We run a stupidly simple (though small scale) gitlab instance in docker (official image its kinda one-click install). You get mattermost automatically, just nee

We run a stupidly simple (though small scale) gitlab instance in docker (official image its kinda one-click install). You get mattermost automatically, just need to enable it in the gitlab config and it will install/run mattermost within the gitlab container without any troubles. So if you already have (self-hosted) gitlab, mattermost is easy to setup and maintain (actually no extra effort at all). Depends of course on the number of users, I guess... The integrations with gitlab issues/groups/etc are also look neat but are barely used tbh. Cant compare with rocket.chat.