Alerting: Update the types of recipient supported by the Slack notifier (#22205)

* Alerting: Update types of supported Slack recipients
* Document Slack recipient requirements

docs/sources/alerting/notifications.md

@@ -85,7 +85,7 @@ Setting | Description
 ---------- | -----------
 Url | Slack incoming webhook URL.
 Username | Set the username for the bot's message.
-Recipient | Allows you to override the Slack recipient.
+Recipient | Allows you to override the Slack recipient. You must either provide a channel Slack ID, a user Slack ID, a username reference (@<user>, all lowercase, no whitespace), or a channel reference (#<channel>, all lowercase, no whitespace).
 Icon emoji | Provide an emoji to use as the icon for the bot's message. Ex :smile:
 Icon URL | Provide a URL to an image to use as the icon for the bot's message.
 Mention Users | Optionally mention one or more users in the Slack notification sent by Grafana. You have to refer to users, comma-separated, via their corresponding Slack IDs (which you can find by clicking the overflow button on each user's Slack profile).

pkg/services/alerting/notifiers/slack.go

@@ -8,6 +8,7 @@ import (
 	"mime/multipart"
 	"os"
 	"path/filepath"
+	"regexp"
 	"strings"
 	"time"
 
@@ -38,7 +39,7 @@ func init() {
           data-placement="right">
         </input>
         <info-popover mode="right-absolute">
-          Override default channel or user, use #channel-name or @username
+          Override default channel or user, use #channel-name, @username (has to be all lowercase, no whitespace), or user/channel Slack ID
         </info-popover>
       </div>
       <div class="gf-form max-width-30">
@@ -118,14 +119,15 @@ func init() {
           data-placement="right">
         </input>
         <info-popover mode="right-absolute">
-          Provide a bot token to use the Slack file.upload API (starts with "xoxb"). Specify #channel-name or @username in Recipient for this to work
+          Provide a bot token to use the Slack file.upload API (starts with "xoxb"). Specify Recipient for this to work
         </info-popover>
       </div>
     `,
 	})
-
 }
 
+var reRecipient *regexp.Regexp = regexp.MustCompile("^((@[a-z0-9][a-zA-Z0-9._-]*)|(#[^ .A-Z]{1,79})|([a-zA-Z0-9]+))$")
+
 // NewSlackNotifier is the constructor for the Slack notifier
 func NewSlackNotifier(model *models.AlertNotification) (alerting.Notifier, error) {
 	url := model.Settings.Get("url").MustString()
@@ -133,7 +135,10 @@ func NewSlackNotifier(model *models.AlertNotification) (alerting.Notifier, error
 		return nil, alerting.ValidationError{Reason: "Could not find url property in settings"}
 	}
 
-	recipient := model.Settings.Get("recipient").MustString()
+	recipient := strings.TrimSpace(model.Settings.Get("recipient").MustString())
+	if recipient != "" && !reRecipient.MatchString(recipient) {
+		return nil, alerting.ValidationError{Reason: fmt.Sprintf("Recipient on invalid format: %q", recipient)}
+	}
 	username := model.Settings.Get("username").MustString()
 	iconEmoji := model.Settings.Get("icon_emoji").MustString()
 	iconURL := model.Settings.Get("icon_url").MustString()
@@ -144,7 +149,9 @@ func NewSlackNotifier(model *models.AlertNotification) (alerting.Notifier, error
 	uploadImage := model.Settings.Get("uploadImage").MustBool(true)
 
 	if mentionChannel != "" && mentionChannel != "here" && mentionChannel != "channel" {
-		return nil, fmt.Errorf(fmt.Sprintf("invalid value for mentionChannel: %q", mentionChannel))
+		return nil, alerting.ValidationError{
+			Reason: fmt.Sprintf("Invalid value for mentionChannel: %q", mentionChannel),
+		}
 	}
 	mentionUsers := []string{}
 	for _, u := range strings.Split(mentionUsersStr, ",") {

pkg/services/alerting/notifiers/slack_test.go

@@ -15,15 +15,16 @@ func TestSlackNotifier(t *testing.T) {
 			Convey("empty settings should return error", func() {
 				json := `{ }`
 
-				settingsJSON, _ := simplejson.NewJson([]byte(json))
+				settingsJSON, err := simplejson.NewJson([]byte(json))
+				So(err, ShouldBeNil)
 				model := &models.AlertNotification{
 					Name:     "ops",
 					Type:     "slack",
 					Settings: settingsJSON,
 				}
 
-				_, err := NewSlackNotifier(model)
-				So(err, ShouldNotBeNil)
+				_, err = NewSlackNotifier(model)
+				So(err, ShouldBeError, "Alert validation error: Could not find url property in settings")
 			})
 
 			//nolint:goconst
@@ -71,7 +72,8 @@ func TestSlackNotifier(t *testing.T) {
                       "token": "xoxb-XXXXXXXX-XXXXXXXX-XXXXXXXXXX"
                     }`
 
-				settingsJSON, _ := simplejson.NewJson([]byte(json))
+				settingsJSON, err := simplejson.NewJson([]byte(json))
+				So(err, ShouldBeNil)
 				model := &models.AlertNotification{
 					Name:     "ops",
 					Type:     "slack",
@@ -94,6 +96,88 @@ func TestSlackNotifier(t *testing.T) {
 				So(slackNotifier.MentionChannel, ShouldEqual, "here")
 				So(slackNotifier.Token, ShouldEqual, "xoxb-XXXXXXXX-XXXXXXXX-XXXXXXXXXX")
 			})
+
+			Convey("with channel recipient with spaces should return an error", func() {
+				json := `
+                    {
+                      "url": "http://google.com",
+                      "recipient": "#open tsdb"
+                    }`
+
+				settingsJSON, err := simplejson.NewJson([]byte(json))
+				So(err, ShouldBeNil)
+				model := &models.AlertNotification{
+					Name:     "ops",
+					Type:     "slack",
+					Settings: settingsJSON,
+				}
+
+				_, err = NewSlackNotifier(model)
+
+				So(err, ShouldBeError, "Alert validation error: Recipient on invalid format: \"#open tsdb\"")
+			})
+
+			Convey("with user recipient with spaces should return an error", func() {
+				json := `
+                    {
+                      "url": "http://google.com",
+                      "recipient": "@user name"
+                    }`
+
+				settingsJSON, err := simplejson.NewJson([]byte(json))
+				So(err, ShouldBeNil)
+				model := &models.AlertNotification{
+					Name:     "ops",
+					Type:     "slack",
+					Settings: settingsJSON,
+				}
+
+				_, err = NewSlackNotifier(model)
+
+				So(err, ShouldBeError, "Alert validation error: Recipient on invalid format: \"@user name\"")
+			})
+
+			Convey("with user recipient with uppercase letters should return an error", func() {
+				json := `
+                    {
+                      "url": "http://google.com",
+                      "recipient": "@User"
+                    }`
+
+				settingsJSON, err := simplejson.NewJson([]byte(json))
+				So(err, ShouldBeNil)
+				model := &models.AlertNotification{
+					Name:     "ops",
+					Type:     "slack",
+					Settings: settingsJSON,
+				}
+
+				_, err = NewSlackNotifier(model)
+
+				So(err, ShouldBeError, "Alert validation error: Recipient on invalid format: \"@User\"")
+			})
+
+			Convey("with Slack ID for recipient should work", func() {
+				json := `
+                    {
+                      "url": "http://google.com",
+                      "recipient": "1ABCDE"
+                    }`
+
+				settingsJSON, err := simplejson.NewJson([]byte(json))
+				So(err, ShouldBeNil)
+				model := &models.AlertNotification{
+					Name:     "ops",
+					Type:     "slack",
+					Settings: settingsJSON,
+				}
+
+				not, err := NewSlackNotifier(model)
+				So(err, ShouldBeNil)
+				slackNotifier := not.(*SlackNotifier)
+
+				So(slackNotifier.Recipient, ShouldEqual, "1ABCDE")
+			})
 		})
 	})
 }