	if alias == "" {
-		alias = "gatus-"
-	}
-	return alias + key
-}
-
-func (provider *AlertProvider) priority() string {
-	priority := provider.Priority
-	if priority == "" {
-		return "P1"
-	}
-	return priority
-}
-
 // GetDefaultAlert returns the provider's default alert configuration
 func (provider *AlertProvider) GetDefaultAlert() *alert.Alert {
 	return provider.DefaultAlert
 }
 
+// GetConfig returns the configuration for the provider with the overrides applied
+func (provider *AlertProvider) GetConfig(group string, alert *alert.Alert) (*Config, error) {
+	cfg := provider.DefaultConfig
+	// Handle alert overrides
+	if len(alert.ProviderOverride) != 0 {
+		overrideConfig := Config{}
+		if err := yaml.Unmarshal(alert.ProviderOverrideAsBytes(), &overrideConfig); err != nil {
+			return nil, err
+		}
+		cfg.Merge(&overrideConfig)
+	}
+	// Validate the configuration
+	err := cfg.Validate()
+	return &cfg, err
+}
+
+// ValidateOverrides validates the alert's provider override and, if present, the group override
+func (provider *AlertProvider) ValidateOverrides(group string, alert *alert.Alert) error {
+	_, err := provider.GetConfig(group, alert)
+	return err
+}
+
 func buildKey(ep *endpoint.Endpoint) string {
 	name := toKebabCase(ep.Name)
 	if ep.Group == "" {

alerting/provider/opsgenie/opsgenie_test.go

@@ -11,13 +11,13 @@ import (
 	"github.com/TwiN/gatus/v5/test"
 )
 
-func TestAlertProvider_IsValid(t *testing.T) {
-	invalidProvider := AlertProvider{APIKey: ""}
-	if invalidProvider.IsValid() {
+func TestAlertProvider_Validate(t *testing.T) {
+	invalidProvider := AlertProvider{DefaultConfig: Config{APIKey: ""}}
+	if err := invalidProvider.Validate(); err == nil {
 		t.Error("provider shouldn't have been valid")
 	}
-	validProvider := AlertProvider{APIKey: "00000000-0000-0000-0000-000000000000"}
-	if !validProvider.IsValid() {
+	validProvider := AlertProvider{DefaultConfig: Config{APIKey: "00000000-0000-0000-0000-000000000000"}}
+	if err := validProvider.Validate(); err != nil {
 		t.Error("provider should've been valid")
 	}
 }
@@ -35,7 +35,7 @@ func TestAlertProvider_Send(t *testing.T) {
 	}{
 		{
 			Name:          "triggered",
-			Provider:      AlertProvider{},
+			Provider:      AlertProvider{DefaultConfig: Config{APIKey: "00000000-0000-0000-0000-000000000000"}},
 			Alert:         alert.Alert{Description: &description, SuccessThreshold: 1, FailureThreshold: 1},
 			Resolved:      false,
 			ExpectedError: false,
@@ -45,7 +45,7 @@ func TestAlertProvider_Send(t *testing.T) {
 		},
 		{
 			Name:          "triggered-error",
-			Provider:      AlertProvider{},
+			Provider:      AlertProvider{DefaultConfig: Config{APIKey: "00000000-0000-0000-0000-000000000000"}},
 			Alert:         alert.Alert{Description: &description, SuccessThreshold: 5, FailureThreshold: 3},
 			Resolved:      false,
 			ExpectedError: true,
@@ -55,7 +55,7 @@ func TestAlertProvider_Send(t *testing.T) {
 		},
 		{
 			Name:          "resolved",
-			Provider:      AlertProvider{},
+			Provider:      AlertProvider{DefaultConfig: Config{APIKey: "00000000-0000-0000-0000-000000000000"}},
 			Alert:         alert.Alert{Description: &description, SuccessThreshold: 5, FailureThreshold: 3},
 			Resolved:      true,
 			ExpectedError: false,
@@ -65,7 +65,7 @@ func TestAlertProvider_Send(t *testing.T) {
 		},
 		{
 			Name:          "resolved-error",
-			Provider:      AlertProvider{},
+			Provider:      AlertProvider{DefaultConfig: Config{APIKey: "00000000-0000-0000-0000-000000000000"}},
 			Alert:         alert.Alert{Description: &description, SuccessThreshold: 5, FailureThreshold: 3},
 			Resolved:      true,
 			ExpectedError: true,
@@ -74,7 +74,6 @@ func TestAlertProvider_Send(t *testing.T) {
 			}),
 		},
 	}
-
 	for _, scenario := range scenarios {
 		t.Run(scenario.Name, func(t *testing.T) {
 			client.InjectHTTPClient(&http.Client{Transport: scenario.MockRoundTripper})
@@ -113,7 +112,7 @@ func TestAlertProvider_buildCreateRequestBody(t *testing.T) {
 	}{
 		{
 			Name:     "missing all params (unresolved)",
-			Provider: &AlertProvider{},
+			Provider: &AlertProvider{DefaultConfig: Config{APIKey: "00000000-0000-0000-0000-000000000000"}},
 			Alert:    &alert.Alert{},
 			Endpoint: &endpoint.Endpoint{},
 			Result:   &endpoint.Result{},
@@ -131,7 +130,7 @@ func TestAlertProvider_buildCreateRequestBody(t *testing.T) {
 		},
 		{
 			Name:     "missing all params (resolved)",
-			Provider: &AlertProvider{},
+			Provider: &AlertProvider{DefaultConfig: Config{APIKey: "00000000-0000-0000-0000-000000000000"}},
 			Alert:    &alert.Alert{},
 			Endpoint: &endpoint.Endpoint{},
 			Result:   &endpoint.Result{},
@@ -149,7 +148,7 @@ func TestAlertProvider_buildCreateRequestBody(t *testing.T) {
 		},
 		{
 			Name:     "with default options (unresolved)",
-			Provider: &AlertProvider{},
+			Provider: &AlertProvider{DefaultConfig: Config{APIKey: "00000000-0000-0000-0000-000000000000"}},
 			Alert: &alert.Alert{
 				Description:      &description,
 				FailureThreshold: 3,
@@ -184,11 +183,13 @@ func TestAlertProvider_buildCreateRequestBody(t *testing.T) {
 		{
 			Name: "with custom options (resolved)",
 			Provider: &AlertProvider{
-				Priority:     "P5",
-				EntityPrefix: "oompa-",
-				AliasPrefix:  "loompa-",
-				Source:       "gatus-hc",
-				Tags:         []string{"do-ba-dee-doo"},
+				DefaultConfig: Config{
+					Priority:     "P5",
+					EntityPrefix: "oompa-",
+					AliasPrefix:  "loompa-",
+					Source:       "gatus-hc",
+					Tags:         []string{"do-ba-dee-doo"},
+				},
 			},
 			Alert: &alert.Alert{
 				Description:      &description,
@@ -220,7 +221,7 @@ func TestAlertProvider_buildCreateRequestBody(t *testing.T) {
 		{
 			Name: "with default options and details (unresolved)",
 			Provider: &AlertProvider{
-				Tags: []string{"foo"},
+				DefaultConfig: Config{Tags: []string{"foo"}, APIKey: "00000000-0000-0000-0000-000000000000"},
 			},
 			Alert: &alert.Alert{
 				Description:      &description,
@@ -265,8 +266,9 @@ func TestAlertProvider_buildCreateRequestBody(t *testing.T) {
 	for _, scenario := range scenarios {
 		actual := scenario
 		t.Run(actual.Name, func(t *testing.T) {
-			if got := actual.Provider.buildCreateRequestBody(actual.Endpoint, actual.Alert, actual.Result, actual.Resolved); !reflect.DeepEqual(got, actual.want) {
-				t.Errorf("buildCreateRequestBody() = %v, want %v", got, actual.want)
+			_ = scenario.Provider.Validate()
+			if got := actual.Provider.buildCreateRequestBody(&scenario.Provider.DefaultConfig, actual.Endpoint, actual.Alert, actual.Result, actual.Resolved); !reflect.DeepEqual(got, actual.want) {
+				t.Errorf("got:\n%v\nwant:\n%v", got, actual.want)
 			}
 		})
 	}
@@ -307,7 +309,6 @@ func TestAlertProvider_buildCloseRequestBody(t *testing.T) {
 			},
 		},
 	}
-
 	for _, scenario := range scenarios {
 		actual := scenario
 		t.Run(actual.Name, func(t *testing.T) {
@@ -317,3 +318,44 @@ func TestAlertProvider_buildCloseRequestBody(t *testing.T) {
 		})
 	}
 }
+
+func TestAlertProvider_GetConfig(t *testing.T) {
+	scenarios := []struct {
+		Name           string
+		Provider       AlertProvider
+		InputAlert     alert.Alert
+		ExpectedOutput Config
+	}{
+		{
+			Name: "provider-no-override-should-default",
+			Provider: AlertProvider{
+				DefaultConfig: Config{APIKey: "00000000-0000-0000-0000-000000000000"},
+			},
+			InputAlert:     alert.Alert{},
+			ExpectedOutput: Config{APIKey: "00000000-0000-0000-0000-000000000000"},
+		},
+		{
+			Name: "provider-with-alert-override--alert-override-should-take-precedence",
+			Provider: AlertProvider{
+				DefaultConfig: Config{APIKey: "00000000-0000-0000-0000-000000000000"},
+			},
+			InputAlert:     alert.Alert{ProviderOverride: map[string]any{"api-key": "00000000-0000-0000-0000-000000000001"}},
+			ExpectedOutput: Config{APIKey: "00000000-0000-0000-0000-000000000001"},
+		},
+	}
+	for _, scenario := range scenarios {
+		t.Run(scenario.Name, func(t *testing.T) {
+			got, err := scenario.Provider.GetConfig("", &scenario.InputAlert)
+			if err != nil {
+				t.Fatalf("unexpected error: %s", err)
+			}
+			if got.APIKey != scenario.ExpectedOutput.APIKey {
+				t.Errorf("expected APIKey to be %s, got %s", scenario.ExpectedOutput.APIKey, got.APIKey)
+			}
+			// Test ValidateOverrides as well, since it really just calls GetConfig
+			if err = scenario.Provider.ValidateOverrides("", &scenario.InputAlert); err != nil {
+				t.Errorf("unexpected error: %s", err)
+			}
+		})
+	}
+}

alerting/provider/pagerduty/pagerduty.go

@@ -3,23 +3,47 @@ package pagerduty
 import (
 	"bytes"
 	"encoding/json"
+	"errors"
 	"fmt"
 	"io"
-	"log"
 	"net/http"
 
 	"github.com/TwiN/gatus/v5/alerting/alert"
 	"github.com/TwiN/gatus/v5/client"
 	"github.com/TwiN/gatus/v5/config/endpoint"
+	"github.com/TwiN/logr"
+	"gopkg.in/yaml.v3"
 )
 
 const (
 	restAPIURL = "https://events.pagerduty.com/v2/enqueue"
 )
 
+var (
+	ErrIntegrationKeyNotSet   = errors.New("integration-key must have exactly 32 characters")
+	ErrDuplicateGroupOverride = errors.New("duplicate group override")
+)
+
+type Config struct {
+	IntegrationKey string `yaml:"integration-key"`
+}
+
+func (cfg *Config) Validate() error {
+	if len(cfg.IntegrationKey) != 32 {
+		return ErrIntegrationKeyNotSet
+	}
+	return nil
+}
+
+func (cfg *Config) Merge(override *Config) {
+	if len(override.IntegrationKey) > 0 {
+		cfg.IntegrationKey = override.IntegrationKey
+	}
+}
+
 // AlertProvider is the configuration necessary for sending an alert using PagerDuty
 type AlertProvider struct {
-	IntegrationKey string `yaml:"integration-key"`
+	DefaultConfig Config `yaml:",inline"`
 
 	// DefaultAlert is the default alert configuration to use for endpoints with an alert of the appropriate type
 	DefaultAlert *alert.Alert `yaml:"default-alert,omitempty"`
@@ -30,30 +54,34 @@ type AlertProvider struct {
 
 // Override is a case under which the default integration is overridden
 type Override struct {
-	Group          string `yaml:"group"`
-	IntegrationKey string `yaml:"integration-key"`
+	Group  string `yaml:"group"`
+	Config `yaml:",inline"`
 }
 
-// IsValid returns whether the provider's configuration is valid
-func (provider *AlertProvider) IsValid() bool {
+// Validate the provider's configuration
+func (provider *AlertProvider) Validate() error {
 	registeredGroups := make(map[string]bool)
 	if provider.Overrides != nil {
 		for _, override := range provider.Overrides {
-			if isAlreadyRegistered := registeredGroups[override.Group]; isAlreadyRegistered || override.Group == "" || len(override.IntegrationKey) != 32 {
-				return false
+			if isAlreadyRegistered := registeredGroups[override.Group]; isAlreadyRegistered || override.Group == "" {
+				return ErrDuplicateGroupOverride
 			}
 			registeredGroups[override.Group] = true
 		}
 	}
 	// Either the default integration key has the right length, or there are overrides who are properly configured.
-	return len(provider.IntegrationKey) == 32 || len(provider.Overrides) != 0
+	return provider.DefaultConfig.Validate()
 }
 
 // Send an alert using the provider
 //
 // Relevant: https://developer.pagerduty.com/docs/events-api-v2/trigger-events/
 func (provider *AlertProvider) Send(ep *endpoint.Endpoint, alert *alert.Alert, result *endpoint.Result, resolved bool) error {
-	buffer := bytes.NewBuffer(provider.buildRequestBody(ep, alert, result, resolved))
+	cfg, err := provider.GetConfig(ep.Group, alert)
+	if err != nil {
+		return err
+	}
+	buffer := bytes.NewBuffer(provider.buildRequestBody(cfg, ep, alert, result, resolved))
 	request, err := http.NewRequest(http.MethodPost, restAPIURL, buffer)
 	if err != nil {
 		return err
@@ -74,11 +102,10 @@ func (provider *AlertProvider) Send(ep *endpoint.Endpoint, alert *alert.Alert, r
 			alert.ResolveKey = ""
 		} else {
 			// We need to retrieve the resolve key from the response
-			body, err := io.ReadAll(response.Body)
 			var payload pagerDutyResponsePayload
-			if err = json.Unmarshal(body, &payload); err != nil {
+			if err = json.NewDecoder(response.Body).Decode(&payload); err != nil {
 				// Silently fail. We don't want to create tons of alerts just because we failed to parse the body.
-				log.Printf("[pagerduty.Send] Ran into error unmarshaling pagerduty response: %s", err.Error())
+				logr.Errorf("[pagerduty.Send] Ran into error decoding pagerduty response: %s", err.Error())
 			} else {
 				alert.ResolveKey = payload.DedupKey
 			}
@@ -101,7 +128,7 @@ type Payload struct {
 }
 
 // buildRequestBody builds the request body for the provider
-func (provider *AlertProvider) buildRequestBody(ep *endpoint.Endpoint, alert *alert.Alert, result *endpoint.Result, resolved bool) []byte {
+func (provider *AlertProvider) buildRequestBody(cfg *Config, ep *endpoint.Endpoint, alert *alert.Alert, result *endpoint.Result, resolved bool) []byte {
 	var message, eventAction, resolveKey string
 	if resolved {
 		message = fmt.Sprintf("RESOLVED: %s - %s", ep.DisplayName(), alert.GetDescription())
@@ -113,7 +140,7 @@ func (provider *AlertProvider) buildRequestBody(ep *endpoint.Endpoint, alert *al
 		resolveKey = ""
 	}
 	body, _ := json.Marshal(Body{
-		RoutingKey:  provider.getIntegrationKeyForGroup(ep.Group),
+		RoutingKey:  cfg.IntegrationKey,
 		DedupKey:    resolveKey,
 		EventAction: eventAction,
 		Payload: Payload{
@@ -125,23 +152,42 @@ func (provider *AlertProvider) buildRequestBody(ep *endpoint.Endpoint, alert *al
 	return body
 }
 
-// getIntegrationKeyForGroup returns the appropriate pagerduty integration key for a given group
-func (provider *AlertProvider) getIntegrationKeyForGroup(group string) string {
-	if provider.Overrides != nil {
-		for _, override := range provider.Overrides {
-			if group == override.Group {
-				return override.IntegrationKey
-			}
-		}
-	}
-	return provider.IntegrationKey
-}
-
 // GetDefaultAlert returns the provider's default alert configuration
 func (provider *AlertProvider) GetDefaultAlert() *alert.Alert {
 	return provider.DefaultAlert
 }
 
+// GetConfig returns the configuration for the provider with the overrides applied
+func (provider *AlertProvider) GetConfig(group string, alert *alert.Alert) (*Config, error) {
+	cfg := provider.DefaultConfig
+	// Handle group overrides
+	if provider.Overrides != nil {
+		for _, override := range provider.Overrides {
+			if group == override.Group {
+				cfg.Merge(&override.Config)
+				break
+			}
+		}
+	}
+	// Handle alert overrides
+	if len(alert.ProviderOverride) != 0 {
+		overrideConfig := Config{}
+		if err := yaml.Unmarshal(alert.ProviderOverrideAsBytes(), &overrideConfig); err != nil {
+			return nil, err
+		}
+		cfg.Merge(&overrideConfig)
+	}
+	// Validate the configuration
+	err := cfg.Validate()
+	return &cfg, err
+}
+
+// ValidateOverrides validates the alert's provider override and, if present, the group override
+func (provider *AlertProvider) ValidateOverrides(group string, alert *alert.Alert) error {
+	_, err := provider.GetConfig(group, alert)
+	return err
+}
+
 type pagerDutyResponsePayload struct {
 	Status   string `json:"status"`
 	Message  string `json:"message"`

alerting/provider/pagerduty/pagerduty_test.go

@@ -11,50 +11,41 @@ import (
 	"github.com/TwiN/gatus/v5/test"
 )
 
-func TestAlertProvider_IsValid(t *testing.T) {
-	invalidProvider := AlertProvider{IntegrationKey: ""}
-	if invalidProvider.IsValid() {
+func TestAlertProvider_Validate(t *testing.T) {
+	invalidProvider := AlertProvider{DefaultConfig: Config{IntegrationKey: ""}}
+	if err := invalidProvider.Validate(); err == nil {
 		t.Error("provider shouldn't have been valid")
 	}
-	validProvider := AlertProvider{IntegrationKey: "00000000000000000000000000000000"}
-	if !validProvider.IsValid() {
+	validProvider := AlertProvider{DefaultConfig: Config{IntegrationKey: "00000000000000000000000000000000"}}
+	if err := validProvider.Validate(); err != nil {
 		t.Error("provider should've been valid")
 	}
 }
 
-func TestAlertProvider_IsValidWithOverride(t *testing.T) {
+func TestAlertProvider_ValidateWithOverride(t *testing.T) {
 	providerWithInvalidOverrideGroup := AlertProvider{
+		DefaultConfig: Config{IntegrationKey: "00000000000000000000000000000001"},
 		Overrides: []Override{
 			{
-				IntegrationKey: "00000000000000000000000000000000",
-				Group:          "",
+				Config: Config{IntegrationKey: "00000000000000000000000000000002"},
+				Group:  "",
 			},
 		},
 	}
-	if providerWithInvalidOverrideGroup.IsValid() {
+	if err := providerWithInvalidOverrideGroup.Validate(); err == nil {
 		t.Error("provider Group shouldn't have been valid")
 	}
-	providerWithInvalidOverrideIntegrationKey := AlertProvider{
-		Overrides: []Override{
-			{
-				IntegrationKey: "",
-				Group:          "group",
-			},
-		},
-	}
-	if providerWithInvalidOverrideIntegrationKey.IsValid() {
-		t.Error("provider integration key shouldn't have been valid")
-	}
 	providerWithValidOverride := AlertProvider{
+		DefaultConfig: Config{IntegrationKey: "00000000000000000000000000000001"},
 		Overrides: []Override{
 			{
-				IntegrationKey: "00000000000000000000000000000000",
-				Group:          "group",
+				Config: Config{IntegrationKey: "00000000000000000000000000000002"},
+				Group:  "group",
 			},
 		},
 	}
-	if !providerWithValidOverride.IsValid() {
-		t.Error("provider should've been valid")
+	if err := providerWithValidOverride.Validate(); err != nil {
+		t.Error("provider should've been valid, got error:", err.Error())
 	}
 }
 
@@ -72,7 +63,7 @@ func TestAlertProvider_Send(t *testing.T) {
 	}{
 		{
 			Name:     "triggered",
-			Provider: AlertProvider{},
+			Provider: AlertProvider{DefaultConfig: Config{IntegrationKey: "00000000000000000000000000000000"}},
 			Alert:    alert.Alert{Description: &firstDescription, SuccessThreshold: 5, FailureThreshold: 3},
 			Resolved: false,
 			MockRoundTripper: test.MockRoundTripper(func(r *http.Request) *http.Response {
@@ -82,7 +73,7 @@ func TestAlertProvider_Send(t *testing.T) {
 		},
 		{
 			Name:     "triggered-error",
-			Provider: AlertProvider{},
+			Provider: AlertProvider{DefaultConfig: Config{IntegrationKey: "00000000000000000000000000000000"}},
 			Alert:    alert.Alert{Description: &firstDescription, SuccessThreshold: 5, FailureThreshold: 3},
 			Resolved: false,
 			MockRoundTripper: test.MockRoundTripper(func(r *http.Request) *http.Response {
@@ -92,7 +83,7 @@ func TestAlertProvider_Send(t *testing.T) {
 		},
 		{
 			Name:     "resolved",
-			Provider: AlertProvider{},
+			Provider: AlertProvider{DefaultConfig: Config{IntegrationKey: "00000000000000000000000000000000"}},
 			Alert:    alert.Alert{Description: &secondDescription, SuccessThreshold: 5, FailureThreshold: 3},
 			Resolved: true,
 			MockRoundTripper: test.MockRoundTripper(func(r *http.Request) *http.Response {
@@ -102,7 +93,7 @@ func TestAlertProvider_Send(t *testing.T) {
 		},
 		{
 			Name:     "resolved-error",
-			Provider: AlertProvider{},
+			Provider: AlertProvider{DefaultConfig: Config{IntegrationKey: "00000000000000000000000000000000"}},
 			Alert:    alert.Alert{Description: &secondDescription, SuccessThreshold: 5, FailureThreshold: 3},
 			Resolved: true,
 			MockRoundTripper: test.MockRoundTripper(func(r *http.Request) *http.Response {
@@ -146,14 +137,14 @@ func TestAlertProvider_buildRequestBody(t *testing.T) {
 	}{
 		{
 			Name:         "triggered",
-			Provider:     AlertProvider{IntegrationKey: "00000000000000000000000000000000"},
+			Provider:     AlertProvider{DefaultConfig: Config{IntegrationKey: "00000000000000000000000000000000"}},
 			Alert:        alert.Alert{Description: &description},
 			Resolved:     false,
 			ExpectedBody: "{\"routing_key\":\"00000000000000000000000000000000\",\"dedup_key\":\"\",\"event_action\":\"trigger\",\"payload\":{\"summary\":\"TRIGGERED: endpoint-name - test\",\"source\":\"Gatus\",\"severity\":\"critical\"}}",
 		},
 		{
 			Name:         "resolved",
-			Provider:     AlertProvider{IntegrationKey: "00000000000000000000000000000000"},
+			Provider:     AlertProvider{DefaultConfig: Config{IntegrationKey: "00000000000000000000000000000000"}},
 			Alert:        alert.Alert{Description: &description, ResolveKey: "key"},
 			Resolved:     true,
 			ExpectedBody: "{\"routing_key\":\"00000000000000000000000000000000\",\"dedup_key\":\"key\",\"event_action\":\"resolve\",\"payload\":{\"summary\":\"RESOLVED: endpoint-name - test\",\"source\":\"Gatus\",\"severity\":\"critical\"}}",
@@ -161,7 +152,7 @@ func TestAlertProvider_buildRequestBody(t *testing.T) {
 	}
 	for _, scenario := range scenarios {
 		t.Run(scenario.Name, func(t *testing.T) {
-			body := scenario.Provider.buildRequestBody(&endpoint.Endpoint{Name: "endpoint-name"}, &scenario.Alert, &endpoint.Result{}, scenario.Resolved)
+			body := scenario.Provider.buildRequestBody(&scenario.Provider.DefaultConfig, &endpoint.Endpoint{Name: "endpoint-name"}, &scenario.Alert, &endpoint.Result{}, scenario.Resolved)
 			if string(body) != scenario.ExpectedBody {
 				t.Errorf("expected:\n%s\ngot:\n%s", scenario.ExpectedBody, body)
 			}
@@ -173,69 +164,6 @@ func TestAlertProvider_buildRequestBody(t *testing.T) {
 	}
 }
 
-func TestAlertProvider_getIntegrationKeyForGroup(t *testing.T) {
-	scenarios := []struct {
-		Name           string
-		Provider       AlertProvider
-		InputGroup     string
-		ExpectedOutput string
-	}{
-		{
-			Name: "provider-no-override-specify-no-group-should-default",
-			Provider: AlertProvider{
-				IntegrationKey: "00000000000000000000000000000001",
-				Overrides:      nil,
-			},
-			InputGroup:     "",
-			ExpectedOutput: "00000000000000000000000000000001",
-		},
-		{
-			Name: "provider-no-override-specify-group-should-default",
-			Provider: AlertProvider{
-				IntegrationKey: "00000000000000000000000000000001",
-				Overrides:      nil,
-			},
-			InputGroup:     "group",
-			ExpectedOutput: "00000000000000000000000000000001",
-		},
-		{
-			Name: "provider-with-override-specify-no-group-should-default",
-			Provider: AlertProvider{
-				IntegrationKey: "00000000000000000000000000000001",
-				Overrides: []Override{
-					{
-						Group:          "group",
-						IntegrationKey: "00000000000000000000000000000002",
-					},
-				},
-			},
-			InputGroup:     "",
-			ExpectedOutput: "00000000000000000000000000000001",
-		},
-		{
-			Name: "provider-with-override-specify-group-should-override",
-			Provider: AlertProvider{
-				IntegrationKey: "00000000000000000000000000000001",
-				Overrides: []Override{
-					{
-						Group:          "group",
-						IntegrationKey: "00000000000000000000000000000002",
-					},
-				},
-			},
-			InputGroup:     "group",
-			ExpectedOutput: "00000000000000000000000000000002",
-		},
-	}
-	for _, scenario := range scenarios {
-		t.Run(scenario.Name, func(t *testing.T) {
-			if output := scenario.Provider.getIntegrationKeyForGroup(scenario.InputGroup); output != scenario.ExpectedOutput {
-				t.Errorf("expected %s, got %s", scenario.ExpectedOutput, output)
-			}
-		})
-	}
-}
-
 func TestAlertProvider_GetDefaultAlert(t *testing.T) {
 	if (&AlertProvider{DefaultAlert: &alert.Alert{}}).GetDefaultAlert() == nil {
 		t.Error("expected default alert to be not nil")
@@ -244,3 +172,94 @@ func TestAlertProvider_GetDefaultAlert(t *testing.T) {
 		t.Error("expected default alert to be nil")
 	}
 }
+
+func TestAlertProvider_GetConfig(t *testing.T) {
+	scenarios := []struct {
+		Name           string
+		Provider       AlertProvider
+		InputGroup     string
+		InputAlert     alert.Alert
+		ExpectedOutput Config
+	}{
+		{
+			Name: "provider-no-override-specify-no-group-should-default",
+			Provider: AlertProvider{
+				DefaultConfig: Config{IntegrationKey: "00000000000000000000000000000001"},
+				Overrides:     nil,
+			},
+			InputGroup:     "",
+			InputAlert:     alert.Alert{},
+			ExpectedOutput: Config{IntegrationKey: "00000000000000000000000000000001"},
+		},
+		{
+			Name: "provider-no-override-specify-group-should-default",
+			Provider: AlertProvider{
+				DefaultConfig: Config{IntegrationKey: "00000000000000000000000000000001"},
+				Overrides:     nil,
+			},
+			InputGroup:     "group",
+			InputAlert:     alert.Alert{},
+			ExpectedOutput: Config{IntegrationKey: "00000000000000000000000000000001"},
+		},
+		{
+			Name: "provider-with-override-specify-no-group-should-default",
+			Provider: AlertProvider{
+				DefaultConfig: Config{IntegrationKey: "00000000000000000000000000000001"},
+				Overrides: []Override{
+					{
+						Group:  "group",
+						Config: Config{IntegrationKey: "00000000000000000000000000000002"},
+					},
+				},
+			},
+			InputGroup:     "",
+			InputAlert:     alert.Alert{},
+			ExpectedOutput: Config{IntegrationKey: "00000000000000000000000000000001"},
+		},
+		{
+			Name: "provider-with-override-specify-group-should-override",
+			Provider: AlertProvider{
+				DefaultConfig: Config{IntegrationKey: "00000000000000000000000000000001"},
+				Overrides: []Override{
+					{
+						Group:  "group",
+						Config: Config{IntegrationKey: "00000000000000000000000000000002"},
+					},
+				},
+			},
+			InputGroup:     "group",
+			InputAlert:     alert.Alert{},
+			ExpectedOutput: Config{IntegrationKey: "00000000000000000000000000000002"},
+		},
+		{
+			Name: "provider-with-group-override-and-alert-override--alert-override-should-take-precedence",
+			Provider: AlertProvider{
+				DefaultConfig: Config{IntegrationKey: "00000000000000000000000000000001"},
+				Overrides: []Override{
+					{
+						Group:  "group",
+						Config: Config{IntegrationKey: "00000000000000000000000000000002"},
+					},
+				},
+			},
+			InputGroup:     "group",
+			InputAlert:     alert.Alert{ProviderOverride: map[string]any{"integration-key": "00000000000000000000000000000003"}},
+			ExpectedOutput: Config{IntegrationKey: "00000000000000000000000000000003"},
+		},
+	}
+	for _, scenario := range scenarios {
+		t.Run(scenario.Name, func(t *testing.T) {
+			got, err := scenario.Provider.GetConfig(scenario.InputGroup, &scenario.InputAlert)
+			if err != nil {
+				t.Fatalf("unexpected error: %s", err)
+			}
+			if got.IntegrationKey != scenario.ExpectedOutput.IntegrationKey {
+				t.Errorf("expected %s, got %s", scenario.ExpectedOutput.IntegrationKey, got.IntegrationKey)
+			}
+			// Test ValidateOverrides as well, since it really just calls GetConfig
+			if err = scenario.Provider.ValidateOverrides(scenario.InputGroup, &scenario.InputAlert); err != nil {
+				t.Errorf("unexpected error: %s", err)
+			}
+		})
+	}
+}

alerting/provider/plivo/plivo.go

@@ -0,0 +1,183 @@
+package plivo
+
+import (
+	"bytes"
+	"encoding/base64"
+	"encoding/json"
+	"errors"
+	"fmt"
+	"io"
+	"net/http"
+
+	"github.com/TwiN/gatus/v5/alerting/alert"
+	"github.com/TwiN/gatus/v5/client"
+	"github.com/TwiN/gatus/v5/config/endpoint"
+	"gopkg.in/yaml.v3"
+)
+
+var (
+	ErrAuthIDNotSet           = errors.New("auth-id not set")
+	ErrAuthTokenNotSet        = errors.New("auth-token not set")
+	ErrFromNotSet             = errors.New("from not set")
+	ErrToNotSet               = errors.New("to not set")
+	ErrDuplicateGroupOverride = errors.New("duplicate group override")
+)
+
+type Config struct {
+	AuthID    string   `yaml:"auth-id"`
+	AuthToken string   `yaml:"auth-token"`
+	From      string   `yaml:"from"`
+	To        []string `yaml:"to"`
+}
+
+func (cfg *Config) Validate() error {
+	if len(cfg.AuthID) == 0 {
+		return ErrAuthIDNotSet
+	}
+	if len(cfg.AuthToken) == 0 {
+		return ErrAuthTokenNotSet
+	}
+	if len(cfg.From) == 0 {
+		return ErrFromNotSet
+	}
+	if len(cfg.To) == 0 {
+		return ErrToNotSet
+	}
+	return nil
+}
+
+func (cfg *Config) Merge(override *Config) {
+	if len(override.AuthID) > 0 {
+		cfg.AuthID = override.AuthID
+	}
+	if len(override.AuthToken) > 0 {
+		cfg.AuthToken = override.AuthToken
+	}
+	if len(override.From) > 0 {
+		cfg.From = override.From
+	}
+	if len(override.To) > 0 {
+		cfg.To = override.To
+	}
+}
+
+// AlertProvider is the configuration necessary for sending an alert using Plivo
+type AlertProvider struct {
+	DefaultConfig Config `yaml:",inline"`
+
+	// DefaultAlert is the default alert configuration to use for endpoints with an alert of the appropriate type
+	DefaultAlert *alert.Alert `yaml:"default-alert,omitempty"`
+
+	// Overrides is a list of Override that may be prioritized over the default configuration
+	Overrides []Override `yaml:"overrides,omitempty"`
+}
+
+// Override is a case under which the default integration is overridden
+type Override struct {
+	Group  string `yaml:"group"`
+	Config `yaml:",inline"`
+}
+
+// Validate the provider's configuration
+func (provider *AlertProvider) Validate() error {
+	registeredGroups := make(map[string]bool)
+	if provider.Overrides != nil {
+		for _, override := range provider.Overrides {
+			if isAlreadyRegistered := registeredGroups[override.Group]; isAlreadyRegistered || override.Group == "" {
+				return ErrDuplicateGroupOverride
+			}
+			registeredGroups[override.Group] = true
+		}
+	}
+	return provider.DefaultConfig.Validate()
+}
+
+// Send an alert using the provider
+func (provider *AlertProvider) Send(ep *endpoint.Endpoint, alert *alert.Alert, result *endpoint.Result, resolved bool) error {
+	cfg, err := provider.GetConfig(ep.Group, alert)
+	if err != nil {
+		return err
+	}
+	message := provider.buildMessage(cfg, ep, alert, result, resolved)
+	// Send individual SMS messages to each recipient
+	for _, to := range cfg.To {
+		if err := provider.sendSMS(cfg, to, message); err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+// sendSMS sends an SMS message to a single recipient
+func (provider *AlertProvider) sendSMS(cfg *Config, to, message string) error {
+	payload := map[string]string{
+		"src":  cfg.From,
+		"dst":  to,
+		"text": message,
+	}
+	payloadBytes, err := json.Marshal(payload)
+	if err != nil {
+		return err
+	}
+	request, err := http.NewRequest(http.MethodPost, fmt.Sprintf("https://api.plivo.com/v1/Account/%s/Message/", cfg.AuthID), bytes.NewBuffer(payloadBytes))
+	if err != nil {
+		return err
+	}
+	request.Header.Set("Content-Type", "application/json")
+	request.Header.Set("Authorization", fmt.Sprintf("Basic %s", base64.StdEncoding.EncodeToString([]byte(cfg.AuthID+":"+cfg.AuthToken))))
+	response, err := client.GetHTTPClient(nil).Do(request)
+	if err != nil {
+		return err
+	}
+	defer response.Body.Close()
+	if response.StatusCode >= 400 {
+		body, _ := io.ReadAll(response.Body)
+		return fmt.Errorf("call to plivo alert returned status code %d: %s", response.StatusCode, string(body))
+	}
+	return nil
+}
+
+// buildMessage builds the message for the provider
+func (provider *AlertProvider) buildMessage(cfg *Config, ep *endpoint.Endpoint, alert *alert.Alert, result *endpoint.Result, resolved bool) string {
+	if resolved {
+		return fmt.Sprintf("RESOLVED: %s - %s", ep.DisplayName(), alert.GetDescription())
+	} else {
+		return fmt.Sprintf("TRIGGERED: %s - %s", ep.DisplayName(), alert.GetDescription())
+	}
+}
+
+// GetDefaultAlert returns the provider's default alert configuration
+func (provider *AlertProvider) GetDefaultAlert() *alert.Alert {
+	return provider.DefaultAlert
+}
+
+// GetConfig returns the configuration for the provider with the overrides applied
+func (provider *AlertProvider) GetConfig(group string, alert *alert.Alert) (*Config, error) {
+	cfg := provider.DefaultConfig
+	// Handle group overrides
+	if provider.Overrides != nil {
+		for _, override := range provider.Overrides {
+			if group == override.Group {
+				cfg.Merge(&override.Config)
+				break
+			}
+		}
+	}
+	// Handle alert overrides
+	if len(alert.ProviderOverride) != 0 {
+		overrideConfig := Config{}
+		if err := yaml.Unmarshal(alert.ProviderOverrideAsBytes(), &overrideConfig); err != nil {
+			return nil, err
+		}
+		cfg.Merge(&overrideConfig)
+	}
+	// Validate the configuration
+	err := cfg.Validate()
+	return &cfg, err
+}
+
+// ValidateOverrides validates the alert's provider override and, if present, the group override
+func (provider *AlertProvider) ValidateOverrides(group string, alert *alert.Alert) error {
+	_, err := provider.GetConfig(group, alert)
+	return err
+}

alerting/provider/plivo/plivo_test.go

@@ -0,0 +1,514 @@
+package plivo
+
+import (
+	"encoding/json"
+	"io"
+	"net/http"
+	"testing"
+
+	"github.com/TwiN/gatus/v5/alerting/alert"
+	"github.com/TwiN/gatus/v5/client"
+	"github.com/TwiN/gatus/v5/config/endpoint"
+	"github.com/TwiN/gatus/v5/test"
+)
+
+func TestPlivoAlertProvider_IsValid(t *testing.T) {
+	scenarios := []struct {
+		Name          string
+		Provider      AlertProvider
+		ExpectedError error
+	}{
+		{
+			Name:          "invalid-provider-missing-config",
+			Provider:      AlertProvider{},
+			ExpectedError: ErrAuthIDNotSet,
+		},
+		{
+			Name: "valid-provider",
+			Provider: AlertProvider{
+				DefaultConfig: Config{
+					AuthID:    "1",
+					AuthToken: "1",
+					From:      "1234567890",
+					To:        []string{"0987654321"},
+				},
+			},
+			ExpectedError: nil,
+		},
+		{
+			Name: "valid-provider-with-override",
+			Provider: AlertProvider{
+				DefaultConfig: Config{
+					AuthID:    "1",
+					AuthToken: "1",
+					From:      "1234567890",
+					To:        []string{"0987654321"},
+				},
+				Overrides: []Override{
+					{
+						Group:  "group1",
+						Config: Config{AuthID: "2", AuthToken: "2", From: "2222222222", To: []string{"3333333333"}},
+					},
+				},
+			},
+			ExpectedError: nil,
+		},
+		{
+			Name: "invalid-provider-duplicate-group-override",
+			Provider: AlertProvider{
+				DefaultConfig: Config{
+					AuthID:    "1",
+					AuthToken: "1",
+					From:      "1234567890",
+					To:        []string{"0987654321"},
+				},
+				Overrides: []Override{
+					{
+						Group:  "group1",
+						Config: Config{AuthID: "2", AuthToken: "2", From: "2222222222", To: []string{"3333333333"}},
+					},
+					{
+						Group:  "group1",
+						Config: Config{AuthID: "3", AuthToken: "3", From: "4444444444", To: []string{"5555555555"}},
+					},
+				},
+			},
+			ExpectedError: ErrDuplicateGroupOverride,
+		},
+		{
+			Name: "invalid-provider-empty-group-override",
+			Provider: AlertProvider{
+				DefaultConfig: Config{
+					AuthID:    "1",
+					AuthToken: "1",
+					From:      "1234567890",
+					To:        []string{"0987654321"},
+				},
+				Overrides: []Override{
+					{
+						Group:  "",
+						Config: Config{AuthID: "2", AuthToken: "2", From: "2222222222", To: []string{"3333333333"}},
+					},
+				},
+			},
+			ExpectedError: ErrDuplicateGroupOverride,
+		},
+	}
+	for _, scenario := range scenarios {
+		t.Run(scenario.Name, func(t *testing.T) {
+			err := scenario.Provider.Validate()
+			if scenario.ExpectedError == nil && err != nil {
+				t.Errorf("expected no error, got %v", err)
+			}
+			if scenario.ExpectedError != nil && err == nil {
+				t.Errorf("expected error %v, got none", scenario.ExpectedError)
+			}
+			if scenario.ExpectedError != nil && err != nil && err.Error() != scenario.ExpectedError.Error() {
+				t.Errorf("expected error %v, got %v", scenario.ExpectedError, err)
+			}
+		})
+	}
+}
+
+func TestAlertProvider_Send(t *testing.T) {
+	defer client.InjectHTTPClient(nil)
+	firstDescription := "description-1"
+	secondDescription := "description-2"
+	scenarios := []struct {
+		Name             string
+		Provider         AlertProvider
+		Alert            alert.Alert
+		Resolved         bool
+		MockRoundTripper test.MockRoundTripper
+		ExpectedError    bool
+	}{
+		{
+			Name:     "triggered",
+			Provider: AlertProvider{DefaultConfig: Config{AuthID: "1", AuthToken: "2", From: "1234567890", To: []string{"0987654321"}}},
+			Alert:    alert.Alert{Description: &firstDescription, SuccessThreshold: 5, FailureThreshold: 3},
+			Resolved: false,
+			MockRoundTripper: test.MockRoundTripper(func(r *http.Request) *http.Response {
+				return &http.Response{StatusCode: http.StatusAccepted, Body: http.NoBody}
+			}),
+			ExpectedError: false,
+		},
+		{
+			Name:     "triggered-error",
+			Provider: AlertProvider{DefaultConfig: Config{AuthID: "1", AuthToken: "2", From: "1234567890", To: []string{"0987654321"}}},
+			Alert:    alert.Alert{Description: &firstDescription, SuccessThreshold: 5, FailureThreshold: 3},
+			Resolved: false,
+			MockRoundTripper: test.MockRoundTripper(func(r *http.Request) *http.Response {
+				return &http.Response{StatusCode: http.StatusInternalServerError, Body: http.NoBody}
+			}),
+			ExpectedError: true,
+		},
+		{
+			Name:     "resolved",
+			Provider: AlertProvider{DefaultConfig: Config{AuthID: "1", AuthToken: "2", From: "1234567890", To: []string{"0987654321"}}},
+			Alert:    alert.Alert{Description: &secondDescription, SuccessThreshold: 5, FailureThreshold: 3},
+			Resolved: true,
+			MockRoundTripper: test.MockRoundTripper(func(r *http.Request) *http.Response {
+				return &http.Response{StatusCode: http.StatusAccepted, Body: http.NoBody}
+			}),
+			ExpectedError: false,
+		},
+		{
+			Name:     "resolved-error",
+			Provider: AlertProvider{DefaultConfig: Config{AuthID: "1", AuthToken: "2", From: "1234567890", To: []string{"0987654321"}}},
+			Alert:    alert.Alert{Description: &secondDescription, SuccessThreshold: 5, FailureThreshold: 3},
+			Resolved: true,
+			MockRoundTripper: test.MockRoundTripper(func(r *http.Request) *http.Response {
+				return &http.Response{StatusCode: http.StatusInternalServerError, Body: http.NoBody}
+			}),
+			ExpectedError: true,
+		},
+		{
+			Name:     "multiple-recipients",
+			Provider: AlertProvider{DefaultConfig: Config{AuthID: "1", AuthToken: "2", From: "1234567890", To: []string{"0987654321", "1122334455"}}},
+			Alert:    alert.Alert{Description: &firstDescription, SuccessThreshold: 5, FailureThreshold: 3},
+			Resolved: false,
+			MockRoundTripper: test.MockRoundTripper(func(r *http.Request) *http.Response {
+				return &http.Response{StatusCode: http.StatusAccepted, Body: http.NoBody}
+			}),
+			ExpectedError: false,
+		},
+	}
+	for _, scenario := range scenarios {
+		t.Run(scenario.Name, func(t *testing.T) {
+			client.InjectHTTPClient(&http.Client{Transport: scenario.MockRoundTripper})
+			err := scenario.Provider.Send(
+				&endpoint.Endpoint{Name: "endpoint-name"},
+				&scenario.Alert,
+				&endpoint.Result{
+					ConditionResults: []*endpoint.ConditionResult{
+						{Condition: "[CONNECTED] == true", Success: scenario.Resolved},
+						{Condition: "[STATUS] == 200", Success: scenario.Resolved},
+					},
+				},
+				scenario.Resolved,
+			)
+			if scenario.ExpectedError && err == nil {
+				t.Error("expected error, got none")
+			}
+			if !scenario.ExpectedError && err != nil {
+				t.Error("expected no error, got", err.Error())
+			}
+		})
+	}
+}
+
+func TestAlertProvider_buildMessage(t *testing.T) {
+	firstDescription := "description-1"
+	secondDescription := "description-2"
+	scenarios := []struct {
+		Name            string
+		Provider        AlertProvider
+		Alert           alert.Alert
+		Resolved        bool
+		ExpectedMessage string
+	}{
+		{
+			Name:            "triggered",
+			Provider:        AlertProvider{DefaultConfig: Config{AuthID: "1", AuthToken: "2", From: "1234567890", To: []string{"0987654321"}}},
+			Alert:           alert.Alert{Description: &firstDescription, SuccessThreshold: 5, FailureThreshold: 3},
+			Resolved:        false,
+			ExpectedMessage: "TRIGGERED: endpoint-name - description-1",
+		},
+		{
+			Name:            "resolved",
+			Provider:        AlertProvider{DefaultConfig: Config{AuthID: "1", AuthToken: "2", From: "1234567890", To: []string{"0987654321"}}},
+			Alert:           alert.Alert{Description: &secondDescription, SuccessThreshold: 5, FailureThreshold: 3},
+			Resolved:        true,
+			ExpectedMessage: "RESOLVED: endpoint-name - description-2",
+		},
+	}
+	for _, scenario := range scenarios {
+		t.Run(scenario.Name, func(t *testing.T) {
+			message := scenario.Provider.buildMessage(
+				&scenario.Provider.DefaultConfig,
+				&endpoint.Endpoint{Name: "endpoint-name"},
+				&scenario.Alert,
+				&endpoint.Result{
+					ConditionResults: []*endpoint.ConditionResult{
+						{Condition: "[CONNECTED] == true", Success: scenario.Resolved},
+						{Condition: "[STATUS] == 200", Success: scenario.Resolved},
+					},
+				},
+				scenario.Resolved,
+			)
+			if message != scenario.ExpectedMessage {
+				t.Errorf("expected %s, got %s", scenario.ExpectedMessage, message)
+			}
+		})
+	}
+}
+
+func TestAlertProvider_sendSMS(t *testing.T) {
+	defer client.InjectHTTPClient(nil)
+	cfg := &Config{
+		AuthID:    "test-auth-id",
+		AuthToken: "test-auth-token",
+		From:      "1234567890",
+	}
+	scenarios := []struct {
+		Name             string
+		To               string
+		Message          string
+		MockRoundTripper test.MockRoundTripper
+		ExpectedError    bool
+	}{
+		{
+			Name:    "successful-sms",
+			To:      "0987654321",
+			Message: "Test message",
+			MockRoundTripper: test.MockRoundTripper(func(r *http.Request) *http.Response {
+				// Verify request structure
+				body, _ := io.ReadAll(r.Body)
+				var payload map[string]string
+				json.Unmarshal(body, &payload)
+				if payload["src"] != cfg.From {
+					t.Errorf("expected src %s, got %s", cfg.From, payload["src"])
+				}
+				if payload["dst"] != "0987654321" {
+					t.Errorf("expected dst %s, got %s", "0987654321", payload["dst"])
+				}
+				if payload["text"] != "Test message" {
+					t.Errorf("expected text %s, got %s", "Test message", payload["text"])
+				}
+				return &http.Response{StatusCode: http.StatusAccepted, Body: http.NoBody}
+			}),
+			ExpectedError: false,
+		},
+		{
+			Name:    "failed-sms",
+			To:      "0987654321",
+			Message: "Test message",
+			MockRoundTripper: test.MockRoundTripper(func(r *http.Request) *http.Response {
+				return &http.Response{StatusCode: http.StatusBadRequest, Body: http.NoBody}
+			}),
+			ExpectedError: true,
+		},
+	}
+	for _, scenario := range scenarios {
+		t.Run(scenario.Name, func(t *testing.T) {
+			client.InjectHTTPClient(&http.Client{Transport: scenario.MockRoundTripper})
+			provider := AlertProvider{}
+			err := provider.sendSMS(cfg, scenario.To, scenario.Message)
+			if scenario.ExpectedError && err == nil {
+				t.Error("expected error, got none")
+			}
+			if !scenario.ExpectedError && err != nil {
+				t.Error("expected no error, got", err.Error())
+			}
+		})
+	}
+}
+
+func TestAlertProvider_GetDefaultAlert(t *testing.T) {
+	if (&AlertProvider{DefaultAlert: &alert.Alert{}}).GetDefaultAlert() == nil {
+		t.Error("expected default alert to be not nil")
+	}
+	if (&AlertProvider{DefaultAlert: nil}).GetDefaultAlert() != nil {
+		t.Error("expected default alert to be nil")
+	}
+}
+
+func TestAlertProvider_GetConfig(t *testing.T) {
+	scenarios := []struct {
+		Name           string
+		Provider       AlertProvider
+		InputGroup     string
+		InputAlert     alert.Alert
+		ExpectedOutput Config
+	}{
+		{
+			Name: "provider-no-override-should-default",
+			Provider: AlertProvider{
+				DefaultConfig: Config{AuthID: "1", AuthToken: "2", From: "1234567890", To: []string{"0987654321"}},
+			},
+			InputGroup:     "",
+			InputAlert:     alert.Alert{},
+			ExpectedOutput: Config{AuthID: "1", AuthToken: "2", From: "1234567890", To: []string{"0987654321"}},
+		},
+		{
+			Name: "provider-with-group-override",
+			Provider: AlertProvider{
+				DefaultConfig: Config{AuthID: "1", AuthToken: "2", From: "1234567890", To: []string{"0987654321"}},
+				Overrides: []Override{
+					{
+						Group:  "group1",
+						Config: Config{AuthID: "3", AuthToken: "4", From: "3333333333", To: []string{"7777777777"}},
+					},
+				},
+			},
+			InputGroup:     "group1",
+			InputAlert:     alert.Alert{},
+			ExpectedOutput: Config{AuthID: "3", AuthToken: "4", From: "3333333333", To: []string{"7777777777"}},
+		},
+		{
+			Name: "provider-with-group-override-no-match",
+			Provider: AlertProvider{
+				DefaultConfig: Config{AuthID: "1", AuthToken: "2", From: "1234567890", To: []string{"0987654321"}},
+				Overrides: []Override{
+					{
+						Group:  "group1",
+						Config: Config{AuthID: "3", AuthToken: "4", From: "3333333333", To: []string{"7777777777"}},
+					},
+				},
+			},
+			InputGroup:     "group2",
+			InputAlert:     alert.Alert{},
+			ExpectedOutput: Config{AuthID: "1", AuthToken: "2", From: "1234567890", To: []string{"0987654321"}},
+		},
+		{
+			Name: "provider-with-alert-override",
+			Provider: AlertProvider{
+				DefaultConfig: Config{AuthID: "1", AuthToken: "2", From: "1234567890", To: []string{"0987654321"}},
+			},
+			InputGroup:     "",
+			InputAlert:     alert.Alert{ProviderOverride: map[string]any{"auth-id": "5", "auth-token": "6", "from": "5555555555", "to": []string{"9999999999"}}},
+			ExpectedOutput: Config{AuthID: "5", AuthToken: "6", From: "5555555555", To: []string{"9999999999"}},
+		},
+		{
+			Name: "provider-with-group-and-alert-override",
+			Provider: AlertProvider{
+				DefaultConfig: Config{AuthID: "1", AuthToken: "2", From: "1234567890", To: []string{"0987654321"}},
+				Overrides: []Override{
+					{
+						Group:  "group1",
+						Config: Config{AuthID: "3", AuthToken: "4", From: "3333333333", To: []string{"7777777777"}},
+					},
+				},
+			},
+			InputGroup:     "group1",
+			InputAlert:     alert.Alert{ProviderOverride: map[string]any{"auth-id": "5", "auth-token": "6"}},
+			ExpectedOutput: Config{AuthID: "5", AuthToken: "6", From: "3333333333", To: []string{"7777777777"}},
+		},
+	}
+	for _, scenario := range scenarios {
+		t.Run(scenario.Name, func(t *testing.T) {
+			got, err := scenario.Provider.GetConfig(scenario.InputGroup, &scenario.InputAlert)
+			if err != nil {
+				t.Error("expected no error, got:", err.Error())
+			}
+			if got.AuthID != scenario.ExpectedOutput.AuthID {
+				t.Errorf("expected AuthID to be %s, got %s", scenario.ExpectedOutput.AuthID, got.AuthID)
+			}
+			if got.AuthToken != scenario.ExpectedOutput.AuthToken {
+				t.Errorf("expected AuthToken to be %s, got %s", scenario.ExpectedOutput.AuthToken, got.AuthToken)
+			}
+			if got.From != scenario.ExpectedOutput.From {
+				t.Errorf("expected From to be %s, got %s", scenario.ExpectedOutput.From, got.From)
+			}
+			if len(got.To) != len(scenario.ExpectedOutput.To) {
+				t.Errorf("expected To length to be %d, got %d", len(scenario.ExpectedOutput.To), len(got.To))
+			}
+			for i, to := range got.To {
+				if to != scenario.ExpectedOutput.To[i] {
+					t.Errorf("expected To[%d] to be %s, got %s", i, scenario.ExpectedOutput.To[i], to)
+				}
+			}
+			// Test ValidateOverrides as well, since it really just calls GetConfig
+			if err = scenario.Provider.ValidateOverrides(scenario.InputGroup, &scenario.InputAlert); err != nil {
+				t.Errorf("unexpected error: %s", err)
+			}
+		})
+	}
+}
+
+func TestConfig_Validate(t *testing.T) {
+	scenarios := []struct {
+		Name          string
+		Config        Config
+		ExpectedError error
+	}{
+		{
+			Name: "valid-config",
+			Config: Config{
+				AuthID:    "test-auth-id",
+				AuthToken: "test-auth-token",
+				From:      "1234567890",
+				To:        []string{"0987654321"},
+			},
+			ExpectedError: nil,
+		},
+		{
+			Name: "missing-auth-id",
+			Config: Config{
+				AuthToken: "test-auth-token",
+				From:      "1234567890",
+				To:        []string{"0987654321"},
+			},
+			ExpectedError: ErrAuthIDNotSet,
+		},
+		{
+			Name: "missing-auth-token",
+			Config: Config{
+				AuthID: "test-auth-id",
+				From:   "1234567890",
+				To:     []string{"0987654321"},
+			},
+			ExpectedError: ErrAuthTokenNotSet,
+		},
+		{
+			Name: "missing-from",
+			Config: Config{
+				AuthID:    "test-auth-id",
+				AuthToken: "test-auth-token",
+				To:        []string{"0987654321"},
+			},
+			ExpectedError: ErrFromNotSet,
+		},
+		{
+			Name: "missing-to",
+			Config: Config{
+				AuthID:    "test-auth-id",
+				AuthToken: "test-auth-token",
+				From:      "1234567890",
+			},
+			ExpectedError: ErrToNotSet,
+		},
+	}
+	for _, scenario := range scenarios {
+		t.Run(scenario.Name, func(t *testing.T) {
+			err := scenario.Config.Validate()
+			if scenario.ExpectedError == nil && err != nil {
+				t.Errorf("expected no error, got %v", err)
+			}
+			if scenario.ExpectedError != nil && err == nil {
+				t.Errorf("expected error %v, got none", scenario.ExpectedError)
+			}
+			if scenario.ExpectedError != nil && err != nil && err.Error() != scenario.ExpectedError.Error() {
+				t.Errorf("expected error %v, got %v", scenario.ExpectedError, err)
+			}
+		})
+	}
+}
+
+func TestConfig_Merge(t *testing.T) {
+	cfg := Config{
+		AuthID:    "original-auth-id",
+		AuthToken: "original-auth-token",
+		From:      "1111111111",
+		To:        []string{"2222222222"},
+	}
+	override := Config{
+		AuthID:    "override-auth-id",
+		AuthToken: "override-auth-token",
+		From:      "3333333333",
+		To:        []string{"4444444444", "5555555555"},
+	}
+	cfg.Merge(&override)
+	if cfg.AuthID != "override-auth-id" {
+		t.Errorf("expected AuthID to be %s, got %s", "override-auth-id", cfg.AuthID)
+	}
+	if cfg.AuthToken != "override-auth-token" {
+		t.Errorf("expected AuthToken to be %s, got %s", "override-auth-token", cfg.AuthToken)
+	}
+	if cfg.From != "3333333333" {
+		t.Errorf("expected From to be %s, got %s", "3333333333", cfg.From)
+	}
+	if len(cfg.To) != 2 || cfg.To[0] != "4444444444" || cfg.To[1] != "5555555555" {
+		t.Errorf("expected To to be [4444444444, 5555555555], got %v", cfg.To)
+	}
+}

alerting/provider/provider.go

@@ -4,41 +4,68 @@ import (
 	"github.com/TwiN/gatus/v5/alerting/alert"
 	"github.com/TwiN/gatus/v5/alerting/provider/awsses"
 	"github.com/TwiN/gatus/v5/alerting/provider/custom"
+	"github.com/TwiN/gatus/v5/alerting/provider/datadog"
 	"github.com/TwiN/gatus/v5/alerting/provider/discord"
 	"github.com/TwiN/gatus/v5/alerting/provider/email"
 	"github.com/TwiN/gatus/v5/alerting/provider/gitea"
 	"github.com/TwiN/gatus/v5/alerting/provider/github"
 	"github.com/TwiN/gatus/v5/alerting/provider/gitlab"
 	"github.com/TwiN/gatus/v5/alerting/provider/googlechat"
+	"github.com/TwiN/gatus/v5/alerting/provider/gotify"
+	"github.com/TwiN/gatus/v5/alerting/provider/homeassistant"
+	"github.com/TwiN/gatus/v5/alerting/provider/ifttt"
+	"github.com/TwiN/gatus/v5/alerting/provider/ilert"
+	"github.com/TwiN/gatus/v5/alerting/provider/incidentio"
 	"github.com/TwiN/gatus/v5/alerting/provider/jetbrainsspace"
+	"github.com/TwiN/gatus/v5/alerting/provider/line"
 	"github.com/TwiN/gatus/v5/alerting/provider/matrix"
 	"github.com/TwiN/gatus/v5/alerting/provider/mattermost"
 	"github.com/TwiN/gatus/v5/alerting/provider/messagebird"
+	"github.com/TwiN/gatus/v5/alerting/provider/newrelic"
 	"github.com/TwiN/gatus/v5/alerting/provider/ntfy"
 	"github.com/TwiN/gatus/v5/alerting/provider/opsgenie"
 	"github.com/TwiN/gatus/v5/alerting/provider/pagerduty"
+	"github.com/TwiN/gatus/v5/alerting/provider/plivo"
 	"github.com/TwiN/gatus/v5/alerting/provider/pushover"
+	"github.com/TwiN/gatus/v5/alerting/provider/rocketchat"
+	"github.com/TwiN/gatus/v5/alerting/provider/sendgrid"
+	"github.com/TwiN/gatus/v5/alerting/provider/signal"
+	"github.com/TwiN/gatus/v5/alerting/provider/signl4"
 	"github.com/TwiN/gatus/v5/alerting/provider/slack"
+	"github.com/TwiN/gatus/v5/alerting/provider/splunk"
+	"github.com/TwiN/gatus/v5/alerting/provider/squadcast"
 	"github.com/TwiN/gatus/v5/alerting/provider/teams"
+	"github.com/TwiN/gatus/v5/alerting/provider/teamsworkflows"
 	"github.com/TwiN/gatus/v5/alerting/provider/telegram"
 	"github.com/TwiN/gatus/v5/alerting/provider/twilio"
+	"github.com/TwiN/gatus/v5/alerting/provider/webex"
+	"github.com/TwiN/gatus/v5/alerting/provider/zapier"
+	"github.com/TwiN/gatus/v5/alerting/provider/zulip"
 	"github.com/TwiN/gatus/v5/config/endpoint"
 )
 
 // AlertProvider is the interface that each provider should implement
 type AlertProvider interface {
-	// IsValid returns whether the provider's configuration is valid
-	IsValid() bool
+	// Validate the provider's configuration
+	Validate() error
+
+	// Send an alert using the provider
+	Send(ep *endpoint.Endpoint, alert *alert.Alert, result *endpoint.Result, resolved bool) error
 
 	// GetDefaultAlert returns the provider's default alert configuration
 	GetDefaultAlert() *alert.Alert
 
-	// Send an alert using the provider
-	Send(ep *endpoint.Endpoint, alert *alert.Alert, result *endpoint.Result, resolved bool) error
+	// ValidateOverrides validates the alert's provider override and, if present, the group override
+	ValidateOverrides(group string, alert *alert.Alert) error
 }
 
-// ParseWithDefaultAlert parses an Endpoint alert by using the provider's default alert as a baseline
-func ParseWithDefaultAlert(providerDefaultAlert, endpointAlert *alert.Alert) {
+type Config[T any] interface {
+	Validate() error
+	Merge(override *T)
+}
+
+// MergeProviderDefaultAlertIntoEndpointAlert parses an Endpoint alert by using the provider's default alert as a baseline
+func MergeProviderDefaultAlertIntoEndpointAlert(providerDefaultAlert, endpointAlert *alert.Alert) {
 	if providerDefaultAlert == nil || endpointAlert == nil {
 		return
 	}
@@ -57,28 +84,91 @@ func ParseWithDefaultAlert(providerDefaultAlert, endpointAlert *alert.Alert) {
 	if endpointAlert.SuccessThreshold == 0 {
 		endpointAlert.SuccessThreshold = providerDefaultAlert.SuccessThreshold
 	}
+	if endpointAlert.MinimumReminderInterval == 0 {
+		endpointAlert.MinimumReminderInterval = providerDefaultAlert.MinimumReminderInterval
+	}
 }
 
 var (
-	// Validate interface implementation on compile
+	// Validate provider interface implementation on compile
 	_ AlertProvider = (*awsses.AlertProvider)(nil)
 	_ AlertProvider = (*custom.AlertProvider)(nil)
+	_ AlertProvider = (*datadog.AlertProvider)(nil)
 	_ AlertProvider = (*discord.AlertProvider)(nil)
 	_ AlertProvider = (*email.AlertProvider)(nil)
+	_ AlertProvider = (*gitea.AlertProvider)(nil)
 	_ AlertProvider = (*github.AlertProvider)(nil)
 	_ AlertProvider = (*gitlab.AlertProvider)(nil)
-	_ AlertProvider = (*gitea.AlertProvider)(nil)
 	_ AlertProvider = (*googlechat.AlertProvider)(nil)
+	_ AlertProvider = (*gotify.AlertProvider)(nil)
+	_ AlertProvider = (*homeassistant.AlertProvider)(nil)
+	_ AlertProvider = (*ifttt.AlertProvider)(nil)
+	_ AlertProvider = (*ilert.AlertProvider)(nil)
+	_ AlertProvider = (*incidentio.AlertProvider)(nil)
 	_ AlertProvider = (*jetbrainsspace.AlertProvider)(nil)
+	_ AlertProvider = (*line.AlertProvider)(nil)
 	_ AlertProvider = (*matrix.AlertProvider)(nil)
 	_ AlertProvider = (*mattermost.AlertProvider)(nil)
 	_ AlertProvider = (*messagebird.AlertProvider)(nil)
+	_ AlertProvider = (*newrelic.AlertProvider)(nil)
 	_ AlertProvider = (*ntfy.AlertProvider)(nil)
 	_ AlertProvider = (*opsgenie.AlertProvider)(nil)
 	_ AlertProvider = (*pagerduty.AlertProvider)(nil)
+	_ AlertProvider = (*plivo.AlertProvider)(nil)
 	_ AlertProvider = (*pushover.AlertProvider)(nil)
+	_ AlertProvider = (*rocketchat.AlertProvider)(nil)
+	_ AlertProvider = (*sendgrid.AlertProvider)(nil)
+	_ AlertProvider = (*signal.AlertProvider)(nil)
+	_ AlertProvider = (*signl4.AlertProvider)(nil)
 	_ AlertProvider = (*slack.AlertProvider)(nil)
+	_ AlertProvider = (*splunk.AlertProvider)(nil)
+	_ AlertProvider = (*squadcast.AlertProvider)(nil)
 	_ AlertProvider = (*teams.AlertProvider)(nil)
+	_ AlertProvider = (*teamsworkflows.AlertProvider)(nil)
 	_ AlertProvider = (*telegram.AlertProvider)(nil)
 	_ AlertProvider = (*twilio.AlertProvider)(nil)
+	_ AlertProvider = (*webex.AlertProvider)(nil)
+	_ AlertProvider = (*zapier.AlertProvider)(nil)
+	_ AlertProvider = (*zulip.AlertProvider)(nil)
+
+	// Validate config interface implementation on compile
+	_ Config[awsses.Config]         = (*awsses.Config)(nil)
+	_ Config[custom.Config]         = (*custom.Config)(nil)
+	_ Config[datadog.Config]        = (*datadog.Config)(nil)
+	_ Config[discord.Config]        = (*discord.Config)(nil)
+	_ Config[email.Config]          = (*email.Config)(nil)
+	_ Config[gitea.Config]          = (*gitea.Config)(nil)
+	_ Config[github.Config]         = (*github.Config)(nil)
+	_ Config[gitlab.Config]         = (*gitlab.Config)(nil)
+	_ Config[googlechat.Config]     = (*googlechat.Config)(nil)
+	_ Config[gotify.Config]         = (*gotify.Config)(nil)
+	_ Config[homeassistant.Config]  = (*homeassistant.Config)(nil)
+	_ Config[ifttt.Config]          = (*ifttt.Config)(nil)
+	_ Config[ilert.Config]          = (*ilert.Config)(nil)
+	_ Config[incidentio.Config]     = (*incidentio.Config)(nil)
+	_ Config[jetbrainsspace.Config] = (*jetbrainsspace.Config)(nil)
+	_ Config[line.Config]           = (*line.Config)(nil)
+	_ Config[matrix.Config]         = (*matrix.Config)(nil)
+	_ Config[mattermost.Config]     = (*mattermost.Config)(nil)
+	_ Config[messagebird.Config]    = (*messagebird.Config)(nil)
+	_ Config[newrelic.Config]       = (*newrelic.Config)(nil)
+	_ Config[ntfy.Config]           = (*ntfy.Config)(nil)
+	_ Config[opsgenie.Config]       = (*opsgenie.Config)(nil)
+	_ Config[pagerduty.Config]      = (*pagerduty.Config)(nil)
+	_ Config[plivo.Config]          = (*plivo.Config)(nil)
+	_ Config[pushover.Config]       = (*pushover.Config)(nil)
+	_ Config[rocketchat.Config]     = (*rocketchat.Config)(nil)
+	_ Config[sendgrid.Config]       = (*sendgrid.Config)(nil)
+	_ Config[signal.Config]         = (*signal.Config)(nil)
+	_ Config[signl4.Config]         = (*signl4.Config)(nil)
+	_ Config[slack.Config]          = (*slack.Config)(nil)
+	_ Config[splunk.Config]         = (*splunk.Config)(nil)
+	_ Config[squadcast.Config]      = (*squadcast.Config)(nil)
+	_ Config[teams.Config]          = (*teams.Config)(nil)
+	_ Config[teamsworkflows.Config] = (*teamsworkflows.Config)(nil)
+	_ Config[telegram.Config]       = (*telegram.Config)(nil)
+	_ Config[twilio.Config]         = (*twilio.Config)(nil)
+	_ Config[webex.Config]          = (*webex.Config)(nil)
+	_ Config[zapier.Config]         = (*zapier.Config)(nil)
+	_ Config[zulip.Config]          = (*zulip.Config)(nil)
 )

alerting/provider/provider_test.go

@@ -2,6 +2,7 @@ package provider
 
 import (
 	"testing"
+	"time"
 
 	"github.com/TwiN/gatus/v5/alerting/alert"
 )
@@ -24,6 +25,7 @@ func TestParseWithDefaultAlert(t *testing.T) {
 				Description:      &firstDescription,
 				FailureThreshold: 5,
 				SuccessThreshold: 10,
+				MinimumReminderInterval: 30 * time.Second,
 			},
 			EndpointAlert: &alert.Alert{
 				Type: alert.TypeDiscord,
@@ -35,6 +37,7 @@ func TestParseWithDefaultAlert(t *testing.T) {
 				Description:      &firstDescription,
 				FailureThreshold: 5,
 				SuccessThreshold: 10,
+				MinimumReminderInterval: 30 * time.Second,
 			},
 		},
 		{
@@ -126,7 +129,7 @@ func TestParseWithDefaultAlert(t *testing.T) {
 	}
 	for _, scenario := range scenarios {
 		t.Run(scenario.Name, func(t *testing.T) {
-			ParseWithDefaultAlert(scenario.DefaultAlert, scenario.EndpointAlert)
+			MergeProviderDefaultAlertIntoEndpointAlert(scenario.DefaultAlert, scenario.EndpointAlert)
 			if scenario.ExpectedOutputAlert == nil {
 				if scenario.EndpointAlert != nil {
 					t.Fail()
@@ -148,6 +151,9 @@ func TestParseWithDefaultAlert(t *testing.T) {
 			if scenario.EndpointAlert.SuccessThreshold != scenario.ExpectedOutputAlert.SuccessThreshold {
 				t.Errorf("expected EndpointAlert.SuccessThreshold to be %v, got %v", scenario.ExpectedOutputAlert.SuccessThreshold, scenario.EndpointAlert.SuccessThreshold)
 			}
+			if int(scenario.EndpointAlert.MinimumReminderInterval) != int(scenario.ExpectedOutputAlert.MinimumReminderInterval) {
+				t.Errorf("expected EndpointAlert.MinimumReminderInterval to be %v, got %v", scenario.ExpectedOutputAlert.MinimumReminderInterval, scenario.EndpointAlert.MinimumReminderInterval)
+			}
 		})
 	}
 }

alerting/provider/pushover/pushover.go

@@ -3,6 +3,7 @@ package pushover
 import (
 	"bytes"
 	"encoding/json"
+	"errors"
 	"fmt"
 	"io"
 	"net/http"
@@ -10,15 +11,22 @@ import (
 	"github.com/TwiN/gatus/v5/alerting/alert"
 	"github.com/TwiN/gatus/v5/client"
 	"github.com/TwiN/gatus/v5/config/endpoint"
+	"gopkg.in/yaml.v3"
 )
 
 const (
-	restAPIURL      = "https://api.pushover.net/1/messages.json"
+	ApiURL          = "https://api.pushover.net/1/messages.json"
 	defaultPriority = 0
 )
 
-// AlertProvider is the configuration necessary for sending an alert using Pushover
-type AlertProvider struct {
+var (
+	ErrInvalidApplicationToken = errors.New("application-token must be 30 characters long")
+	ErrInvalidUserKey          = errors.New("user-key must be 30 characters long")
+	ErrInvalidPriority         = errors.New("priority and resolved-priority must be between -2 and 2")
+	ErrInvalidDevice           = errors.New("device name must have 25 characters or less")
+)
+
+type Config struct {
 	// Key used to authenticate the application sending
 	// See "Your Applications" on the dashboard, or add a new one: https://pushover.net/apps/build
 	ApplicationToken string `yaml:"application-token"`
@@ -26,35 +34,103 @@ type AlertProvider struct {
 	// Key of the user or group the messages should be sent to
 	UserKey string `yaml:"user-key"`
 
-	// The title of your message, likely the application name
-	// default: the name of your application in Pushover
+	// The title of your message
+	// default: "Gatus: <endpoint>""
 	Title string `yaml:"title,omitempty"`
 
 	// Priority of all messages, ranging from -2 (very low) to 2 (Emergency)
 	// default: 0
 	Priority int `yaml:"priority,omitempty"`
 
+	// Priority of resolved messages, ranging from -2 (very low) to 2 (Emergency)
+	// default: 0
+	ResolvedPriority int `yaml:"resolved-priority,omitempty"`
+
 	// Sound of the messages (see: https://pushover.net/api#sounds)
 	// default: "" (pushover)
 	Sound string `yaml:"sound,omitempty"`
 
+	// TTL of your message (https://pushover.net/api#ttl)
+	// If priority is 2 then this parameter is ignored
+	// default: 0
+	TTL int `yaml:"ttl,omitempty"`
+
+	// Device to send the message to (see: https://pushover.net/api#devices)
+	// default: "" (all devices)
+	Device string `yaml:"device,omitempty"`
+}
+
+func (cfg *Config) Validate() error {
+	if cfg.Priority == 0 {
+		cfg.Priority = defaultPriority
+	}
+	if cfg.ResolvedPriority == 0 {
+		cfg.ResolvedPriority = defaultPriority
+	}
+	if len(cfg.ApplicationToken) != 30 {
+		return ErrInvalidApplicationToken
+	}
+	if len(cfg.UserKey) != 30 {
+		return ErrInvalidUserKey
+	}
+	if cfg.Priority < -2 || cfg.Priority > 2 || cfg.ResolvedPriority < -2 || cfg.ResolvedPriority > 2 {
+		return ErrInvalidPriority
+	}
+	if len(cfg.Device) > 25 {
+		return ErrInvalidDevice
+	}
+	return nil
+}
+
+func (cfg *Config) Merge(override *Config) {
+	if len(override.ApplicationToken) > 0 {
+		cfg.ApplicationToken = override.ApplicationToken
+	}
+	if len(override.UserKey) > 0 {
+		cfg.UserKey = override.UserKey
+	}
+	if len(override.Title) > 0 {
+		cfg.Title = override.Title
+	}
+	if override.Priority != 0 {
+		cfg.Priority = override.Priority
+	}
+	if override.ResolvedPriority != 0 {
+		cfg.ResolvedPriority = override.ResolvedPriority
+	}
+	if len(override.Sound) > 0 {
+		cfg.Sound = override.Sound
+	}
+	if override.TTL > 0 {
+		cfg.TTL = override.TTL
+	}
+	if len(override.Device) > 0 {
+		cfg.Device = override.Device
+	}
+}
+
+// AlertProvider is the configuration necessary for sending an alert using Pushover
+type AlertProvider struct {
+	DefaultConfig Config `yaml:",inline"`
+
 	// DefaultAlert is the default alert configuration to use for endpoints with an alert of the appropriate type
 	DefaultAlert *alert.Alert `yaml:"default-alert,omitempty"`
 }
 
-// IsValid returns whether the provider's configuration is valid
-func (provider *AlertProvider) IsValid() bool {
-	if provider.Priority == 0 {
-		provider.Priority = defaultPriority
-	}
-	return len(provider.ApplicationToken) == 30 && len(provider.UserKey) == 30 && provider.Priority >= -2 && provider.Priority <= 2
+// Validate the provider's configuration
+func (provider *AlertProvider) Validate() error {
+	return provider.DefaultConfig.Validate()
 }
 
 // Send an alert using the provider
 // Reference doc for pushover: https://pushover.net/api
 func (provider *AlertProvider) Send(ep *endpoint.Endpoint, alert *alert.Alert, result *endpoint.Result, resolved bool) error {
-	buffer := bytes.NewBuffer(provider.buildRequestBody(ep, alert, result, resolved))
-	request, err := http.NewRequest(http.MethodPost, restAPIURL, buffer)
+	cfg, err := provider.GetConfig(ep.Group, alert)
+	if err != nil {
+		return err
+	}
+	buffer := bytes.NewBuffer(provider.buildRequestBody(cfg, ep, alert, result, resolved))
+	request, err := http.NewRequest(http.MethodPost, ApiURL, buffer)
 	if err != nil {
 		return err
 	}
@@ -77,36 +153,76 @@ type Body struct {
 	Title    string `json:"title,omitempty"`
 	Message  string `json:"message"`
 	Priority int    `json:"priority"`
+	Html     int    `json:"html"`
 	Sound    string `json:"sound,omitempty"`
+	TTL      int    `json:"ttl,omitempty"`
+	Device   string `json:"device,omitempty"`
 }
 
 // buildRequestBody builds the request body for the provider
-func (provider *AlertProvider) buildRequestBody(ep *endpoint.Endpoint, alert *alert.Alert, result *endpoint.Result, resolved bool) []byte {
-	var message string
+func (provider *AlertProvider) buildRequestBody(cfg *Config, ep *endpoint.Endpoint, alert *alert.Alert, result *endpoint.Result, resolved bool) []byte {
+	var message, formattedConditionResults string
+	priority := cfg.Priority
 	if resolved {
-		message = fmt.Sprintf("RESOLVED: %s - %s", ep.DisplayName(), alert.GetDescription())
+		priority = cfg.ResolvedPriority
+		message = fmt.Sprintf("An alert for <b>%s</b> has been resolved after passing successfully %d time(s) in a row", ep.DisplayName(), alert.SuccessThreshold)
 	} else {
-		message = fmt.Sprintf("TRIGGERED: %s - %s", ep.DisplayName(), alert.GetDescription())
+		message = fmt.Sprintf("An alert for <b>%s</b> has been triggered due to having failed %d time(s) in a row", ep.DisplayName(), alert.FailureThreshold)
+	}
+	for _, conditionResult := range result.ConditionResults {
+		var prefix string
+		if conditionResult.Success {
+			prefix = "✅"
+		} else {
+			prefix = "❌"
+		}
+		formattedConditionResults += fmt.Sprintf("\n%s - %s", prefix, conditionResult.Condition)
+	}
+	if len(alert.GetDescription()) > 0 {
+		message += " with the following description: " + alert.GetDescription()
+	}
+	message += formattedConditionResults
+	title := "Gatus: " + ep.DisplayName()
+	if cfg.Title != "" {
+		title = cfg.Title
 	}
 	body, _ := json.Marshal(Body{
-		Token:    provider.ApplicationToken,
-		User:     provider.UserKey,
-		Title:    provider.Title,
+		Token:    cfg.ApplicationToken,
+		User:     cfg.UserKey,
+		Title:    title,
 		Message:  message,
-		Priority: provider.priority(),
-		Sound:    provider.Sound,
+		Priority: priority,
+		Html:     1,
+		Sound:    cfg.Sound,
+		TTL:      cfg.TTL,
+		Device:   cfg.Device,
 	})
 	return body
 }
 
-func (provider *AlertProvider) priority() int {
-	if provider.Priority == 0 {
-		return defaultPriority
-	}
-	return provider.Priority
-}
-
 // GetDefaultAlert returns the provider's default alert configuration
 func (provider *AlertProvider) GetDefaultAlert() *alert.Alert {
 	return provider.DefaultAlert
 }
+
+// GetConfig returns the configuration for the provider with the overrides applied
+func (provider *AlertProvider) GetConfig(group string, alert *alert.Alert) (*Config, error) {
+	cfg := provider.DefaultConfig
+	// Handle alert overrides
+	if len(alert.ProviderOverride) != 0 {
+		overrideConfig := Config{}
+		if err := yaml.Unmarshal(alert.ProviderOverrideAsBytes(), &overrideConfig); err != nil {
+			return nil, err
+		}
+		cfg.Merge(&overrideConfig)
+	}
+	// Validate the configuration
+	err := cfg.Validate()
+	return &cfg, err
+}
+
+// ValidateOverrides validates the alert's provider override and, if present, the group override
+func (provider *AlertProvider) ValidateOverrides(group string, alert *alert.Alert) error {
+	_, err := provider.GetConfig(group, alert)
+	return err
+}

alerting/provider/pushover/pushover_test.go

@@ -12,30 +12,38 @@ import (
 )
 
 func TestPushoverAlertProvider_IsValid(t *testing.T) {
-	invalidProvider := AlertProvider{}
-	if invalidProvider.IsValid() {
-		t.Error("provider shouldn't have been valid")
-	}
-	validProvider := AlertProvider{
-		ApplicationToken: "aTokenWithLengthOf30characters",
-		UserKey:          "aTokenWithLengthOf30characters",
-		Title:            "Gatus Notification",
-		Priority:         1,
-	}
-	if !validProvider.IsValid() {
-		t.Error("provider should've been valid")
-	}
-}
-
-func TestPushoverAlertProvider_IsInvalid(t *testing.T) {
-	invalidProvider := AlertProvider{
-		ApplicationToken: "aTokenWithLengthOfMoreThan30characters",
-		UserKey:          "aTokenWithLengthOfMoreThan30characters",
-		Priority:         5,
-	}
-	if invalidProvider.IsValid() {
-		t.Error("provider should've been invalid")
-	}
+	t.Run("empty-invalid-provider", func(t *testing.T) {
+		invalidProvider := AlertProvider{}
+		if err := invalidProvider.Validate(); err == nil {
+			t.Error("provider shouldn't have been valid")
+		}
+	})
+	t.Run("valid-provider", func(t *testing.T) {
+		validProvider := AlertProvider{
+			DefaultConfig: Config{
+				ApplicationToken: "aTokenWithLengthOf30characters",
+				UserKey:          "aTokenWithLengthOf30characters",
+				Title:            "Gatus Notification",
+				Priority:         1,
+				ResolvedPriority: 1,
+			},
+		}
+		if err := validProvider.Validate(); err != nil {
+			t.Error("provider should've been valid")
+		}
+	})
+	t.Run("invalid-provider", func(t *testing.T) {
+		invalidProvider := AlertProvider{
+			DefaultConfig: Config{
+				ApplicationToken: "aTokenWithLengthOfMoreThan30characters",
+				UserKey:          "aTokenWithLengthOfMoreThan30characters",
+				Priority:         5,
+			},
+		}
+		if err := invalidProvider.Validate(); err == nil {
+			t.Error("provider should've been invalid")
+		}
+	})
 }
 
 func TestAlertProvider_Send(t *testing.T) {
@@ -52,7 +60,7 @@ func TestAlertProvider_Send(t *testing.T) {
 	}{
 		{
 			Name:     "triggered",
-			Provider: AlertProvider{},
+			Provider: AlertProvider{DefaultConfig: Config{ApplicationToken: "aTokenWithLengthOf30characters", UserKey: "aTokenWithLengthOf30characters"}},
 			Alert:    alert.Alert{Description: &firstDescription, SuccessThreshold: 5, FailureThreshold: 3},
 			Resolved: false,
 			MockRoundTripper: test.MockRoundTripper(func(r *http.Request) *http.Response {
@@ -62,7 +70,7 @@ func TestAlertProvider_Send(t *testing.T) {
 		},
 		{
 			Name:     "triggered-error",
-			Provider: AlertProvider{},
+			Provider: AlertProvider{DefaultConfig: Config{ApplicationToken: "aTokenWithLengthOf30characters", UserKey: "aTokenWithLengthOf30characters"}},
 			Alert:    alert.Alert{Description: &firstDescription, SuccessThreshold: 5, FailureThreshold: 3},
 			Resolved: false,
 			MockRoundTripper: test.MockRoundTripper(func(r *http.Request) *http.Response {
@@ -72,7 +80,7 @@ func TestAlertProvider_Send(t *testing.T) {
 		},
 		{
 			Name:     "resolved",
-			Provider: AlertProvider{},
+			Provider: AlertProvider{DefaultConfig: Config{ApplicationToken: "aTokenWithLengthOf30characters", UserKey: "aTokenWithLengthOf30characters"}},
 			Alert:    alert.Alert{Description: &secondDescription, SuccessThreshold: 5, FailureThreshold: 3},
 			Resolved: true,
 			MockRoundTripper: test.MockRoundTripper(func(r *http.Request) *http.Response {
@@ -82,7 +90,7 @@ func TestAlertProvider_Send(t *testing.T) {
 		},
 		{
 			Name:     "resolved-error",
-			Provider: AlertProvider{},
+			Provider: AlertProvider{DefaultConfig: Config{ApplicationToken: "aTokenWithLengthOf30characters", UserKey: "aTokenWithLengthOf30characters"}},
 			Alert:    alert.Alert{Description: &secondDescription, SuccessThreshold: 5, FailureThreshold: 3},
 			Resolved: true,
 			MockRoundTripper: test.MockRoundTripper(func(r *http.Request) *http.Response {
@@ -119,37 +127,67 @@ func TestAlertProvider_buildRequestBody(t *testing.T) {
 	firstDescription := "description-1"
 	secondDescription := "description-2"
 	scenarios := []struct {
-		Name         string
-		Provider     AlertProvider
-		Alert        alert.Alert
-		Resolved     bool
-		ExpectedBody string
+		Name             string
+		Provider         AlertProvider
+		Alert            alert.Alert
+		Resolved         bool
+		ResolvedPriority bool
+		ExpectedBody     string
 	}{
 		{
 			Name:         "triggered",
-			Provider:     AlertProvider{ApplicationToken: "TokenWithLengthOf30Characters1", UserKey: "TokenWithLengthOf30Characters4"},
+			Provider:     AlertProvider{DefaultConfig: Config{ApplicationToken: "TokenWithLengthOf30Characters1", UserKey: "TokenWithLengthOf30Characters4"}},
 			Alert:        alert.Alert{Description: &firstDescription, SuccessThreshold: 5, FailureThreshold: 3},
 			Resolved:     false,
-			ExpectedBody: "{\"token\":\"TokenWithLengthOf30Characters1\",\"user\":\"TokenWithLengthOf30Characters4\",\"message\":\"TRIGGERED: endpoint-name - description-1\",\"priority\":0}",
+			ExpectedBody: "{\"token\":\"TokenWithLengthOf30Characters1\",\"user\":\"TokenWithLengthOf30Characters4\",\"title\":\"Gatus: endpoint-name\",\"message\":\"An alert for \\u003cb\\u003eendpoint-name\\u003c/b\\u003e has been triggered due to having failed 3 time(s) in a row with the following description: description-1\\n❌ - [CONNECTED] == true\\n❌ - [STATUS] == 200\",\"priority\":0,\"html\":1}",
+		},
+		{
+			Name:         "triggered-customtitle",
+			Provider:     AlertProvider{DefaultConfig: Config{ApplicationToken: "TokenWithLengthOf30Characters1", UserKey: "TokenWithLengthOf30Characters4", Title: "Gatus Notifications"}},
+			Alert:        alert.Alert{Description: &firstDescription, SuccessThreshold: 5, FailureThreshold: 3},
+			Resolved:     false,
+			ExpectedBody: "{\"token\":\"TokenWithLengthOf30Characters1\",\"user\":\"TokenWithLengthOf30Characters4\",\"title\":\"Gatus Notifications\",\"message\":\"An alert for \\u003cb\\u003eendpoint-name\\u003c/b\\u003e has been triggered due to having failed 3 time(s) in a row with the following description: description-1\\n❌ - [CONNECTED] == true\\n❌ - [STATUS] == 200\",\"priority\":0,\"html\":1}",
 		},
 		{
 			Name:         "resolved",
-			Provider:     AlertProvider{ApplicationToken: "TokenWithLengthOf30Characters2", UserKey: "TokenWithLengthOf30Characters5", Title: "Gatus Notifications", Priority: 2},
+			Provider:     AlertProvider{DefaultConfig: Config{ApplicationToken: "TokenWithLengthOf30Characters2", UserKey: "TokenWithLengthOf30Characters5", Priority: 2, ResolvedPriority: 2}},
 			Alert:        alert.Alert{Description: &secondDescription, SuccessThreshold: 5, FailureThreshold: 3},
 			Resolved:     true,
-			ExpectedBody: "{\"token\":\"TokenWithLengthOf30Characters2\",\"user\":\"TokenWithLengthOf30Characters5\",\"title\":\"Gatus Notifications\",\"message\":\"RESOLVED: endpoint-name - description-2\",\"priority\":2}",
+			ExpectedBody: "{\"token\":\"TokenWithLengthOf30Characters2\",\"user\":\"TokenWithLengthOf30Characters5\",\"title\":\"Gatus: endpoint-name\",\"message\":\"An alert for \\u003cb\\u003eendpoint-name\\u003c/b\\u003e has been resolved after passing successfully 5 time(s) in a row with the following description: description-2\\n✅ - [CONNECTED] == true\\n✅ - [STATUS] == 200\",\"priority\":2,\"html\":1}",
+		},
+		{
+			Name:         "resolved-priority",
+			Provider:     AlertProvider{DefaultConfig: Config{ApplicationToken: "TokenWithLengthOf30Characters2", UserKey: "TokenWithLengthOf30Characters5", Title: "Gatus Notifications", Priority: 2, ResolvedPriority: 0}},
+			Alert:        alert.Alert{Description: &secondDescription, SuccessThreshold: 5, FailureThreshold: 3},
+			Resolved:     true,
+			ExpectedBody: "{\"token\":\"TokenWithLengthOf30Characters2\",\"user\":\"TokenWithLengthOf30Characters5\",\"title\":\"Gatus Notifications\",\"message\":\"An alert for \\u003cb\\u003eendpoint-name\\u003c/b\\u003e has been resolved after passing successfully 5 time(s) in a row with the following description: description-2\\n✅ - [CONNECTED] == true\\n✅ - [STATUS] == 200\",\"priority\":0,\"html\":1}",
 		},
 		{
 			Name:         "with-sound",
-			Provider:     AlertProvider{ApplicationToken: "TokenWithLengthOf30Characters2", UserKey: "TokenWithLengthOf30Characters5", Title: "Gatus Notifications", Priority: 2, Sound: "falling"},
+			Provider:     AlertProvider{DefaultConfig: Config{ApplicationToken: "TokenWithLengthOf30Characters2", UserKey: "TokenWithLengthOf30Characters5", Title: "Gatus Notifications", Priority: 2, ResolvedPriority: 2, Sound: "falling"}},
 			Alert:        alert.Alert{Description: &secondDescription, SuccessThreshold: 5, FailureThreshold: 3},
 			Resolved:     true,
-			ExpectedBody: "{\"token\":\"TokenWithLengthOf30Characters2\",\"user\":\"TokenWithLengthOf30Characters5\",\"title\":\"Gatus Notifications\",\"message\":\"RESOLVED: endpoint-name - description-2\",\"priority\":2,\"sound\":\"falling\"}",
+			ExpectedBody: "{\"token\":\"TokenWithLengthOf30Characters2\",\"user\":\"TokenWithLengthOf30Characters5\",\"title\":\"Gatus Notifications\",\"message\":\"An alert for \\u003cb\\u003eendpoint-name\\u003c/b\\u003e has been resolved after passing successfully 5 time(s) in a row with the following description: description-2\\n✅ - [CONNECTED] == true\\n✅ - [STATUS] == 200\",\"priority\":2,\"html\":1,\"sound\":\"falling\"}",
 		},
+		{
+			Name:         "with-ttl",
+			Provider:     AlertProvider{DefaultConfig: Config{ApplicationToken: "TokenWithLengthOf30Characters2", UserKey: "TokenWithLengthOf30Characters5", Title: "Gatus Notifications", Priority: 2, ResolvedPriority: 2, TTL: 3600}},
+			Alert:        alert.Alert{Description: &secondDescription, SuccessThreshold: 5, FailureThreshold: 3},
+			Resolved:     true,
+			ExpectedBody: "{\"token\":\"TokenWithLengthOf30Characters2\",\"user\":\"TokenWithLengthOf30Characters5\",\"title\":\"Gatus Notifications\",\"message\":\"An alert for \\u003cb\\u003eendpoint-name\\u003c/b\\u003e has been resolved after passing successfully 5 time(s) in a row with the following description: description-2\\n✅ - [CONNECTED] == true\\n✅ - [STATUS] == 200\",\"priority\":2,\"html\":1,\"ttl\":3600}",
+		},
+        {
+            Name:       "with-device",
+            Provider:   AlertProvider{DefaultConfig: Config{ApplicationToken: "TokenWithLengthOf30Characters2", UserKey: "TokenWithLengthOf30Characters5", Title: "Gatus Notifications", Priority: 2, ResolvedPriority: 2, TTL: 3600, Device: "iphone15pro",}},
+            Alert:      alert.Alert{Description: &secondDescription, SuccessThreshold: 5, FailureThreshold: 3},
+            Resolved:   true,
+            ExpectedBody: "{\"token\":\"TokenWithLengthOf30Characters2\",\"user\":\"TokenWithLengthOf30Characters5\",\"title\":\"Gatus Notifications\",\"message\":\"An alert for \\u003cb\\u003eendpoint-name\\u003c/b\\u003e has been resolved after passing successfully 5 time(s) in a row with the following description: description-2\\n✅ - [CONNECTED] == true\\n✅ - [STATUS] == 200\",\"priority\":2,\"html\":1,\"ttl\":3600,\"device\":\"iphone15pro\"}",
+        },
 	}
 	for _, scenario := range scenarios {
 		t.Run(scenario.Name, func(t *testing.T) {
 			body := scenario.Provider.buildRequestBody(
+				&scenario.Provider.DefaultConfig,
 				&endpoint.Endpoint{Name: "endpoint-name"},
 				&scenario.Alert,
 				&endpoint.Result{
@@ -179,3 +217,50 @@ func TestAlertProvider_GetDefaultAlert(t *testing.T) {
 		t.Error("expected default alert to be nil")
 	}
 }
+
+func TestAlertProvider_GetConfig(t *testing.T) {
+	scenarios := []struct {
+		Name           string
+		Provider       AlertProvider
+		InputGroup     string
+		InputAlert     alert.Alert
+		ExpectedOutput Config
+	}{
+		{
+			Name: "provider-no-override-specify-no-group-should-default",
+			Provider: AlertProvider{
+				DefaultConfig: Config{ApplicationToken: "aTokenWithLengthOf30characters", UserKey: "aTokenWithLengthOf30characters"},
+			},
+			InputGroup:     "",
+			InputAlert:     alert.Alert{},
+			ExpectedOutput: Config{ApplicationToken: "aTokenWithLengthOf30characters", UserKey: "aTokenWithLengthOf30characters"},
+		},
+		{
+			Name: "provider-with-alert-override",
+			Provider: AlertProvider{
+				DefaultConfig: Config{ApplicationToken: "aTokenWithLengthOf30characters", UserKey: "aTokenWithLengthOf30characters"},
+			},
+			InputGroup:     "group",
+			InputAlert:     alert.Alert{ProviderOverride: map[string]any{"application-token": "TokenWithLengthOf30Characters2", "user-key": "TokenWithLengthOf30Characters3"}},
+			ExpectedOutput: Config{ApplicationToken: "TokenWithLengthOf30Characters2", UserKey: "TokenWithLengthOf30Characters3"},
+		},
+	}
+	for _, scenario := range scenarios {
+		t.Run(scenario.Name, func(t *testing.T) {
+			got, err := scenario.Provider.GetConfig(scenario.InputGroup, &scenario.InputAlert)
+			if err != nil {
+				t.Fatalf("unexpected error: %s", err)
+			}
+			if got.ApplicationToken != scenario.ExpectedOutput.ApplicationToken {
+				t.Errorf("expected application token to be %s, got %s", scenario.ExpectedOutput.ApplicationToken, got.ApplicationToken)
+			}
+			if got.UserKey != scenario.ExpectedOutput.UserKey {
+				t.Errorf("expected user key to be %s, got %s", scenario.ExpectedOutput.UserKey, got.UserKey)
+			}
+			// Test ValidateOverrides as well, since it really just calls GetConfig
+			if err = scenario.Provider.ValidateOverrides(scenario.InputGroup, &scenario.InputAlert); err != nil {
+				t.Errorf("unexpected error: %s", err)
+			}
+		})
+	}
+}

alerting/provider/rocketchat/rocketchat.go

@@ -0,0 +1,212 @@
+package rocketchat
+
+import (
+	"bytes"
+	"encoding/json"
+	"errors"
+	"fmt"
+	"io"
+	"net/http"
+
+	"github.com/TwiN/gatus/v5/alerting/alert"
+	"github.com/TwiN/gatus/v5/client"
+	"github.com/TwiN/gatus/v5/config/endpoint"
+	"gopkg.in/yaml.v3"
+)
+
+var (
+	ErrWebhookURLNotSet       = errors.New("webhook-url not set")
+	ErrDuplicateGroupOverride = errors.New("duplicate group override")
+)
+
+type Config struct {
+	WebhookURL string `yaml:"webhook-url"`       // Rocket.Chat incoming webhook URL
+	Channel    string `yaml:"channel,omitempty"` // Optional channel override
+}
+
+func (cfg *Config) Validate() error {
+	if len(cfg.WebhookURL) == 0 {
+		return ErrWebhookURLNotSet
+	}
+	return nil
+}
+
+func (cfg *Config) Merge(override *Config) {
+	if len(override.WebhookURL) > 0 {
+		cfg.WebhookURL = override.WebhookURL
+	}
+	if len(override.Channel) > 0 {
+		cfg.Channel = override.Channel
+	}
+}
+
+// AlertProvider is the configuration necessary for sending an alert using Rocket.Chat
+type AlertProvider struct {
+	DefaultConfig Config `yaml:",inline"`
+
+	// DefaultAlert is the default alert configuration to use for endpoints with an alert of the appropriate type
+	DefaultAlert *alert.Alert `yaml:"default-alert,omitempty"`
+
+	// Overrides is a list of Override that may be prioritized over the default configuration
+	Overrides []Override `yaml:"overrides,omitempty"`
+}
+
+// Override is a case under which the default integration is overridden
+type Override struct {
+	Group  string `yaml:"group"`
+	Config `yaml:",inline"`
+}
+
+// Validate the provider's configuration
+func (provider *AlertProvider) Validate() error {
+	registeredGroups := make(map[string]bool)
+	if provider.Overrides != nil {
+		for _, override := range provider.Overrides {
+			if isAlreadyRegistered := registeredGroups[override.Group]; isAlreadyRegistered || override.Group == "" {
+				return ErrDuplicateGroupOverride
+			}
+			registeredGroups[override.Group] = true
+		}
+	}
+	return provider.DefaultConfig.Validate()
+}
+
+// Send an alert using the provider
+func (provider *AlertProvider) Send(ep *endpoint.Endpoint, alert *alert.Alert, result *endpoint.Result, resolved bool) error {
+	cfg, err := provider.GetConfig(ep.Group, alert)
+	if err != nil {
+		return err
+	}
+	body, err := provider.buildRequestBody(cfg, ep, alert, result, resolved)
+	if err != nil {
+		return err
+	}
+	buffer := bytes.NewBuffer(body)
+	request, err := http.NewRequest(http.MethodPost, cfg.WebhookURL, buffer)
+	if err != nil {
+		return err
+	}
+	request.Header.Set("Content-Type", "application/json")
+	response, err := client.GetHTTPClient(nil).Do(request)
+	if err != nil {
+		return err
+	}
+	defer response.Body.Close()
+	if response.StatusCode >= 400 {
+		body, _ := io.ReadAll(response.Body)
+		return fmt.Errorf("call to rocketchat alert returned status code %d: %s", response.StatusCode, string(body))
+	}
+	return nil
+}
+
+type Body struct {
+	Text        string       `json:"text"`
+	Channel     string       `json:"channel,omitempty"`
+	Username    string       `json:"username"`
+	Attachments []Attachment `json:"attachments"`
+}
+
+type Attachment struct {
+	Title      string  `json:"title"`
+	Text       string  `json:"text"`
+	Color      string  `json:"color"`
+	Fields     []Field `json:"fields,omitempty"`
+	AuthorName string  `json:"author_name"`
+	AuthorIcon string  `json:"author_icon"`
+}
+
+type Field struct {
+	Title string `json:"title"`
+	Value string `json:"value"`
+	Short bool   `json:"short"`
+}
+
+// buildRequestBody builds the request body for the provider
+func (provider *AlertProvider) buildRequestBody(cfg *Config, ep *endpoint.Endpoint, alert *alert.Alert, result *endpoint.Result, resolved bool) ([]byte, error) {
+	var message, color string
+	if resolved {
+		message = fmt.Sprintf("An alert for *%s* has been resolved after passing successfully %d time(s) in a row", ep.DisplayName(), alert.SuccessThreshold)
+		color = "#36a64f"
+	} else {
+		message = fmt.Sprintf("An alert for *%s* has been triggered due to having failed %d time(s) in a row", ep.DisplayName(), alert.FailureThreshold)
+		color = "#dd0000"
+	}
+	var formattedConditionResults string
+	for _, conditionResult := range result.ConditionResults {
+		var prefix string
+		if conditionResult.Success {
+			prefix = "✅"
+		} else {
+			prefix = "❌"
+		}
+		formattedConditionResults += fmt.Sprintf("%s - `%s`\n", prefix, conditionResult.Condition)
+	}
+	var description string
+	if alertDescription := alert.GetDescription(); len(alertDescription) > 0 {
+		description = ":\n> " + alertDescription
+	}
+	body := Body{
+		Text:     "",
+		Username: "Gatus",
+		Attachments: []Attachment{
+			{
+				Title:      "🚨 Gatus Alert",
+				Text:       message + description,
+				Color:      color,
+				AuthorName: "Gatus",
+				AuthorIcon: "https://raw.githubusercontent.com/TwiN/gatus/master/.github/assets/logo.png",
+			},
+		},
+	}
+	if cfg.Channel != "" {
+		body.Channel = cfg.Channel
+	}
+	if len(formattedConditionResults) > 0 {
+		body.Attachments[0].Fields = append(body.Attachments[0].Fields, Field{
+			Title: "Condition results",
+			Value: formattedConditionResults,
+			Short: false,
+		})
+	}
+	bodyAsJSON, err := json.Marshal(body)
+	if err != nil {
+		return nil, err
+	}
+	return bodyAsJSON, nil
+}
+
+// GetDefaultAlert returns the provider's default alert configuration
+func (provider *AlertProvider) GetDefaultAlert() *alert.Alert {
+	return provider.DefaultAlert
+}
+
+// GetConfig returns the configuration for the provider with the overrides applied
+func (provider *AlertProvider) GetConfig(group string, alert *alert.Alert) (*Config, error) {
+	cfg := provider.DefaultConfig
+	// Handle group overrides
+	if provider.Overrides != nil {
+		for _, override := range provider.Overrides {
+			if group == override.Group {
+				cfg.Merge(&override.Config)
+				break
+			}
+		}
+	}
+	// Handle alert overrides
+	if len(alert.ProviderOverride) != 0 {
+		overrideConfig := Config{}
+		if err := yaml.Unmarshal(alert.ProviderOverrideAsBytes(), &overrideConfig); err != nil {
+			return nil, err
+		}
+		cfg.Merge(&overrideConfig)
+	}
+	// Validate the configuration
+	err := cfg.Validate()
+	return &cfg, err
+}
+
+// ValidateOverrides validates the alert's provider override and, if present, the group override
+func (provider *AlertProvider) ValidateOverrides(group string, alert *alert.Alert) error {
+	_, err := provider.GetConfig(group, alert)
+	return err
+}

alerting/provider/rocketchat/rocketchat_test.go

@@ -0,0 +1,164 @@
+package rocketchat
+
+import (
+	"encoding/json"
+	"net/http"
+	"strings"
+	"testing"
+
+	"github.com/TwiN/gatus/v5/alerting/alert"
+	"github.com/TwiN/gatus/v5/client"
+	"github.com/TwiN/gatus/v5/config/endpoint"
+	"github.com/TwiN/gatus/v5/test"
+)
+
+func TestAlertProvider_Validate(t *testing.T) {
+	scenarios := []struct {
+		name     string
+		provider AlertProvider
+		expected error
+	}{
+		{
+			name:     "valid",
+			provider: AlertProvider{DefaultConfig: Config{WebhookURL: "https://rocketchat.com/hooks/123/abc"}},
+			expected: nil,
+		},
+		{
+			name:     "valid-with-channel",
+			provider: AlertProvider{DefaultConfig: Config{WebhookURL: "https://rocketchat.com/hooks/123/abc", Channel: "#alerts"}},
+			expected: nil,
+		},
+		{
+			name:     "invalid-webhook-url",
+			provider: AlertProvider{DefaultConfig: Config{}},
+			expected: ErrWebhookURLNotSet,
+		},
+	}
+	for _, scenario := range scenarios {
+		t.Run(scenario.name, func(t *testing.T) {
+			err := scenario.provider.Validate()
+			if err != scenario.expected {
+				t.Errorf("expected %v, got %v", scenario.expected, err)
+			}
+		})
+	}
+}
+
+func TestAlertProvider_Send(t *testing.T) {
+	defer client.InjectHTTPClient(nil)
+	firstDescription := "description-1"
+	secondDescription := "description-2"
+	scenarios := []struct {
+		name             string
+		provider         AlertProvider
+		alert            alert.Alert
+		resolved         bool
+		mockRoundTripper test.MockRoundTripper
+		expectedError    bool
+	}{
+		{
+			name:     "triggered",
+			provider: AlertProvider{DefaultConfig: Config{WebhookURL: "https://rocketchat.com/hooks/123/abc"}},
+			alert:    alert.Alert{Description: &firstDescription, SuccessThreshold: 5, FailureThreshold: 3},
+			resolved: false,
+			mockRoundTripper: test.MockRoundTripper(func(r *http.Request) *http.Response {
+				body := make(map[string]interface{})
+				json.NewDecoder(r.Body).Decode(&body)
+				if body["username"] != "Gatus" {
+					t.Errorf("expected username to be 'Gatus', got %v", body["username"])
+				}
+				attachments := body["attachments"].([]interface{})
+				if len(attachments) != 1 {
+					t.Errorf("expected 1 attachment, got %d", len(attachments))
+				}
+				attachment := attachments[0].(map[string]interface{})
+				if attachment["color"] != "#dd0000" {
+					t.Errorf("expected color to be '#dd0000', got %v", attachment["color"])
+				}
+				text := attachment["text"].(string)
+				if !strings.Contains(text, "failed 3 time(s)") {
+					t.Errorf("expected text to contain failure count, got %s", text)
+				}
+				return &http.Response{StatusCode: http.StatusOK, Body: http.NoBody}
+			}),
+			expectedError: false,
+		},
+		{
+			name:     "triggered-with-channel",
+			provider: AlertProvider{DefaultConfig: Config{WebhookURL: "https://rocketchat.com/hooks/123/abc", Channel: "#alerts"}},
+			alert:    alert.Alert{Description: &firstDescription, SuccessThreshold: 5, FailureThreshold: 3},
+			resolved: false,
+			mockRoundTripper: test.MockRoundTripper(func(r *http.Request) *http.Response {
+				body := make(map[string]interface{})
+				json.NewDecoder(r.Body).Decode(&body)
+				if body["channel"] != "#alerts" {
+					t.Errorf("expected channel to be '#alerts', got %v", body["channel"])
+				}
+				return &http.Response{StatusCode: http.StatusOK, Body: http.NoBody}
+			}),
+			expectedError: false,
+		},
+		{
+			name:     "resolved",
+			provider: AlertProvider{DefaultConfig: Config{WebhookURL: "https://rocketchat.com/hooks/123/abc"}},
+			alert:    alert.Alert{Description: &secondDescription, SuccessThreshold: 5, FailureThreshold: 3},
+			resolved: true,
+			mockRoundTripper: test.MockRoundTripper(func(r *http.Request) *http.Response {
+				body := make(map[string]interface{})
+				json.NewDecoder(r.Body).Decode(&body)
+				attachments := body["attachments"].([]interface{})
+				attachment := attachments[0].(map[string]interface{})
+				if attachment["color"] != "#36a64f" {
+					t.Errorf("expected color to be '#36a64f', got %v", attachment["color"])
+				}
+				text := attachment["text"].(string)
+				if !strings.Contains(text, "resolved") {
+					t.Errorf("expected text to contain 'resolved', got %s", text)
+				}
+				return &http.Response{StatusCode: http.StatusOK, Body: http.NoBody}
+			}),
+			expectedError: false,
+		},
+		{
+			name:     "error-response",
+			provider: AlertProvider{DefaultConfig: Config{WebhookURL: "https://rocketchat.com/hooks/123/abc"}},
+			alert:    alert.Alert{Description: &firstDescription, SuccessThreshold: 5, FailureThreshold: 3},
+			resolved: false,
+			mockRoundTripper: test.MockRoundTripper(func(r *http.Request) *http.Response {
+				return &http.Response{StatusCode: http.StatusBadRequest, Body: http.NoBody}
+			}),
+			expectedError: true,
+		},
+	}
+	for _, scenario := range scenarios {
+		t.Run(scenario.name, func(t *testing.T) {
+			client.InjectHTTPClient(&http.Client{Transport: scenario.mockRoundTripper})
+			err := scenario.provider.Send(
+				&endpoint.Endpoint{Name: "endpoint-name"},
+				&scenario.alert,
+				&endpoint.Result{
+					ConditionResults: []*endpoint.ConditionResult{
+						{Condition: "[CONNECTED] == true", Success: scenario.resolved},
+						{Condition: "[STATUS] == 200", Success: scenario.resolved},
+					},
+				},
+				scenario.resolved,
+			)
+			if scenario.expectedError && err == nil {
+				t.Error("expected error, got none")
+			}
+			if !scenario.expectedError && err != nil {
+				t.Error("expected no error, got", err.Error())
+			}
+		})
+	}
+}
+
+func TestAlertProvider_GetDefaultAlert(t *testing.T) {
+	if (&AlertProvider{DefaultAlert: &alert.Alert{}}).GetDefaultAlert() == nil {
+		t.Error("expected default alert to be not nil")
+	}
+	if (&AlertProvider{DefaultAlert: nil}).GetDefaultAlert() != nil {
+		t.Error("expected default alert to be nil")
+	}
+}

alerting/provider/sendgrid/sendgrid.go

@@ -0,0 +1,248 @@
+package sendgrid
+
+import (
+	"bytes"
+	"encoding/json"
+	"errors"
+	"fmt"
+	"io"
+	"net/http"
+	"strings"
+
+	"github.com/TwiN/gatus/v5/alerting/alert"
+	"github.com/TwiN/gatus/v5/client"
+	"github.com/TwiN/gatus/v5/config/endpoint"
+	"gopkg.in/yaml.v3"
+)
+
+const (
+	ApiURL = "https://api.sendgrid.com/v3/mail/send"
+)
+
+var (
+	ErrAPIKeyNotSet           = errors.New("api-key not set")
+	ErrFromNotSet             = errors.New("from not set")
+	ErrToNotSet               = errors.New("to not set")
+	ErrDuplicateGroupOverride = errors.New("duplicate group override")
+)
+
+type Config struct {
+	APIKey string `yaml:"api-key"`
+	From   string `yaml:"from"`
+	To     string `yaml:"to"`
+
+	// ClientConfig is the configuration of the client used to communicate with the provider's target
+	ClientConfig *client.Config `yaml:"client,omitempty"`
+}
+
+func (cfg *Config) Validate() error {
+	if len(cfg.APIKey) == 0 {
+		return ErrAPIKeyNotSet
+	}
+	if len(cfg.From) == 0 {
+		return ErrFromNotSet
+	}
+	if len(cfg.To) == 0 {
+		return ErrToNotSet
+	}
+	return nil
+}
+
+func (cfg *Config) Merge(override *Config) {
+	if override.ClientConfig != nil {
+		cfg.ClientConfig = override.ClientConfig
+	}
+	if len(override.APIKey) > 0 {
+		cfg.APIKey = override.APIKey
+	}
+	if len(override.From) > 0 {
+		cfg.From = override.From
+	}
+	if len(override.To) > 0 {
+		cfg.To = override.To
+	}
+}
+
+// AlertProvider is the configuration necessary for sending an alert using SendGrid
+type AlertProvider struct {
+	DefaultConfig Config `yaml:",inline"`
+
+	// DefaultAlert is the default alert configuration to use for endpoints with an alert of the appropriate type
+	DefaultAlert *alert.Alert `yaml:"default-alert,omitempty"`
+
+	// Overrides is a list of Override that may be prioritized over the default configuration
+	Overrides []Override `yaml:"overrides,omitempty"`
+}
+
+// Override is a case under which the default integration is overridden
+type Override struct {
+	Group  string `yaml:"group"`
+	Config `yaml:",inline"`
+}
+
+// Validate the provider's configuration
+func (provider *AlertProvider) Validate() error {
+	registeredGroups := make(map[string]bool)
+	if provider.Overrides != nil {
+		for _, override := range provider.Overrides {
+			if isAlreadyRegistered := registeredGroups[override.Group]; isAlreadyRegistered || override.Group == "" {
+				return ErrDuplicateGroupOverride
+			}
+			registeredGroups[override.Group] = true
+		}
+	}
+	return provider.DefaultConfig.Validate()
+}
+
+// Send an alert using the provider
+func (provider *AlertProvider) Send(ep *endpoint.Endpoint, alert *alert.Alert, result *endpoint.Result, resolved bool) error {
+	cfg, err := provider.GetConfig(ep.Group, alert)
+	if err != nil {
+		return err
+	}
+	subject, body := provider.buildMessageSubjectAndBody(ep, alert, result, resolved)
+	payload := provider.buildSendGridPayload(cfg, subject, body)
+	payloadBytes, err := json.Marshal(payload)
+	if err != nil {
+		return err
+	}
+	request, err := http.NewRequest(http.MethodPost, ApiURL, bytes.NewBuffer(payloadBytes))
+	if err != nil {
+		return err
+	}
+	request.Header.Set("Content-Type", "application/json")
+	request.Header.Set("Authorization", "Bearer "+cfg.APIKey)
+	response, err := client.GetHTTPClient(cfg.ClientConfig).Do(request)
+	if err != nil {
+		return err
+	}
+	defer response.Body.Close()
+	if response.StatusCode >= 400 {
+		body, _ := io.ReadAll(response.Body)
+		return fmt.Errorf("call to sendgrid alert returned status code %d: %s", response.StatusCode, string(body))
+	}
+	return nil
+}
+
+type SendGridPayload struct {
+	Personalizations []Personalization `json:"personalizations"`
+	From             Email             `json:"from"`
+	Subject          string            `json:"subject"`
+	Content          []Content         `json:"content"`
+}
+
+type Personalization struct {
+	To []Email `json:"to"`
+}
+
+type Email struct {
+	Email string `json:"email"`
+}
+
+type Content struct {
+	Type  string `json:"type"`
+	Value string `json:"value"`
+}
+
+// buildSendGridPayload builds the SendGrid API payload
+func (provider *AlertProvider) buildSendGridPayload(cfg *Config, subject, body string) SendGridPayload {
+	toEmails := strings.Split(cfg.To, ",")
+	var recipients []Email
+	for _, email := range toEmails {
+		recipients = append(recipients, Email{Email: strings.TrimSpace(email)})
+	}
+	return SendGridPayload{
+		Personalizations: []Personalization{
+			{
+				To: recipients,
+			},
+		},
+		From: Email{
+			Email: cfg.From,
+		},
+		Subject: subject,
+		Content: []Content{
+			{
+				Type:  "text/plain",
+				Value: body,
+			},
+			{
+				Type:  "text/html",
+				Value: strings.ReplaceAll(body, "\n", "<br>"),
+			},
+		},
+	}
+}
+
+// buildMessageSubjectAndBody builds the message subject and body
+func (provider *AlertProvider) buildMessageSubjectAndBody(ep *endpoint.Endpoint, alert *alert.Alert, result *endpoint.Result, resolved bool) (string, string) {
+	var subject, message string
+	if resolved {
+		subject = fmt.Sprintf("[%s] Alert resolved", ep.DisplayName())
+		message = fmt.Sprintf("An alert for %s has been resolved after passing successfully %d time(s) in a row", ep.DisplayName(), alert.SuccessThreshold)
+	} else {
+		subject = fmt.Sprintf("[%s] Alert triggered", ep.DisplayName())
+		message = fmt.Sprintf("An alert for %s has been triggered due to having failed %d time(s) in a row", ep.DisplayName(), alert.FailureThreshold)
+	}
+	var formattedConditionResults string
+	if len(result.ConditionResults) > 0 {
+		formattedConditionResults = "\n\nCondition results:\n"
+		for _, conditionResult := range result.ConditionResults {
+			var prefix string
+			if conditionResult.Success {
+				prefix = "✅"
+			} else {
+				prefix = "❌"
+			}
+			formattedConditionResults += fmt.Sprintf("%s %s\n", prefix, conditionResult.Condition)
+		}
+	}
+	var description string
+	if alertDescription := alert.GetDescription(); len(alertDescription) > 0 {
+		description = "\n\nAlert description: " + alertDescription
+	}
+	var extraLabels string
+	if len(ep.ExtraLabels) > 0 {
+		extraLabels = "\n\nExtra labels:\n"
+		for key, value := range ep.ExtraLabels {
+			extraLabels += fmt.Sprintf("  %s: %s\n", key, value)
+		}
+	}
+	return subject, message + description + extraLabels + formattedConditionResults
+}
+
+// GetDefaultAlert returns the provider's default alert configuration
+func (provider *AlertProvider) GetDefaultAlert() *alert.Alert {
+	return provider.DefaultAlert
+}
+
+// GetConfig returns the configuration for the provider with the overrides applied
+func (provider *AlertProvider) GetConfig(group string, alert *alert.Alert) (*Config, error) {
+	cfg := provider.DefaultConfig
+	// Handle group overrides
+	if provider.Overrides != nil {
+		for _, override := range provider.Overrides {
+			if group == override.Group {
+				cfg.Merge(&override.Config)
+				break
+			}
+		}
+	}
+	// Handle alert overrides
+	if len(alert.ProviderOverride) != 0 {
+		overrideConfig := Config{}
+		if err := yaml.Unmarshal(alert.ProviderOverrideAsBytes(), &overrideConfig); err != nil {
+			return nil, err
+		}
+		cfg.Merge(&overrideConfig)
+	}
+	// Validate the configuration
+	err := cfg.Validate()
+	return &cfg, err
+}
+
+// ValidateOverrides validates the alert's provider override and, if present, the group override
+func (provider *AlertProvider) ValidateOverrides(group string, alert *alert.Alert) error {
+	_, err := provider.GetConfig(group, alert)
+	return err
+}

alerting/provider/sendgrid/sendgrid_test.go

@@ -0,0 +1,517 @@
+package sendgrid
+
+import (
+	"io"
+	"net/http"
+	"strings"
+	"testing"
+
+	"github.com/TwiN/gatus/v5/alerting/alert"
+	"github.com/TwiN/gatus/v5/client"
+	"github.com/TwiN/gatus/v5/config/endpoint"
+	"github.com/TwiN/gatus/v5/test"
+)
+
+func TestAlertProvider_Validate(t *testing.T) {
+	invalidProvider := AlertProvider{DefaultConfig: Config{APIKey: "", From: "", To: ""}}
+	if err := invalidProvider.Validate(); err == nil {
+		t.Error("provider shouldn't have been valid")
+	}
+	validProvider := AlertProvider{DefaultConfig: Config{APIKey: "SG.test", From: "from@example.com", To: "to@example.com"}}
+	if err := validProvider.Validate(); err != nil {
+		t.Error("provider should've been valid")
+	}
+}
+
+func TestAlertProvider_ValidateWithOverride(t *testing.T) {
+	providerWithInvalidOverrideGroup := AlertProvider{
+		DefaultConfig: Config{
+			APIKey: "SG.test",
+			From:   "from@example.com",
+			To:     "to@example.com",
+		},
+		Overrides: []Override{
+			{
+				Config: Config{To: "to@example.com"},
+				Group:  "",
+			},
+		},
+	}
+	if err := providerWithInvalidOverrideGroup.Validate(); err == nil {
+		t.Error("provider with empty Group should not have been valid")
+	}
+	if err := providerWithInvalidOverrideGroup.Validate(); err != ErrDuplicateGroupOverride {
+		t.Error("provider with empty Group should return ErrDuplicateGroupOverride")
+	}
+	providerWithDuplicateOverrideGroups := AlertProvider{
+		DefaultConfig: Config{
+			APIKey: "SG.test",
+			From:   "from@example.com",
+			To:     "to@example.com",
+		},
+		Overrides: []Override{
+			{
+				Config: Config{To: "to1@example.com"},
+				Group:  "group",
+			},
+			{
+				Config: Config{To: "to2@example.com"},
+				Group:  "group",
+			},
+		},
+	}
+	if err := providerWithDuplicateOverrideGroups.Validate(); err == nil {
+		t.Error("provider with duplicate group overrides should not have been valid")
+	}
+	if err := providerWithDuplicateOverrideGroups.Validate(); err != ErrDuplicateGroupOverride {
+		t.Error("provider with duplicate group overrides should return ErrDuplicateGroupOverride")
+	}
+	providerWithValidOverride := AlertProvider{
+		DefaultConfig: Config{
+			APIKey: "SG.test",
+			From:   "from@example.com",
+			To:     "to@example.com",
+		},
+		Overrides: []Override{
+			{
+				Config: Config{To: "to@example.com"},
+				Group:  "group",
+			},
+		},
+	}
+	if err := providerWithValidOverride.Validate(); err != nil {
+		t.Error("provider should've been valid")
+	}
+	providerWithValidMultipleOverrides := AlertProvider{
+		DefaultConfig: Config{
+			APIKey: "SG.test",
+			From:   "from@example.com",
+			To:     "to@example.com",
+		},
+		Overrides: []Override{
+			{
+				Config: Config{To: "group1@example.com"},
+				Group:  "group1",
+			},
+			{
+				Config: Config{To: "group2@example.com"},
+				Group:  "group2",
+			},
+		},
+	}
+	if err := providerWithValidMultipleOverrides.Validate(); err != nil {
+		t.Error("provider with multiple valid overrides should've been valid")
+	}
+}
+
+func TestAlertProvider_Send(t *testing.T) {
+	defer client.InjectHTTPClient(nil)
+	firstDescription := "description-1"
+	secondDescription := "description-2"
+	scenarios := []struct {
+		Name             string
+		Provider         AlertProvider
+		Alert            alert.Alert
+		Resolved         bool
+		MockRoundTripper test.MockRoundTripper
+		ExpectedError    bool
+	}{
+		{
+			Name:     "triggered",
+			Provider: AlertProvider{DefaultConfig: Config{APIKey: "SG.test", From: "from@example.com", To: "to@example.com"}},
+			Alert:    alert.Alert{Description: &firstDescription, SuccessThreshold: 5, FailureThreshold: 3},
+			Resolved: false,
+			MockRoundTripper: test.MockRoundTripper(func(r *http.Request) *http.Response {
+				return &http.Response{StatusCode: http.StatusAccepted, Body: http.NoBody}
+			}),
+			ExpectedError: false,
+		},
+		{
+			Name:     "triggered-error",
+			Provider: AlertProvider{DefaultConfig: Config{APIKey: "SG.test", From: "from@example.com", To: "to@example.com"}},
+			Alert:    alert.Alert{Description: &firstDescription, SuccessThreshold: 5, FailureThreshold: 3},
+			Resolved: false,
+			MockRoundTripper: test.MockRoundTripper(func(r *http.Request) *http.Response {
+				return &http.Response{StatusCode: http.StatusBadRequest, Body: io.NopCloser(strings.NewReader(`{"errors": [{"message": "Invalid API key"}]}`))}
+			}),
+			ExpectedError: true,
+		},
+		{
+			Name:     "resolved",
+			Provider: AlertProvider{DefaultConfig: Config{APIKey: "SG.test", From: "from@example.com", To: "to@example.com"}},
+			Alert:    alert.Alert{Description: &secondDescription, SuccessThreshold: 5, FailureThreshold: 3},
+			Resolved: true,
+			MockRoundTripper: test.MockRoundTripper(func(r *http.Request) *http.Response {
+				return &http.Response{StatusCode: http.StatusAccepted, Body: http.NoBody}
+			}),
+			ExpectedError: false,
+		},
+	}
+	for _, scenario := range scenarios {
+		t.Run(scenario.Name, func(t *testing.T) {
+			client.InjectHTTPClient(&http.Client{Transport: scenario.MockRoundTripper})
+			err := scenario.Provider.Send(
+				&endpoint.Endpoint{Name: "endpoint-name"},
+				&scenario.Alert,
+				&endpoint.Result{
+					ConditionResults: []*endpoint.ConditionResult{
+						{Condition: "[CONNECTED] == true", Success: scenario.Resolved},
+						{Condition: "[STATUS] == 200", Success: scenario.Resolved},
+					},
+				},
+				scenario.Resolved,
+			)
+			if scenario.ExpectedError && err == nil {
+				t.Error("expected error, got none")
+			}
+			if !scenario.ExpectedError && err != nil {
+				t.Error("expected no error, got", err.Error())
+			}
+		})
+	}
+}
+
+func TestAlertProvider_buildSendGridPayload(t *testing.T) {
+	provider := &AlertProvider{}
+	cfg := &Config{
+		From: "test@example.com",
+		To:   "to1@example.com,to2@example.com",
+	}
+	subject := "Test Subject"
+	body := "Test Body\nWith new line"
+	payload := provider.buildSendGridPayload(cfg, subject, body)
+	if payload.Subject != subject {
+		t.Errorf("expected subject to be %s, got %s", subject, payload.Subject)
+	}
+	if payload.From.Email != cfg.From {
+		t.Errorf("expected from email to be %s, got %s", cfg.From, payload.From.Email)
+	}
+	if len(payload.Personalizations) != 1 {
+		t.Errorf("expected 1 personalization, got %d", len(payload.Personalizations))
+	}
+	if len(payload.Personalizations[0].To) != 2 {
+		t.Errorf("expected 2 recipients, got %d", len(payload.Personalizations[0].To))
+	}
+	if payload.Personalizations[0].To[0].Email != "to1@example.com" {
+		t.Errorf("expected first recipient to be to1@example.com, got %s", payload.Personalizations[0].To[0].Email)
+	}
+	if payload.Personalizations[0].To[1].Email != "to2@example.com" {
+		t.Errorf("expected second recipient to be to2@example.com, got %s", payload.Personalizations[0].To[1].Email)
+	}
+	if len(payload.Content) != 2 {
+		t.Errorf("expected 2 content types, got %d", len(payload.Content))
+	}
+	if payload.Content[0].Type != "text/plain" {
+		t.Errorf("expected first content type to be text/plain, got %s", payload.Content[0].Type)
+	}
+	if payload.Content[0].Value != body {
+		t.Errorf("expected plain text content to be %s, got %s", body, payload.Content[0].Value)
+	}
+	if payload.Content[1].Type != "text/html" {
+		t.Errorf("expected second content type to be text/html, got %s", payload.Content[1].Type)
+	}
+	expectedHTML := "Test Body<br>With new line"
+	if payload.Content[1].Value != expectedHTML {
+		t.Errorf("expected HTML content to be %s, got %s", expectedHTML, payload.Content[1].Value)
+	}
+}
+
+func TestAlertProvider_buildMessageSubjectAndBody(t *testing.T) {
+	firstDescription := "description-1"
+	secondDescription := "description-2"
+	scenarios := []struct {
+		Name            string
+		Provider        AlertProvider
+		Alert           alert.Alert
+		Resolved        bool
+		Endpoint        *endpoint.Endpoint
+		ExpectedSubject string
+		ExpectedBody    string
+	}{
+		{
+			Name:            "triggered",
+			Provider:        AlertProvider{},
+			Alert:           alert.Alert{Description: &firstDescription, SuccessThreshold: 5, FailureThreshold: 3},
+			Resolved:        false,
+			Endpoint:        &endpoint.Endpoint{Name: "endpoint-name"},
+			ExpectedSubject: "[endpoint-name] Alert triggered",
+			ExpectedBody:    "An alert for endpoint-name has been triggered due to having failed 3 time(s) in a row\n\nAlert description: description-1\n\nCondition results:\n❌ [CONNECTED] == true\n❌ [STATUS] == 200\n",
+		},
+		{
+			Name:            "resolved",
+			Provider:        AlertProvider{},
+			Alert:           alert.Alert{Description: &secondDescription, SuccessThreshold: 5, FailureThreshold: 3},
+			Resolved:        true,
+			Endpoint:        &endpoint.Endpoint{Name: "endpoint-name"},
+			ExpectedSubject: "[endpoint-name] Alert resolved",
+			ExpectedBody:    "An alert for endpoint-name has been resolved after passing successfully 5 time(s) in a row\n\nAlert description: description-2\n\nCondition results:\n✅ [CONNECTED] == true\n✅ [STATUS] == 200\n",
+		},
+		{
+			Name:            "triggered-with-single-extra-label",
+			Provider:        AlertProvider{},
+			Alert:           alert.Alert{Description: &firstDescription, SuccessThreshold: 5, FailureThreshold: 3},
+			Resolved:        false,
+			Endpoint:        &endpoint.Endpoint{Name: "endpoint-name", ExtraLabels: map[string]string{"environment": "production"}},
+			ExpectedSubject: "[endpoint-name] Alert triggered",
+			ExpectedBody:    "An alert for endpoint-name has been triggered due to having failed 3 time(s) in a row\n\nAlert description: description-1\n\nExtra labels:\n  environment: production\n\n\nCondition results:\n❌ [CONNECTED] == true\n❌ [STATUS] == 200\n",
+		},
+		{
+			Name:            "resolved-with-single-extra-label",
+			Provider:        AlertProvider{},
+			Alert:           alert.Alert{Description: &secondDescription, SuccessThreshold: 5, FailureThreshold: 3},
+			Resolved:        true,
+			Endpoint:        &endpoint.Endpoint{Name: "endpoint-name", ExtraLabels: map[string]string{"service": "api"}},
+			ExpectedSubject: "[endpoint-name] Alert resolved",
+			ExpectedBody:    "An alert for endpoint-name has been resolved after passing successfully 5 time(s) in a row\n\nAlert description: description-2\n\nExtra labels:\n  service: api\n\n\nCondition results:\n✅ [CONNECTED] == true\n✅ [STATUS] == 200\n",
+		},
+		{
+			Name:            "triggered-with-no-extra-labels",
+			Provider:        AlertProvider{},
+			Alert:           alert.Alert{Description: &firstDescription, SuccessThreshold: 5, FailureThreshold: 3},
+			Resolved:        false,
+			Endpoint:        &endpoint.Endpoint{Name: "endpoint-name", ExtraLabels: map[string]string{}},
+			ExpectedSubject: "[endpoint-name] Alert triggered",
+			ExpectedBody:    "An alert for endpoint-name has been triggered due to having failed 3 time(s) in a row\n\nAlert description: description-1\n\nCondition results:\n❌ [CONNECTED] == true\n❌ [STATUS] == 200\n",
+		},
+	}
+	for _, scenario := range scenarios {
+		t.Run(scenario.Name, func(t *testing.T) {
+			subject, body := scenario.Provider.buildMessageSubjectAndBody(
+				scenario.Endpoint,
+				&scenario.Alert,
+				&endpoint.Result{
+					ConditionResults: []*endpoint.ConditionResult{
+						{Condition: "[CONNECTED] == true", Success: scenario.Resolved},
+						{Condition: "[STATUS] == 200", Success: scenario.Resolved},
+					},
+				},
+				scenario.Resolved,
+			)
+			if subject != scenario.ExpectedSubject {
+				t.Errorf("expected subject to be %s, got %s", scenario.ExpectedSubject, subject)
+			}
+			if body != scenario.ExpectedBody {
+				t.Errorf("expected body to be %s, got %s", scenario.ExpectedBody, body)
+			}
+		})
+	}
+}
+
+func TestAlertProvider_GetDefaultAlert(t *testing.T) {
+	if (&AlertProvider{DefaultAlert: &alert.Alert{}}).GetDefaultAlert() == nil {
+		t.Error("expected default alert to be not nil")
+	}
+	if (&AlertProvider{DefaultAlert: nil}).GetDefaultAlert() != nil {
+		t.Error("expected default alert to be nil")
+	}
+}
+
+func TestAlertProvider_GetConfig(t *testing.T) {
+	scenarios := []struct {
+		Name           string
+		Provider       AlertProvider
+		InputGroup     string
+		InputAlert     alert.Alert
+		ExpectedOutput Config
+	}{
+		{
+			Name: "provider-no-override-specify-no-group-should-default",
+			Provider: AlertProvider{
+				DefaultConfig: Config{APIKey: "SG.test", From: "from@example.com", To: "to@example.com"},
+				Overrides:     nil,
+			},
+			InputGroup:     "",
+			InputAlert:     alert.Alert{},
+			ExpectedOutput: Config{APIKey: "SG.test", From: "from@example.com", To: "to@example.com"},
+		},
+		{
+			Name: "provider-no-override-specify-group-should-default",
+			Provider: AlertProvider{
+				DefaultConfig: Config{APIKey: "SG.test", From: "from@example.com", To: "to@example.com"},
+				Overrides:     nil,
+			},
+			InputGroup:     "group",
+			InputAlert:     alert.Alert{},
+			ExpectedOutput: Config{APIKey: "SG.test", From: "from@example.com", To: "to@example.com"},
+		},
+		{
+			Name: "provider-with-override-specify-no-group-should-default",
+			Provider: AlertProvider{
+				DefaultConfig: Config{APIKey: "SG.test", From: "from@example.com", To: "to@example.com"},
+				Overrides: []Override{
+					{
+						Group:  "group",
+						Config: Config{To: "to01@example.com"},
+					},
+				},
+			},
+			InputGroup:     "",
+			InputAlert:     alert.Alert{},
+			ExpectedOutput: Config{APIKey: "SG.test", From: "from@example.com", To: "to@example.com"},
+		},
+		{
+			Name: "provider-with-override-specify-group-should-override",
+			Provider: AlertProvider{
+				DefaultConfig: Config{APIKey: "SG.test", From: "from@example.com", To: "to@example.com"},
+				Overrides: []Override{
+					{
+						Group:  "group",
+						Config: Config{To: "group-to@example.com"},
+					},
+				},
+			},
+			InputGroup:     "group",
+			InputAlert:     alert.Alert{},
+			ExpectedOutput: Config{APIKey: "SG.test", From: "from@example.com", To: "group-to@example.com"},
+		},
+		{
+			Name: "provider-with-group-override-and-alert-override--alert-override-should-take-precedence",
+			Provider: AlertProvider{
+				DefaultConfig: Config{APIKey: "SG.test", From: "from@example.com", To: "to@example.com"},
+				Overrides: []Override{
+					{
+						Group:  "group",
+						Config: Config{To: "group-to@example.com"},
+					},
+				},
+			},
+			InputGroup:     "group",
+			InputAlert:     alert.Alert{ProviderOverride: map[string]any{"api-key": "SG.override", "to": "alert-to@example.com", "from": "alert-from@example.com"}},
+			ExpectedOutput: Config{APIKey: "SG.override", From: "alert-from@example.com", To: "alert-to@example.com"},
+		},
+		{
+			Name: "provider-with-multiple-overrides-pick-correct-group",
+			Provider: AlertProvider{
+				DefaultConfig: Config{APIKey: "SG.default", From: "default@example.com", To: "default@example.com"},
+				Overrides: []Override{
+					{
+						Group:  "group1",
+						Config: Config{APIKey: "SG.group1", To: "group1@example.com"},
+					},
+					{
+						Group:  "group2",
+						Config: Config{APIKey: "SG.group2", From: "group2@example.com"},
+					},
+				},
+			},
+			InputGroup:     "group2",
+			InputAlert:     alert.Alert{},
+			ExpectedOutput: Config{APIKey: "SG.group2", From: "group2@example.com", To: "default@example.com"},
+		},
+		{
+			Name: "provider-partial-override-hierarchy",
+			Provider: AlertProvider{
+				DefaultConfig: Config{APIKey: "SG.default", From: "default@example.com", To: "default@example.com"},
+				Overrides: []Override{
+					{
+						Group:  "test-group",
+						Config: Config{From: "group@example.com"},
+					},
+				},
+			},
+			InputGroup:     "test-group",
+			InputAlert:     alert.Alert{ProviderOverride: map[string]any{"to": "alert@example.com"}},
+			ExpectedOutput: Config{APIKey: "SG.default", From: "group@example.com", To: "alert@example.com"},
+		},
+	}
+	for _, scenario := range scenarios {
+		t.Run(scenario.Name, func(t *testing.T) {
+			got, err := scenario.Provider.GetConfig(scenario.InputGroup, &scenario.InputAlert)
+			if err != nil {
+				t.Fatalf("unexpected error: %s", err)
+			}
+			if got.APIKey != scenario.ExpectedOutput.APIKey {
+				t.Errorf("expected APIKey to be %s, got %s", scenario.ExpectedOutput.APIKey, got.APIKey)
+			}
+			if got.From != scenario.ExpectedOutput.From {
+				t.Errorf("expected From to be %s, got %s", scenario.ExpectedOutput.From, got.From)
+			}
+			if got.To != scenario.ExpectedOutput.To {
+				t.Errorf("expected To to be %s, got %s", scenario.ExpectedOutput.To, got.To)
+			}
+			// Test ValidateOverrides as well, since it really just calls GetConfig
+			if err = scenario.Provider.ValidateOverrides(scenario.InputGroup, &scenario.InputAlert); err != nil {
+				t.Errorf("unexpected error: %s", err)
+			}
+		})
+	}
+}
+
+func TestConfig_Validate(t *testing.T) {
+	scenarios := []struct {
+		Name          string
+		Config        Config
+		ExpectedError error
+	}{
+		{
+			Name:          "missing-api-key",
+			Config:        Config{APIKey: "", From: "test@example.com", To: "to@example.com"},
+			ExpectedError: ErrAPIKeyNotSet,
+		},
+		{
+			Name:          "missing-from",
+			Config:        Config{APIKey: "SG.test", From: "", To: "to@example.com"},
+			ExpectedError: ErrFromNotSet,
+		},
+		{
+			Name:          "missing-to",
+			Config:        Config{APIKey: "SG.test", From: "test@example.com", To: ""},
+			ExpectedError: ErrToNotSet,
+		},
+		{
+			Name:          "valid-config",
+			Config:        Config{APIKey: "SG.test", From: "test@example.com", To: "to@example.com"},
+			ExpectedError: nil,
+		},
+	}
+	for _, scenario := range scenarios {
+		t.Run(scenario.Name, func(t *testing.T) {
+			err := scenario.Config.Validate()
+			if scenario.ExpectedError == nil && err != nil {
+				t.Errorf("expected no error, got %v", err)
+			}
+			if scenario.ExpectedError != nil && err == nil {
+				t.Errorf("expected error %v, got none", scenario.ExpectedError)
+			}
+			if scenario.ExpectedError != nil && err != nil && err.Error() != scenario.ExpectedError.Error() {
+				t.Errorf("expected error %v, got %v", scenario.ExpectedError, err)
+			}
+		})
+	}
+}
+
+func TestConfig_Merge(t *testing.T) {
+	config := Config{APIKey: "SG.original", From: "from@example.com", To: "to@example.com"}
+	override := Config{APIKey: "SG.override", To: "override@example.com"}
+	config.Merge(&override)
+	if config.APIKey != "SG.override" {
+		t.Errorf("expected APIKey to be SG.override, got %s", config.APIKey)
+	}
+	if config.From != "from@example.com" {
+		t.Errorf("expected From to remain from@example.com, got %s", config.From)
+	}
+	if config.To != "override@example.com" {
+		t.Errorf("expected To to be override@example.com, got %s", config.To)
+	}
+}
+
+func TestConfig_MergeWithClientConfig(t *testing.T) {
+	config := Config{APIKey: "SG.original", From: "from@example.com", To: "to@example.com"}
+	override := Config{APIKey: "SG.override", ClientConfig: &client.Config{Timeout: 30000}}
+	config.Merge(&override)
+	if config.APIKey != "SG.override" {
+		t.Errorf("expected APIKey to be SG.override, got %s", config.APIKey)
+	}
+	if config.ClientConfig == nil {
+		t.Error("expected ClientConfig to be set")
+	}
+	if config.ClientConfig.Timeout != 30000 {
+		t.Errorf("expected ClientConfig.Timeout to be 30000, got %d", config.ClientConfig.Timeout)
+	}
+	config2 := Config{APIKey: "SG.test", From: "from@example.com", To: "to@example.com", ClientConfig: &client.Config{Timeout: 10000}}
+	override2 := Config{APIKey: "SG.override2"}
+	config2.Merge(&override2)
+	if config2.ClientConfig.Timeout != 10000 {
+		t.Errorf("expected ClientConfig.Timeout to remain 10000, got %d", config2.ClientConfig.Timeout)
+	}
+}

alerting/provider/signal/signal.go

@@ -0,0 +1,196 @@
+package signal
+
+import (
+	"bytes"
+	"encoding/json"
+	"errors"
+	"fmt"
+	"io"
+	"net/http"
+	"strings"
+
+	"github.com/TwiN/gatus/v5/alerting/alert"
+	"github.com/TwiN/gatus/v5/client"
+	"github.com/TwiN/gatus/v5/config/endpoint"
+	"gopkg.in/yaml.v3"
+)
+
+var (
+	ErrApiURLNotSet           = errors.New("api-url not set")
+	ErrNumberNotSet           = errors.New("number not set")
+	ErrRecipientsNotSet       = errors.New("recipients not set")
+	ErrDuplicateGroupOverride = errors.New("duplicate group override")
+)
+
+type Config struct {
+	ApiURL     string   `yaml:"api-url"`    // Signal API URL (e.g., signal-cli-rest-api instance)
+	Number     string   `yaml:"number"`     // Sender phone number
+	Recipients []string `yaml:"recipients"` // List of recipient phone numbers
+}
+
+func (cfg *Config) Validate() error {
+	if len(cfg.ApiURL) == 0 {
+		return ErrApiURLNotSet
+	}
+	if !strings.HasSuffix(cfg.ApiURL, "/v2/send") {
+		cfg.ApiURL = cfg.ApiURL + "/v2/send"
+	}
+	if len(cfg.Number) == 0 {
+		return ErrNumberNotSet
+	}
+	if len(cfg.Recipients) == 0 {
+		return ErrRecipientsNotSet
+	}
+	return nil
+}
+
+func (cfg *Config) Merge(override *Config) {
+	if len(override.ApiURL) > 0 {
+		cfg.ApiURL = override.ApiURL
+	}
+	if len(override.Number) > 0 {
+		cfg.Number = override.Number
+	}
+	if len(override.Recipients) > 0 {
+		cfg.Recipients = override.Recipients
+	}
+}
+
+// AlertProvider is the configuration necessary for sending an alert using Signal
+type AlertProvider struct {
+	DefaultConfig Config `yaml:",inline"`
+
+	// DefaultAlert is the default alert configuration to use for endpoints with an alert of the appropriate type
+	DefaultAlert *alert.Alert `yaml:"default-alert,omitempty"`
+
+	// Overrides is a list of Override that may be prioritized over the default configuration
+	Overrides []Override `yaml:"overrides,omitempty"`
+}
+
+// Override is a case under which the default integration is overridden
+type Override struct {
+	Group  string `yaml:"group"`
+	Config `yaml:",inline"`
+}
+
+// Validate the provider's configuration
+func (provider *AlertProvider) Validate() error {
+	registeredGroups := make(map[string]bool)
+	if provider.Overrides != nil {
+		for _, override := range provider.Overrides {
+			if isAlreadyRegistered := registeredGroups[override.Group]; isAlreadyRegistered || override.Group == "" {
+				return ErrDuplicateGroupOverride
+			}
+			registeredGroups[override.Group] = true
+		}
+	}
+	return provider.DefaultConfig.Validate()
+}
+
+// Send an alert using the provider
+func (provider *AlertProvider) Send(ep *endpoint.Endpoint, alert *alert.Alert, result *endpoint.Result, resolved bool) error {
+	cfg, err := provider.GetConfig(ep.Group, alert)
+	if err != nil {
+		return err
+	}
+	for _, recipient := range cfg.Recipients {
+		body, err := provider.buildRequestBody(cfg, ep, alert, result, resolved, recipient)
+		if err != nil {
+			return err
+		}
+		buffer := bytes.NewBuffer(body)
+		request, err := http.NewRequest(http.MethodPost, cfg.ApiURL, buffer)
+		if err != nil {
+			return err
+		}
+		request.Header.Set("Content-Type", "application/json")
+		response, err := client.GetHTTPClient(nil).Do(request)
+		if err != nil {
+			return err
+		}
+		if response.StatusCode >= 400 {
+			body, _ := io.ReadAll(response.Body)
+			response.Body.Close()
+			return fmt.Errorf("call to signal alert returned status code %d: %s", response.StatusCode, string(body))
+		}
+		response.Body.Close()
+	}
+	return nil
+}
+
+type Body struct {
+	Message    string   `json:"message"`
+	Number     string   `json:"number"`
+	Recipients []string `json:"recipients"`
+}
+
+// buildRequestBody builds the request body for the provider
+func (provider *AlertProvider) buildRequestBody(cfg *Config, ep *endpoint.Endpoint, alert *alert.Alert, result *endpoint.Result, resolved bool, recipient string) ([]byte, error) {
+	var message string
+	if resolved {
+		message = fmt.Sprintf("🟢 RESOLVED: %s\nAlert has been resolved after passing successfully %d time(s) in a row", ep.DisplayName(), alert.SuccessThreshold)
+	} else {
+		message = fmt.Sprintf("🔴 ALERT: %s\nEndpoint has failed %d time(s) in a row", ep.DisplayName(), alert.FailureThreshold)
+	}
+	if alertDescription := alert.GetDescription(); len(alertDescription) > 0 {
+		message += fmt.Sprintf("\n\nDescription: %s", alertDescription)
+	}
+	if len(result.ConditionResults) > 0 {
+		message += "\n\nCondition results:"
+		for _, conditionResult := range result.ConditionResults {
+			var status string
+			if conditionResult.Success {
+				status = "✅"
+			} else {
+				status = "❌"
+			}
+			message += fmt.Sprintf("\n%s %s", status, conditionResult.Condition)
+		}
+	}
+	body := Body{
+		Message:    message,
+		Number:     cfg.Number,
+		Recipients: []string{recipient},
+	}
+	bodyAsJSON, err := json.Marshal(body)
+	if err != nil {
+		return nil, err
+	}
+	return bodyAsJSON, nil
+}
+
+// GetDefaultAlert returns the provider's default alert configuration
+func (provider *AlertProvider) GetDefaultAlert() *alert.Alert {
+	return provider.DefaultAlert
+}
+
+// GetConfig returns the configuration for the provider with the overrides applied
+func (provider *AlertProvider) GetConfig(group string, alert *alert.Alert) (*Config, error) {
+	cfg := provider.DefaultConfig
+	// Handle group overrides
+	if provider.Overrides != nil {
+		for _, override := range provider.Overrides {
+			if group == override.Group {
+				cfg.Merge(&override.Config)
+				break
+			}
+		}
+	}
+	// Handle alert overrides
+	if len(alert.ProviderOverride) != 0 {
+		overrideConfig := Config{}
+		if err := yaml.Unmarshal(alert.ProviderOverrideAsBytes(), &overrideConfig); err != nil {
+			return nil, err
+		}
+		cfg.Merge(&overrideConfig)
+	}
+	// Validate the configuration
+	err := cfg.Validate()
+	return &cfg, err
+}
+
+// ValidateOverrides validates the alert's provider override and, if present, the group override
+func (provider *AlertProvider) ValidateOverrides(group string, alert *alert.Alert) error {
+	_, err := provider.GetConfig(group, alert)
+	return err
+}

alerting/provider/signal/signal_test.go

@@ -0,0 +1,151 @@
+package signal
+
+import (
+	"encoding/json"
+	"net/http"
+	"strings"
+	"testing"
+
+	"github.com/TwiN/gatus/v5/alerting/alert"
+	"github.com/TwiN/gatus/v5/client"
+	"github.com/TwiN/gatus/v5/config/endpoint"
+	"github.com/TwiN/gatus/v5/test"
+)
+
+func TestAlertProvider_Validate(t *testing.T) {
+	scenarios := []struct {
+		name     string
+		provider AlertProvider
+		expected error
+	}{
+		{
+			name:     "valid",
+			provider: AlertProvider{DefaultConfig: Config{ApiURL: "http://localhost:8080", Number: "+1234567890", Recipients: []string{"+0987654321"}}},
+			expected: nil,
+		},
+		{
+			name:     "invalid-api-url",
+			provider: AlertProvider{DefaultConfig: Config{Number: "+1234567890", Recipients: []string{"+0987654321"}}},
+			expected: ErrApiURLNotSet,
+		},
+		{
+			name:     "invalid-number",
+			provider: AlertProvider{DefaultConfig: Config{ApiURL: "http://localhost:8080", Recipients: []string{"+0987654321"}}},
+			expected: ErrNumberNotSet,
+		},
+		{
+			name:     "invalid-recipients",
+			provider: AlertProvider{DefaultConfig: Config{ApiURL: "http://localhost:8080", Number: "+1234567890"}},
+			expected: ErrRecipientsNotSet,
+		},
+	}
+	for _, scenario := range scenarios {
+		t.Run(scenario.name, func(t *testing.T) {
+			err := scenario.provider.Validate()
+			if err != scenario.expected {
+				t.Errorf("expected %v, got %v", scenario.expected, err)
+			}
+		})
+	}
+}
+
+func TestAlertProvider_Send(t *testing.T) {
+	defer client.InjectHTTPClient(nil)
+	firstDescription := "description-1"
+	secondDescription := "description-2"
+	scenarios := []struct {
+		name             string
+		provider         AlertProvider
+		alert            alert.Alert
+		resolved         bool
+		mockRoundTripper test.MockRoundTripper
+		expectedError    bool
+	}{
+		{
+			name:     "triggered",
+			provider: AlertProvider{DefaultConfig: Config{ApiURL: "http://localhost:8080", Number: "+1234567890", Recipients: []string{"+0987654321", "+1111111111"}}},
+			alert:    alert.Alert{Description: &firstDescription, SuccessThreshold: 5, FailureThreshold: 3},
+			resolved: false,
+			mockRoundTripper: test.MockRoundTripper(func(r *http.Request) *http.Response {
+				if r.URL.Path != "/v2/send" {
+					t.Errorf("expected path /v2/send, got %s", r.URL.Path)
+				}
+				body := make(map[string]interface{})
+				json.NewDecoder(r.Body).Decode(&body)
+				if body["number"] != "+1234567890" {
+					t.Errorf("expected number to be '+1234567890', got %v", body["number"])
+				}
+				recipients := body["recipients"].([]interface{})
+				if len(recipients) != 1 {
+					t.Errorf("expected 1 recipient per request, got %d", len(recipients))
+				}
+				message := body["message"].(string)
+				if !strings.Contains(message, "ALERT") {
+					t.Errorf("expected message to contain 'ALERT', got %s", message)
+				}
+				if !strings.Contains(message, "failed 3 time(s)") {
+					t.Errorf("expected message to contain failure count, got %s", message)
+				}
+				return &http.Response{StatusCode: http.StatusOK, Body: http.NoBody}
+			}),
+			expectedError: false,
+		},
+		{
+			name:     "resolved",
+			provider: AlertProvider{DefaultConfig: Config{ApiURL: "http://localhost:8080", Number: "+1234567890", Recipients: []string{"+0987654321"}}},
+			alert:    alert.Alert{Description: &secondDescription, SuccessThreshold: 5, FailureThreshold: 3},
+			resolved: true,
+			mockRoundTripper: test.MockRoundTripper(func(r *http.Request) *http.Response {
+				body := make(map[string]interface{})
+				json.NewDecoder(r.Body).Decode(&body)
+				message := body["message"].(string)
+				if !strings.Contains(message, "RESOLVED") {
+					t.Errorf("expected message to contain 'RESOLVED', got %s", message)
+				}
+				return &http.Response{StatusCode: http.StatusOK, Body: http.NoBody}
+			}),
+			expectedError: false,
+		},
+		{
+			name:     "error-response",
+			provider: AlertProvider{DefaultConfig: Config{ApiURL: "http://localhost:8080", Number: "+1234567890", Recipients: []string{"+0987654321"}}},
+			alert:    alert.Alert{Description: &firstDescription, SuccessThreshold: 5, FailureThreshold: 3},
+			resolved: false,
+			mockRoundTripper: test.MockRoundTripper(func(r *http.Request) *http.Response {
+				return &http.Response{StatusCode: http.StatusInternalServerError, Body: http.NoBody}
+			}),
+			expectedError: true,
+		},
+	}
+	for _, scenario := range scenarios {
+		t.Run(scenario.name, func(t *testing.T) {
+			client.InjectHTTPClient(&http.Client{Transport: scenario.mockRoundTripper})
+			err := scenario.provider.Send(
+				&endpoint.Endpoint{Name: "endpoint-name"},
+				&scenario.alert,
+				&endpoint.Result{
+					ConditionResults: []*endpoint.ConditionResult{
+						{Condition: "[CONNECTED] == true", Success: scenario.resolved},
+						{Condition: "[STATUS] == 200", Success: scenario.resolved},
+					},
+				},
+				scenario.resolved,
+			)
+			if scenario.expectedError && err == nil {
+				t.Error("expected error, got none")
+			}
+			if !scenario.expectedError && err != nil {
+				t.Error("expected no error, got", err.Error())
+			}
+		})
+	}
+}
+
+func TestAlertProvider_GetDefaultAlert(t *testing.T) {
+	if (&AlertProvider{DefaultAlert: &alert.Alert{}}).GetDefaultAlert() == nil {
+		t.Error("expected default alert to be not nil")
+	}
+	if (&AlertProvider{DefaultAlert: nil}).GetDefaultAlert() != nil {
+		t.Error("expected default alert to be nil")
+	}
+}

alerting/provider/signl4/signl4.go

@@ -0,0 +1,184 @@
+package signl4
+
+import (
+	"bytes"
+	"encoding/json"
+	"errors"
+	"fmt"
+	"io"
+	"net/http"
+
+	"github.com/TwiN/gatus/v5/alerting/alert"
+	"github.com/TwiN/gatus/v5/client"
+	"github.com/TwiN/gatus/v5/config/endpoint"
+	"gopkg.in/yaml.v3"
+)
+
+var (
+	ErrTeamSecretNotSet       = errors.New("team-secret not set")
+	ErrDuplicateGroupOverride = errors.New("duplicate group override")
+)
+
+type Config struct {
+	TeamSecret string `yaml:"team-secret"` // SIGNL4 team secret
+}
+
+func (cfg *Config) Validate() error {
+	if len(cfg.TeamSecret) == 0 {
+		return ErrTeamSecretNotSet
+	}
+	return nil
+}
+
+func (cfg *Config) Merge(override *Config) {
+	if len(override.TeamSecret) > 0 {
+		cfg.TeamSecret = override.TeamSecret
+	}
+}
+
+// AlertProvider is the configuration necessary for sending an alert using SIGNL4
+type AlertProvider struct {
+	DefaultConfig Config `yaml:",inline"`
+
+	// DefaultAlert is the default alert configuration to use for endpoints with an alert of the appropriate type
+	DefaultAlert *alert.Alert `yaml:"default-alert,omitempty"`
+
+	// Overrides is a list of Override that may be prioritized over the default configuration
+	Overrides []Override `yaml:"overrides,omitempty"`
+}
+
+// Override is a case under which the default integration is overridden
+type Override struct {
+	Group  string `yaml:"group"`
+	Config `yaml:",inline"`
+}
+
+// Validate the provider's configuration
+func (provider *AlertProvider) Validate() error {
+	registeredGroups := make(map[string]bool)
+	if provider.Overrides != nil {
+		for _, override := range provider.Overrides {
+			if isAlreadyRegistered := registeredGroups[override.Group]; isAlreadyRegistered || override.Group == "" {
+				return ErrDuplicateGroupOverride
+			}
+			registeredGroups[override.Group] = true
+		}
+	}
+	return provider.DefaultConfig.Validate()
+}
+
+// Send an alert using the provider
+func (provider *AlertProvider) Send(ep *endpoint.Endpoint, alert *alert.Alert, result *endpoint.Result, resolved bool) error {
+	cfg, err := provider.GetConfig(ep.Group, alert)
+	if err != nil {
+		return err
+	}
+	body, err := provider.buildRequestBody(ep, alert, result, resolved)
+	if err != nil {
+		return err
+	}
+	buffer := bytes.NewBuffer(body)
+	webhookURL := fmt.Sprintf("https://connect.signl4.com/webhook/%s", cfg.TeamSecret)
+	request, err := http.NewRequest(http.MethodPost, webhookURL, buffer)
+	if err != nil {
+		return err
+	}
+	request.Header.Set("Content-Type", "application/json")
+	response, err := client.GetHTTPClient(nil).Do(request)
+	if err != nil {
+		return err
+	}
+	defer response.Body.Close()
+	if response.StatusCode >= 400 {
+		body, _ := io.ReadAll(response.Body)
+		return fmt.Errorf("call to signl4 alert returned status code %d: %s", response.StatusCode, string(body))
+	}
+	return nil
+}
+
+type Body struct {
+	Title         string `json:"Title"`
+	Message       string `json:"Message"`
+	XS4Service    string `json:"X-S4-Service"`
+	XS4Status     string `json:"X-S4-Status"`
+	XS4ExternalID string `json:"X-S4-ExternalID"`
+}
+
+// buildRequestBody builds the request body for the provider
+func (provider *AlertProvider) buildRequestBody(ep *endpoint.Endpoint, alert *alert.Alert, result *endpoint.Result, resolved bool) ([]byte, error) {
+	var title, message, status string
+	if resolved {
+		title = fmt.Sprintf("RESOLVED: %s", ep.DisplayName())
+		message = fmt.Sprintf("An alert for %s has been resolved after passing successfully %d time(s) in a row", ep.DisplayName(), alert.SuccessThreshold)
+		status = "resolved"
+	} else {
+		title = fmt.Sprintf("TRIGGERED: %s", ep.DisplayName())
+		message = fmt.Sprintf("An alert for %s has been triggered due to having failed %d time(s) in a row", ep.DisplayName(), alert.FailureThreshold)
+		status = "new"
+	}
+	var conditionResults string
+	if len(result.ConditionResults) > 0 {
+		conditionResults = "\n\nCondition results:\n"
+		for _, conditionResult := range result.ConditionResults {
+			var prefix string
+			if conditionResult.Success {
+				prefix = "✓"
+			} else {
+				prefix = "✗"
+			}
+			conditionResults += fmt.Sprintf("%s %s\n", prefix, conditionResult.Condition)
+		}
+	}
+	if alertDescription := alert.GetDescription(); len(alertDescription) > 0 {
+		message += "\n\nDescription: " + alertDescription
+	}
+	message += conditionResults
+	body := Body{
+		Title:         title,
+		Message:       message,
+		XS4Service:    ep.DisplayName(),
+		XS4Status:     status,
+		XS4ExternalID: fmt.Sprintf("gatus-%s", ep.Key()),
+	}
+	bodyAsJSON, err := json.Marshal(body)
+	if err != nil {
+		return nil, err
+	}
+	return bodyAsJSON, nil
+}
+
+// GetDefaultAlert returns the provider's default alert configuration
+func (provider *AlertProvider) GetDefaultAlert() *alert.Alert {
+	return provider.DefaultAlert
+}
+
+// GetConfig returns the configuration for the provider with the overrides applied
+func (provider *AlertProvider) GetConfig(group string, alert *alert.Alert) (*Config, error) {
+	cfg := provider.DefaultConfig
+	// Handle group overrides
+	if provider.Overrides != nil {
+		for _, override := range provider.Overrides {
+			if group == override.Group {
+				cfg.Merge(&override.Config)
+				break
+			}
+		}
+	}
+	// Handle alert overrides
+	if len(alert.ProviderOverride) != 0 {
+		overrideConfig := Config{}
+		if err := yaml.Unmarshal(alert.ProviderOverrideAsBytes(), &overrideConfig); err != nil {
+			return nil, err
+		}
+		cfg.Merge(&overrideConfig)
+	}
+	// Validate the configuration
+	err := cfg.Validate()
+	return &cfg, err
+}
+
+// ValidateOverrides validates the alert's provider override and, if present, the group override
+func (provider *AlertProvider) ValidateOverrides(group string, alert *alert.Alert) error {
+	_, err := provider.GetConfig(group, alert)
+	return err
+}

alerting/provider/signl4/signl4_test.go

@@ -0,0 +1,392 @@
+package signl4
+
+import (
+	"encoding/json"
+	"net/http"
+	"testing"
+
+	"github.com/TwiN/gatus/v5/alerting/alert"
+	"github.com/TwiN/gatus/v5/client"
+	"github.com/TwiN/gatus/v5/config/endpoint"
+	"github.com/TwiN/gatus/v5/test"
+)
+
+func TestAlertProvider_Validate(t *testing.T) {
+	invalidProvider := AlertProvider{DefaultConfig: Config{TeamSecret: ""}}
+	if err := invalidProvider.Validate(); err == nil {
+		t.Error("provider shouldn't have been valid")
+	}
+	validProvider := AlertProvider{DefaultConfig: Config{TeamSecret: "team-secret-123"}}
+	if err := validProvider.Validate(); err != nil {
+		t.Error("provider should've been valid")
+	}
+}
+
+func TestAlertProvider_ValidateWithOverride(t *testing.T) {
+	providerWithInvalidOverrideGroup := AlertProvider{
+		Overrides: []Override{
+			{
+				Config: Config{TeamSecret: "team-secret-123"},
+				Group:  "",
+			},
+		},
+	}
+	if err := providerWithInvalidOverrideGroup.Validate(); err == nil {
+		t.Error("provider Group shouldn't have been valid")
+	}
+	providerWithInvalidOverrideTo := AlertProvider{
+		Overrides: []Override{
+			{
+				Config: Config{TeamSecret: ""},
+				Group:  "group",
+			},
+		},
+	}
+	if err := providerWithInvalidOverrideTo.Validate(); err == nil {
+		t.Error("provider team secret shouldn't have been valid")
+	}
+	providerWithValidOverride := AlertProvider{
+		DefaultConfig: Config{TeamSecret: "team-secret-123"},
+		Overrides: []Override{
+			{
+				Config: Config{TeamSecret: "team-secret-override"},
+				Group:  "group",
+			},
+		},
+	}
+	if err := providerWithValidOverride.Validate(); err != nil {
+		t.Error("provider should've been valid")
+	}
+}
+
+func TestAlertProvider_Send(t *testing.T) {
+	defer client.InjectHTTPClient(nil)
+	firstDescription := "description-1"
+	secondDescription := "description-2"
+	scenarios := []struct {
+		Name             string
+		Provider         AlertProvider
+		Alert            alert.Alert
+		Resolved         bool
+		MockRoundTripper test.MockRoundTripper
+		ExpectedError    bool
+	}{
+		{
+			Name:     "triggered",
+			Provider: AlertProvider{DefaultConfig: Config{TeamSecret: "team-secret-123"}},
+			Alert:    alert.Alert{Description: &firstDescription, SuccessThreshold: 5, FailureThreshold: 3},
+			Resolved: false,
+			MockRoundTripper: test.MockRoundTripper(func(r *http.Request) *http.Response {
+				return &http.Response{StatusCode: http.StatusOK, Body: http.NoBody}
+			}),
+			ExpectedError: false,
+		},
+		{
+			Name:     "triggered-error",
+			Provider: AlertProvider{DefaultConfig: Config{TeamSecret: "team-secret-123"}},
+			Alert:    alert.Alert{Description: &firstDescription, SuccessThreshold: 5, FailureThreshold: 3},
+			Resolved: false,
+			MockRoundTripper: test.MockRoundTripper(func(r *http.Request) *http.Response {
+				return &http.Response{StatusCode: http.StatusInternalServerError, Body: http.NoBody}
+			}),
+			ExpectedError: true,
+		},
+		{
+			Name:     "resolved",
+			Provider: AlertProvider{DefaultConfig: Config{TeamSecret: "team-secret-123"}},
+			Alert:    alert.Alert{Description: &secondDescription, SuccessThreshold: 5, FailureThreshold: 3},
+			Resolved: true,
+			MockRoundTripper: test.MockRoundTripper(func(r *http.Request) *http.Response {
+				return &http.Response{StatusCode: http.StatusOK, Body: http.NoBody}
+			}),
+			ExpectedError: false,
+		},
+		{
+			Name:     "resolved-error",
+			Provider: AlertProvider{DefaultConfig: Config{TeamSecret: "team-secret-123"}},
+			Alert:    alert.Alert{Description: &secondDescription, SuccessThreshold: 5, FailureThreshold: 3},
+			Resolved: true,
+			MockRoundTripper: test.MockRoundTripper(func(r *http.Request) *http.Response {
+				return &http.Response{StatusCode: http.StatusInternalServerError, Body: http.NoBody}
+			}),
+			ExpectedError: true,
+		},
+	}
+	for _, scenario := range scenarios {
+		t.Run(scenario.Name, func(t *testing.T) {
+			client.InjectHTTPClient(&http.Client{Transport: scenario.MockRoundTripper})
+			err := scenario.Provider.Send(
+				&endpoint.Endpoint{Name: "endpoint-name"},
+				&scenario.Alert,
+				&endpoint.Result{
+					ConditionResults: []*endpoint.ConditionResult{
+						{Condition: "[CONNECTED] == true", Success: scenario.Resolved},
+						{Condition: "[STATUS] == 200", Success: scenario.Resolved},
+					},
+				},
+				scenario.Resolved,
+			)
+			if scenario.ExpectedError && err == nil {
+				t.Error("expected error, got none")
+			}
+			if !scenario.ExpectedError && err != nil {
+				t.Error("expected no error, got", err.Error())
+			}
+		})
+	}
+}
+
+func TestAlertProvider_buildRequestBody(t *testing.T) {
+	firstDescription := "description-1"
+	secondDescription := "description-2"
+	scenarios := []struct {
+		Name         string
+		Provider     AlertProvider
+		Endpoint     endpoint.Endpoint
+		Alert        alert.Alert
+		NoConditions bool
+		Resolved     bool
+		ExpectedBody string
+	}{
+		{
+			Name:         "triggered",
+			Provider:     AlertProvider{},
+			Endpoint:     endpoint.Endpoint{Name: "name"},
+			Alert:        alert.Alert{Description: &firstDescription, SuccessThreshold: 5, FailureThreshold: 3},
+			Resolved:     false,
+			ExpectedBody: "{\"Title\":\"TRIGGERED: name\",\"Message\":\"An alert for name has been triggered due to having failed 3 time(s) in a row\\n\\nDescription: description-1\\n\\nCondition results:\\n✗ [CONNECTED] == true\\n✗ [STATUS] == 200\\n\",\"X-S4-Service\":\"name\",\"X-S4-Status\":\"new\",\"X-S4-ExternalID\":\"gatus-_name\"}",
+		},
+		{
+			Name:         "triggered-with-group",
+			Provider:     AlertProvider{},
+			Endpoint:     endpoint.Endpoint{Name: "name", Group: "group"},
+			Alert:        alert.Alert{Description: &firstDescription, SuccessThreshold: 5, FailureThreshold: 3},
+			Resolved:     false,
+			ExpectedBody: "{\"Title\":\"TRIGGERED: group/name\",\"Message\":\"An alert for group/name has been triggered due to having failed 3 time(s) in a row\\n\\nDescription: description-1\\n\\nCondition results:\\n✗ [CONNECTED] == true\\n✗ [STATUS] == 200\\n\",\"X-S4-Service\":\"group/name\",\"X-S4-Status\":\"new\",\"X-S4-ExternalID\":\"gatus-group_name\"}",
+		},
+		{
+			Name:         "triggered-with-no-conditions",
+			NoConditions: true,
+			Provider:     AlertProvider{},
+			Endpoint:     endpoint.Endpoint{Name: "name"},
+			Alert:        alert.Alert{Description: &firstDescription, SuccessThreshold: 5, FailureThreshold: 3},
+			Resolved:     false,
+			ExpectedBody: "{\"Title\":\"TRIGGERED: name\",\"Message\":\"An alert for name has been triggered due to having failed 3 time(s) in a row\\n\\nDescription: description-1\",\"X-S4-Service\":\"name\",\"X-S4-Status\":\"new\",\"X-S4-ExternalID\":\"gatus-_name\"}",
+		},
+		{
+			Name:         "resolved",
+			Provider:     AlertProvider{},
+			Endpoint:     endpoint.Endpoint{Name: "name"},
+			Alert:        alert.Alert{Description: &secondDescription, SuccessThreshold: 5, FailureThreshold: 3},
+			Resolved:     true,
+			ExpectedBody: "{\"Title\":\"RESOLVED: name\",\"Message\":\"An alert for name has been resolved after passing successfully 5 time(s) in a row\\n\\nDescription: description-2\\n\\nCondition results:\\n✓ [CONNECTED] == true\\n✓ [STATUS] == 200\\n\",\"X-S4-Service\":\"name\",\"X-S4-Status\":\"resolved\",\"X-S4-ExternalID\":\"gatus-_name\"}",
+		},
+		{
+			Name:         "resolved-with-group",
+			Provider:     AlertProvider{},
+			Endpoint:     endpoint.Endpoint{Name: "name", Group: "group"},
+			Alert:        alert.Alert{Description: &secondDescription, SuccessThreshold: 5, FailureThreshold: 3},
+			Resolved:     true,
+			ExpectedBody: "{\"Title\":\"RESOLVED: group/name\",\"Message\":\"An alert for group/name has been resolved after passing successfully 5 time(s) in a row\\n\\nDescription: description-2\\n\\nCondition results:\\n✓ [CONNECTED] == true\\n✓ [STATUS] == 200\\n\",\"X-S4-Service\":\"group/name\",\"X-S4-Status\":\"resolved\",\"X-S4-ExternalID\":\"gatus-group_name\"}",
+		},
+	}
+	for _, scenario := range scenarios {
+		t.Run(scenario.Name, func(t *testing.T) {
+			var conditionResults []*endpoint.ConditionResult
+			if !scenario.NoConditions {
+				conditionResults = []*endpoint.ConditionResult{
+					{Condition: "[CONNECTED] == true", Success: scenario.Resolved},
+					{Condition: "[STATUS] == 200", Success: scenario.Resolved},
+				}
+			}
+			body, err := scenario.Provider.buildRequestBody(
+				&scenario.Endpoint,
+				&scenario.Alert,
+				&endpoint.Result{
+					ConditionResults: conditionResults,
+				},
+				scenario.Resolved,
+			)
+			if err != nil {
+				t.Fatalf("buildRequestBody returned an error: %v", err)
+			}
+			if string(body) != scenario.ExpectedBody {
+				t.Errorf("expected:\n%s\ngot:\n%s", scenario.ExpectedBody, body)
+			}
+			out := make(map[string]interface{})
+			if err := json.Unmarshal(body, &out); err != nil {
+				t.Error("expected body to be valid JSON, got error:", err.Error())
+			}
+		})
+	}
+}
+
+func TestAlertProvider_GetDefaultAlert(t *testing.T) {
+	if (&AlertProvider{DefaultAlert: &alert.Alert{}}).GetDefaultAlert() == nil {
+		t.Error("expected default alert to be not nil")
+	}
+	if (&AlertProvider{DefaultAlert: nil}).GetDefaultAlert() != nil {
+		t.Error("expected default alert to be nil")
+	}
+}
+
+func TestAlertProvider_GetConfig(t *testing.T) {
+	scenarios := []struct {
+		Name           string
+		Provider       AlertProvider
+		InputGroup     string
+		InputAlert     alert.Alert
+		ExpectedOutput Config
+	}{
+		{
+			Name: "provider-no-override-specify-no-group-should-default",
+			Provider: AlertProvider{
+				DefaultConfig: Config{TeamSecret: "team-secret-123"},
+				Overrides:     nil,
+			},
+			InputGroup:     "",
+			InputAlert:     alert.Alert{},
+			ExpectedOutput: Config{TeamSecret: "team-secret-123"},
+		},
+		{
+			Name: "provider-no-override-specify-group-should-default",
+			Provider: AlertProvider{
+				DefaultConfig: Config{TeamSecret: "team-secret-123"},
+				Overrides:     nil,
+			},
+			InputGroup:     "group",
+			InputAlert:     alert.Alert{},
+			ExpectedOutput: Config{TeamSecret: "team-secret-123"},
+		},
+		{
+			Name: "provider-with-override-specify-no-group-should-default",
+			Provider: AlertProvider{
+				DefaultConfig: Config{TeamSecret: "team-secret-123"},
+				Overrides: []Override{
+					{
+						Group:  "group",
+						Config: Config{TeamSecret: "team-secret-override"},
+					},
+				},
+			},
+			InputGroup:     "",
+			InputAlert:     alert.Alert{},
+			ExpectedOutput: Config{TeamSecret: "team-secret-123"},
+		},
+		{
+			Name: "provider-with-override-specify-group-should-override",
+			Provider: AlertProvider{
+				DefaultConfig: Config{TeamSecret: "team-secret-123"},
+				Overrides: []Override{
+					{
+						Group:  "group",
+						Config: Config{TeamSecret: "team-secret-override"},
+					},
+				},
+			},
+			InputGroup:     "group",
+			InputAlert:     alert.Alert{},
+			ExpectedOutput: Config{TeamSecret: "team-secret-override"},
+		},
+		{
+			Name: "provider-with-group-override-and-alert-override--alert-override-should-take-precedence",
+			Provider: AlertProvider{
+				DefaultConfig: Config{TeamSecret: "team-secret-123"},
+				Overrides: []Override{
+					{
+						Group:  "group",
+						Config: Config{TeamSecret: "team-secret-override"},
+					},
+				},
+			},
+			InputGroup:     "group",
+			InputAlert:     alert.Alert{ProviderOverride: map[string]any{"team-secret": "team-secret-alert"}},
+			ExpectedOutput: Config{TeamSecret: "team-secret-alert"},
+		},
+	}
+	for _, scenario := range scenarios {
+		t.Run(scenario.Name, func(t *testing.T) {
+			got, err := scenario.Provider.GetConfig(scenario.InputGroup, &scenario.InputAlert)
+			if err != nil {
+				t.Fatalf("unexpected error: %s", err)
+			}
+			if got.TeamSecret != scenario.ExpectedOutput.TeamSecret {
+				t.Errorf("expected team secret to be %s, got %s", scenario.ExpectedOutput.TeamSecret, got.TeamSecret)
+			}
+			// Test ValidateOverrides as well, since it really just calls GetConfig
+			if err = scenario.Provider.ValidateOverrides(scenario.InputGroup, &scenario.InputAlert); err != nil {
+				t.Errorf("unexpected error: %s", err)
+			}
+		})
+	}
+}
+
+func TestAlertProvider_GetConfigWithInvalidAlertOverride(t *testing.T) {
+	// Test case 1: Empty override should be ignored, default config should be used
+	provider := AlertProvider{
+		DefaultConfig: Config{TeamSecret: "team-secret-123"},
+	}
+	alertWithEmptyOverride := alert.Alert{
+		ProviderOverride: map[string]any{"team-secret": ""},
+	}
+	cfg, err := provider.GetConfig("", &alertWithEmptyOverride)
+	if err != nil {
+		t.Errorf("unexpected error: %v", err)
+	}
+	if cfg.TeamSecret != "team-secret-123" {
+		t.Errorf("expected team secret to remain default 'team-secret-123', got %s", cfg.TeamSecret)
+	}
+
+	// Test case 2: Invalid default config with no valid override should fail
+	providerWithInvalidDefault := AlertProvider{
+		DefaultConfig: Config{TeamSecret: ""},
+	}
+	alertWithEmptyOverride2 := alert.Alert{
+		ProviderOverride: map[string]any{"team-secret": ""},
+	}
+	_, err = providerWithInvalidDefault.GetConfig("", &alertWithEmptyOverride2)
+	if err == nil {
+		t.Error("expected error due to invalid default config, got none")
+	}
+	if err != ErrTeamSecretNotSet {
+		t.Errorf("expected ErrTeamSecretNotSet, got %v", err)
+	}
+}
+
+func TestAlertProvider_ValidateWithDuplicateGroupOverride(t *testing.T) {
+	providerWithDuplicateOverride := AlertProvider{
+		DefaultConfig: Config{TeamSecret: "team-secret-123"},
+		Overrides: []Override{
+			{
+				Group:  "group1",
+				Config: Config{TeamSecret: "team-secret-override-1"},
+			},
+			{
+				Group:  "group1",
+				Config: Config{TeamSecret: "team-secret-override-2"},
+			},
+		},
+	}
+	if err := providerWithDuplicateOverride.Validate(); err == nil {
+		t.Error("provider should not have been valid due to duplicate group override")
+	}
+	if err := providerWithDuplicateOverride.Validate(); err != ErrDuplicateGroupOverride {
+		t.Errorf("expected ErrDuplicateGroupOverride, got %v", providerWithDuplicateOverride.Validate())
+	}
+}
+
+func TestAlertProvider_ValidateOverridesWithInvalidAlert(t *testing.T) {
+	provider := AlertProvider{
+		DefaultConfig: Config{TeamSecret: ""},
+	}
+	alertWithEmptyOverride := alert.Alert{
+		ProviderOverride: map[string]any{"team-secret": ""},
+	}
+	err := provider.ValidateOverrides("", &alertWithEmptyOverride)
+	if err == nil {
+		t.Error("expected error due to invalid default config, got none")
+	}
+	if err != ErrTeamSecretNotSet {
+		t.Errorf("expected ErrTeamSecretNotSet, got %v", err)
+	}
+}

alerting/provider/slack/slack.go

@@ -3,6 +3,7 @@ package slack
 import (
 	"bytes"
 	"encoding/json"
+	"errors"
 	"fmt"
 	"io"
 	"net/http"
@@ -10,41 +11,74 @@ import (
 	"github.com/TwiN/gatus/v5/alerting/alert"
 	"github.com/TwiN/gatus/v5/client"
 	"github.com/TwiN/gatus/v5/config/endpoint"
+	"gopkg.in/yaml.v3"
 )
 
+var (
+	ErrWebhookURLNotSet       = errors.New("webhook-url not set")
+	ErrDuplicateGroupOverride = errors.New("duplicate group override")
+)
+
+type Config struct {
+	WebhookURL string `yaml:"webhook-url"`     // Slack webhook URL
+	Title      string `yaml:"title,omitempty"` // Title of the message that will be sent
+}
+
+func (cfg *Config) Validate() error {
+	if len(cfg.WebhookURL) == 0 {
+		return ErrWebhookURLNotSet
+	}
+	return nil
+}
+
+func (cfg *Config) Merge(override *Config) {
+	if len(override.WebhookURL) > 0 {
+		cfg.WebhookURL = override.WebhookURL
+	}
+	if len(override.Title) > 0 {
+		cfg.Title = override.Title
+	}
+}
+
 // AlertProvider is the configuration necessary for sending an alert using Slack
 type AlertProvider struct {
-	WebhookURL string `yaml:"webhook-url"` // Slack webhook URL
+	DefaultConfig Config `yaml:",inline"`
+
 	// DefaultAlert is the default alert configuration to use for endpoints with an alert of the appropriate type
 	DefaultAlert *alert.Alert `yaml:"default-alert,omitempty"`
+
 	// Overrides is a list of Override that may be prioritized over the default configuration
 	Overrides []Override `yaml:"overrides,omitempty"`
 }
 
 // Override is a case under which the default integration is overridden
 type Override struct {
-	Group      string `yaml:"group"`
-	WebhookURL string `yaml:"webhook-url"`
+	Group  string `yaml:"group"`
+	Config `yaml:",inline"`
 }
 
-// IsValid returns whether the provider's configuration is valid
-func (provider *AlertProvider) IsValid() bool {
+// Validate the provider's configuration
+func (provider *AlertProvider) Validate() error {
 	registeredGroups := make(map[string]bool)
 	if provider.Overrides != nil {
 		for _, override := range provider.Overrides {
-			if isAlreadyRegistered := registeredGroups[override.Group]; isAlreadyRegistered || override.Group == "" || len(override.WebhookURL) == 0 {
-				return false
+			if isAlreadyRegistered := registeredGroups[override.Group]; isAlreadyRegistered || override.Group == "" {
+				return ErrDuplicateGroupOverride
 			}
 			registeredGroups[override.Group] = true
 		}
 	}
-	return len(provider.WebhookURL) > 0
+	return provider.DefaultConfig.Validate()
 }
 
 // Send an alert using the provider
 func (provider *AlertProvider) Send(ep *endpoint.Endpoint, alert *alert.Alert, result *endpoint.Result, resolved bool) error {
-	buffer := bytes.NewBuffer(provider.buildRequestBody(ep, alert, result, resolved))
-	request, err := http.NewRequest(http.MethodPost, provider.getWebhookURLForGroup(ep.Group), buffer)
+	cfg, err := provider.GetConfig(ep.Group, alert)
+	if err != nil {
+		return err
+	}
+	buffer := bytes.NewBuffer(provider.buildRequestBody(cfg, ep, alert, result, resolved))
+	request, err := http.NewRequest(http.MethodPost, cfg.WebhookURL, buffer)
 	if err != nil {
 		return err
 	}
@@ -81,7 +115,7 @@ type Field struct {
 }
 
 // buildRequestBody builds the request body for the provider
-func (provider *AlertProvider) buildRequestBody(ep *endpoint.Endpoint, alert *alert.Alert, result *endpoint.Result, resolved bool) []byte {
+func (provider *AlertProvider) buildRequestBody(cfg *Config, ep *endpoint.Endpoint, alert *alert.Alert, result *endpoint.Result, resolved bool) []byte {
 	var message, color string
 	if resolved {
 		message = fmt.Sprintf("An alert for *%s* has been resolved after passing successfully %d time(s) in a row", ep.DisplayName(), alert.SuccessThreshold)
@@ -108,13 +142,16 @@ func (provider *AlertProvider) buildRequestBody(ep *endpoint.Endpoint, alert *al
 		Text: "",
 		Attachments: []Attachment{
 			{
-				Title: ":helmet_with_white_cross: Gatus",
+				Title: cfg.Title,
 				Text:  message + description,
 				Short: false,
 				Color: color,
 			},
 		},
 	}
+	if len(body.Attachments[0].Title) == 0 {
+		body.Attachments[0].Title = ":helmet_with_white_cross: Gatus"
+	}
 	if len(formattedConditionResults) > 0 {
 		body.Attachments[0].Fields = append(body.Attachments[0].Fields, Field{
 			Title: "Condition results",
@@ -126,19 +163,38 @@ func (provider *AlertProvider) buildRequestBody(ep *endpoint.Endpoint, alert *al
 	return bodyAsJSON
 }
 
-// getWebhookURLForGroup returns the appropriate Webhook URL integration to for a given group
-func (provider *AlertProvider) getWebhookURLForGroup(group string) string {
-	if provider.Overrides != nil {
-		for _, override := range provider.Overrides {
-			if group == override.Group {
-				return override.WebhookURL
-			}
-		}
-	}
-	return provider.WebhookURL
-}
-
 // GetDefaultAlert returns the provider's default alert configuration
 func (provider *AlertProvider) GetDefaultAlert() *alert.Alert {
 	return provider.DefaultAlert
 }
+
+// GetConfig returns the configuration for the provider with the overrides applied
+func (provider *AlertProvider) GetConfig(group string, alert *alert.Alert) (*Config, error) {
+	cfg := provider.DefaultConfig
+	// Handle group overrides
+	if provider.Overrides != nil {
+		for _, override := range provider.Overrides {
+			if group == override.Group {
+				cfg.Merge(&override.Config)
+				break
+			}
+		}
+	}
+	// Handle alert overrides
+	if len(alert.ProviderOverride) != 0 {
+		overrideConfig := Config{}
+		if err := yaml.Unmarshal(alert.ProviderOverrideAsBytes(), &overrideConfig); err != nil {
+			return nil, err
+		}
+		cfg.Merge(&overrideConfig)
+	}
+	// Validate the configuration
+	err := cfg.Validate()
+	return &cfg, err
+}
+
+// ValidateOverrides validates the alert's provider override and, if present, the group override
+func (provider *AlertProvider) ValidateOverrides(group string, alert *alert.Alert) error {
+	_, err := provider.GetConfig(group, alert)
+	return err
+}

alerting/provider/slack/slack_test.go

@@ -11,50 +11,50 @@ import (
 	"github.com/TwiN/gatus/v5/test"
 )
 
-func TestAlertDefaultProvider_IsValid(t *testing.T) {
-	invalidProvider := AlertProvider{WebhookURL: ""}
-	if invalidProvider.IsValid() {
+func TestAlertProvider_Validate(t *testing.T) {
+	invalidProvider := AlertProvider{DefaultConfig: Config{WebhookURL: ""}}
+	if err := invalidProvider.Validate(); err == nil {
 		t.Error("provider shouldn't have been valid")
 	}
-	validProvider := AlertProvider{WebhookURL: "https://example.com"}
-	if !validProvider.IsValid() {
+	validProvider := AlertProvider{DefaultConfig: Config{WebhookURL: "https://example.com"}}
+	if err := validProvider.Validate(); err != nil {
 		t.Error("provider should've been valid")
 	}
 }
 
-func TestAlertProvider_IsValidWithOverride(t *testing.T) {
+func TestAlertProvider_ValidateWithOverride(t *testing.T) {
 	providerWithInvalidOverrideGroup := AlertProvider{
 		Overrides: []Override{
 			{
-				WebhookURL: "http://example.com",
-				Group:      "",
+				Config: Config{WebhookURL: "http://example.com"},
+				Group:  "",
 			},
 		},
 	}
-	if providerWithInvalidOverrideGroup.IsValid() {
+	if err := providerWithInvalidOverrideGroup.Validate(); err == nil {
 		t.Error("provider Group shouldn't have been valid")
 	}
 	providerWithInvalidOverrideTo := AlertProvider{
 		Overrides: []Override{
 			{
-				WebhookURL: "",
-				Group:      "group",
+				Config: Config{WebhookURL: ""},
+				Group:  "group",
 			},
 		},
 	}
-	if providerWithInvalidOverrideTo.IsValid() {
+	if err := providerWithInvalidOverrideTo.Validate(); err == nil {
 		t.Error("provider integration key shouldn't have been valid")
 	}
 	providerWithValidOverride := AlertProvider{
-		WebhookURL: "http://example.com",
+		DefaultConfig: Config{WebhookURL: "http://example.com"},
 		Overrides: []Override{
 			{
-				WebhookURL: "http://example.com",
-				Group:      "group",
+				Config: Config{WebhookURL: "http://example.com"},
+				Group:  "group",
 			},
 		},
 	}
-	if !providerWithValidOverride.IsValid() {
+	if err := providerWithValidOverride.Validate(); err != nil {
 		t.Error("provider should've been valid")
 	}
 }
@@ -73,7 +73,7 @@ func TestAlertProvider_Send(t *testing.T) {
 	}{
 		{
 			Name:     "triggered",
-			Provider: AlertProvider{},
+			Provider: AlertProvider{DefaultConfig: Config{WebhookURL: "http://example.com"}},
 			Alert:    alert.Alert{Description: &firstDescription, SuccessThreshold: 5, FailureThreshold: 3},
 			Resolved: false,
 			MockRoundTripper: test.MockRoundTripper(func(r *http.Request) *http.Response {
@@ -83,7 +83,7 @@ func TestAlertProvider_Send(t *testing.T) {
 		},
 		{
 			Name:     "triggered-error",
-			Provider: AlertProvider{},
+			Provider: AlertProvider{DefaultConfig: Config{WebhookURL: "http://example.com"}},
 			Alert:    alert.Alert{Description: &firstDescription, SuccessThreshold: 5, FailureThreshold: 3},
 			Resolved: false,
 			MockRoundTripper: test.MockRoundTripper(func(r *http.Request) *http.Response {
@@ -93,7 +93,7 @@ func TestAlertProvider_Send(t *testing.T) {
 		},
 		{
 			Name:     "resolved",
-			Provider: AlertProvider{},
+			Provider: AlertProvider{DefaultConfig: Config{WebhookURL: "http://example.com"}},
 			Alert:    alert.Alert{Description: &secondDescription, SuccessThreshold: 5, FailureThreshold: 3},
 			Resolved: true,
 			MockRoundTripper: test.MockRoundTripper(func(r *http.Request) *http.Response {
@@ -103,7 +103,7 @@ func TestAlertProvider_Send(t *testing.T) {
 		},
 		{
 			Name:     "resolved-error",
-			Provider: AlertProvider{},
+			Provider: AlertProvider{DefaultConfig: Config{WebhookURL: "http://example.com"}},
 			Alert:    alert.Alert{Description: &secondDescription, SuccessThreshold: 5, FailureThreshold: 3},
 			Resolved: true,
 			MockRoundTripper: test.MockRoundTripper(func(r *http.Request) *http.Response {
@@ -150,7 +150,7 @@ func TestAlertProvider_buildRequestBody(t *testing.T) {
 	}{
 		{
 			Name:         "triggered",
-			Provider:     AlertProvider{},
+			Provider:     AlertProvider{DefaultConfig: Config{WebhookURL: "http://example.com"}},
 			Endpoint:     endpoint.Endpoint{Name: "name"},
 			Alert:        alert.Alert{Description: &firstDescription, SuccessThreshold: 5, FailureThreshold: 3},
 			Resolved:     false,
@@ -158,7 +158,7 @@ func TestAlertProvider_buildRequestBody(t *testing.T) {
 		},
 		{
 			Name:         "triggered-with-group",
-			Provider:     AlertProvider{},
+			Provider:     AlertProvider{DefaultConfig: Config{WebhookURL: "http://example.com"}},
 			Endpoint:     endpoint.Endpoint{Name: "name", Group: "group"},
 			Alert:        alert.Alert{Description: &firstDescription, SuccessThreshold: 5, FailureThreshold: 3},
 			Resolved:     false,
@@ -167,7 +167,7 @@ func TestAlertProvider_buildRequestBody(t *testing.T) {
 		{
 			Name:         "triggered-with-no-conditions",
 			NoConditions: true,
-			Provider:     AlertProvider{},
+			Provider:     AlertProvider{DefaultConfig: Config{WebhookURL: "http://example.com"}},
 			Endpoint:     endpoint.Endpoint{Name: "name"},
 			Alert:        alert.Alert{Description: &firstDescription, SuccessThreshold: 5, FailureThreshold: 3},
 			Resolved:     false,
@@ -175,7 +175,7 @@ func TestAlertProvider_buildRequestBody(t *testing.T) {
 		},
 		{
 			Name:         "resolved",
-			Provider:     AlertProvider{},
+			Provider:     AlertProvider{DefaultConfig: Config{WebhookURL: "http://example.com"}},
 			Endpoint:     endpoint.Endpoint{Name: "name"},
 			Alert:        alert.Alert{Description: &secondDescription, SuccessThreshold: 5, FailureThreshold: 3},
 			Resolved:     true,
@@ -183,12 +183,20 @@ func TestAlertProvider_buildRequestBody(t *testing.T) {
 		},
 		{
 			Name:         "resolved-with-group",
-			Provider:     AlertProvider{},
+			Provider:     AlertProvider{DefaultConfig: Config{WebhookURL: "http://example.com"}},
 			Endpoint:     endpoint.Endpoint{Name: "name", Group: "group"},
 			Alert:        alert.Alert{Description: &secondDescription, SuccessThreshold: 5, FailureThreshold: 3},
 			Resolved:     true,
 			ExpectedBody: "{\"text\":\"\",\"attachments\":[{\"title\":\":helmet_with_white_cross: Gatus\",\"text\":\"An alert for *group/name* has been resolved after passing successfully 5 time(s) in a row:\\n\\u003e description-2\",\"short\":false,\"color\":\"#36A64F\",\"fields\":[{\"title\":\"Condition results\",\"value\":\":white_check_mark: - `[CONNECTED] == true`\\n:white_check_mark: - `[STATUS] == 200`\\n\",\"short\":false}]}]}",
 		},
+		{
+			Name:         "resolved-with-group-and-custom-title",
+			Provider:     AlertProvider{DefaultConfig: Config{WebhookURL: "http://example.com", Title: "custom title"}},
+			Endpoint:     endpoint.Endpoint{Name: "name", Group: "group"},
+			Alert:        alert.Alert{Description: &secondDescription, SuccessThreshold: 5, FailureThreshold: 3},
+			Resolved:     true,
+			ExpectedBody: "{\"text\":\"\",\"attachments\":[{\"title\":\"custom title\",\"text\":\"An alert for *group/name* has been resolved after passing successfully 5 time(s) in a row:\\n\\u003e description-2\",\"short\":false,\"color\":\"#36A64F\",\"fields\":[{\"title\":\"Condition results\",\"value\":\":white_check_mark: - `[CONNECTED] == true`\\n:white_check_mark: - `[STATUS] == 200`\\n\",\"short\":false}]}]}",
+		},
 	}
 	for _, scenario := range scenarios {
 		t.Run(scenario.Name, func(t *testing.T) {
@@ -199,7 +207,12 @@ func TestAlertProvider_buildRequestBody(t *testing.T) {
 					{Condition: "[STATUS] == 200", Success: scenario.Resolved},
 				}
 			}
+			cfg, err := scenario.Provider.GetConfig(scenario.Endpoint.Group, &scenario.Alert)
+			if err != nil {
+				t.Fatal("couldn't get config:", err.Error())
+			}
 			body := scenario.Provider.buildRequestBody(
+				cfg,
 				&scenario.Endpoint,
 				&scenario.Alert,
 				&endpoint.Result{
@@ -227,64 +240,92 @@ func TestAlertProvider_GetDefaultAlert(t *testing.T) {
 	}
 }
 
-func TestAlertProvider_getWebhookURLForGroup(t *testing.T) {
-	tests := []struct {
+func TestAlertProvider_GetConfig(t *testing.T) {
+	scenarios := []struct {
 		Name           string
 		Provider       AlertProvider
 		InputGroup     string
-		ExpectedOutput string
+		InputAlert     alert.Alert
+		ExpectedOutput Config
 	}{
 		{
 			Name: "provider-no-override-specify-no-group-should-default",
 			Provider: AlertProvider{
-				WebhookURL: "http://example.com",
-				Overrides:  nil,
+				DefaultConfig: Config{WebhookURL: "http://example.com"},
+				Overrides:     nil,
 			},
 			InputGroup:     "",
-			ExpectedOutput: "http://example.com",
+			InputAlert:     alert.Alert{},
+			ExpectedOutput: Config{WebhookURL: "http://example.com"},
 		},
 		{
 			Name: "provider-no-override-specify-group-should-default",
 			Provider: AlertProvider{
-				WebhookURL: "http://example.com",
-				Overrides:  nil,
+				DefaultConfig: Config{WebhookURL: "http://example.com"},
+				Overrides:     nil,
 			},
 			InputGroup:     "group",
-			ExpectedOutput: "http://example.com",
+			InputAlert:     alert.Alert{},
+			ExpectedOutput: Config{WebhookURL: "http://example.com"},
 		},
 		{
 			Name: "provider-with-override-specify-no-group-should-default",
 			Provider: AlertProvider{
-				WebhookURL: "http://example.com",
+				DefaultConfig: Config{WebhookURL: "http://example.com"},
 				Overrides: []Override{
 					{
-						Group:      "group",
-						WebhookURL: "http://example01.com",
+						Group:  "group",
+						Config: Config{WebhookURL: "http://example01.com"},
 					},
 				},
 			},
 			InputGroup:     "",
-			ExpectedOutput: "http://example.com",
+			InputAlert:     alert.Alert{},
+			ExpectedOutput: Config{WebhookURL: "http://example.com"},
 		},
 		{
 			Name: "provider-with-override-specify-group-should-override",
 			Provider: AlertProvider{
-				WebhookURL: "http://example.com",
+				DefaultConfig: Config{WebhookURL: "http://example.com"},
 				Overrides: []Override{
 					{
-						Group:      "group",
-						WebhookURL: "http://example01.com",
+						Group:  "group",
+						Config: Config{WebhookURL: "http://group-example.com"},
 					},
 				},
 			},
 			InputGroup:     "group",
-			ExpectedOutput: "http://example01.com",
+			InputAlert:     alert.Alert{},
+			ExpectedOutput: Config{WebhookURL: "http://group-example.com"},
+		},
+		{
+			Name: "provider-with-group-override-and-alert-override--alert-override-should-take-precedence",
+			Provider: AlertProvider{
+				DefaultConfig: Config{WebhookURL: "http://example.com"},
+				Overrides: []Override{
+					{
+						Group:  "group",
+						Config: Config{WebhookURL: "http://group-example.com"},
+					},
+				},
+			},
+			InputGroup:     "group",
+			InputAlert:     alert.Alert{ProviderOverride: map[string]any{"webhook-url": "http://alert-example.com"}},
+			ExpectedOutput: Config{WebhookURL: "http://alert-example.com"},
 		},
 	}
-	for _, tt := range tests {
-		t.Run(tt.Name, func(t *testing.T) {
-			if got := tt.Provider.getWebhookURLForGroup(tt.InputGroup); got != tt.ExpectedOutput {
-				t.Errorf("AlertProvider.getWebhookURLForGroup() = %v, want %v", got, tt.ExpectedOutput)
+	for _, scenario := range scenarios {
+		t.Run(scenario.Name, func(t *testing.T) {
+			got, err := scenario.Provider.GetConfig(scenario.InputGroup, &scenario.InputAlert)
+			if err != nil {
+				t.Fatalf("unexpected error: %s", err)
+			}
+			if got.WebhookURL != scenario.ExpectedOutput.WebhookURL {
+				t.Errorf("expected webhook URL to be %s, got %s", scenario.ExpectedOutput.WebhookURL, got.WebhookURL)
+			}
+			// Test ValidateOverrides as well, since it really just calls GetConfig
+			if err = scenario.Provider.ValidateOverrides(scenario.InputGroup, &scenario.InputAlert); err != nil {
+				t.Errorf("unexpected error: %s", err)
 			}
 		})
 	}

alerting/provider/splunk/splunk.go

@@ -0,0 +1,220 @@
+package splunk
+
+import (
+	"bytes"
+	"encoding/json"
+	"errors"
+	"fmt"
+	"io"
+	"net/http"
+	"time"
+
+	"github.com/TwiN/gatus/v5/alerting/alert"
+	"github.com/TwiN/gatus/v5/client"
+	"github.com/TwiN/gatus/v5/config/endpoint"
+	"gopkg.in/yaml.v3"
+)
+
+var (
+	ErrHecURLNotSet           = errors.New("hec-url not set")
+	ErrHecTokenNotSet         = errors.New("hec-token not set")
+	ErrDuplicateGroupOverride = errors.New("duplicate group override")
+)
+
+type Config struct {
+	HecURL     string `yaml:"hec-url"`              // Splunk HEC (HTTP Event Collector) URL
+	HecToken   string `yaml:"hec-token"`            // Splunk HEC token
+	Source     string `yaml:"source,omitempty"`     // Event source
+	SourceType string `yaml:"sourcetype,omitempty"` // Event source type
+	Index      string `yaml:"index,omitempty"`      // Splunk index
+}
+
+func (cfg *Config) Validate() error {
+	if len(cfg.HecURL) == 0 {
+		return ErrHecURLNotSet
+	}
+	if len(cfg.HecToken) == 0 {
+		return ErrHecTokenNotSet
+	}
+	return nil
+}
+
+func (cfg *Config) Merge(override *Config) {
+	if len(override.HecURL) > 0 {
+		cfg.HecURL = override.HecURL
+	}
+	if len(override.HecToken) > 0 {
+		cfg.HecToken = override.HecToken
+	}
+	if len(override.Source) > 0 {
+		cfg.Source = override.Source
+	}
+	if len(override.SourceType) > 0 {
+		cfg.SourceType = override.SourceType
+	}
+	if len(override.Index) > 0 {
+		cfg.Index = override.Index
+	}
+}
+
+// AlertProvider is the configuration necessary for sending an alert using Splunk
+type AlertProvider struct {
+	DefaultConfig Config `yaml:",inline"`
+
+	// DefaultAlert is the default alert configuration to use for endpoints with an alert of the appropriate type
+	DefaultAlert *alert.Alert `yaml:"default-alert,omitempty"`
+
+	// Overrides is a list of Override that may be prioritized over the default configuration
+	Overrides []Override `yaml:"overrides,omitempty"`
+}
+
+// Override is a case under which the default integration is overridden
+type Override struct {
+	Group  string `yaml:"group"`
+	Config `yaml:",inline"`
+}
+
+// Validate the provider's configuration
+func (provider *AlertProvider) Validate() error {
+	registeredGroups := make(map[string]bool)
+	if provider.Overrides != nil {
+		for _, override := range provider.Overrides {
+			if isAlreadyRegistered := registeredGroups[override.Group]; isAlreadyRegistered || override.Group == "" {
+				return ErrDuplicateGroupOverride
+			}
+			registeredGroups[override.Group] = true
+		}
+	}
+	return provider.DefaultConfig.Validate()
+}
+
+// Send an alert using the provider
+func (provider *AlertProvider) Send(ep *endpoint.Endpoint, alert *alert.Alert, result *endpoint.Result, resolved bool) error {
+	cfg, err := provider.GetConfig(ep.Group, alert)
+	if err != nil {
+		return err
+	}
+	body, err := provider.buildRequestBody(cfg, ep, alert, result, resolved)
+	if err != nil {
+		return err
+	}
+	buffer := bytes.NewBuffer(body)
+	request, err := http.NewRequest(http.MethodPost, fmt.Sprintf("%s/services/collector/event", cfg.HecURL), buffer)
+	if err != nil {
+		return err
+	}
+	request.Header.Set("Content-Type", "application/json")
+	request.Header.Set("Authorization", fmt.Sprintf("Splunk %s", cfg.HecToken))
+	response, err := client.GetHTTPClient(nil).Do(request)
+	if err != nil {
+		return err
+	}
+	defer response.Body.Close()
+	if response.StatusCode >= 400 {
+		body, _ := io.ReadAll(response.Body)
+		return fmt.Errorf("call to splunk alert returned status code %d: %s", response.StatusCode, string(body))
+	}
+	return nil
+}
+
+type Body struct {
+	Time       int64  `json:"time"`
+	Source     string `json:"source,omitempty"`
+	SourceType string `json:"sourcetype,omitempty"`
+	Index      string `json:"index,omitempty"`
+	Event      Event  `json:"event"`
+}
+
+type Event struct {
+	AlertType   string                      `json:"alert_type"`
+	Endpoint    string                      `json:"endpoint"`
+	Group       string                      `json:"group,omitempty"`
+	Status      string                      `json:"status"`
+	Message     string                      `json:"message"`
+	Description string                      `json:"description,omitempty"`
+	Conditions  []*endpoint.ConditionResult `json:"conditions,omitempty"`
+}
+
+// buildRequestBody builds the request body for the provider
+func (provider *AlertProvider) buildRequestBody(cfg *Config, ep *endpoint.Endpoint, alert *alert.Alert, result *endpoint.Result, resolved bool) ([]byte, error) {
+	var alertType, status, message string
+	if resolved {
+		alertType = "resolved"
+		status = "ok"
+		message = fmt.Sprintf("Alert for %s has been resolved after passing successfully %d time(s) in a row", ep.DisplayName(), alert.SuccessThreshold)
+	} else {
+		alertType = "triggered"
+		status = "critical"
+		message = fmt.Sprintf("Alert for %s has been triggered due to having failed %d time(s) in a row", ep.DisplayName(), alert.FailureThreshold)
+	}
+	event := Event{
+		AlertType:   alertType,
+		Endpoint:    ep.DisplayName(),
+		Group:       ep.Group,
+		Status:      status,
+		Message:     message,
+		Description: alert.GetDescription(),
+	}
+	if len(result.ConditionResults) > 0 {
+		event.Conditions = result.ConditionResults
+	}
+	body := Body{
+		Time:  time.Now().Unix(),
+		Event: event,
+	}
+	// Set optional fields
+	if cfg.Source != "" {
+		body.Source = cfg.Source
+	} else {
+		body.Source = "gatus"
+	}
+	if cfg.SourceType != "" {
+		body.SourceType = cfg.SourceType
+	} else {
+		body.SourceType = "gatus:alert"
+	}
+	if cfg.Index != "" {
+		body.Index = cfg.Index
+	}
+	bodyAsJSON, err := json.Marshal(body)
+	if err != nil {
+		return nil, err
+	}
+	return bodyAsJSON, nil
+}
+
+// GetDefaultAlert returns the provider's default alert configuration
+func (provider *AlertProvider) GetDefaultAlert() *alert.Alert {
+	return provider.DefaultAlert
+}
+
+// GetConfig returns the configuration for the provider with the overrides applied
+func (provider *AlertProvider) GetConfig(group string, alert *alert.Alert) (*Config, error) {
+	cfg := provider.DefaultConfig
+	// Handle group overrides
+	if provider.Overrides != nil {
+		for _, override := range provider.Overrides {
+			if group == override.Group {
+				cfg.Merge(&override.Config)
+				break
+			}
+		}
+	}
+	// Handle alert overrides
+	if len(alert.ProviderOverride) != 0 {
+		overrideConfig := Config{}
+		if err := yaml.Unmarshal(alert.ProviderOverrideAsBytes(), &overrideConfig); err != nil {
+			return nil, err
+		}
+		cfg.Merge(&overrideConfig)
+	}
+	// Validate the configuration
+	err := cfg.Validate()
+	return &cfg, err
+}
+
+// ValidateOverrides validates the alert's provider override and, if present, the group override
+func (provider *AlertProvider) ValidateOverrides(group string, alert *alert.Alert) error {
+	_, err := provider.GetConfig(group, alert)
+	return err
+}

alerting/provider/splunk/splunk_test.go

@@ -0,0 +1,155 @@
+package splunk
+
+import (
+	"encoding/json"
+	"net/http"
+	"testing"
+
+	"github.com/TwiN/gatus/v5/alerting/alert"
+	"github.com/TwiN/gatus/v5/client"
+	"github.com/TwiN/gatus/v5/config/endpoint"
+	"github.com/TwiN/gatus/v5/test"
+)
+
+func TestAlertProvider_Validate(t *testing.T) {
+	scenarios := []struct {
+		name     string
+		provider AlertProvider
+		expected error
+	}{
+		{
+			name:     "valid",
+			provider: AlertProvider{DefaultConfig: Config{HecURL: "https://splunk.example.com:8088", HecToken: "token123"}},
+			expected: nil,
+		},
+		{
+			name:     "valid-with-index",
+			provider: AlertProvider{DefaultConfig: Config{HecURL: "https://splunk.example.com:8088", HecToken: "token123", Index: "main"}},
+			expected: nil,
+		},
+		{
+			name:     "invalid-hec-url",
+			provider: AlertProvider{DefaultConfig: Config{HecToken: "token123"}},
+			expected: ErrHecURLNotSet,
+		},
+		{
+			name:     "invalid-hec-token",
+			provider: AlertProvider{DefaultConfig: Config{HecURL: "https://splunk.example.com:8088"}},
+			expected: ErrHecTokenNotSet,
+		},
+	}
+	for _, scenario := range scenarios {
+		t.Run(scenario.name, func(t *testing.T) {
+			err := scenario.provider.Validate()
+			if err != scenario.expected {
+				t.Errorf("expected %v, got %v", scenario.expected, err)
+			}
+		})
+	}
+}
+
+func TestAlertProvider_Send(t *testing.T) {
+	defer client.InjectHTTPClient(nil)
+	firstDescription := "description-1"
+	secondDescription := "description-2"
+	scenarios := []struct {
+		name             string
+		provider         AlertProvider
+		alert            alert.Alert
+		resolved         bool
+		mockRoundTripper test.MockRoundTripper
+		expectedError    bool
+	}{
+		{
+			name:     "triggered",
+			provider: AlertProvider{DefaultConfig: Config{HecURL: "https://splunk.example.com:8088", HecToken: "token123"}},
+			alert:    alert.Alert{Description: &firstDescription, SuccessThreshold: 5, FailureThreshold: 3},
+			resolved: false,
+			mockRoundTripper: test.MockRoundTripper(func(r *http.Request) *http.Response {
+				if r.URL.Path != "/services/collector/event" {
+					t.Errorf("expected path /services/collector/event, got %s", r.URL.Path)
+				}
+				if r.Header.Get("Authorization") != "Splunk token123" {
+					t.Errorf("expected Authorization header to be 'Splunk token123', got %s", r.Header.Get("Authorization"))
+				}
+				body := make(map[string]interface{})
+				json.NewDecoder(r.Body).Decode(&body)
+				if body["time"] == nil {
+					t.Error("expected 'time' field in request body")
+				}
+				event := body["event"].(map[string]interface{})
+				if event["alert_type"] != "triggered" {
+					t.Errorf("expected alert_type to be 'triggered', got %v", event["alert_type"])
+				}
+				if event["status"] != "critical" {
+					t.Errorf("expected status to be 'critical', got %v", event["status"])
+				}
+				return &http.Response{StatusCode: http.StatusOK, Body: http.NoBody}
+			}),
+			expectedError: false,
+		},
+		{
+			name:     "resolved",
+			provider: AlertProvider{DefaultConfig: Config{HecURL: "https://splunk.example.com:8088", HecToken: "token123", Index: "main"}},
+			alert:    alert.Alert{Description: &secondDescription, SuccessThreshold: 5, FailureThreshold: 3},
+			resolved: true,
+			mockRoundTripper: test.MockRoundTripper(func(r *http.Request) *http.Response {
+				body := make(map[string]interface{})
+				json.NewDecoder(r.Body).Decode(&body)
+				if body["index"] != "main" {
+					t.Errorf("expected index to be 'main', got %v", body["index"])
+				}
+				event := body["event"].(map[string]interface{})
+				if event["alert_type"] != "resolved" {
+					t.Errorf("expected alert_type to be 'resolved', got %v", event["alert_type"])
+				}
+				if event["status"] != "ok" {
+					t.Errorf("expected status to be 'ok', got %v", event["status"])
+				}
+				return &http.Response{StatusCode: http.StatusOK, Body: http.NoBody}
+			}),
+			expectedError: false,
+		},
+		{
+			name:     "error-response",
+			provider: AlertProvider{DefaultConfig: Config{HecURL: "https://splunk.example.com:8088", HecToken: "token123"}},
+			alert:    alert.Alert{Description: &firstDescription, SuccessThreshold: 5, FailureThreshold: 3},
+			resolved: false,
+			mockRoundTripper: test.MockRoundTripper(func(r *http.Request) *http.Response {
+				return &http.Response{StatusCode: http.StatusForbidden, Body: http.NoBody}
+			}),
+			expectedError: true,
+		},
+	}
+	for _, scenario := range scenarios {
+		t.Run(scenario.name, func(t *testing.T) {
+			client.InjectHTTPClient(&http.Client{Transport: scenario.mockRoundTripper})
+			err := scenario.provider.Send(
+				&endpoint.Endpoint{Name: "endpoint-name"},
+				&scenario.alert,
+				&endpoint.Result{
+					ConditionResults: []*endpoint.ConditionResult{
+						{Condition: "[CONNECTED] == true", Success: scenario.resolved},
+						{Condition: "[STATUS] == 200", Success: scenario.resolved},
+					},
+				},
+				scenario.resolved,
+			)
+			if scenario.expectedError && err == nil {
+				t.Error("expected error, got none")
+			}
+			if !scenario.expectedError && err != nil {
+				t.Error("expected no error, got", err.Error())
+			}
+		})
+	}
+}
+
+func TestAlertProvider_GetDefaultAlert(t *testing.T) {
+	if (&AlertProvider{DefaultAlert: &alert.Alert{}}).GetDefaultAlert() == nil {
+		t.Error("expected default alert to be not nil")
+	}
+	if (&AlertProvider{DefaultAlert: nil}).GetDefaultAlert() != nil {
+		t.Error("expected default alert to be nil")
+	}
+}

alerting/provider/squadcast/squadcast.go

@@ -0,0 +1,190 @@
+package squadcast
+
+import (
+	"bytes"
+	"encoding/json"
+	"errors"
+	"fmt"
+	"io"
+	"net/http"
+
+	"github.com/TwiN/gatus/v5/alerting/alert"
+	"github.com/TwiN/gatus/v5/client"
+	"github.com/TwiN/gatus/v5/config/endpoint"
+	"gopkg.in/yaml.v3"
+)
+
+var (
+	ErrWebhookURLNotSet       = errors.New("webhook-url not set")
+	ErrDuplicateGroupOverride = errors.New("duplicate group override")
+)
+
+type Config struct {
+	WebhookURL string `yaml:"webhook-url"` // Squadcast webhook URL
+}
+
+func (cfg *Config) Validate() error {
+	if len(cfg.WebhookURL) == 0 {
+		return ErrWebhookURLNotSet
+	}
+	return nil
+}
+
+func (cfg *Config) Merge(override *Config) {
+	if len(override.WebhookURL) > 0 {
+		cfg.WebhookURL = override.WebhookURL
+	}
+}
+
+// AlertProvider is the configuration necessary for sending an alert using Squadcast
+type AlertProvider struct {
+	DefaultConfig Config `yaml:",inline"`
+
+	// DefaultAlert is the default alert configuration to use for endpoints with an alert of the appropriate type
+	DefaultAlert *alert.Alert `yaml:"default-alert,omitempty"`
+
+	// Overrides is a list of Override that may be prioritized over the default configuration
+	Overrides []Override `yaml:"overrides,omitempty"`
+}
+
+// Override is a case under which the default integration is overridden
+type Override struct {
+	Group  string `yaml:"group"`
+	Config `yaml:",inline"`
+}
+
+// Validate the provider's configuration
+func (provider *AlertProvider) Validate() error {
+	registeredGroups := make(map[string]bool)
+	if provider.Overrides != nil {
+		for _, override := range provider.Overrides {
+			if isAlreadyRegistered := registeredGroups[override.Group]; isAlreadyRegistered || override.Group == "" {
+				return ErrDuplicateGroupOverride
+			}
+			registeredGroups[override.Group] = true
+		}
+	}
+	return provider.DefaultConfig.Validate()
+}
+
+// Send an alert using the provider
+func (provider *AlertProvider) Send(ep *endpoint.Endpoint, alert *alert.Alert, result *endpoint.Result, resolved bool) error {
+	cfg, err := provider.GetConfig(ep.Group, alert)
+	if err != nil {
+		return err
+	}
+	body, err := provider.buildRequestBody(ep, alert, result, resolved)
+	if err != nil {
+		return err
+	}
+	buffer := bytes.NewBuffer(body)
+	request, err := http.NewRequest(http.MethodPost, cfg.WebhookURL, buffer)
+	if err != nil {
+		return err
+	}
+	request.Header.Set("Content-Type", "application/json")
+	response, err := client.GetHTTPClient(nil).Do(request)
+	if err != nil {
+		return err
+	}
+	defer response.Body.Close()
+	if response.StatusCode >= 400 {
+		body, _ := io.ReadAll(response.Body)
+		return fmt.Errorf("call to squadcast alert returned status code %d: %s", response.StatusCode, string(body))
+	}
+	return nil
+}
+
+type Body struct {
+	Message     string            `json:"message"`
+	Description string            `json:"description,omitempty"`
+	EventID     string            `json:"event_id"`
+	Status      string            `json:"status"`
+	Tags        map[string]string `json:"tags,omitempty"`
+}
+
+// buildRequestBody builds the request body for the provider
+func (provider *AlertProvider) buildRequestBody(ep *endpoint.Endpoint, alert *alert.Alert, result *endpoint.Result, resolved bool) ([]byte, error) {
+	var message, status string
+	eventID := fmt.Sprintf("gatus-%s", ep.Key())
+	if resolved {
+		message = fmt.Sprintf("RESOLVED: %s", ep.DisplayName())
+		status = "resolve"
+	} else {
+		message = fmt.Sprintf("ALERT: %s", ep.DisplayName())
+		status = "trigger"
+	}
+	description := fmt.Sprintf("Endpoint: %s\n", ep.DisplayName())
+	if resolved {
+		description += fmt.Sprintf("Alert has been resolved after passing successfully %d time(s) in a row\n", alert.SuccessThreshold)
+	} else {
+		description += fmt.Sprintf("Endpoint has failed %d time(s) in a row\n", alert.FailureThreshold)
+	}
+	if alertDescription := alert.GetDescription(); len(alertDescription) > 0 {
+		description += fmt.Sprintf("\nDescription: %s", alertDescription)
+	}
+	if len(result.ConditionResults) > 0 {
+		description += "\n\nCondition Results:"
+		for _, conditionResult := range result.ConditionResults {
+			var status string
+			if conditionResult.Success {
+				status = "✅"
+			} else {
+				status = "❌"
+			}
+			description += fmt.Sprintf("\n%s %s", status, conditionResult.Condition)
+		}
+	}
+	body := Body{
+		Message:     message,
+		Description: description,
+		EventID:     eventID,
+		Status:      status,
+		Tags: map[string]string{
+			"endpoint": ep.Name,
+			"group":    ep.Group,
+			"source":   "gatus",
+		},
+	}
+	bodyAsJSON, err := json.Marshal(body)
+	if err != nil {
+		return nil, err
+	}
+	return bodyAsJSON, nil
+}
+
+// GetDefaultAlert returns the provider's default alert configuration
+func (provider *AlertProvider) GetDefaultAlert() *alert.Alert {
+	return provider.DefaultAlert
+}
+
+// GetConfig returns the configuration for the provider with the overrides applied
+func (provider *AlertProvider) GetConfig(group string, alert *alert.Alert) (*Config, error) {
+	cfg := provider.DefaultConfig
+	// Handle group overrides
+	if provider.Overrides != nil {
+		for _, override := range provider.Overrides {
+			if group == override.Group {
+				cfg.Merge(&override.Config)
+				break
+			}
+		}
+	}
+	// Handle alert overrides
+	if len(alert.ProviderOverride) != 0 {
+		overrideConfig := Config{}
+		if err := yaml.Unmarshal(alert.ProviderOverrideAsBytes(), &overrideConfig); err != nil {
+			return nil, err
+		}
+		cfg.Merge(&overrideConfig)
+	}
+	// Validate the configuration
+	err := cfg.Validate()
+	return &cfg, err
+}
+
+// ValidateOverrides validates the alert's provider override and, if present, the group override
+func (provider *AlertProvider) ValidateOverrides(group string, alert *alert.Alert) error {
+	_, err := provider.GetConfig(group, alert)
+	return err
+}

alerting/provider/squadcast/squadcast_test.go

@@ -0,0 +1,141 @@
+package squadcast
+
+import (
+	"encoding/json"
+	"net/http"
+	"strings"
+	"testing"
+
+	"github.com/TwiN/gatus/v5/alerting/alert"
+	"github.com/TwiN/gatus/v5/client"
+	"github.com/TwiN/gatus/v5/config/endpoint"
+	"github.com/TwiN/gatus/v5/test"
+)
+
+func TestAlertProvider_Validate(t *testing.T) {
+	scenarios := []struct {
+		name     string
+		provider AlertProvider
+		expected error
+	}{
+		{
+			name:     "valid",
+			provider: AlertProvider{DefaultConfig: Config{WebhookURL: "https://api.squadcast.com/v3/incidents/api/abcd1234"}},
+			expected: nil,
+		},
+		{
+			name:     "invalid-webhook-url",
+			provider: AlertProvider{DefaultConfig: Config{}},
+			expected: ErrWebhookURLNotSet,
+		},
+	}
+	for _, scenario := range scenarios {
+		t.Run(scenario.name, func(t *testing.T) {
+			err := scenario.provider.Validate()
+			if err != scenario.expected {
+				t.Errorf("expected %v, got %v", scenario.expected, err)
+			}
+		})
+	}
+}
+
+func TestAlertProvider_Send(t *testing.T) {
+	defer client.InjectHTTPClient(nil)
+	firstDescription := "description-1"
+	secondDescription := "description-2"
+	scenarios := []struct {
+		name             string
+		provider         AlertProvider
+		alert            alert.Alert
+		resolved         bool
+		mockRoundTripper test.MockRoundTripper
+		expectedError    bool
+	}{
+		{
+			name:     "triggered",
+			provider: AlertProvider{DefaultConfig: Config{WebhookURL: "https://api.squadcast.com/v3/incidents/api/abcd1234"}},
+			alert:    alert.Alert{Description: &firstDescription, SuccessThreshold: 5, FailureThreshold: 3},
+			resolved: false,
+			mockRoundTripper: test.MockRoundTripper(func(r *http.Request) *http.Response {
+				body := make(map[string]interface{})
+				json.NewDecoder(r.Body).Decode(&body)
+				if body["status"] != "trigger" {
+					t.Errorf("expected status to be 'trigger', got %v", body["status"])
+				}
+				if body["event_id"] == nil {
+					t.Error("expected 'event_id' field in request body")
+				}
+				message := body["message"].(string)
+				if !strings.Contains(message, "ALERT") {
+					t.Errorf("expected message to contain 'ALERT', got %s", message)
+				}
+				description := body["description"].(string)
+				if !strings.Contains(description, "failed 3 time(s)") {
+					t.Errorf("expected description to contain failure count, got %s", description)
+				}
+				return &http.Response{StatusCode: http.StatusOK, Body: http.NoBody}
+			}),
+			expectedError: false,
+		},
+		{
+			name:     "resolved",
+			provider: AlertProvider{DefaultConfig: Config{WebhookURL: "https://api.squadcast.com/v3/incidents/api/abcd1234"}},
+			alert:    alert.Alert{Description: &secondDescription, SuccessThreshold: 5, FailureThreshold: 3},
+			resolved: true,
+			mockRoundTripper: test.MockRoundTripper(func(r *http.Request) *http.Response {
+				body := make(map[string]interface{})
+				json.NewDecoder(r.Body).Decode(&body)
+				if body["status"] != "resolve" {
+					t.Errorf("expected status to be 'resolve', got %v", body["status"])
+				}
+				message := body["message"].(string)
+				if !strings.Contains(message, "RESOLVED") {
+					t.Errorf("expected message to contain 'RESOLVED', got %s", message)
+				}
+				return &http.Response{StatusCode: http.StatusOK, Body: http.NoBody}
+			}),
+			expectedError: false,
+		},
+		{
+			name:     "error-response",
+			provider: AlertProvider{DefaultConfig: Config{WebhookURL: "https://api.squadcast.com/v3/incidents/api/abcd1234"}},
+			alert:    alert.Alert{Description: &firstDescription, SuccessThreshold: 5, FailureThreshold: 3},
+			resolved: false,
+			mockRoundTripper: test.MockRoundTripper(func(r *http.Request) *http.Response {
+				return &http.Response{StatusCode: http.StatusUnauthorized, Body: http.NoBody}
+			}),
+			expectedError: true,
+		},
+	}
+	for _, scenario := range scenarios {
+		t.Run(scenario.name, func(t *testing.T) {
+			client.InjectHTTPClient(&http.Client{Transport: scenario.mockRoundTripper})
+			err := scenario.provider.Send(
+				&endpoint.Endpoint{Name: "endpoint-name"},
+				&scenario.alert,
+				&endpoint.Result{
+					ConditionResults: []*endpoint.ConditionResult{
+						{Condition: "[CONNECTED] == true", Success: scenario.resolved},
+						{Condition: "[STATUS] == 200", Success: scenario.resolved},
+					},
+				},
+				scenario.resolved,
+			)
+			if scenario.expectedError && err == nil {
+				t.Error("expected error, got none")
+			}
+			if !scenario.expectedError && err != nil {
+				t.Error("expected no error, got", err.Error())
+			}
+		})
+	}
+}
+
+func TestAlertProvider_GetDefaultAlert(t *testing.T) {
+	if (&AlertProvider{DefaultAlert: &alert.Alert{}}).GetDefaultAlert() == nil {
+		t.Error("expected default alert to be not nil")
+	}
+	if (&AlertProvider{DefaultAlert: nil}).GetDefaultAlert() != nil {
+		t.Error("expected default alert to be nil")
+	}
+}

alerting/provider/teams/teams.go

@@ -3,6 +3,7 @@ package teams
 import (
 	"bytes"
 	"encoding/json"
+	"errors"
 	"fmt"
 	"io"
 	"net/http"
@@ -10,51 +11,85 @@ import (
 	"github.com/TwiN/gatus/v5/alerting/alert"
 	"github.com/TwiN/gatus/v5/client"
 	"github.com/TwiN/gatus/v5/config/endpoint"
+	"gopkg.in/yaml.v3"
 )
 
+var (
+	ErrWebhookURLNotSet       = errors.New("webhook-url not set")
+	ErrDuplicateGroupOverride = errors.New("duplicate group override")
+)
+
+type Config struct {
+	WebhookURL string `yaml:"webhook-url"`
+	Title      string `yaml:"title,omitempty"` // Title of the message that will be sent
+
+	// ClientConfig is the configuration of the client used to communicate with the provider's target
+	ClientConfig *client.Config `yaml:"client,omitempty"`
+}
+
+func (cfg *Config) Validate() error {
+	if len(cfg.WebhookURL) == 0 {
+		return ErrWebhookURLNotSet
+	}
+	return nil
+}
+
+func (cfg *Config) Merge(override *Config) {
+	if override.ClientConfig != nil {
+		cfg.ClientConfig = override.ClientConfig
+	}
+	if len(override.WebhookURL) > 0 {
+		cfg.WebhookURL = override.WebhookURL
+	}
+	if len(override.Title) > 0 {
+		cfg.Title = override.Title
+	}
+}
+
 // AlertProvider is the configuration necessary for sending an alert using Teams
 type AlertProvider struct {
-	WebhookURL string `yaml:"webhook-url"`
+	DefaultConfig Config `yaml:",inline"`
 
 	// DefaultAlert is the default alert configuration to use for endpoints with an alert of the appropriate type
 	DefaultAlert *alert.Alert `yaml:"default-alert,omitempty"`
 
 	// Overrides is a list of Override that may be prioritized over the default configuration
 	Overrides []Override `yaml:"overrides,omitempty"`
-
-	// Title is the title of the message that will be sent
-	Title string `yaml:"title,omitempty"`
 }
 
 // Override is a case under which the default integration is overridden
 type Override struct {
-	Group      string `yaml:"group"`
-	WebhookURL string `yaml:"webhook-url"`
+	Group  string `yaml:"group"`
+	Config `yaml:",inline"`
 }
 
-// IsValid returns whether the provider's configuration is valid
-func (provider *AlertProvider) IsValid() bool {
+// Validate the provider's configuration
+func (provider *AlertProvider) Validate() error {
 	registeredGroups := make(map[string]bool)
 	if provider.Overrides != nil {
 		for _, override := range provider.Overrides {
-			if isAlreadyRegistered := registeredGroups[override.Group]; isAlreadyRegistered || override.Group == "" || len(override.WebhookURL) == 0 {
-				return false
+			if isAlreadyRegistered := registeredGroups[override.Group]; isAlreadyRegistered || override.Group == "" {
+				return ErrDuplicateGroupOverride
 			}
 			registeredGroups[override.Group] = true
 		}
 	}
-	return len(provider.WebhookURL) > 0
+	return provider.DefaultConfig.Validate()
 }
 
 // Send an alert using the provider
 func (provider *AlertProvider) Send(ep *endpoint.Endpoint, alert *alert.Alert, result *endpoint.Result, resolved bool) error {
-	buffer := bytes.NewBuffer(provider.buildRequestBody(ep, alert, result, resolved))
-	request, err := http.NewRequest(http.MethodPost, provider.getWebhookURLForGroup(ep.Group), buffer)
+	cfg, err := provider.GetConfig(ep.Group, alert)
+	if err != nil {
+		return err
+	}
+	buffer := bytes.NewBuffer(provider.buildRequestBody(cfg, ep, alert, result, resolved))
+	request, err := http.NewRequest(http.MethodPost, cfg.WebhookURL, buffer)
 	if err != nil {
 		return err
 	}
 	request.Header.Set("Content-Type", "application/json")
-	response, err := client.GetHTTPClient(nil).Do(request)
+	response, err := client.GetHTTPClient(cfg.ClientConfig).Do(request)
 	if err != nil {
 		return err
 	}
@@ -81,7 +116,7 @@ type Section struct {
 }
 
 // buildRequestBody builds the request body for the provider
-func (provider *AlertProvider) buildRequestBody(ep *endpoint.Endpoint, alert *alert.Alert, result *endpoint.Result, resolved bool) []byte {
+func (provider *AlertProvider) buildRequestBody(cfg *Config, ep *endpoint.Endpoint, alert *alert.Alert, result *endpoint.Result, resolved bool) []byte {
 	var message, color string
 	if resolved {
 		message = fmt.Sprintf("An alert for *%s* has been resolved after passing successfully %d time(s) in a row", ep.DisplayName(), alert.SuccessThreshold)
@@ -108,7 +143,7 @@ func (provider *AlertProvider) buildRequestBody(ep *endpoint.Endpoint, alert *al
 		Type:       "MessageCard",
 		Context:    "http://schema.org/extensions",
 		ThemeColor: color,
-		Title:      provider.Title,
+		Title:      cfg.Title,
 		Text:       message + description,
 	}
 	if len(body.Title) == 0 {
@@ -124,19 +159,38 @@ func (provider *AlertProvider) buildRequestBody(ep *endpoint.Endpoint, alert *al
 	return bodyAsJSON
 }
 
-// getWebhookURLForGroup returns the appropriate Webhook URL integration to for a given group
-func (provider *AlertProvider) getWebhookURLForGroup(group string) string {
-	if provider.Overrides != nil {
-		for _, override := range provider.Overrides {
-			if group == override.Group {
-				return override.WebhookURL
-			}
-		}
-	}
-	return provider.WebhookURL
-}
-
 // GetDefaultAlert returns the provider's default alert configuration
 func (provider *AlertProvider) GetDefaultAlert() *alert.Alert {
 	return provider.DefaultAlert
 }
+
+// GetConfig returns the configuration for the provider with the overrides applied
+func (provider *AlertProvider) GetConfig(group string, alert *alert.Alert) (*Config, error) {
+	cfg := provider.DefaultConfig
+	// Handle group overrides
+	if provider.Overrides != nil {
+		for _, override := range provider.Overrides {
+			if group == override.Group {
+				cfg.Merge(&override.Config)
+				break
+			}
+		}
+	}
+	// Handle alert overrides
+	if len(alert.ProviderOverride) != 0 {
+		overrideConfig := Config{}
+		if err := yaml.Unmarshal(alert.ProviderOverrideAsBytes(), &overrideConfig); err != nil {
+			return nil, err
+		}
+		cfg.Merge(&overrideConfig)
+	}
+	// Validate the configuration
+	err := cfg.Validate()
+	return &cfg, err
+}
+
+// ValidateOverrides validates the alert's provider override and, if present, the group override
+func (provider *AlertProvider) ValidateOverrides(group string, alert *alert.Alert) error {
+	_, err := provider.GetConfig(group, alert)
+	return err
+}