Alerting: Attach image URLs to Google Chat notifications. (#49445)

* Add a test card to see what styles look like

* Add text and image cards

* Address feedback

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

@@ -23,6 +23,7 @@ type GoogleChatNotifier struct {
 	URL     string
 	log     log.Logger
 	ns      notifications.WebhookSender
+	images  ImageStore
 	tmpl    *template.Template
 	content string
 }
@@ -41,7 +42,7 @@ func GoogleChatFactory(fc FactoryConfig) (NotificationChannel, error) {
 			Cfg:    *fc.Config,
 		}
 	}
-	return NewGoogleChatNotifier(cfg, fc.NotificationService, fc.Template), nil
+	return NewGoogleChatNotifier(cfg, fc.ImageStore, fc.NotificationService, fc.Template), nil
 }
 
 func NewGoogleChatConfig(config *NotificationChannelConfig) (*GoogleChatConfig, error) {
@@ -56,7 +57,7 @@ func NewGoogleChatConfig(config *NotificationChannelConfig) (*GoogleChatConfig,
 	}, nil
 }
 
-func NewGoogleChatNotifier(config *GoogleChatConfig, ns notifications.WebhookSender, t *template.Template) *GoogleChatNotifier {
+func NewGoogleChatNotifier(config *GoogleChatConfig, images ImageStore, ns notifications.WebhookSender, t *template.Template) *GoogleChatNotifier {
 	return &GoogleChatNotifier{
 		Base: NewBase(&models.AlertNotification{
 			Uid:                   config.UID,
@@ -69,6 +70,7 @@ func NewGoogleChatNotifier(config *GoogleChatConfig, ns notifications.WebhookSen
 		URL:     config.URL,
 		log:     log.New("alerting.notifier.googlechat"),
 		ns:      ns,
+		images:  images,
 		tmpl:    t,
 	}
 }
@@ -138,6 +140,9 @@ func (gcn *GoogleChatNotifier) Notify(ctx context.Context, as ...*types.Alert) (
 			},
 		},
 	}
+	if screenshots := gcn.buildScreenshotCard(ctx, as); screenshots != nil {
+		res.Cards = append(res.Cards, *screenshots)
+	}
 
 	if tmplErr != nil {
 		gcn.log.Warn("failed to template GoogleChat message", "err", tmplErr.Error())
@@ -176,6 +181,53 @@ func (gcn *GoogleChatNotifier) SendResolved() bool {
 	return !gcn.GetDisableResolveMessage()
 }
 
+func (gcn *GoogleChatNotifier) buildScreenshotCard(ctx context.Context, alerts []*types.Alert) *card {
+	card := card{
+		Header: header{
+			Title: "Screenshots",
+		},
+		Sections: []section{},
+	}
+	for _, alert := range alerts {
+		imgToken := getTokenFromAnnotations(alert.Annotations)
+		if len(imgToken) == 0 {
+			continue
+		}
+
+		timeoutCtx, cancel := context.WithTimeout(ctx, ImageStoreTimeout)
+		imgURL, err := gcn.images.GetURL(timeoutCtx, imgToken)
+		cancel()
+		if err != nil {
+			if !errors.Is(err, ErrImagesUnavailable) {
+				// Ignore errors. Don't log "ImageUnavailable", which means the storage doesn't exist.
+				gcn.log.Warn("failed to retrieve image url from store", "error", err)
+			}
+		}
+
+		if len(imgURL) > 0 {
+			section := section{
+				Widgets: []widget{
+					textParagraphWidget{
+						Text: text{
+							Text: fmt.Sprintf("%s: %s", alert.Status(), alert.Name()),
+						},
+					},
+					imageWidget{
+						Image: imageData{
+							ImageURL: imgURL,
+						},
+					},
+				},
+			}
+			card.Sections = append(card.Sections, section)
+		}
+	}
+	if len(card.Sections) == 0 {
+		return nil
+	}
+	return &card
+}
+
 // Structs used to build a custom Google Hangouts Chat message card.
 // See: https://developers.google.com/hangouts/chat/reference/message-formats/cards
 type outerStruct struct {
@@ -208,6 +260,14 @@ type textParagraphWidget struct {
 	Text text `json:"textParagraph"`
 }
 
+type imageWidget struct {
+	Image imageData `json:"image"`
+}
+
+type imageData struct {
+	ImageURL string `json:"imageUrl"`
+}
+
 type text struct {
 	Text string `json:"text"`
 }

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

@@ -329,10 +329,11 @@ func TestGoogleChatNotifier(t *testing.T) {
 				return
 			}
 			require.NoError(t, err)
+			imageStore := &UnavailableImageStore{}
 
 			ctx := notify.WithGroupKey(context.Background(), "alertname")
 			ctx = notify.WithGroupLabels(ctx, model.LabelSet{"alertname": ""})
-			pn := NewGoogleChatNotifier(cfg, webhookSender, tmpl)
+			pn := NewGoogleChatNotifier(cfg, imageStore, webhookSender, tmpl)
 			ok, err := pn.Notify(ctx, c.alerts...)
 			if c.expMsgError != nil {
 				require.False(t, ok)