fix(alerting): Limit minimum-reminder-interval to >5m (#1290)

alerting/alert/alert.go

@@ -15,6 +15,8 @@ import (
 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 endpoint.Endpoint's alert configuration
@@ -78,6 +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
 	}

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) {