Gitlab Active Directory LDAP Authentication

28-05-2013 | Remy van Elst

Table of Contents

Gitlab is a self hosted git based source control application similar to Github, written in Ruby on Rails. It is used by many organisations and is a wonderfull piece of software. It supports LDAP Authentication (via the OmniAuth Gem), but it is tricky to set up with Active Directory and Windows Server 2003/2008/2012. This tutorials shows you how to set up Gitlab to authenticate against Active Directory LDAP.

You have to have a working Gitlab installation for this. It is tested with Gitlab 3 and up to 5.2, with an Active Directory 2008 env, and a Mixed 2008 & 2003 AD. Gitlab is installed on a Ubuntu box.

First create a user in the Active Directory. My CN is Users, and my user is named gitlab. It does not have any special permissions, it is just a normal user. Note the Full Name you use, in my example it is "Gitlab LDAP". See the image below for an example:


Now go to your Gitlab server, log in and become the git user:

sudo su - git

And edit the ~/gitlab/config/gitlab.yml file. (Assuming you followed the official installation guide, otherwise adapt path.). The relevant LDAP section should contain this:

    enabled: true
    host: 'pdc1.domain.tld'
    base: 'CN=Users,DC=Domain,DC=tld'
    port: 389
    uid: 'sAMAccountName'
    method: 'plain' # or "ssl"
    bind_dn: 'CN=Gitlab LDAP,CN=Users,DC=Domain,DC=tld'
    password: 'example_password'

It took me a while to find the correct bind_dn and base_dn. It appears that they are capital sensitive, cn=Users would not work, but CN=Users does. Also, the bind_dn does not use the users email address, but the Display Name. So CN=gitlab@domain.tld does not work, but CN=Gitlab LDAP does.

Hope this helps you setting up Gitlab with LDAP auth. More info on Gitlab can be found on their website:

Tags: active-directory, git, github, gitlab, gitlabshell, ldap, microsoft, scm, source-control, windows-server,