Google Secure LDAP [CORE ONLY]

Introduced in GitLab 11.9.

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

Secure LDAP requires a slightly different configuration than standard LDAP servers. The steps below cover:

Configuring the Secure LDAP Client in the Google Admin console.
Required GitLab configuration.

Configuring Google LDAP client

Navigate to https://admin.google.com and sign in as a GSuite domain administrator.
Go to Apps > LDAP > Add Client.
Provide an LDAP client name and an optional Description. Any descriptive values are acceptable. For example, the name could be 'GitLab' and the description could be 'GitLab LDAP Client'. Click the Continue button.
Set Access Permission according to your needs. You must choose either 'Entire domain (GitLab)' or 'Selected organizational units' for both 'Verify user credentials' and 'Read user information'. Select 'Add LDAP Client'

TIP: Tip: If you plan to use GitLab LDAP Group Sync , turn on 'Read group information'.
Download the generated certificate. This is required for GitLab to communicate with the Google Secure LDAP service. Save the downloaded certificates for later use. After downloading, click the Continue to Client Details button.
Expand the Service Status section and turn the LDAP client 'ON for everyone'. After selecting 'Save', click on the 'Service Status' bar again to collapse and return to the rest of the settings.
Expand the Authentication section and choose 'Generate New Credentials'. Copy/note these credentials for later use. After selecting 'Close', click on the 'Authentication' bar again to collapse and return to the rest of the settings.

Now the Google Secure LDAP Client configuration is finished. The screenshot below shows an example of the final settings. Continue on to configure GitLab.

Configuring GitLab

Edit GitLab configuration, inserting the access credentials and certificate obtained earlier.

The following are the configuration keys that need to be modified using the values obtained during the LDAP client configuration earlier:

bind_dn: The access credentials username
password: The access credentials password
cert: The .crt file text from the downloaded certificate bundle
key: The .key file text from the downloaded certificate bundle

For Omnibus installations

Edit /etc/gitlab/gitlab.rb:

gitlab_rails['ldap_enabled'] = true
gitlab_rails['ldap_servers'] = YAML.load <<-EOS # remember to close this block with 'EOS' below
 main: # 'main' is the GitLab 'provider ID' of this LDAP server
   label: 'Google Secure LDAP'

   host: 'ldap.google.com'
   port: 636
   uid: 'uid'
   bind_dn: 'DizzyHorse'
   password: 'd6V5H8nhMUW9AuDP25abXeLd'
   encryption: 'simple_tls'
   verify_certificates: true

   tls_options:
     cert: |
       -----BEGIN CERTIFICATE-----
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       KCSvK1UmaMxNaZyTHg8JnMf0ZuRpv26iSg==
       -----END CERTIFICATE-----

     key: |
       -----BEGIN PRIVATE KEY-----
       MIIEvQIBADANBgkqhkiG9w0BAQEFAASCBKcwggSjAgEAAoIBAQCzk8uGgt/HcoxEpOjfH0bCpPAz
       dt2V/xmjRS+TlJpgNSls671QvPNTszXbRpt7zTiMa/XJbXhBv7UMLJrCb0E+VPhpAbfrRihf85u8
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       AcZSFJQjdg5BTyvdEDhaYUKGdRw=
       -----END PRIVATE KEY-----
EOS

Save the file and reconfigure GitLab for the changes to take effect.

For installations from source

Edit config/gitlab.yml:

ldap:
 enabled: true
 servers:
   main: # 'main' is the GitLab 'provider ID' of this LDAP server
     label: 'Google Secure LDAP'

     host: 'ldap.google.com'
     port: 636
     uid: 'uid'
     bind_dn: 'DizzyHorse'
     password: 'd6V5H8nhMUW9AuDP25abXeLd'
     encryption: 'simple_tls'
     verify_certificates: true

     tls_options:
       cert: |
         -----BEGIN CERTIFICATE-----
         MIIDbDCCAlSgAwIBAgIGAWlzxiIfMA0GCSqGSIb3DQEBCwUAMHcxFDASBgNVBAoTC0dvb2dsZSBJ
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         4fG/gAXkFbCNxwh1eiQXXRTfruasCZ4/mHfX7MVm8JmWU9uAVIOLW+DSWOFhrDQduJdGBXJOyC2r
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         KCSvK1UmaMxNaZyTHg8JnMf0ZuRpv26iSg==
         -----END CERTIFICATE-----

       key: |
         -----BEGIN PRIVATE KEY-----
         MIIEvQIBADANBgkqhkiG9w0BAQEFAASCBKcwggSjAgEAAoIBAQCzk8uGgt/HcoxEpOjfH0bCpPAz
         dt2V/xmjRS+TlJpgNSls671QvPNTszXbRpt7zTiMa/XJbXhBv7UMLJrCb0E+VPhpAbfrRihf85u8
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         AcZSFJQjdg5BTyvdEDhaYUKGdRw=
         -----END PRIVATE KEY-----

Save the file and restart GitLab for the changes to take effect.