Testing Active Directory without Active Directory

Active Directory (AD) is a directory service developed by Microsoft. It is widely used by most medium to big company to store information about employees and manage access rights to resources such as shared directories, printers and so on.

AD stores and serves its data using Lightweight Directory Access Protocol or LDAP for short, the open standard for this kind of stuff.

Now let’s say you develop a service and you want to offer the possibility to import data from an AD. How would you do ?

The most straight forward way would be to setup an AD lab following such a tutorial. It’s great because it gives you access to an actual AD. But in my opinion, it has a couple of problem: - It is not a really lightweight solution. It takes a lot of time to setup something like this. - It requires at least one Windows license which is not a good deal but still, it would be better to do without. - This is not an easily hackable and scriptable solution which is usually needed when developing.

Looking into OSS alternatives, the most obvious stop would be to give a try to openldap. Indeed AD serves its data using the LDAP protocol, openldap is an OSS LDAP server, that should work. Unfortunately, it is not really widely knows, but openldap cannot easily simulate the LDAP side of an AD server. But samba does, and this is the right tool to reach out for testing AD integration in a software.

Now all we need to do is to wrap samba in some kind of VM or container. For this kind of stuff I like to use vagrant along ansible. I find these two tools a great combination.

Here is an example of a basic Vagrantfile.

Vagrant.configure("2") do |config|

  config.vm.box = "peru/ubuntu-20.04-server-amd64"

  config.vm.provision  do |ansible|
    ansible.extra_vars = {
    ansible.playbook = "samba.yml"


It creates an Ubuntu VM and provision it using this ansible playbook (save it as samba.yml):

- hosts: all
  become: yes


  - name: "Install tools"
      - ldap-utils
      - samba
      update_cache: yes

  - name: "Stop and disable smbd"
      name: smbd
      enabled: no
      state: stopped

  - block:

    - name: "Remove the original smb.conf"
        path: /etc/samba/smb.conf
        state: absent

    - name: "Provision the domain and create a new smb.conf"
        cmd: >
          samba-tool domain provision
          --realm={{ realm }}
          --domain={{ domain }}
          --adminpass={{ adminpass }}
        creates: ldb.stat.path

  - name: "Enable only the ldap service"
      path: /etc/samba/smb.conf
      line: "server services = ldap, cldap"
      search_string: 'server services ='

  - name: "Disable strong auth for ldap"
      path: /etc/samba/smb.conf
      line: "ldap server require strong auth = no"
      insertafter: "server services ="

  - name: "Start samba-ad-dc"
      name: samba-ad-dc
      masked: no
      enabled: yes
      state: started

  - name: "Add a few users"
    shell: |
      samba-tool user create --random-password user-1
      samba-tool user create --random-password user-2
      samba-tool user create --random-password user-3

Then we can create and provision the VM using:

$ vagrant up

We need to lookup the IP address of the newly created VM.

$ vagrant ssh-config
Host default
  User vagrant
  Port 22

Once the server is up and running we can search something in it just like we would have done with an actual AD server:

$ ldapsearch -H ldap:// -D Administrator@somewhere.local -w "VerySecretPassword;" -b "cn=Users,dc=somewhere,dc=local" "(&(objectCategory=person)(objectClass=user))" | grep dn:
dn: CN=Guest,CN=Users,DC=somewhere,DC=local
dn: CN=user-1,CN=Users,DC=somewhere,DC=local
dn: CN=Administrator,CN=Users,DC=somewhere,DC=local
dn: CN=krbtgt,CN=Users,DC=somewhere,DC=local
dn: CN=user-3,CN=Users,DC=somewhere,DC=local
dn: CN=user-2,CN=Users,DC=somewhere,DC=local
dn: CN=dns-localhost,CN=Users,DC=somewhere,DC=local

And there you go! This demonstrates how to replace an AD by an easy deployable OSS solution. This can be used for testing or various development tasks. I have found this information difficult to find so hopefully that will help somebody out there !

October 31, 2022