✨ Add Mettermost Alerting

alerting/provider/mattermost/mattermost.go

@@ -0,0 +1,73 @@
+package mattermost
+
+import (
+	"fmt"
+	"github.com/TwinProduction/gatus/alerting/provider/custom"
+	"github.com/TwinProduction/gatus/core"
+)
+
+// AlertProvider is the configuration necessary for sending an alert using Mattermost
+type AlertProvider struct {
+	WebhookURL string `yaml:"webhook-url"`
+	Insecure   bool   `yaml:"insecure,omitempty"`
+}
+
+// IsValid returns whether the provider's configuration is valid
+func (provider *AlertProvider) IsValid() bool {
+	return len(provider.WebhookURL) > 0
+}
+
+// ToCustomAlertProvider converts the provider into a custom.AlertProvider
+func (provider *AlertProvider) ToCustomAlertProvider(service *core.Service, alert *core.Alert, result *core.Result, resolved bool) *custom.AlertProvider {
+	var message string
+	var color string
+	if resolved {
+		message = fmt.Sprintf("An alert for *%s* has been resolved after passing successfully %d time(s) in a row", service.Name, 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", service.Name, alert.FailureThreshold)
+		color = "#DD0000"
+	}
+	var results string
+	for _, conditionResult := range result.ConditionResults {
+		var prefix string
+		if conditionResult.Success {
+			prefix = ":white_check_mark: "
+		} else {
+			prefix = ":x:"
+		}
+		results += fmt.Sprintf("%s - `%s`\n", prefix, conditionResult.Condition)
+	}
+	return &custom.AlertProvider{
+		URL:    provider.WebhookURL,
+		Method: "POST",
+		Insecure: provider.Insecure,
+		Body: fmt.Sprintf(`{
+			"text": "",
+			"username": "gatus",
+			"icon_url": "https://raw.githubusercontent.com/TwinProduction/gatus/master/static/logo.png",
+			"attachments": [
+				{
+					"title": ":rescue_worker_helmet: Gatus",
+					"fallback": "Gatus - %s",
+					"text": "%s:\n> %s",
+					"short": false,
+					"color": "%s",
+					"fields": [
+						{
+						"title": "URL",
+						"value": "%s",
+						"short": false
+						},
+						{
+						"title": "Condition results",
+						"value": "%s",
+						"short": false
+						}
+					]
+				}
+			]
+		}`, message, message, alert.Description, color, service.URL, results),
+		Headers: map[string]string{"Content-Type": "application/json"},
+	}
+}

alerting/provider/mattermost/mattermost_test.go

@@ -0,0 +1,40 @@
+package mattermost
+
+import (
+	"github.com/TwinProduction/gatus/core"
+	"strings"
+	"testing"
+)
+
+func TestAlertProvider_IsValid(t *testing.T) {
+	invalidProvider := AlertProvider{WebhookURL: ""}
+	if invalidProvider.IsValid() {
+		t.Error("provider shouldn't have been valid")
+	}
+	validProvider := AlertProvider{WebhookURL: "http://example.com"}
+	if !validProvider.IsValid() {
+		t.Error("provider should've been valid")
+	}
+}
+
+func TestAlertProvider_ToCustomAlertProviderWithResolvedAlert(t *testing.T) {
+	provider := AlertProvider{WebhookURL: "http://example.com"}
+	customAlertProvider := provider.ToCustomAlertProvider(&core.Service{}, &core.Alert{}, &core.Result{ConditionResults: []*core.ConditionResult{{Condition: "SUCCESSFUL_CONDITION", Success: true}}}, true)
+	if customAlertProvider == nil {
+		t.Error("customAlertProvider shouldn't have been nil")
+	}
+	if !strings.Contains(customAlertProvider.Body, "resolved") {
+		t.Error("customAlertProvider.Body should've contained the substring resolved")
+	}
+}
+
+func TestAlertProvider_ToCustomAlertProviderWithTriggeredAlert(t *testing.T) {
+	provider := AlertProvider{WebhookURL: "http://example.com"}
+	customAlertProvider := provider.ToCustomAlertProvider(&core.Service{}, &core.Alert{}, &core.Result{ConditionResults: []*core.ConditionResult{{Condition: "UNSUCCESSFUL_CONDITION", Success: false}}}, false)
+	if customAlertProvider == nil {
+		t.Error("customAlertProvider shouldn't have been nil")
+	}
+	if !strings.Contains(customAlertProvider.Body, "triggered") {
+		t.Error("customAlertProvider.Body should've contained the substring triggered")
+	}
+}

alerting/provider/provider.go

@@ -4,6 +4,7 @@ import (
 	"github.com/TwinProduction/gatus/alerting/provider/custom"
 	"github.com/TwinProduction/gatus/alerting/provider/pagerduty"
 	"github.com/TwinProduction/gatus/alerting/provider/slack"
+	"github.com/TwinProduction/gatus/alerting/provider/mattermost"
 	"github.com/TwinProduction/gatus/alerting/provider/twilio"
 	"github.com/TwinProduction/gatus/core"
 )
@@ -22,5 +23,6 @@ var (
 	_ AlertProvider = (*custom.AlertProvider)(nil)
 	_ AlertProvider = (*twilio.AlertProvider)(nil)
 	_ AlertProvider = (*slack.AlertProvider)(nil)
+	_ AlertProvider = (*mattermost.AlertProvider)(nil)
 	_ AlertProvider = (*pagerduty.AlertProvider)(nil)
 )