{mattermost_url}
= your Mattermost instance url
- https://{mattermost_url}/oauth/authorize #
auth_url
- https://{mattermost_url}/oauth/access_token #
token_url
- https://{mattermost_url}/api/v4/users/me # so-called
api_url
In Grafana config, there's this section:
; Set to true to enable sending client_id and client_secret via POST body instead of Basic authentication HTTP header
; This might be required if the OAuth provider is not RFC6749 compliant, only supporting credentials passed via POST payload
send_client_credentials_via_post = true
Setting this to true made Mattermost speak with Grafana properly.