gitlab-org--gitlab-foss/doc/integration/omniauth.md

stage	group	info
Ecosystem	Integrations	To determine the technical writer assigned to the Stage/Group associated with this page, see https://about.gitlab.com/handbook/engineering/ux/technical-writing/#assignments

OmniAuth (FREE SELF)

Users can sign in to GitLab by using their credentials from Twitter, GitHub, and other popular services. OmniAuth is the Rack framework that GitLab uses to provide this authentication.

If you configure OmniAuth, users can continue to sign in using other mechanisms, including standard GitLab authentication or LDAP (if configured).

Supported providers

GitLab supports the following OmniAuth providers.

Provider documentation	OmniAuth provider name
Atlassian Crowd	crowd
Atlassian	atlassian_oauth2
Auth0	auth0
Authentiq	authentiq
AWS Cognito	cognito
Azure v2	azure_activedirectory_v2
Azure v1	azure_oauth2
Bitbucket Cloud	bitbucket
CAS	cas3
DingTalk	ding_talk
Facebook	facebook
Generic OAuth 2.0	oauth2_generic
GitHub	github
GitLab.com	gitlab
Google	google_oauth2
JWT	jwt
Kerberos	kerberos
OpenID Connect	openid_connect
Salesforce	salesforce
SAML	saml
Shibboleth	shibboleth
Twitter	twitter

Configure initial settings

NOTE: In GitLab 11.4 and later, OmniAuth is enabled by default. If you're using an earlier version, you must explicitly enable it.

Before you configure the OmniAuth provider, configure the settings that are common for all providers.

Setting	Description	Default value
allow_single_sign_on	Enables you to list the providers that automatically create a GitLab account. The provider names are available in the OmniAuth provider name column in the supported providers table.	The default is false. If false, users must be created manually, or they can't sign in using OmniAuth.
auto_link_ldap_user	If enabled, creates an LDAP identity in GitLab for users that are created through an OmniAuth provider. You can enable this setting if you have the LDAP (ActiveDirectory) integration enabled. Requires the uid of the user to be the same in both LDAP and the OmniAuth provider.	The default is false.
block_auto_created_users	If enabled, blocks users that are automatically created from signing in until they are approved by an administrator.	The default is true. If you set the value to false, make sure you only define providers for allow_single_sign_on that you can control, like SAML, Shibboleth, Crowd, or Google. Otherwise, any user on the internet can sign in to GitLab without an administrator's approval.

To change these settings:

• For Omnibus package

  1. Open the configuration file:

     sudo editor /etc/gitlab/gitlab.rb
     

  2. Update the following section:

     # CAUTION!
     # This allows users to sign in without having a user account first. Define the allowed providers
     # using an array, for example, ["saml", "twitter"], or as true/false to allow all providers or none.
     # User accounts will be created automatically when authentication was successful.
     gitlab_rails['omniauth_allow_single_sign_on'] = ['saml', 'twitter']
     gitlab_rails['omniauth_auto_link_ldap_user'] = true
     gitlab_rails['omniauth_block_auto_created_users'] = true
     

• For installations from source

  1. Open the configuration file:

     cd /home/git/gitlab
     
     sudo -u git -H editor config/gitlab.yml
     

  2. Update the following section:

     ## OmniAuth settings
     omniauth:
       # Allow sign-in by using Twitter, Google, etc. using OmniAuth providers
       # Versions prior to 11.4 require this to be set to true
       # enabled: true
     
       # CAUTION!
       # This allows users to sign in without having a user account first. Define the allowed providers
       # using an array, for example, ["saml", "twitter"], or as true/false to allow all providers or none.
       # User accounts will be created automatically when authentication was successful.
       allow_single_sign_on: ["saml", "twitter"]
     
       auto_link_ldap_user: true
     
       # Locks down those users until they have been cleared by the admin (default: true).
       block_auto_created_users: true
     

After configuring these settings, you can configure your chosen provider.

Enable OmniAuth for an existing user

Existing users can enable OmniAuth for specific providers after the account is created. For example, if the user originally signed in with LDAP, an OmniAuth provider such as Twitter can be enabled. Follow the steps below to enable an OmniAuth provider for an existing user.

1. Sign in normally - whether standard sign in, LDAP, or another OmniAuth provider.
2. In the top-right corner, select your avatar.
3. Select Edit profile.
4. On the left sidebar, select Account.
5. In the Connected Accounts section, select the desired OmniAuth provider, such as Twitter.
6. The user is redirected to the provider. After the user authorizes GitLab, they are redirected back to GitLab.

The chosen OmniAuth provider is now active and can be used to sign in to GitLab from then on.

Link existing users to OmniAuth users

Introduced in GitLab 13.4.

You can automatically link OmniAuth users with existing GitLab users if their email addresses match. Automatic linking using this method works for all providers except the SAML provider. For automatic linking using the SAML provider, see SAML-specific instructions.

As an example, the following configuration is used to enable the auto link feature for both an OpenID Connect provider and a Twitter OAuth provider.

• For Omnibus installations

  gitlab_rails['omniauth_auto_link_user'] = ["openid_connect", "twitter"]
  

• For installations from source

  omniauth:
    auto_link_user: ["openid_connect", "twitter"]
  

Configure OmniAuth providers as external

You can define which OmniAuth providers you want to be external. Users creating accounts, or logging in by using these external providers cannot have access to internal projects. You must use the full name of the provider, like google_oauth2 for Google. Refer to the examples for the full names of the supported providers.

NOTE: If you decide to remove an OmniAuth provider from the external providers list, you must manually update the users that use this method to sign in if you want their accounts to be upgraded to full internal accounts.

• For Omnibus installations

  gitlab_rails['omniauth_external_providers'] = ['twitter', 'google_oauth2']
  

• For installations from source

  omniauth:
    external_providers: ['twitter', 'google_oauth2']
  

Use a custom OmniAuth provider

NOTE: The following information only applies for installations from source.

GitLab uses OmniAuth for authentication and already ships with a few providers pre-installed, such as LDAP, GitHub, and Twitter. You may also have to integrate with other authentication solutions. For these cases, you can use the OmniAuth provider.

These steps are fairly general and you must figure out the exact details from the OmniAuth provider's documentation.

• Stop GitLab:

  sudo service gitlab stop
  

• Add the gem to your Gemfile:

  gem "omniauth-your-auth-provider"
  

• Install the new OmniAuth provider gem by running the following command:

  sudo -u git -H bundle install --without development test mysql --path vendor/bundle --no-deployment
  

  These are the same commands you used during initial installation in the Install Gems section with --path vendor/bundle --no-deployment instead of --deployment.

• Start GitLab:

  sudo service gitlab start
  

Custom OmniAuth provider examples

If you have successfully set up a provider that is not shipped with GitLab itself, please let us know.

While we can't officially support every possible authentication mechanism out there, we'd like to at least help those with specific needs.

Enable or disable sign-in with an OmniAuth provider without disabling import sources

Administrators are able to enable or disable Sign In by using some OmniAuth providers.

NOTE: By default, Sign In is enabled by using all the OAuth Providers that have been configured in config/gitlab.yml.

To enable/disable an OmniAuth provider:

1. On the top bar, select Menu > Admin.

2. On the left sidebar, go to Settings.

3. Scroll to the Sign-in Restrictions section, and click Expand.

4. Below Enabled OAuth Sign-In sources, select the checkbox for each provider you want to enable or disable.

   

Disable OmniAuth

Starting from version 11.4 of GitLab, OmniAuth is enabled by default. This only has an effect if providers are configured and enabled.

If OmniAuth providers are causing problems even when individually disabled, you can disable the entire OmniAuth subsystem by modifying the configuration file:

• For Omnibus installations

  gitlab_rails['omniauth_enabled'] = false
  

• For installations from source:

  omniauth:
    enabled: false
  

Keep OmniAuth user profiles up to date

You can enable profile syncing from selected OmniAuth providers and for all or for specific user information.

When authenticating using LDAP, the user's name and email are always synced.

• For Omnibus installations

  gitlab_rails['omniauth_sync_profile_from_provider'] = ['twitter', 'google_oauth2']
  gitlab_rails['omniauth_sync_profile_attributes'] = ['name', 'email', 'location']
  

• For installations from source

  omniauth:
    sync_profile_from_provider: ['twitter', 'google_oauth2']
    sync_profile_attributes: ['email', 'location']
  

Bypass two-factor authentication

In GitLab 12.3 or later, users can sign in with specified providers without using two factor authentication.

Define the allowed providers using an array (for example, ["twitter", 'google_oauth2']), or as true or false to allow all providers (or none). This option should be configured only for providers which already have two factor authentication (default: false). This configuration doesn't apply to SAML.

• For Omnibus package

  gitlab_rails['omniauth_allow_bypass_two_factor'] = ['twitter', 'google_oauth2']
  

• For installations from source

  omniauth:
    allow_bypass_two_factor: ['twitter', 'google_oauth2']
  

Sign in with a provider automatically

You can add the auto_sign_in_with_provider setting to your GitLab configuration to redirect login requests to your OmniAuth provider for authentication. This removes the need to click a button before actually signing in.

For example, when using the Azure v2 integration, set the following to enable auto sign-in:

• For Omnibus package

  gitlab_rails['omniauth_auto_sign_in_with_provider'] = 'azure_activedirectory_v2'
  

• For installations from source

  omniauth:
    auto_sign_in_with_provider: azure_activedirectory_v2
  

Keep in mind that every sign-in attempt is redirected to the OmniAuth provider; you can't sign in using local credentials. Ensure at least one of the OmniAuth users has an administrator role.

You may also bypass the auto sign in feature by browsing to https://gitlab.example.com/users/sign_in?auto_sign_in=false.

Passwords for users created via OmniAuth

The Generated passwords for users created through integrated authentication guide provides an overview about how GitLab generates and sets passwords for users created with OmniAuth.

Custom OmniAuth provider icon

Most supported providers include a built-in icon for the rendered sign-in button. After you ensure your image is optimized for rendering at 64 x 64 pixels, you can override this icon in one of two ways:

• Provide a custom image path:

  1. If you are hosting the image outside of your GitLab server domain, ensure your content security policies are configured to allow access to the image file.
  2. Depending on your method of installing GitLab, add a custom icon parameter to your GitLab configuration file. Read OpenID Connect OmniAuth provider for an example for the OpenID Connect provider.

• Directly embed an image in a configuration file: This example creates a Base64-encoded version of your image you can serve through a Data URL:

  1. Encode your image file with GNU base64 command (such as base64 -w 0 <logo.png>) which returns a single-line <base64-data> string.

  2. Add the Base64-encoded data to a custom icon parameter in your GitLab configuration file:

     omniauth:
       providers:
         - { name: '...'
             icon: 'data:image/png;base64,<base64-data>'
             ...
           }