feat(telegram): add support for chat topics

docs/notif/telegram.md

@@ -27,6 +27,8 @@ Multiple chat IDs can be provided in order to deliver notifications to multiple
 | `tokenFile`        |                                    | Use content of secret file as Telegram bot token if `token` not defined   |
 | `chatIDs`          |                                    | List of chat IDs to send notifications to                                 |
 | `chatIDsFile`      |                                    | Use content of secret file as chat IDs if `chatIDs` not defined           |
+| `chatTopics`       |                                    | List of chat topic IDs to send notifications to.                          |
+| `chatTopicsFile`   |                                    | Use content of secret file as chat topic IDs if `chatTopics` not defined  |
 | `templateBody`[^1] | See [below](#default-templatebody) | [Notification template](../faq.md#notification-template) for message body |
 
 !!! abstract "Environment variables"
@@ -39,6 +41,9 @@ Multiple chat IDs can be provided in order to deliver notifications to multiple
 !!! example "chat IDs secret file"
     Chat IDs secret file must be a valid JSON array like: `[123456789,987654321]`
 
+!!! example "chat topic IDS secret file"
+    Chat topics is also an array, so you can specify a topic ID per chat ID: `[10,20]`
+
 ### Default `templateBody`
 
 ```

internal/model/notif_telegram.go

@@ -5,11 +5,13 @@ const NotifTelegramDefaultTemplateBody = `Docker tag {{ if .Entry.Image.HubLink
 
 // NotifTelegram holds Telegram notification configuration details
 type NotifTelegram struct {
-	Token        string  `yaml:"token,omitempty" json:"token,omitempty" validate:"omitempty"`
-	TokenFile    string  `yaml:"tokenFile,omitempty" json:"tokenFile,omitempty" validate:"omitempty,file"`
-	ChatIDs      []int64 `yaml:"chatIDs,omitempty" json:"chatIDs,omitempty" validate:"omitempty"`
-	ChatIDsFile  string  `yaml:"chatIDsFile,omitempty" json:"chatIDsFile,omitempty" validate:"omitempty,file"`
-	TemplateBody string  `yaml:"templateBody,omitempty" json:"templateBody,omitempty" validate:"required"`
+	Token          string             `yaml:"token,omitempty" json:"token,omitempty" validate:"omitempty"`
+	TokenFile      string             `yaml:"tokenFile,omitempty" json:"tokenFile,omitempty" validate:"omitempty,file"`
+	ChatIDs        []int64            `yaml:"chatIDs,omitempty" json:"chatIDs,omitempty" validate:"omitempty"`
+	ChatIDsFile    string             `yaml:"chatIDsFile,omitempty" json:"chatIDsFile,omitempty" validate:"omitempty,file"`
+	ChatTopics     map[string][]int64 `yaml:"chatTopics,omitempty" json:"chatTopics,omitempty" validate:"omitempty"`
+	ChatTopicsFile string             `yaml:"chatTopicsFile,omitempty" json:"chatTopicsFile,omitempty" validate:"omitempty,file"`
+	TemplateBody   string             `yaml:"templateBody,omitempty" json:"templateBody,omitempty" validate:"required"`
 }
 
 // GetDefaults gets the default values

internal/notif/telegram/client.go

@@ -2,6 +2,7 @@ package telegram
 
 import (
 	"encoding/json"
+	"fmt"
 	"net/http"
 	"strings"
 	"text/template"
@@ -54,6 +55,17 @@ func (c *Client) Send(entry model.NotifEntry) error {
 		}
 	}
 
+	chatTopics := c.cfg.ChatTopics
+	chatTopicsRaw, err := utl.GetSecret("", c.cfg.ChatTopicsFile)
+	if err != nil {
+		return errors.Wrap(err, "cannot retrieve chat topics secret for Telegram notifier")
+	}
+	if len(chatTopicsRaw) > 0 {
+		if err = json.Unmarshal([]byte(chatTopicsRaw), &chatTopics); err != nil {
+			return errors.Wrap(err, "cannot unmarshal chat topics secret for Telegram notifier")
+		}
+	}
+
 	bot, err := gotgbot.NewBot(token, &gotgbot.BotOpts{
 		BotClient: &gotgbot.BaseBotClient{
 			Client: http.Client{},
@@ -91,14 +103,29 @@ func (c *Client) Send(entry model.NotifEntry) error {
 	}
 
 	for _, chatID := range chatIDs {
-		_, err := bot.SendMessage(chatID, string(body), &gotgbot.SendMessageOpts{
-			ParseMode:          gotgbot.ParseModeMarkdown,
-			LinkPreviewOptions: &gotgbot.LinkPreviewOptions{IsDisabled: true},
-		})
-		if err != nil {
-			return err
+		if topics, ok := chatTopics[fmt.Sprintf("%d", chatID)]; ok {
+			for _, topic := range topics {
+				err = sendTelegramMessage(bot, chatID, topic, string(body))
+				if err != nil {
+					return err
+				}
+			}
+		} else {
+			err = sendTelegramMessage(bot, chatID, 0, string(body))
+			if err != nil {
+				return err
+			}
 		}
 	}
 
 	return nil
 }
+
+func sendTelegramMessage(bot *gotgbot.Bot, chatID int64, threadID int64, message string) error {
+	_, err := bot.SendMessage(chatID, message, &gotgbot.SendMessageOpts{
+		MessageThreadId:    threadID,
+		ParseMode:          gotgbot.ParseModeMarkdown,
+		LinkPreviewOptions: &gotgbot.LinkPreviewOptions{IsDisabled: true},
+	})
+	return err
+}