Merge pull request #245 from dmitriishaburov/slack-app-support

Add support for Slack app

docs/spec/v1beta1/provider.md

@@ -339,6 +339,42 @@ The provider will send the following labels for the event.
 | namespace   | The namespace of the involved object associated with the event                                     |
 
 
+### Slack App
+
+It is possible to use Slack Apps bot integration to send messages. To obtain bot token, follow the [Slack's guide](https://api.slack.com/bot-users).
+
+Differences from Slack [webhook method](#notifications):
+
+* Possible to use single credentials to post into different channels (integration should be added to each channel)
+* All messages would be posted from app username, losing the `helm-controller`, `source-controller` usernames
+
+In that case, Slack secret should contain URL of [chat.postMessage](https://api.slack.com/methods/chat.postMessage) method and your Slack bot token (starts with `xoxb-`):
+
+```shell
+kubectl create secret generic slack-token \
+--from-literal=address=https://slack.com/api/chat.postMessage \
+--from-literal=token=xoxb-YOUR-TOKEN
+```
+
+Then reference this secret in `spec.secretRef`:
+
+```yaml
+apiVersion: notification.toolkit.fluxcd.io/v1beta1
+kind: Provider
+metadata:
+  name: slack
+  namespace: default
+spec:
+  type: slack
+  channel: general
+  # HTTP(S) proxy (optional)
+  proxy: https://proxy.corp:8080
+  # secret containing Slack API address and token
+  secretRef:
+    name: slack-token
+```
+
+
 ### Git commit status
 
 The GitHub, GitLab, Bitbucket, and Azure DevOps provider will write to the
@@ -366,7 +402,7 @@ spec:
 
 The provider type can be: `github`, `gitlab`, `bitbucket` or `azuredevops`.
 
-For bitbucket, the token should contain the username and [app password](https://support.atlassian.com/bitbucket-cloud/docs/app-passwords/#Create-an-app-password) 
+For bitbucket, the token should contain the username and [app password](https://support.atlassian.com/bitbucket-cloud/docs/app-passwords/#Create-an-app-password)
 in the format `<username>:<password>`. The app password should have `Repositories (Read/Write)` permission.
 
 You can create the secret using this command:

internal/notifier/factory.go

@@ -54,7 +54,7 @@ func (f Factory) Notifier(provider string) (Interface, error) {
 	case v1beta1.GenericProvider:
 		n, err = NewForwarder(f.URL, f.ProxyURL, f.CertPool)
 	case v1beta1.SlackProvider:
-		n, err = NewSlack(f.URL, f.ProxyURL, f.CertPool, f.Username, f.Channel)
+		n, err = NewSlack(f.URL, f.ProxyURL, f.Token, f.CertPool, f.Username, f.Channel)
 	case v1beta1.DiscordProvider:
 		n, err = NewDiscord(f.URL, f.ProxyURL, f.Username, f.Channel)
 	case v1beta1.RocketProvider:

internal/notifier/slack.go

@@ -23,12 +23,14 @@ import (
 	"strings"
 
 	"github.com/fluxcd/pkg/runtime/events"
+	"github.com/hashicorp/go-retryablehttp"
 )
 
 // Slack holds the hook URL
 type Slack struct {
 	URL      string
 	ProxyURL string
+	Token    string
 	Username string
 	Channel  string
 	CertPool *x509.CertPool
@@ -60,7 +62,7 @@ type SlackField struct {
 }
 
 // NewSlack validates the Slack URL and returns a Slack object
-func NewSlack(hookURL string, proxyURL string, certPool *x509.CertPool, username string, channel string) (*Slack, error) {
+func NewSlack(hookURL string, proxyURL string, token string, certPool *x509.CertPool, username string, channel string) (*Slack, error) {
 	_, err := url.ParseRequestURI(hookURL)
 	if err != nil {
 		return nil, fmt.Errorf("invalid Slack hook URL %s", hookURL)
@@ -71,6 +73,7 @@ func NewSlack(hookURL string, proxyURL string, certPool *x509.CertPool, username
 		Username: username,
 		URL:      hookURL,
 		ProxyURL: proxyURL,
+		Token:    token,
 		CertPool: certPool,
 	}, nil
 }
@@ -114,7 +117,11 @@ func (s *Slack) Post(event events.Event) error {
 
 	payload.Attachments = []SlackAttachment{a}
 
-	err := postMessage(s.URL, s.ProxyURL, s.CertPool, payload)
+	err := postMessage(s.URL, s.ProxyURL, s.CertPool, payload, func(request *retryablehttp.Request) {
+		if s.Token != "" {
+			request.Header.Add("Authorization", "Bearer "+s.Token)
+		}
+	})
 	if err != nil {
 		return fmt.Errorf("postMessage failed: %w", err)
 	}

internal/notifier/slack_test.go

@@ -39,15 +39,15 @@ func TestSlack_Post(t *testing.T) {
 	}))
 	defer ts.Close()
 
-	slack, err := NewSlack(ts.URL, "", nil, "", "test")
+	slack, err := NewSlack(ts.URL, "", "", nil, "", "test")
 	require.NoError(t, err)
 
 	err = slack.Post(testEvent())
 	require.NoError(t, err)
 }
 
 func TestSlack_PostUpdate(t *testing.T) {
-	slack, err := NewSlack("http://localhost", "", nil, "", "test")
+	slack, err := NewSlack("http://localhost", "", "", nil, "", "test")
 	require.NoError(t, err)
 
 	event := testEvent()