Is your SSL termination for Gitlab happening at a proxy in front of the actual Gitlab rails service or is Gitlab doing the SSL termination itself? Is Mattermost by any chance running on the same host as your Gitlab instance?
Is your SSL termination for Gitlab happening at a proxy in front of the actual Gitlab rails service or is Gitlab doing the SSL termination itself? Is Mattermost by any chance running on the same host as your Gitlab instance?