Extend discord messages with content (prometheus#4007)

* Extend discord messages with content
Signed-off-by: Yevhen Sydorenko <[email protected]>

Signed-off-by: Yevhen Sydorenko <[email protected]>

* Updated configuration.md
Updated assets_vfsdata.go

Signed-off-by: Yevhen Sydorenko <[email protected]>

* Fix grammar

Signed-off-by: Yevhen Sydorenko <[email protected]>

* Updated vfsdata

Signed-off-by: Yevhen Sydorenko <[email protected]>

---------

Signed-off-by: Yevhen Sydorenko <[email protected]>

Author: mogoll92

asset/assets_vfsdata.go

@@ -251,6 +251,7 @@ type DiscordConfig struct {
 	WebhookURL     *SecretURL                  `yaml:"webhook_url,omitempty" json:"webhook_url,omitempty"`
 	WebhookURLFile string                      `yaml:"webhook_url_file,omitempty" json:"webhook_url_file,omitempty"`
 
+	Content string `yaml:"content,omitempty" json:"content,omitempty"`
 	Title   string `yaml:"title,omitempty" json:"title,omitempty"`
 	Message string `yaml:"message,omitempty" json:"message,omitempty"`
 }

config/notifiers.go

@@ -883,6 +883,9 @@ webhook_url_file: <filepath>
 # Message body template.
 [ message: <tmpl_string> | default = '{{ template "discord.default.message" . }}' ]
 
+# Message content template. Limited to 2000 characters.
+[ content: <tmpl_string> | default = '{{ template "discord.default.content" . }}' ]
+
 # The HTTP client's configuration.
 [ http_config: <http_config> | default = global.http_config ]
 ```

docs/configuration.md

@@ -38,6 +38,8 @@ const (
 	maxTitleLenRunes = 256
 	// https://discord.com/developers/docs/resources/channel#embed-object-embed-limits - 4096 characters or runes.
 	maxDescriptionLenRunes = 4096
+
+	maxContentLenRunes = 2000
 )
 
 const (
@@ -115,6 +117,14 @@ func (n *Notifier) Notify(ctx context.Context, as ...*types.Alert) (bool, error)
 		level.Warn(n.logger).Log("msg", "Truncated message", "key", key, "max_runes", maxDescriptionLenRunes)
 	}
 
+	content, truncated := notify.TruncateInRunes(tmpl(n.conf.Content), maxContentLenRunes)
+	if err != nil {
+		return false, err
+	}
+	if truncated {
+		level.Warn(n.logger).Log("msg", "Truncated message", "key", key, "max_runes", maxContentLenRunes)
+	}
+
 	color := colorGrey
 	if alerts.Status() == model.AlertFiring {
 		color = colorRed
@@ -135,6 +145,7 @@ func (n *Notifier) Notify(ctx context.Context, as ...*types.Alert) (bool, error)
 	}
 
 	w := webhook{
+		Content: content,
 		Embeds: []webhookEmbed{{
 			Title:       title,
 			Description: description,

notify/discord/discord.go

@@ -123,6 +123,7 @@ Alerts Resolved:
 {{ end }}
 {{ end }}
 
+{{ define "discord.default.content" }}{{ end }}
 {{ define "discord.default.title" }}{{ template "__subject" . }}{{ end }}
 {{ define "discord.default.message" }}
 {{ if gt (len .Alerts.Firing) 0 }}