Configure Keycloak (OIDC)

If your organization uses Keycloak Identity Provider (IdP) for user authentication, you can configure Rancher to allow your users to log in using their IdP credentials. Rancher supports integration with Keycloak using the OpenID Connect (OIDC) protocol and the SAML protocol. Both implementations are functionally equivalent when used with Rancher. This page describes the process to configure Rancher to work with Keycloak using the OIDC protocol.

If you prefer to use Keycloak with the SAML protocol instead, refer to this page.

If you have an existing configuration using the SAML protocol and want to switch to the OIDC protocol, refer to this section.

Prerequisites

• On Rancher, Keycloak (SAML) is disabled.

• You must have a Keycloak IdP Server configured.

• In Keycloak, create a new OIDC client, with the settings below. See the Keycloak documentation for help.

  Setting	Value
  Client ID	<CLIENT_ID> (e.g. rancher)
  Name	<CLIENT_NAME> (e.g. rancher)
  Client Protocol	openid-connect
  Access Type	confidential
  Valid Redirect URI	https://yourRancherHostURL/verify-auth

• In the new OIDC client, create Mappers to expose the users fields.

  • Create a new "Groups Mapper" with the settings below.

    Setting	Value
    Name	Groups Mapper
    Mapper Type	Group Membership
    Token Claim Name	groups
    Add to ID token	OFF
    Add to access token	OFF
    Add to user info	ON

  • Create a new "Client Audience" with the settings below.

    Setting	Value
    Name	Client Audience
    Mapper Type	Audience
    Included Client Audience	<CLIENT_NAME>
    Add to access token	ON

  • Create a new "Groups Path" with the settings below.

    Setting	Value
    Name	Group Path
    Mapper Type	Group Membership
    Token Claim Name	full_group_path
    Full group path	ON
    Add to user info	ON

Configuring Keycloak in Rancher

1. In the Rancher UI, click ☰ > Users & Authentication.

2. In the left navigation bar, click Auth Provider.

3. Select Keycloak (OIDC).

4. Complete the Configure a Keycloak OIDC account form. For help with filling the form, see the configuration reference.

5. After you complete the Configure a Keycloak OIDC account form, click Enable.

   Rancher redirects you to the IdP login page. Enter credentials that authenticate with Keycloak IdP to validate your Rancher Keycloak configuration.

   note

   You may need to disable your popup blocker to see the IdP login page.

Result: Rancher is configured to work with Keycloak using the OIDC protocol. Your users can now sign into Rancher using their Keycloak logins.

Configuration Reference

Field	Description
Client ID	The Client ID of your Keycloak client.
Client Secret	The generated Secret of your Keycloak client. In the Keycloak console, select Clients, select the client you created, select the Credentials tab and copy the value of the Secret field.
Private Key / Certificate	A key/certificate pair to create a secure shell between Rancher and your IdP. Required if HTTPS/SSL is enabled on your Keycloak server.
Endpoints	Choose whether to use the generated values for the Rancher URL, Issue, and Auth Endpoint fields or to provide manual overrides if incorrect.
Keycloak URL	The URL for your Keycloak server.
Keycloak Realm	The name of the realm in which the Keycloak client was created in.
Rancher URL	The URL for your Rancher Server.
Issuer	The URL of your IdP.
Auth Endpoint	The URL where users are redirected to authenticate.

Migrating from SAML to OIDC

This section describes the process to transition from using Rancher with Keycloak (SAML) to Keycloak (OIDC).

Reconfigure Keycloak

1. Change the existing client to use the OIDC protocol. In the Keycloak console, select Clients, select the SAML client to migrate, select the Settings tab, change Client Protocol from saml to openid-connect, and click Save

2. Verify the Valid Redirect URIs are still valid.

3. Select the Mappers tab and create a new Mapper with the settings below.

   Setting	Value
   Name	Groups Mapper
   Mapper Type	Group Membership
   Token Claim Name	groups
   Add to ID token	ON
   Add to access token	ON
   Add to user info	ON

Reconfigure Rancher

Before configuring Rancher to use Keycloak (OIDC), Keycloak (SAML) must be first disabled.

1. In the Rancher UI, click ☰ > Users & Authentication.
2. In the left navigation bar, click Auth Provider.
3. Select Keycloak (SAML).
4. Click Disable.

Configure Rancher to use Keycloak (OIDC) by following the steps in this section.

note

After configuration is completed, Rancher user permissions will need to be reapplied as they are not automatically migrated.

Annex: Troubleshooting

If you are experiencing issues while testing the connection to the Keycloak server, first double-check the configuration options of your OIDC client. You may also inspect the Rancher logs to help pinpoint what's causing issues. Debug logs may contain more detailed information about the error. Please refer to How can I enable debug logging in this documentation.

All Keycloak related log entries will be prepended with either [generic oidc] or [keycloak oidc].

You are not redirected to Keycloak

When you fill the Configure a Keycloak OIDC account form and click on Enable, you are not redirected to your IdP.

• Verify your Keycloak client configuration.

The generated Issuer and Auth Endpoint are incorrect

• On the Configure a Keycloak OIDC account form, change Endpoints to Specify (advanced) and override the Issuer and Auth Endpoint values. To find the values, go to the Keycloak console and select Realm Settings, select the General tab, and click OpenID Endpoint Configuration. The JSON output will display values for issuer and authorization_endpoint.

Keycloak Error: "Invalid grant_type"

• In some cases, this error message may be misleading and is actually caused by setting the Valid Redirect URI incorrectly.