In this article, the screenshots and the GUI navigation described have not yet been updated to Checkmk version 2.0.0. However, nothing fundamental has changed in the described functions themselves and most of the functions can be found quickly with the Monitor or Setup menu search of the Checkmk 2.0.0 user interface. We will update this article as soon as possible.
With the Slack Messenger you can conveniently receive notifications via a webhook. This works on self-hosted or rented servers, as well as via the free public Slack service.
2. Configuring Slack
To activate webhooks and create a new webhook, you must first create a Slack App. Log in to Slack and create a Workspace. Then proceed as follows:
Create a new app via this link using the Slack API.
Assign any name you like and choose your workspace.
In the next dialog choose Incoming Webhook as the app function.
Next activate webhooks by setting the switch to on.
Create the webhook with the Add New Webhook to Workspace button.
Finally, set the channel (group) where the app should post to, and confirm the rights request.
For testing purposes, on completion you will receive a curl statement which posts Hello World to the desired channel. Copy the Webhook URL and switch to Checkmk.
3. Configuration in Checkmk
The configuration in Checkmk requires only the specification of the webhook URL copied above:
For the Notification Method select Slack or Mattermost.
Enter (insert) the copied Web Hook URL.
Optionally, you may specify URL prefixes to control links on your Checkmk GUI within the notification. Instead of specifying the webhook URL directly here, you can also use WATO’s password store and read the URL from one of its entries.
For testing you can use the Fake check results and Custom notification commands.