Mattermost: Cannot post in private channel with a non-admin bot account

[styladj1]

Describe the bug
Mattermost: Cannot post in private channel with a non-admin bot account
team_id is set in the sinkConfiguration, bot account is a member of the channel

To Reproduce
Steps to reproduce the behavior:

1. Deploy Robusta via Helm chart
2. Create bot account in Mattermost with 'Member' role (non-admin)
3. Configure Mattermost sink according to the documentation
4. Restart Robusta deployment
5. Deploy crashpod

Logs
I see entries like this one in the Runner logs:

2025-10-09 12:14:29.884 DEBUG    Try to proceed GET request to https://mattermost.company.com/api/v4//users/me
2025-10-09 12:14:29.904 WARNING  Bot is not an admin. You will not be able to post to private channels.
2025-10-09 12:14:29.904 DEBUG    Try to proceed POST request to https://mattermost.company.com/api/v4/teams/<team-id>/channels/search
2025-10-09 12:14:29.919 WARNING  No channel found, messages won't be sent

Expected
Notifications should reach Mattermost when the channel is set to Private.

Workaround
Convert channel to Public.

Desktop (please complete the following information):

• OS: Debian 12
• Robusta 0.28.1
• Kubernetes 1.30.14

From my understanding, bot accounts cannot post to a private channel unless they are a member of that channel.

Please provide some guidance.

Thanks in advance.

Br,

Matthias