Alerting: Add integration tests for dual-stage email templating (#43484)

* Resolve merge conflicts

* Remove cruft from local exploration

* Move integration tests to intercept using new abstraction layer instead of channel

* Fix linter error after rebase

pkg/services/ngalert/notifier/channels/email_test.go

@@ -10,7 +10,10 @@ import (
 	"github.com/prometheus/common/model"
 	"github.com/stretchr/testify/require"
 
+	"github.com/grafana/grafana/pkg/bus"
 	"github.com/grafana/grafana/pkg/components/simplejson"
+	"github.com/grafana/grafana/pkg/services/notifications"
+	"github.com/grafana/grafana/pkg/setting"
 )
 
 func TestEmailNotifier(t *testing.T) {
@@ -102,3 +105,202 @@ func TestEmailNotifier(t *testing.T) {
 		}, expected)
 	})
 }
+
+func TestEmailNotifierIntegration(t *testing.T) {
+	ns := createCoreEmailService(t)
+
+	emailTmpl := templateForTests(t)
+	externalURL, err := url.Parse("http://localhost/base")
+	require.NoError(t, err)
+	emailTmpl.ExternalURL = externalURL
+
+	cases := []struct {
+		name        string
+		alerts      []*types.Alert
+		messageTmpl string
+		expSubject  string
+		expSnippets []string
+	}{
+		{
+			name: "single alert with templated message",
+			alerts: []*types.Alert{
+				{
+					Alert: model.Alert{
+						Labels:      model.LabelSet{"alertname": "AlwaysFiring", "severity": "warning"},
+						Annotations: model.LabelSet{"runbook_url": "http://fix.me", "__dashboardUid__": "abc", "__panelId__": "5"},
+					},
+				},
+			},
+			messageTmpl: `Hi, this is a custom template.
+				{{ if gt (len .Alerts.Firing) 0 }}
+					You have {{ len .Alerts.Firing }} alerts firing.
+					{{ range .Alerts.Firing }} Firing: {{ .Labels.alertname }} at {{ .Labels.severity }} {{ end }}
+				{{ end }}`,
+			expSubject: "[FIRING:1]  (AlwaysFiring warning)",
+			expSnippets: []string{
+				"Hi, this is a custom template.",
+				"You have 1 alerts firing.",
+				"Firing: AlwaysFiring at warning",
+			},
+		},
+		{
+			name: "multiple alerts with templated message",
+			alerts: []*types.Alert{
+				{
+					Alert: model.Alert{
+						Labels:      model.LabelSet{"alertname": "FiringOne", "severity": "warning"},
+						Annotations: model.LabelSet{"runbook_url": "http://fix.me", "__dashboardUid__": "abc", "__panelId__": "5"},
+					},
+				},
+				{
+					Alert: model.Alert{
+						Labels:      model.LabelSet{"alertname": "FiringTwo", "severity": "critical"},
+						Annotations: model.LabelSet{"runbook_url": "http://fix.me", "__dashboardUid__": "abc", "__panelId__": "5"},
+					},
+				},
+			},
+			messageTmpl: `Hi, this is a custom template.
+				{{ if gt (len .Alerts.Firing) 0 }}
+					You have {{ len .Alerts.Firing }} alerts firing.
+					{{ range .Alerts.Firing }} Firing: {{ .Labels.alertname }} at {{ .Labels.severity }} {{ end }}
+				{{ end }}`,
+			expSubject: "[FIRING:2]  ",
+			expSnippets: []string{
+				"Hi, this is a custom template.",
+				"You have 2 alerts firing.",
+				"Firing: FiringOne at warning",
+				"Firing: FiringTwo at critical",
+			},
+		},
+		{
+			name: "empty message with alerts uses default template content",
+			alerts: []*types.Alert{
+				{
+					Alert: model.Alert{
+						Labels:      model.LabelSet{"alertname": "FiringOne", "severity": "warning"},
+						Annotations: model.LabelSet{"runbook_url": "http://fix.me", "__dashboardUid__": "abc", "__panelId__": "5"},
+					},
+				},
+				{
+					Alert: model.Alert{
+						Labels:      model.LabelSet{"alertname": "FiringTwo", "severity": "critical"},
+						Annotations: model.LabelSet{"runbook_url": "http://fix.me", "__dashboardUid__": "abc", "__panelId__": "5"},
+					},
+				},
+			},
+			messageTmpl: "",
+			expSubject:  "[FIRING:2]  ",
+			expSnippets: []string{
+				"Firing: 2 alerts",
+				"<li>alertname: FiringOne</li><li>severity: warning</li>",
+				"<li>alertname: FiringTwo</li><li>severity: critical</li>",
+				"<a href=\"http://fix.me\"",
+				"<a href=\"http://localhost/base/d/abc",
+				"<a href=\"http://localhost/base/d/abc?viewPanel=5",
+			},
+		},
+		{
+			name: "message containing HTML gets HTMLencoded",
+			alerts: []*types.Alert{
+				{
+					Alert: model.Alert{
+						Labels:      model.LabelSet{"alertname": "AlwaysFiring", "severity": "warning"},
+						Annotations: model.LabelSet{"runbook_url": "http://fix.me", "__dashboardUid__": "abc", "__panelId__": "5"},
+					},
+				},
+			},
+			messageTmpl: `<marquee>Hi, this is a custom template.</marquee>
+				{{ if gt (len .Alerts.Firing) 0 }}
+					<ol>
+					{{range .Alerts.Firing }}<li>Firing: {{ .Labels.alertname }} at {{ .Labels.severity }} </li> {{ end }}
+					</ol>
+				{{ end }}`,
+			expSubject: "[FIRING:1]  (AlwaysFiring warning)",
+			expSnippets: []string{
+				"&lt;marquee&gt;Hi, this is a custom template.&lt;/marquee&gt;",
+				"&lt;li&gt;Firing: AlwaysFiring at warning &lt;/li&gt;",
+			},
+		},
+	}
+
+	for _, c := range cases {
+		t.Run(c.name, func(t *testing.T) {
+			emailNotifier := createSut(t, c.messageTmpl, emailTmpl, ns)
+
+			ok, err := emailNotifier.Notify(context.Background(), c.alerts...)
+			require.NoError(t, err)
+			require.True(t, ok)
+
+			sentMsg := getSingleSentMessage(t, ns)
+
+			require.NotNil(t, sentMsg)
+
+			require.Equal(t, "\"Grafana Admin\" <from@address.com>", sentMsg.From)
+			require.Equal(t, sentMsg.To[0], "someops@example.com")
+
+			require.Equal(t, c.expSubject, sentMsg.Subject)
+
+			require.Contains(t, sentMsg.Body, "text/html")
+			html := sentMsg.Body["text/html"]
+			require.NotNil(t, html)
+
+			for _, s := range c.expSnippets {
+				require.Contains(t, html, s)
+			}
+		})
+	}
+}
+
+func createCoreEmailService(t *testing.T) *notifications.NotificationService {
+	t.Helper()
+
+	bus := bus.New()
+	cfg := setting.NewCfg()
+	cfg.StaticRootPath = "../../../../../public/"
+	cfg.BuildVersion = "4.0.0"
+	cfg.Smtp.Enabled = true
+	cfg.Smtp.TemplatesPatterns = []string{"emails/*.html", "emails/*.txt"}
+	cfg.Smtp.FromAddress = "from@address.com"
+	cfg.Smtp.FromName = "Grafana Admin"
+	cfg.Smtp.ContentTypes = []string{"text/html", "text/plain"}
+	cfg.Smtp.Host = "localhost:1234"
+	mailer := notifications.NewFakeMailer()
+
+	ns, err := notifications.ProvideService(bus, cfg, mailer)
+	require.NoError(t, err)
+
+	return ns
+}
+
+func createSut(t *testing.T, messageTmpl string, emailTmpl *template.Template, ns notifications.EmailSender) *EmailNotifier {
+	t.Helper()
+
+	json := `{
+		"addresses": "someops@example.com;somedev@example.com",
+		"singleEmail": true
+	}`
+	settingsJSON, err := simplejson.NewJson([]byte(json))
+	if messageTmpl != "" {
+		settingsJSON.Set("message", messageTmpl)
+	}
+	require.NoError(t, err)
+
+	emailNotifier, err := NewEmailNotifier(&NotificationChannelConfig{
+		Name:     "ops",
+		Type:     "email",
+		Settings: settingsJSON,
+	}, ns, emailTmpl)
+	require.NoError(t, err)
+
+	return emailNotifier
+}
+
+func getSingleSentMessage(t *testing.T, ns *notifications.NotificationService) *notifications.Message {
+	t.Helper()
+
+	mailer := ns.GetMailer().(*notifications.FakeMailer)
+	require.Len(t, mailer.Sent, 1)
+	sent := mailer.Sent[0]
+	mailer.Sent = []*notifications.Message{}
+	return sent
+}

pkg/services/notifications/notifications.go

@@ -118,6 +118,10 @@ func (ns *NotificationService) Run(ctx context.Context) error {
 	}
 }
 
+func (ns *NotificationService) GetMailer() Mailer {
+	return ns.mailer
+}
+
 func (ns *NotificationService) SendWebhookSync(ctx context.Context, cmd *models.SendWebhookSync) error {
 	return ns.sendWebRequestSync(ctx, &Webhook{
 		Url:         cmd.Url,