Add support for Google Chat alerts (#953)

Add gchat alerting support

Signed-off-by: fpinna <fplkid@gmail.com>

README.md

@@ -16,7 +16,7 @@ Flagger implements several deployment strategies (Canary releases, A/B testing,
 using a service mesh (App Mesh, Istio, Linkerd, Open Service Mesh)
 or an ingress controller (Contour, Gloo, NGINX, Skipper, Traefik) for traffic routing.
 For release analysis, Flagger can query Prometheus, Datadog, New Relic or CloudWatch
-and for alerting it uses Slack, MS Teams, Discord and Rocket.
+and for alerting it uses Slack, MS Teams, Discord, Rocket and Google Chat.
 
 Flagger is a [Cloud Native Computing Foundation](https://cncf.io/) project
 and part of [Flux](https://fluxcd.io) family of GitOps tools.

artifacts/flagger/crd.yaml

@@ -1191,6 +1191,7 @@ spec:
                     - msteams
                     - discord
                     - rocket
+                    - gchat
                 channel:
                   description: Alert channel for this provider
                   type: string

charts/flagger/crds/crd.yaml

@@ -1191,6 +1191,7 @@ spec:
                     - msteams
                     - discord
                     - rocket
+                    - gchat
                 channel:
                   description: Alert channel for this provider
                   type: string

go.sum

@@ -283,6 +283,7 @@ golang.org/x/crypto v0.0.0-20190611184440-5c40567a22f8/go.mod h1:yigFU9vqHzYiE8U
 golang.org/x/crypto v0.0.0-20191011191535-87dc89f01550/go.mod h1:yigFU9vqHzYiE8UmvKecakEJjdnWj3jj499lnFckfCI=
 golang.org/x/crypto v0.0.0-20200622213623-75b288015ac9/go.mod h1:LzIPMQfyMNhhGPhUkYOs5KpL4U8rLKemX1yGLhDgUto=
 golang.org/x/crypto v0.0.0-20201002170205-7f63de1d35b0/go.mod h1:LzIPMQfyMNhhGPhUkYOs5KpL4U8rLKemX1yGLhDgUto=
+golang.org/x/crypto v0.0.0-20210220033148-5ea612d1eb83 h1:/ZScEX8SfEmUGRHs0gxpqteO5nfNW6axyZbBdw9A12g=
 golang.org/x/crypto v0.0.0-20210220033148-5ea612d1eb83/go.mod h1:jdWPYTVW3xRLrWPugEBEK3UY2ZEsg3UU495nc5E+M+I=
 golang.org/x/exp v0.0.0-20190121172915-509febef88a4/go.mod h1:CJ0aWSM057203Lf6IL+f9T1iT9GByDxfZKAQTCR3kQA=
 golang.org/x/exp v0.0.0-20190306152737-a1d7652674e8/go.mod h1:CJ0aWSM057203Lf6IL+f9T1iT9GByDxfZKAQTCR3kQA=

kustomize/base/flagger/crd.yaml

@@ -1191,6 +1191,7 @@ spec:
                     - msteams
                     - discord
                     - rocket
+                    - gchat
                 channel:
                   description: Alert channel for this provider
                   type: string

pkg/notifier/factory.go

@@ -52,6 +52,8 @@ func (f Factory) Notifier(provider string) (Interface, error) {
 		n, err = NewRocket(f.URL, f.ProxyURL, f.Username, f.Channel)
 	case "msteams":
 		n, err = NewMSTeams(f.URL, f.ProxyURL)
+	case "gchat":
+		n, err = NewGChat(f.URL, f.ProxyURL)
 	default:
 		err = fmt.Errorf("provider %s not supported", provider)
 	}

pkg/notifier/gchat.go

@@ -0,0 +1,120 @@
+/*
+Copyright 2020 The Flux authors
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package notifier
+
+import (
+	"fmt"
+	"net/url"
+)
+
+// Google Chat holds the incoming webhook URL
+type GChat struct {
+	URL      string
+	ProxyURL string
+}
+
+// GChatPayload holds the message
+type GChatPayload struct {
+	Cards []GChatCards `json:"cards"`
+}
+
+// Start - GChatCards holds the canary analysis result
+type GChatCards struct {
+	Header   GChatHeader      `json:"header"`
+	Sections []*GChatSections `json:"sections"`
+}
+
+type GChatHeader struct {
+	Title    string `json:"title"`
+	SubTitle string `json:"subtitle"`
+	ImageUrl string `json:"imageUrl"`
+}
+
+type GChatSections struct {
+	Widgets []GChatWidgets `json:"widgets"`
+}
+
+type GChatWidgets struct {
+	TextParagraph GChatText `json:"textParagraph"`
+}
+
+type GChatField struct {
+	Name  string `json:"name"`
+	Value string `json:"value"`
+}
+
+type GChatText struct {
+	Text string `json:"text"`
+}
+
+// NewGChat validates the GChat URL and returns a GChat object
+func NewGChat(hookURL string, proxyURL string) (*GChat, error) {
+	_, err := url.ParseRequestURI(hookURL)
+	if err != nil {
+		return nil, fmt.Errorf("invalid Google Chat webhook URL %s", hookURL)
+	}
+
+	return &GChat{
+		URL:      hookURL,
+		ProxyURL: proxyURL,
+	}, nil
+}
+
+// Post Google Chat message
+func (s *GChat) Post(workload string, namespace string, message string, fields []Field, severity string) error {
+	facts := make([]*GChatSections, 0, len(fields))
+	facts = append(facts, &GChatSections{
+		Widgets: []GChatWidgets{
+			{
+				TextParagraph: GChatText{
+					Text: "<font color=#848484><strong>" + message + "</strong></font>",
+				},
+			},
+		},
+	})
+	for _, f := range fields {
+		facts = append(facts, &GChatSections{
+			Widgets: []GChatWidgets{
+				{
+					TextParagraph: GChatText{
+						Text: f.Name + "<br><font color=#848484><strong>" + f.Value + "</strong></font>",
+					},
+				},
+			},
+		})
+	}
+
+	payload := GChatPayload{
+		Cards: []GChatCards{
+			{
+				Header: GChatHeader{
+					Title:    "Flagger",
+					SubTitle: fmt.Sprintf("%s.%s", workload, namespace),
+					ImageUrl: "https://flagger.app/favicon.png",
+				},
+				Sections: facts,
+			},
+		},
+	}
+
+	err := postMessage(s.URL, s.ProxyURL, payload)
+	if err != nil {
+		return fmt.Errorf("postMessage failed: %w", err)
+	}
+
+	return nil
+}

pkg/notifier/gchat_test.go

@@ -0,0 +1,53 @@
+/*
+Copyright 2020 The Flux authors
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package notifier
+
+import (
+	"encoding/json"
+	"io/ioutil"
+	"net/http"
+	"net/http/httptest"
+	"testing"
+
+	"github.com/stretchr/testify/require"
+)
+
+func TestGChat_Post(t *testing.T) {
+
+	fields := []Field{
+		{Name: "name1", Value: "value1"},
+		{Name: "name2", Value: "value2"},
+	}
+
+	ts := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		b, err := ioutil.ReadAll(r.Body)
+		require.NoError(t, err)
+
+		var payload = GChatPayload{}
+		err = json.Unmarshal(b, &payload)
+		require.NoError(t, err)
+		require.Equal(t, "podinfo.test", payload.Cards[0].Header.SubTitle)
+		require.Equal(t, len(fields), len(payload.Cards[0].Sections)-1)
+	}))
+	defer ts.Close()
+
+	GChat, err := NewGChat(ts.URL, "")
+	require.NoError(t, err)
+
+	err = GChat.Post("podinfo", "test", "test", fields, "info")
+	require.NoError(t, err)
+}