Slack replacement: is Mattermost the only one with GitLab integration? What about Rocket.Chat and Matrix/Riot?

Hello,

I am looking for a Slack replacement and, obviously I am considering Mattermost.
But I’ve also discovered Rocket.Chat and Matrix/Riot.

I have found some material (docs/posts/videos) comparing the 3 solutions but, none with GitLab integration in mind.
As I want to provide a fluid GitLab-communication for the developer team (Issues/MR/CI notifications on a project-dedicated channel, merge or deploy actions directly from the channel, etc.), I’ll be grateful for any advice, pointers or return of experience you can give me

Thanks

GitLab has, as far as i know no built-in support for Rocket.Chat, but there is a manual setup via webhooks possible:
https://rocket.chat/docs/administrator-guides/integrations/gitlab/

Historical Note: Way back when GitLab first included Mattermost, there were a lot of people who wanted to see GitLab ship Rocket.Chat instead. The discussion around doing that basically was centered around Rocket.Chat’s dependence on MongoDB, which GitLab’s developers did not want to ship (and which many of us do not trust and/or do not like for many reasons, even before the whole licensing issue that is going on now). Rocket.Chat’s developers started working on making it database agnostic (so that it could run on the PostgreSQL that GitLab already ships) but that project stalled around four years ago, shortly after it was announced.

Maybe its wise that Gitlab (re)considers native support for rocket.chat integration.

Gitter is also an option, though many chat services can be bridged.

I agree with you.