Notice: if you're looking for an IRC Bot (idling in your channel, taking commands etc.) take a look at my other project: gitlab-cinch-bot.

Tiny Sinatra App that takes POST Calls from Gitlab Web Hooks and pushes them in your IRC Channel of choice.

22:59 < GitLabBot> New Commits for 'repo-name'
22:59 < GitLabBot> by Aleks | Got shit done | http://yourgitlabhost.com/repo-name/commits/f9cbbe01c....
22:59 < GitLabBot> by Aleks | Got even more shit done | http://yourgitlabhost.com/repo-name/commits/f9cbbe01c....

Set IRC settings in gitlab-irc.rb

# IRC Config
IRC_HOST = 'irc.freenode.org'
IRC_PORT = 6667
IRC_CHANNEL = '#yourchannel'
IRC_NICK = 'GitLabBot'
IRC_REALNAME = 'GitLabBot'

ruby gitlab-irc.rb

You should see output like this:

» ruby gitlab-irc.rb  
== Sinatra/1.3.3 has taken the stage on 4567 for development with backup from Thin
>> Thin web server (v1.4.1 codename Chromeo)
>> Maximum connections set to 1024
>> Listening on 0.0.0.0:4567, CTRL+C to stop

Every Gitlab repository can have individual Web Hooks. Copy your gitlab-irc address http://xxx.xxx.xxx.xxx:4567/commit and set it for every Repository that should send notifications to your IRC channel.

To keep gitlab-irc running, you should start it in some kind of background task. A good choice would be tmux or screen.

If you want to configure the webserver port, take a look at the Sinatra Documentation. You can also run it like any other Sinatra app.