• Security
  • Security risks
• Configure LDAP
  • Basic configuration settings
  • SSL configuration settings
  • Attribute configuration settings
  • LDAP sync configuration settings
  • Use multiple LDAP servers
  • Set up LDAP user filter
    • Escape special characters in user_filter
  • Enable LDAP username lowercase
  • Disable LDAP web sign in
  • Use encrypted credentials
• Updating LDAP DN and email
• Disable anonymous LDAP authentication
• Users deleted from LDAP
• Update user email addresses
• Google Secure LDAP
• Synchronize users and groups
• Troubleshooting

Integrate LDAP with GitLab

GitLab integrates with LDAP - Lightweight Directory Access Protocol to support user authentication.

This integration works with most LDAP-compliant directory servers, including:

• Microsoft Active Directory.
• Apple Open Directory.
• Open LDAP.
• 389 Server.

Users added through LDAP:

• Usually use a licensed seat.
• Can authenticate with Git using either their GitLab username or their email and LDAP password, even if password authentication for Git is disabled.

The LDAP DN is associated with existing GitLab users when:

• The existing user signs in to GitLab with LDAP for the first time.
• The LDAP email address is the primary email address of an existing GitLab user. If the LDAP email attribute isn’t found in the GitLab user database, a new user is created.

If an existing GitLab user wants to enable LDAP sign-in for themselves, they should:

1. Check that their GitLab email address matches their LDAP email address.
2. Sign in to GitLab by using their LDAP credentials.

Security

GitLab has multiple mechanisms to verify a user is still active in LDAP. If the user is no longer active in LDAP, they are placed in an ldap_blocked status and are signed out. They are unable to sign in using any authentication provider until they are reactivated in LDAP.

Users are considered inactive in LDAP when they:

• Are removed from the directory completely.
• Reside outside the configured base DN or user_filter search.
• Are marked as disabled or deactivated in Active Directory through the user account control attribute. This means attribute userAccountControl:1.2.840.113556.1.4.803 has bit 2 set.

Status is checked for all LDAP users:

• When signing in using any authentication provider. In GitLab 14.4 and earlier, status was checked only when signing in using LDAP directly.
• Once per hour for active web sessions or Git requests using tokens or SSH keys.
• When performing Git over HTTP requests using LDAP username and password.
• Once per day during User Sync.

Security risks

You should only use LDAP integration if your LDAP users cannot:

• Change their mail, email or userPrincipalName attributes on the LDAP server. These users can potentially take over any account on your GitLab server.
• Share email addresses. LDAP users with the same email address can share the same GitLab account.

Configure LDAP

LDAP users must have a set email address, regardless of whether or not it’s used to sign in.

Here’s an example of setting up LDAP with only the required options.

::Tabs

:::TabTitle Linux package (Omnibus)

1. Edit /etc/gitlab/gitlab.rb:

   gitlab_rails['ldap_enabled'] = true
   gitlab_rails['ldap_servers'] = {
     'main' => {
       'label' => 'LDAP',
       'host' =>  'ldap.mydomain.com',
       'port' => 636,
       'uid' => 'sAMAccountName',
       'encryption' => 'simple_tls',
       'base' => 'dc=example,dc=com',
     }
   }
   

2. Save the file and reconfigure GitLab:

   sudo gitlab-ctl reconfigure
   

:::TabTitle Helm chart (Kubernetes)

1. Export the Helm values:

   helm get values gitlab > gitlab_values.yaml
   

2. Edit gitlab_values.yaml:

   global:
     appConfig:
       ldap:
         servers:
           main:
             label: 'LDAP'
             host: 'ldap.mydomain.com'
             port: 636
             uid: 'sAMAccountName'
             base: 'dc=example,dc=com'
             encryption: 'simple_tls'
   

3. Save the file and apply the new values:

   helm upgrade -f gitlab_values.yaml gitlab gitlab/gitlab
   

For more information, see how to configure LDAP for a GitLab instance that was installed by using the Helm chart.

:::TabTitle Docker

1. Edit docker-compose.yml:

   version: "3.6"
   services:
     gitlab:
       image: 'gitlab/gitlab-ee:latest'
       restart: always
       hostname: 'gitlab.example.com'
       environment:
         GITLAB_OMNIBUS_CONFIG: |
           gitlab_rails['ldap_enabled'] = true
           gitlab_rails['ldap_servers'] = {
             'main' => {
               'label' => 'LDAP',
               'host' =>  'ldap.mydomain.com',
               'port' => 636,
               'uid' => 'sAMAccountName',
               'encryption' => 'simple_tls',
               'base' => 'dc=example,dc=com',
             }
           }
   

2. Save the file and restart GitLab:

   docker compose up -d
   

:::TabTitle Self-compiled (source)

1. Edit /home/git/gitlab/config/gitlab.yml:

   production: &base
     ldap:
       enabled: true
       servers:
         main:
           label: 'LDAP'
           host: 'ldap.mydomain.com'
           port: 636
           uid: 'sAMAccountName'
           encryption: 'simple_tls'
           base: 'dc=example,dc=com'
   

2. Save the file and restart GitLab:

   # For systems running systemd
   sudo systemctl restart gitlab.target
   
   # For systems running SysV init
   sudo service gitlab restart
   

For more information about the various LDAP options, see the ldap setting in gitlab.yml.example.

::EndTabs

After configuring LDAP, to test the configuration, use the LDAP check Rake task.

Basic configuration settings

You can configure either:

• A single LDAP server using host and port.
• Many LDAP servers using hosts. This setting takes precedence over host and port. GitLab attempts to use the LDAP servers in the order specified, and the first reachable LDAP server is used.

These configuration settings are available:

SSL configuration settings

These SSL configuration settings are available:

Attribute configuration settings

GitLab uses these LDAP attributes to create an account for the LDAP user. The specified attribute can be either:

• The attribute name as a string. For example, 'mail'.
• An array of attribute names to try in order. For example, ['mail', 'email'].

The user’s LDAP sign in is the LDAP attribute specified as uid.

LDAP sync configuration settings

These LDAP sync configuration settings are available:

Use multiple LDAP servers

If you have users on multiple LDAP servers, you can configure GitLab to use them. To add additional LDAP servers:

1. Duplicate the main LDAP configuration.
2. Edit each duplicate configuration with the details of the additional servers.
   • For each additional server, choose a different provider ID, like main, secondary, or tertiary. Use lowercase alphanumeric characters. GitLab uses the provider ID to associate each user with a specific LDAP server.
   • For each entry, use a unique label value. These values are used for the tab names on the sign-in page.

The following example shows how to configure three LDAP servers with minimal configuration:

::Tabs

:::TabTitle Linux package (Omnibus)

1. Edit /etc/gitlab/gitlab.rb:

   gitlab_rails['ldap_enabled'] = true
   gitlab_rails['ldap_servers'] = {
     'main' => {
       'label' => 'GitLab AD',
       'host' =>  'ad.mydomain.com',
       'port' => 636,
       'uid' => 'sAMAccountName',
       'encryption' => 'simple_tls',
       'base' => 'dc=example,dc=com',
     },
   
     'secondary' => {
       'label' => 'GitLab Secondary AD',
       'host' =>  'ad-secondary.mydomain.com',
       'port' => 636,
       'uid' => 'sAMAccountName',
       'encryption' => 'simple_tls',
       'base' => 'dc=example,dc=com',
     },
   
     'tertiary' => {
       'label' => 'GitLab Tertiary AD',
       'host' =>  'ad-tertiary.mydomain.com',
       'port' => 636,
       'uid' => 'sAMAccountName',
       'encryption' => 'simple_tls',
       'base' => 'dc=example,dc=com',
     }
   }
   

2. Save the file and reconfigure GitLab:

   sudo gitlab-ctl reconfigure
   

:::TabTitle Helm chart (Kubernetes)

1. Export the Helm values:

   helm get values gitlab > gitlab_values.yaml
   

2. Edit gitlab_values.yaml:

   global:
     appConfig:
       ldap:
         servers:
           main:
             label: 'GitLab AD'
             host: 'ad.mydomain.com'
             port: 636
             uid: 'sAMAccountName'
             base: 'dc=example,dc=com'
             encryption: 'simple_tls'
           secondary:
             label: 'GitLab Secondary AD'
             host: 'ad-secondary.mydomain.com'
             port: 636
             uid: 'sAMAccountName'
             base: 'dc=example,dc=com'
             encryption: 'simple_tls'
           tertiary:
             label: 'GitLab Tertiary AD'
             host: 'ad-tertiary.mydomain.com'
             port: 636
             uid: 'sAMAccountName'
             base: 'dc=example,dc=com'
             encryption: 'simple_tls'
   

3. Save the file and apply the new values:

   helm upgrade -f gitlab_values.yaml gitlab gitlab/gitlab
   

:::TabTitle Docker

1. Edit docker-compose.yml:

   version: "3.6"
   services:
     gitlab:
       image: 'gitlab/gitlab-ee:latest'
       restart: always
       hostname: 'gitlab.example.com'
       environment:
         GITLAB_OMNIBUS_CONFIG: |
           gitlab_rails['ldap_enabled'] = true
           gitlab_rails['ldap_servers'] = {
             'main' => {
               'label' => 'GitLab AD',
               'host' =>  'ad.mydomain.com',
               'port' => 636,
               'uid' => 'sAMAccountName',
               'encryption' => 'simple_tls',
               'base' => 'dc=example,dc=com',
             },
   
             'secondary' => {
               'label' => 'GitLab Secondary AD',
               'host' =>  'ad-secondary.mydomain.com',
               'port' => 636,
               'uid' => 'sAMAccountName',
               'encryption' => 'simple_tls',
               'base' => 'dc=example,dc=com',
             },
   
             'tertiary' => {
               'label' => 'GitLab Tertiary AD',
               'host' =>  'ad-tertiary.mydomain.com',
               'port' => 636,
               'uid' => 'sAMAccountName',
               'encryption' => 'simple_tls',
               'base' => 'dc=example,dc=com',
             }
           }
   

2. Save the file and restart GitLab:

   docker compose up -d
   

:::TabTitle Self-compiled (source)

1. Edit /home/git/gitlab/config/gitlab.yml:

   production: &base
     ldap:
       enabled: true
       servers:
         main:
           label: 'GitLab AD'
           host: 'ad.mydomain.com'
           port: 636
           uid: 'sAMAccountName'
           base: 'dc=example,dc=com'
           encryption: 'simple_tls'
         secondary:
           label: 'GitLab Secondary AD'
           host: 'ad-secondary.mydomain.com'
           port: 636
           uid: 'sAMAccountName'
           base: 'dc=example,dc=com'
           encryption: 'simple_tls'
         tertiary:
           label: 'GitLab Tertiary AD'
           host: 'ad-tertiary.mydomain.com'
           port: 636
           uid: 'sAMAccountName'
           base: 'dc=example,dc=com'
           encryption: 'simple_tls'
   

2. Save the file and restart GitLab:

   # For systems running systemd
   sudo systemctl restart gitlab.target
   
   # For systems running SysV init
   sudo service gitlab restart
   

For more information about the various LDAP options, see the ldap setting in gitlab.yml.example.

::EndTabs

This example results in a sign-in page with the following tabs:

• GitLab AD.
• GitLab Secondary AD.
• GitLab Tertiary AD.

Set up LDAP user filter

To limit all GitLab access to a subset of the LDAP users on your LDAP server, first narrow the configured base. However, to further filter users if necessary, you can set up an LDAP user filter. The filter must comply with RFC 4515.

::Tabs

:::TabTitle Linux package (Omnibus)

1. Edit /etc/gitlab/gitlab.rb:

   gitlab_rails['ldap_servers'] = {
     'main' => {
       'user_filter' => '(employeeType=developer)'
     }
   }
   

2. Save the file and reconfigure GitLab:

   sudo gitlab-ctl reconfigure
   

:::TabTitle Helm chart (Kubernetes)

1. Export the Helm values:

   helm get values gitlab > gitlab_values.yaml
   

2. Edit gitlab_values.yaml:

   global:
     appConfig:
       ldap:
         servers:
           main:
             user_filter: '(employeeType=developer)'
   

3. Save the file and apply the new values:

   helm upgrade -f gitlab_values.yaml gitlab gitlab/gitlab
   

:::TabTitle Docker

1. Edit docker-compose.yml:

   version: "3.6"
   services:
     gitlab:
       image: 'gitlab/gitlab-ee:latest'
       restart: always
       hostname: 'gitlab.example.com'
       environment:
         GITLAB_OMNIBUS_CONFIG: |
           gitlab_rails['ldap_servers'] = {
             'main' => {
               'user_filter' => '(employeeType=developer)'
             }
           }
   

2. Save the file and restart GitLab:

   docker compose up -d
   

:::TabTitle Self-compiled (source)

1. Edit /home/git/gitlab/config/gitlab.yml:

   production: &base
     ldap:
       servers:
         main:
           user_filter: '(employeeType=developer)'
   

2. Save the file and restart GitLab:

   # For systems running systemd
   sudo systemctl restart gitlab.target
   
   # For systems running SysV init
   sudo service gitlab restart
   

::EndTabs

To limit access to the nested members of an Active Directory group, use the following syntax:

(memberOf:1.2.840.113556.1.4.1941:=CN=My Group,DC=Example,DC=com)

For more information about LDAP_MATCHING_RULE_IN_CHAIN filters, see Search Filter Syntax.

Support for nested members in the user filter shouldn’t be confused with group sync nested groups support.

GitLab does not support the custom filter syntax used by OmniAuth LDAP.

Escape special characters in user_filter

The user_filter DN can contain special characters. For example:

• A comma:

  OU=GitLab, Inc,DC=gitlab,DC=com
  

• Open and close brackets:

  OU=GitLab (Inc),DC=gitlab,DC=com
  

These characters must be escaped as documented in RFC 4515.

• Escape commas with \2C. For example:

  OU=GitLab\2C Inc,DC=gitlab,DC=com
  

• Escape open brackets with \28 and close brackets with \29. For example:

  OU=GitLab \28Inc\29,DC=gitlab,DC=com
  

Enable LDAP username lowercase

Some LDAP servers, depending on their configuration, can return uppercase usernames. This can lead to several confusing issues such as creating links or namespaces with uppercase names.

GitLab can automatically lowercase usernames provided by the LDAP server by enabling the configuration option lowercase_usernames. By default, this configuration option is false.

::Tabs

:::TabTitle Linux package (Omnibus)

1. Edit /etc/gitlab/gitlab.rb:

   gitlab_rails['ldap_servers'] = {
     'main' => {
       'lowercase_usernames' => true
     }
   }
   

2. Save the file and reconfigure GitLab:

   sudo gitlab-ctl reconfigure
   

:::TabTitle Helm chart (Kubernetes)

1. Export the Helm values:

   helm get values gitlab > gitlab_values.yaml
   

2. Edit gitlab_values.yaml:

   global:
     appConfig:
       ldap:
         servers:
           main:
            lowercase_usernames: true
   

3. Save the file and apply the new values:

   helm upgrade -f gitlab_values.yaml gitlab gitlab/gitlab
   

:::TabTitle Docker

1. Edit docker-compose.yml:

   version: "3.6"
   services:
     gitlab:
       image: 'gitlab/gitlab-ee:latest'
       restart: always
       hostname: 'gitlab.example.com'
       environment:
         GITLAB_OMNIBUS_CONFIG: |
           gitlab_rails['ldap_servers'] = {
             'main' => {
               'lowercase_usernames' => true
             }
           }
   

2. Save the file and restart GitLab:

   docker compose up -d
   

:::TabTitle Self-compiled (source)

1. Edit config/gitlab.yaml:

   production:
     ldap:
       servers:
         main:
           lowercase_usernames: true
   

2. Save the file and restart GitLab:

   # For systems running systemd
   sudo systemctl restart gitlab.target
   
   # For systems running SysV init
   sudo service gitlab restart
   

::EndTabs

Disable LDAP web sign in

It can be useful to prevent using LDAP credentials through the web UI when an alternative such as SAML is preferred. This allows LDAP to be used for group sync, while also allowing your SAML identity provider to handle additional checks like custom 2FA.

When LDAP web sign in is disabled, users don’t see an LDAP tab on the sign-in page. This does not disable using LDAP credentials for Git access.

::Tabs

:::TabTitle Linux package (Omnibus)

1. Edit /etc/gitlab/gitlab.rb:

   gitlab_rails['prevent_ldap_sign_in'] = true
   

2. Save the file and reconfigure GitLab:

   sudo gitlab-ctl reconfigure
   

:::TabTitle Helm chart (Kubernetes)

1. Export the Helm values:

   helm get values gitlab > gitlab_values.yaml
   

2. Edit gitlab_values.yaml:

   global:
     appConfig:
       ldap:
         preventSignin: true
   

3. Save the file and apply the new values:

   helm upgrade -f gitlab_values.yaml gitlab gitlab/gitlab
   

:::TabTitle Docker

1. Edit docker-compose.yml:

   version: "3.6"
   services:
     gitlab:
       image: 'gitlab/gitlab-ee:latest'
       restart: always
       hostname: 'gitlab.example.com'
       environment:
         GITLAB_OMNIBUS_CONFIG: |
           gitlab_rails['prevent_ldap_sign_in'] = true
   

2. Save the file and restart GitLab:

   docker compose up -d
   

:::TabTitle Self-compiled (source)

1. Edit config/gitlab.yaml:

   production:
     ldap:
       prevent_ldap_sign_in: true
   

2. Save the file and restart GitLab:

   # For systems running systemd
   sudo systemctl restart gitlab.target
   
   # For systems running SysV init
   sudo service gitlab restart
   

::EndTabs

Use encrypted credentials

Instead of having the LDAP integration credentials stored in plaintext in the configuration files, you can optionally use an encrypted file for the LDAP credentials.

Prerequisites:

• To use encrypted credentials, you must first enable the encrypted configuration.

The encrypted configuration for LDAP exists in an encrypted YAML file. The unencrypted contents of the file should be a subset of the secret settings from your servers block in the LDAP configuration.

The supported configuration items for the encrypted file are:

• bind_dn
• password

::Tabs

:::TabTitle Linux package (Omnibus)

1. If initially your LDAP configuration in /etc/gitlab/gitlab.rb looked like:

     gitlab_rails['ldap_servers'] = {
       'main' => {
         'bind_dn' => 'admin',
         'password' => '123'
       }
     }
   

2. Edit the encrypted secret:

   sudo gitlab-rake gitlab:ldap:secret:edit EDITOR=vim
   

3. Enter the unencrypted contents of the LDAP secret:

   main:
     bind_dn: admin
     password: '123'
   

4. Edit /etc/gitlab/gitlab.rb and remove the settings for bind_dn and password.

5. Save the file and reconfigure GitLab:

   sudo gitlab-ctl reconfigure
   

:::TabTitle Helm chart (Kubernetes)

Use a Kubernetes secret to store the LDAP password. For more information, read about Helm LDAP secrets.

:::TabTitle Docker

1. If initially your LDAP configuration in docker-compose.yml looked like:

   version: "3.6"
   services:
     gitlab:
       image: 'gitlab/gitlab-ee:latest'
       restart: always
       hostname: 'gitlab.example.com'
       environment:
         GITLAB_OMNIBUS_CONFIG: |
           gitlab_rails['ldap_servers'] = {
             'main' => {
               'bind_dn' => 'admin',
               'password' => '123'
             }
           }
   

2. Get inside the container, and edit the encrypted secret:

   sudo docker exec -t <container_name> bash
   gitlab-rake gitlab:ldap:secret:edit EDITOR=vim
   

3. Enter the unencrypted contents of the LDAP secret:

   main:
     bind_dn: admin
     password: '123'
   

4. Edit docker-compose.yml and remove the settings for bind_dn and password.

5. Save the file and restart GitLab:

   docker compose up -d
   

:::TabTitle Self-compiled (source)

1. If initially your LDAP configuration in /home/git/gitlab/config/gitlab.yml looked like:

   production:
     ldap:
       servers:
         main:
           bind_dn: admin
           password: '123'
   

2. Edit the encrypted secret:

   bundle exec rake gitlab:ldap:secret:edit EDITOR=vim RAILS_ENVIRONMENT=production
   

3. Enter the unencrypted contents of the LDAP secret:

   main:
    bind_dn: admin
    password: '123'
   

4. Edit /home/git/gitlab/config/gitlab.yml and remove the settings for bind_dn and password.

5. Save the file and restart GitLab:

   # For systems running systemd
   sudo systemctl restart gitlab.target
   
   # For systems running SysV init
   sudo service gitlab restart
   

::EndTabs

Updating LDAP DN and email

When an LDAP server creates a user in GitLab, the user’s LDAP distinguished name (DN) is linked to their GitLab account as an identifier.

When a user tries to sign in with LDAP, GitLab tries to find the user using the DN saved on that user’s account.

• If GitLab finds the user by the DN and the user’s email address:
  • Matches the GitLab account’s email address, GitLab does not take any further action.
  • Has changed, GitLab updates its record of the user’s email to match the one in LDAP.
• If GitLab cannot find a user by their DN, it tries to find the user by their email. If GitLab:
  • Finds the user by their email, GitLab updates the DN stored in the user’s GitLab account. Both values now match the information stored in LDAP.
  • Cannot find the user by their email address (both the DN and the email address have changed), see User DN and email have changed.

Disable anonymous LDAP authentication

GitLab doesn’t support TLS client authentication. Complete these steps on your LDAP server.

1. Disable anonymous authentication.
2. Enable one of the following authentication types:
   • Simple authentication.
   • Simple Authentication and Security Layer (SASL) authentication.

The TLS client authentication setting in your LDAP server cannot be mandatory and clients cannot be authenticated with the TLS protocol.

Users deleted from LDAP

Users deleted from the LDAP server:

• Are immediately blocked from signing in to GitLab.
• No longer consume a license.

However, these users can continue to use Git with SSH until the next time the LDAP check cache runs.

To delete the account immediately, you can manually block the user.

Update user email addresses

Email addresses on the LDAP server are considered the source of truth for users when LDAP is used to sign in.

Updating user email addresses must be done on the LDAP server that manages the user. The email address for GitLab is updated either:

• When the user next signs in.
• When the next user sync is run.

The updated user’s previous email address becomes the secondary email address to preserve that user’s commit history.

You can find more details on the expected behavior of user updates in our LDAP troubleshooting section.

Google Secure LDAP

Google Cloud Identity provides a Secure LDAP service that can be configured with GitLab for authentication and group sync. See Google Secure LDAP for detailed configuration instructions.

Synchronize users and groups

For more information on synchronizing users and groups between LDAP and GitLab, see LDAP synchronization.

Troubleshooting

See our administrator guide to troubleshooting LDAP.