feat(alerting): Add support for n8n alerts (#1309)

This commit is contained in:
TwiN
2025-10-03 16:51:26 -04:00
committed by GitHub
parent 03ec18a703
commit 8853140cb2
7 changed files with 604 additions and 5 deletions

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@@ -0,0 +1,179 @@
package n8n
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"`
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 n8n
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(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)
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 {
Title string `json:"title"`
EndpointName string `json:"endpoint_name"`
EndpointGroup string `json:"endpoint_group,omitempty"`
EndpointURL string `json:"endpoint_url"`
AlertDescription string `json:"alert_description,omitempty"`
Resolved bool `json:"resolved"`
Message string `json:"message"`
ConditionResults []ConditionResult `json:"condition_results,omitempty"`
}
type ConditionResult struct {
Condition string `json:"condition"`
Success bool `json:"success"`
}
// 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 {
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)
} 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)
}
title := "Gatus"
if cfg.Title != "" {
title = cfg.Title
}
var conditionResults []ConditionResult
for _, conditionResult := range result.ConditionResults {
conditionResults = append(conditionResults, ConditionResult{
Condition: conditionResult.Condition,
Success: conditionResult.Success,
})
}
body := Body{
Title: title,
EndpointName: ep.Name,
EndpointGroup: ep.Group,
EndpointURL: ep.URL,
AlertDescription: alert.GetDescription(),
Resolved: resolved,
Message: message,
ConditionResults: conditionResults,
}
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
// 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
}

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@@ -0,0 +1,364 @@
package n8n
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{WebhookURL: ""}}
if err := invalidProvider.Validate(); err == nil {
t.Error("provider shouldn't have been valid")
}
validProvider := AlertProvider{DefaultConfig: Config{WebhookURL: "https://example.com"}}
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{WebhookURL: "http://example.com"},
Group: "",
},
},
}
if err := providerWithInvalidOverrideGroup.Validate(); err == nil {
t.Error("provider Group shouldn't have been valid")
}
providerWithInvalidOverrideTo := AlertProvider{
Overrides: []Override{
{
Config: Config{WebhookURL: ""},
Group: "group",
},
},
}
if err := providerWithInvalidOverrideTo.Validate(); err == nil {
t.Error("provider webhook URL shouldn't have been valid")
}
providerWithValidOverride := AlertProvider{
DefaultConfig: Config{WebhookURL: "http://example.com"},
Overrides: []Override{
{
Config: Config{WebhookURL: "http://example.com"},
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{WebhookURL: "http://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{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 {
return &http.Response{StatusCode: http.StatusInternalServerError, Body: http.NoBody}
}),
ExpectedError: true,
},
{
Name: "resolved",
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 {
return &http.Response{StatusCode: http.StatusOK, Body: http.NoBody}
}),
ExpectedError: false,
},
{
Name: "resolved-error",
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 {
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
Resolved bool
ExpectedBody Body
}{
{
Name: "triggered",
Provider: AlertProvider{DefaultConfig: Config{WebhookURL: "http://example.com"}},
Endpoint: endpoint.Endpoint{Name: "name", URL: "https://example.org"},
Alert: alert.Alert{Description: &firstDescription, SuccessThreshold: 5, FailureThreshold: 3},
Resolved: false,
ExpectedBody: Body{
Title: "Gatus",
EndpointName: "name",
EndpointURL: "https://example.org",
AlertDescription: "description-1",
Resolved: false,
Message: "An alert for name has been triggered due to having failed 3 time(s) in a row",
ConditionResults: []ConditionResult{
{Condition: "[CONNECTED] == true", Success: false},
{Condition: "[STATUS] == 200", Success: false},
},
},
},
{
Name: "triggered-with-group",
Provider: AlertProvider{DefaultConfig: Config{WebhookURL: "http://example.com"}},
Endpoint: endpoint.Endpoint{Name: "name", Group: "group", URL: "https://example.org"},
Alert: alert.Alert{Description: &firstDescription, SuccessThreshold: 5, FailureThreshold: 3},
Resolved: false,
ExpectedBody: Body{
Title: "Gatus",
EndpointName: "name",
EndpointGroup: "group",
EndpointURL: "https://example.org",
AlertDescription: "description-1",
Resolved: false,
Message: "An alert for group/name has been triggered due to having failed 3 time(s) in a row",
ConditionResults: []ConditionResult{
{Condition: "[CONNECTED] == true", Success: false},
{Condition: "[STATUS] == 200", Success: false},
},
},
},
{
Name: "resolved",
Provider: AlertProvider{DefaultConfig: Config{WebhookURL: "http://example.com"}},
Endpoint: endpoint.Endpoint{Name: "name", URL: "https://example.org"},
Alert: alert.Alert{Description: &secondDescription, SuccessThreshold: 5, FailureThreshold: 3},
Resolved: true,
ExpectedBody: Body{
Title: "Gatus",
EndpointName: "name",
EndpointURL: "https://example.org",
AlertDescription: "description-2",
Resolved: true,
Message: "An alert for name has been resolved after passing successfully 5 time(s) in a row",
ConditionResults: []ConditionResult{
{Condition: "[CONNECTED] == true", Success: true},
{Condition: "[STATUS] == 200", Success: true},
},
},
},
{
Name: "resolved-with-custom-title",
Provider: AlertProvider{DefaultConfig: Config{WebhookURL: "http://example.com", Title: "Custom Title"}},
Endpoint: endpoint.Endpoint{Name: "name", URL: "https://example.org"},
Alert: alert.Alert{Description: &secondDescription, SuccessThreshold: 5, FailureThreshold: 3},
Resolved: true,
ExpectedBody: Body{
Title: "Custom Title",
EndpointName: "name",
EndpointURL: "https://example.org",
AlertDescription: "description-2",
Resolved: true,
Message: "An alert for name has been resolved after passing successfully 5 time(s) in a row",
ConditionResults: []ConditionResult{
{Condition: "[CONNECTED] == true", Success: true},
{Condition: "[STATUS] == 200", Success: true},
},
},
},
}
for _, scenario := range scenarios {
t.Run(scenario.Name, func(t *testing.T) {
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{
ConditionResults: []*endpoint.ConditionResult{
{Condition: "[CONNECTED] == true", Success: scenario.Resolved},
{Condition: "[STATUS] == 200", Success: scenario.Resolved},
},
},
scenario.Resolved,
)
var actualBody Body
if err := json.Unmarshal(body, &actualBody); err != nil {
t.Error("expected body to be valid JSON, got error:", err.Error())
}
if actualBody.Title != scenario.ExpectedBody.Title {
t.Errorf("expected title to be %s, got %s", scenario.ExpectedBody.Title, actualBody.Title)
}
if actualBody.EndpointName != scenario.ExpectedBody.EndpointName {
t.Errorf("expected endpoint name to be %s, got %s", scenario.ExpectedBody.EndpointName, actualBody.EndpointName)
}
if actualBody.Resolved != scenario.ExpectedBody.Resolved {
t.Errorf("expected resolved to be %v, got %v", scenario.ExpectedBody.Resolved, actualBody.Resolved)
}
if actualBody.Message != scenario.ExpectedBody.Message {
t.Errorf("expected message to be %s, got %s", scenario.ExpectedBody.Message, actualBody.Message)
}
})
}
}
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{WebhookURL: "http://example.com"},
Overrides: nil,
},
InputGroup: "",
InputAlert: alert.Alert{},
ExpectedOutput: Config{WebhookURL: "http://example.com"},
},
{
Name: "provider-no-override-specify-group-should-default",
Provider: AlertProvider{
DefaultConfig: Config{WebhookURL: "http://example.com"},
Overrides: nil,
},
InputGroup: "group",
InputAlert: alert.Alert{},
ExpectedOutput: Config{WebhookURL: "http://example.com"},
},
{
Name: "provider-with-override-specify-no-group-should-default",
Provider: AlertProvider{
DefaultConfig: Config{WebhookURL: "http://example.com"},
Overrides: []Override{
{
Group: "group",
Config: Config{WebhookURL: "http://example01.com"},
},
},
},
InputGroup: "",
InputAlert: alert.Alert{},
ExpectedOutput: Config{WebhookURL: "http://example.com"},
},
{
Name: "provider-with-override-specify-group-should-override",
Provider: AlertProvider{
DefaultConfig: Config{WebhookURL: "http://example.com"},
Overrides: []Override{
{
Group: "group",
Config: Config{WebhookURL: "http://group-example.com"},
},
},
},
InputGroup: "group",
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 _, 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)
}
})
}
}