feat(notifications): make it possible to send test alert notifications

closes #5847

pkg/services/alerting/test_notification.go

@@ -0,0 +1,93 @@
+package alerting
+
+import (
+	"github.com/grafana/grafana/pkg/bus"
+	"github.com/grafana/grafana/pkg/components/simplejson"
+	"github.com/grafana/grafana/pkg/log"
+	"github.com/grafana/grafana/pkg/models"
+)
+
+type NotificationTestCommand struct {
+	Severity string
+	Name     string
+	Type     string
+	Settings *simplejson.Json
+}
+
+func init() {
+	bus.AddHandler("alerting", handleNotificationTestCommand)
+
+}
+
+func handleNotificationTestCommand(cmd *NotificationTestCommand) error {
+	notifier := NewRootNotifier()
+
+	model := &models.AlertNotification{
+		Name:     cmd.Name,
+		Type:     cmd.Type,
+		Settings: cmd.Settings,
+	}
+
+	notifiers, err := notifier.getNotifierFor(model)
+
+	if err != nil {
+		log.Error2("Failed to create notifier", "error", err.Error())
+		return err
+	}
+
+	severity := models.AlertSeverityType(cmd.Severity)
+	notifier.sendNotifications([]Notifier{notifiers}, createTestEvalContext(severity))
+
+	return nil
+}
+
+func createTestEvalContext(severity models.AlertSeverityType) *EvalContext {
+	state := models.AlertStateOK
+	firing := false
+	if severity == models.AlertSeverityCritical {
+		state = models.AlertStateCritical
+		firing = true
+	}
+	if severity == models.AlertSeverityWarning {
+		state = models.AlertStateWarning
+		firing = true
+	}
+
+	testRule := &Rule{
+		DashboardId: 1,
+		PanelId:     1,
+		Name:        "Test notification",
+		Message:     "Someone is testing the alert notification within grafana.",
+		State:       state,
+		Severity:    severity,
+	}
+
+	ctx := NewEvalContext(testRule)
+	ctx.ImagePublicUrl = "http://grafana.org/assets/img/blog/mixed_styles.png"
+
+	ctx.IsTestRun = true
+	ctx.Firing = firing
+	ctx.Error = nil
+	ctx.EvalMatches = evalMatchesBasedOnSeverity(severity)
+
+	return ctx
+}
+
+func evalMatchesBasedOnSeverity(severity models.AlertSeverityType) []*EvalMatch {
+	matches := make([]*EvalMatch, 0)
+	if severity == models.AlertSeverityOK {
+		return matches
+	}
+
+	matches = append(matches, &EvalMatch{
+		Metric: "High value",
+		Value:  100,
+	})
+
+	matches = append(matches, &EvalMatch{
+		Metric: "Higher Value",
+		Value:  200,
+	})
+
+	return matches
+}