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SAML Group Sync

DETAILS: Tier: Premium, Ultimate Offering: GitLab.com, Self-managed, GitLab Dedicated

  • Introduced for self-managed instances in GitLab 15.1.

WARNING: Adding or changing Group Sync configuration can remove users from the mapped GitLab group. Removal happens if there is any mismatch between the group names and the list of groups in the SAML response. Before making changes, ensure either the SAML response includes the groups attribute and the AttributeValue value matches the SAML Group Name in GitLab, or that all groups are removed from GitLab to disable Group Sync.

SAML group sync allows users to be assigned to pre-existing GitLab groups with specific permissions based on the user's group assignment in the SAML identity provider (IdP). This feature allows you to create a many-to-many mapping between SAML IdP groups and GitLab groups. For example, if the user @amelia is assigned to the security group in the SAML IdP, SAML group sync allows you to assign @amelia to the security-gitlab and vulnerability GitLab groups with maintainer and reporter permissions, respectively. SAML group sync does not create groups. You create groups separately, and then create the mapping.

For a demo of Group Sync using Azure, see Demo: SAML Group Sync.

Configure SAML Group Links

SAML Group Sync only manages a group if that group has one or more SAML group links.

Prerequisites:

  • Self-managed GitLab instances must have configured SAML Group Sync. GitLab.com instances are already configured for SAML Group Sync, and require no extra configuration.

When SAML is enabled, users with the Owner role see a new menu item in group Settings > SAML Group Links.

  • You can configure one or more SAML Group Links to map a SAML IdP group name to a GitLab role.
  • Members of the SAML IdP group are added as members of the GitLab group on their next SAML sign-in.
  • Group membership is evaluated each time a user signs in using SAML.
  • SAML Group Links can be configured for a top-level group or any subgroup.
  • If a SAML group link is created then removed, and there are:
    • Other SAML group links configured, users that were in the removed group link are automatically removed from the group during sync.
    • No other SAML group links configured, users remain in the group during sync. Those users must be manually removed from the group.

To link the SAML groups:

  1. In SAML Group Name, enter the value of the relevant saml:AttributeValue. The value entered here must exactly match the value sent in the SAML response. For some IdPs, this may be a group ID or object ID (Azure AD) instead of a friendly group name.
  2. Choose a default role or custom role in Access Level.
  3. Select Save.
  4. Repeat to add additional group links if required.

SAML Group Links

Self-managed GitLab with multiple SAML IdPs

When a user signs in, GitLab:

  • Checks all the configured SAML group links.
  • Adds that user to the corresponding GitLab groups based on the SAML groups the user belongs to across the different IdPs.

The group link mapping in GitLab is not tied to a specific IdP so you must configure all SAML IdPs to contain group attributes in the SAML response. This means that GitLab is able to match groups in the SAML response, regardless of the IdP that was used to sign in.

As an example, you have 2 IdPs: SAML1 and SAML2.

In GitLab, on a specific group, you have configured two group links:

  • gtlb-owner => Owner role.
  • gtlb-dev => Developer role.

In SAML1, the user is a member of gtlb-owner but not gtlb-dev.

In SAML2, the user is a member of gtlb-dev but not gtlb-owner.

When a user signs in to a group with SAML1, the SAML response shows that the user is a member of gtlb-owner, so GitLab sets the user's role in that group to be Owner.

The user then signs out and signs back in to the group with SAML2. The SAML response shows that the user is a member of gtlb-dev, so GitLab sets the user's role in that group to be Developer.

Now let's change the previous example so that the user is not a member of either gtlb-owner or gtlb-dev in SAML2.

  • When the user signs in to a group with SAML1, the user is given the Owner role in that group.
  • When the user signs in with SAML2, the user is removed from the group because they are not a member of either configured group link.

Role prioritization

Members of multiple mapped SAML groups

If a user is a member of multiple SAML groups mapped to the same GitLab group, the user gets the highest role from the groups. For example, if one group is linked as Guest and another Maintainer, a user in both groups gets the Maintainer role.

Parent group role is higher than child group

Users granted:

  • A higher role with Group Sync are displayed as having direct membership of the group.
  • A lower or the same role with Group Sync are displayed as having inherited membership of the group.

Use the API

You can use the GitLab API to list, add, and delete SAML group links.

Configure SAML Group Sync

NOTE: You must include the SAML configuration block on all Sidekiq nodes in addition to Rails application nodes if you use SAML Group Sync and have multiple GitLab nodes, for example in a distributed or highly available architecture.

WARNING: To prevent users being accidentally removed from the GitLab group, follow these instructions closely before enabling Group Sync in GitLab.

To configure SAML Group Sync for self-managed GitLab instances:

  1. Configure the SAML OmniAuth Provider.

  2. Ensure your SAML identity provider sends an attribute statement with the same name as the value of the groups_attribute setting. See the following provider configuration example in /etc/gitlab/gitlab.rb for reference:

    gitlab_rails['omniauth_providers'] = [
  {
    name: "saml",
    label: "Provider name", # optional label for login button, defaults to "Saml",
    groups_attribute: 'Groups',
    args: {
      assertion_consumer_service_url: "https://gitlab.example.com/users/auth/saml/callback",
      idp_cert_fingerprint: "43:51:43:a1:b5:fc:8b:b7:0a:3a:a9:b1:0f:66:73:a8",
      idp_sso_target_url: "https://login.example.com/idp",
      issuer: "https://gitlab.example.com",
      name_identifier_format: "urn:oasis:names:tc:SAML:2.0:nameid-format:persistent"
    }
  }
]

To configure SAML Group Sync for GitLab.com instances:

  1. See SAML SSO for GitLab.com groups.
  2. Ensure your SAML identity provider sends an attribute statement named Groups or groups.

NOTE: The value for Groups or groups in the SAML response may be either the group name or an ID. For example, Azure AD sends the Azure Group Object ID instead of the name. Use the ID value when configuring SAML Group Links.

<saml:AttributeStatement>
  <saml:Attribute Name="Groups">
    <saml:AttributeValue xsi:type="xs:string">Developers</saml:AttributeValue>
    <saml:AttributeValue xsi:type="xs:string">Product Managers</saml:AttributeValue>
  </saml:Attribute>
</saml:AttributeStatement>

Other attribute names such as http://schemas.microsoft.com/ws/2008/06/identity/claims/groups are not accepted as a source of groups.

For more information on configuring the required group attribute name in the SAML identity provider's settings, see example configurations for Azure AD and Okta.

Microsoft Azure Active Directory integration

NOTE: Microsoft has announced that Azure Active Directory (AD) is being renamed to Entra ID.

Azure AD sends up to 150 groups in the groups claim. When users are members of more than 150 groups Azure AD sends a group overage claim attribute in the SAML response. Then group memberships must be obtained using the Microsoft Graph API.

The Graph API endpoint supports only a user object ID or userPrincipalName as the configured Unique User Identifier (Name identifier) attribute.

When the integration processes Group Sync, only Group Links configured with group unique identifiers (like 12345678-9abc-def0-1234-56789abcde) are supported.

To integrate Microsoft Azure AD, you:

  • Configure Azure AD to enable GitLab to communicate with the Microsoft Graph API.
  • Configure GitLab.

GitLab settings to Azure AD fields

| GitLab setting | Azure field | | ============== | ========================================== | | Tenant ID | Directory (tenant) ID | | Client ID | Application (client) ID | | Client Secret | Value (on Certificates & secrets page) |

Configure Azure AD

  1. In the Azure Portal, go to Microsoft Entra ID > App registrations > All applications, and select your GitLab SAML application.
  2. Under Essentials, the Application (client) ID and Directory (tenant) ID values are displayed. Copy these values, because you need them for the GitLab configuration.
  3. In the left navigation, select Certificates & secrets.
  4. On the Client secrets tab, select New client secret.
    1. In the Description text box, add a description.
    2. In the Expires dropdown list, set the expiration date for the credentials. If the secret expires, the GitLab integration will no longer work until the credentials are updated.
    3. To generate the credentials, select Add.
    4. Copy the Value of the credential. This value is displayed only once, and you need it for the GitLab configuration.
  5. In the left navigation, select API permissions.
  6. Select Microsoft Graph > Application permissions.
  7. Select the checkboxes GroupMember.Read.All and User.Read.All.
  8. Select Add permissions to save.
  9. Select Grant admin consent for <application_name>, then on the confirmation dialog select Yes. The Status column for both permissions should change to a green check with Granted for <application_name>.

Configure GitLab

To configure for a GitLab.com group:

  1. On the left sidebar, select Search or go to and find your top-level group.
  2. Select Settings > SAML SSO.
  3. Configure SAML SSO for the group.
  4. In the Microsoft Azure integration section, select the Enable Microsoft Azure integration for this group checkbox. This section is only visible if SAML SSO is configured and enabled for the group.
  5. Enter the Tenant ID, Client ID, and Client secret obtained earlier when configuring Azure Active Directory in the Azure Portal.
  6. Optional. If using Azure AD for US Government or Azure AD China, enter the appropriate Login API endpoint and Graph API endpoint. The default values work for most organizations.
  7. Select Save changes.

To configure for self-managed:

  1. Configure SAML SSO for the instance.
  2. On the left sidebar, at the bottom, select Admin.
  3. Select Settings > General.
  4. In the Microsoft Azure integration section, select the Enable Microsoft Azure integration for this group checkbox.
  5. Enter the Tenant ID, Client ID, and Client secret obtained earlier when configuring Azure Active Directory in the Azure Portal.
  6. Optional. If using Azure AD for US Government or Azure AD China, enter the appropriate Login API endpoint and Graph API endpoint. The default values work for most organizations.
  7. Select Save changes.

With this configuration, if a user signs in with SAML and Azure sends a group overage claim in the response, GitLab initiates a Group Sync job to call the Microsoft Graph API and retrieve the user's group membership. Then the GitLab Group membership is updated according to SAML Group Links.

Global SAML group memberships lock

DETAILS: Tier: Premium, Ultimate Offering: Self-managed, GitLab Dedicated

GitLab administrators can use the global SAML group memberships lock to prevent group members from inviting new members to subgroups that have their membership synchronized with SAML Group Links.

Global group memberships lock only applies to subgroups of a top-level group where SAML Group Links synchronization is configured. No user can modify the membership of a top-level group configured for SAML Group Links synchronization.

When global group memberships lock is enabled:

  • Only an administrator can manage memberships of any group including access levels.
  • Users cannot:

    • Share a project with other groups.

      NOTE: This limits the use of groups in other product features such as adding a group as a Code Owner.

    • Invite members to a project created in a group.

To enable global group memberships lock:

  1. Configure SAML for your self-managed GitLab instance.
  2. On the left sidebar, at the bottom, select Admin.
  3. Select Settings > General.
  4. Expand the Visibility and access controls section.
  5. Ensure that Lock memberships to SAML Group Links synchronization is selected.

Automatic member removal

After a group sync, users who are not members of a mapped SAML group are removed from the group. On GitLab.com, users in the top-level group are assigned the default membership role instead of being removed.

For example, in the following diagram:

  • Alex Garcia signs into GitLab and is removed from GitLab Group C because they don't belong to SAML Group C.
  • Sidney Jones belongs to SAML Group C, but is not added to GitLab Group C because they have not yet signed in.
%%{init: { "fontFamily": "GitLab Sans" }}%%
graph TB
accTitle: Automatic member removal
accDescr: How group membership of users is determined before sign in if group sync is set up.

   subgraph SAML users
      SAMLUserA[Sidney Jones]
      SAMLUserB[Zhang Wei]
      SAMLUserC[Alex Garcia]
      SAMLUserD[Charlie Smith]
   end

   subgraph SAML groups
      SAMLGroupA["Group A"] --> SAMLGroupB["Group B"]
      SAMLGroupA --> SAMLGroupC["Group C"]
      SAMLGroupA --> SAMLGroupD["Group D"]
   end

   SAMLGroupB --> |Member|SAMLUserA
   SAMLGroupB --> |Member|SAMLUserB

   SAMLGroupC --> |Member|SAMLUserA
   SAMLGroupC --> |Member|SAMLUserB

   SAMLGroupD --> |Member|SAMLUserD
   SAMLGroupD --> |Member|SAMLUserC
%%{init: { "fontFamily": "GitLab Sans" }}%%
graph TB
accTitle: Automatic member removal
accDescr: User membership for Sidney when she has not signed into group C, and group B has not configured group links.

    subgraph GitLab users
      GitLabUserA[Sidney Jones]
      GitLabUserB[Zhang Wei]
      GitLabUserC[Alex Garcia]
      GitLabUserD[Charlie Smith]
    end

   subgraph GitLab groups
      GitLabGroupA["Group A<br> (SAML configured)"] --> GitLabGroupB["Group B<br> (SAML Group Link not configured)"]
      GitLabGroupA --> GitLabGroupC["Group C<br> (SAML Group Link configured)"]
      GitLabGroupA --> GitLabGroupD["Group D<br> (SAML Group Link configured)"]
   end

   GitLabGroupB --> |Member|GitLabUserA

   GitLabGroupC --> |Member|GitLabUserB
   GitLabGroupC --> |Member|GitLabUserC

   GitLabGroupD --> |Member|GitLabUserC
   GitLabGroupD --> |Member|GitLabUserD
%%{init: { "fontFamily": "GitLab Sans" }}%%
graph TB
accTitle: Automatic member removal
accDescr: How membership of Alex Garcia works once she has signed into a group that has group links enabled.

   subgraph GitLab users
      GitLabUserA[Sidney Jones]
      GitLabUserB[Zhang Wei]
      GitLabUserC[Alex Garcia]
      GitLabUserD[Charlie Smith]
   end

   subgraph GitLab groups after Alex Garcia signs in
      GitLabGroupA[Group A]
      GitLabGroupA["Group A<br> (SAML configured)"] --> GitLabGroupB["Group B<br> (SAML Group Link not configured)"]
      GitLabGroupA --> GitLabGroupC["Group C<br> (SAML Group Link configured)"]
      GitLabGroupA --> GitLabGroupD["Group D<br> (SAML Group Link configured)"]
   end

   GitLabGroupB --> |Member|GitLabUserA
   GitLabGroupC --> |Member|GitLabUserB
   GitLabGroupD --> |Member|GitLabUserC
   GitLabGroupD --> |Member|GitLabUserD

User that belongs to many SAML groups automatically removed from GitLab group

When using Azure AD with SAML, if any user in your organization is a member of more than 150 groups and you use SAML Group Sync, that user may lose their group memberships. For more information, see Microsoft Group overages.

GitLab has a Microsoft Azure Active Directory integration that enables SAML Group Sync for organizations with users in more than 150 groups. This integration uses the Microsoft Graph API to obtain all user memberships and is not limited to 150 groups.

Otherwise, you can work around this issue by changing the group claims to use the Groups assigned to the application option instead.

Manage Group Claims