Implement alert manager for telegram

Author: richardgreg

docs/alert-routing.md

@@ -36,7 +36,7 @@ Pessimism currently supports the following alert destinations:
 |-----------|-------------------------------------|
 | slack     | Sends alerts to a Slack channel     |
 | pagerduty | Sends alerts to a PagerDuty service |
-| pagerduty | Sends alerts to a PagerDuty service |
+| telegram  | Sends alerts to a Telegram service  |
 
 ## Alert Severity
 

internal/alert/manager.go

@@ -142,6 +142,35 @@ func (am *alertManager) handlePagerDutyPost(alert core.Alert) error {
 	return nil
 }
 
+func (am *alertManager) handleTelegramPost(alert core.Alert, policy *core.AlertPolicy) error {
+	telegramClients := am.cm.GetTelegramClients(alert.Sev)
+	if telegramClients == nil {
+		am.logger.Warn("No telegram clients defined for criticality", zap.Any("alert", alert))
+		return nil
+	}
+
+	// Create Telegram event trigger
+	event := &client.AlertEventTrigger{
+		Message:  am.interpolator.TelegramMessage(alert, policy.Msg),
+		Severity: alert.Sev,
+	}
+
+	for _, tc := range telegramClients {
+		resp, err := tc.PostEvent(am.ctx, event)
+		if err != nil {
+			return err
+		}
+
+		if resp.Status != core.SuccessStatus {
+			return fmt.Errorf("client %s could not post to telegram: %s", tc.GetName(), resp.Message)
+		}
+		am.logger.Debug("Successfully posted to Telegram", zap.String("resp", resp.Message))
+		am.metrics.RecordAlertGenerated(alert, core.Telegram, tc.GetName())
+	}
+
+	return nil
+}
+
 // EventLoop ... Event loop for alert manager subsystem
 func (am *alertManager) EventLoop() error {
 	ticker := time.NewTicker(time.Second * 1)
@@ -202,6 +231,10 @@ func (am *alertManager) HandleAlert(alert core.Alert, policy *core.AlertPolicy)
 	if err := am.handlePagerDutyPost(alert); err != nil {
 		am.logger.Error("could not post to pagerduty", zap.Error(err))
 	}
+
+	if err := am.handleTelegramPost(alert, policy); err != nil {
+		am.logger.Error("could not post to telegram", zap.Error(err))
+	}
 }
 
 // Shutdown ... Shuts down the alert manager subsystem

internal/alert/routing.go

@@ -109,8 +109,8 @@ func (rd *routingDirectory) paramsToRouteDirectory(acc *core.AlertClientCfg, sev
 	if acc.Telegram != nil {
 		for name, cfg := range acc.Telegram {
 			conf := &client.TelegramConfig{
-				Bot:   cfg.Bot.String(),
-				Token: cfg.Token.String(),
+				ChatID: cfg.ChatID.String(),
+				Token:  cfg.Token.String(),
 			}
 			client := client.NewTelegramClient(conf, name)
 			rd.telegramClients[sev] = append(rd.telegramClients[sev], client)

internal/client/telegram.go

@@ -22,19 +22,21 @@ type TelegramConfig struct {
 }
 
 type telegramClient struct {
+	name   string
 	token  string
 	chatID string
 	client *http.Client
 }
 
-func NewTelegramClient(cfg *TelegramConfig) TelegramClient {
+func NewTelegramClient(cfg *TelegramConfig, name string) TelegramClient {
 	if cfg.Token == "" {
 		logging.NoContext().Warn("No Telegram token provided")
 	}
 
 	return &telegramClient{
 		token:  cfg.Token,
 		chatID: cfg.ChatID,
+		name:   name,
 		client: &http.Client{},
 	}
 }
@@ -101,5 +103,5 @@ func (tc *telegramClient) PostEvent(ctx context.Context, data *AlertEventTrigger
 }
 
 func (tc *telegramClient) GetName() string {
-	return "TelegramClient"
+	return tc.name
 }

internal/core/alert.go

@@ -141,9 +141,9 @@ type AlertClientCfg struct {
 
 // AlertConfig ... The config for an alert client
 type AlertConfig struct {
-	URL              StringFromEnv `yaml:"url"`
-	Channel          StringFromEnv `yaml:"channel"`
-	IntegrationKey   StringFromEnv `yaml:"integration_key"`
-	TelegramBotToken StringFromEnv `yaml:"telegram_bot_token"`
-	TelegramChatID   StringFromEnv `yaml:"telegram_chat_id"`
+	URL            StringFromEnv `yaml:"url"`
+	Channel        StringFromEnv `yaml:"channel"`
+	IntegrationKey StringFromEnv `yaml:"integration_key"`
+	Token          StringFromEnv `yaml:"telegram_bot_token"`
+	ChatID         StringFromEnv `yaml:"telegram_chat_id"`
 }

internal/core/constants.go

@@ -173,6 +173,7 @@ const (
 	Slack AlertDestination = iota + 1
 	PagerDuty
 	ThirdParty
+	Telegram
 )
 
 // String ... Converts an alerting destination type to a string
@@ -182,6 +183,8 @@ func (ad AlertDestination) String() string {
 		return "slack"
 	case PagerDuty:
 		return "pager_duty"
+	case Telegram:
+		return "telegram"
 	case ThirdParty:
 		return "third_party"
 	default:
@@ -196,6 +199,8 @@ func StringToAlertingDestType(stringType string) AlertDestination {
 		return Slack
 	case "pager_duty":
 		return PagerDuty
+	case "telegram":
+		return Telegram
 	case "third_party":
 		return ThirdParty
 	}