Changes:

• Escape characters - => \- https://core.telegram.org/bots/api#markdownv2-style

This is a Checkmk plugin to send notifications via Telegram.

The initial version of this plugin was posted in 2016 on my blog: Monitoring Notifications via Telegram

The latest version can always be found under Releases.

The plugin is also available at Checkmk Exchange but it may take some time to see new releases.

Sending messages via a Telegram bot requires two pieces of information:

1. The token of a Telegram Bot to send messages with
2. The chat id for any user to send notifications to

The instructions for talking to BotFather (the Telegram bot used to create a new bot) should be straightforward to follow. The resulting token will be needed for all following steps.

To send messages to a Telegram user, one needs to know the internal chat id for the chat/conversation between the user and the bot.

To find out the chat id, open a private conversation with the bot and send at least one message. Afterwards query the list of incoming messages via the getUpdates function of the Telegram Bot API by fetching https://api.telegram.org/botTOKEN/getUpdates (replacing TOKEN with the actual bot token).

For example using curl and jq (opening the URL in a web browser will work as well):

curl --silent "https://api.telegram.org/bot${TOKEN}/getUpdates" | jq '.result[].message.chat'

Output:

"chat": {
    "id": 144553322,
    "first_name": "Stefan",
    "type": "private"
}

In the above example the chat id would be 144553322.

With both the bot token as well as the chat id being known one can now create a notification rule in Checkmk.