Single log out from Keycloak and OpenShift

OpenShift Security Authentication

- Thomas Jungbauer Thomas Jungbauer ( Lastmod: 2025-05-25 ) - 2 min read

The following 1-minute article is a follow-up to my previous article about how to use Keycloak as an authentication provider for OpenShift. In this article, I will show you how to configure Keycloak and OpenShift for Single Log Out (SLO). This means that when you log out from Keycloak, you will also be logged out from OpenShift automatically. This requires some additional configuration in Keycloak and OpenShift, but it is not too complicated.

Prerequisites

The following prerequisites are required to follow this article:

Keycloak Configuration

Configure the logout URL in Keycloak. This is done by adding a new Valid post logout redirect URIs to the Keycloak client configuration. In this case, we want to call the OpenShift logout URL. Which is: https://oauth-openshift.apps.<your-cluster-name>/logout

This is done in the client settings:

Set Logout URL

OpenShift Configuration

Now we need to configure OpenShift to use the logout URL. This is done by adding a new Post Logout Redirect URI to the OpenShift Console configuration.

Modify the existing Console resource named cluster and add the logoutRedirect parameter to the authentication section. The important pieces of the logout URL are the client_id and the post_logout_redirect_uri. The client ID must be the same as the Keycloak client ID, and the post logout redirect URI must be the OpenShift logout URL. (Also change the <keycloakURL> and <realm> to your Keycloak URL and realm name.)

Actually, instead of client_id, the id_token_hint should be used. But OpenShift does not store the token, so we are using the client ID instead.
apiVersion: config.openshift.io/v1
kind: Console
metadata:
  name: cluster
spec:
  authentication:
    logoutRedirect: 'https://<keycloakURL>/realms/<realm>/protocol/openid-connect/logout?client_id=<realm>&post_logout_redirect_uri=https://console-openshift-console.apps.ocp.aws.ispworld.at' (1)
1The logout URL for OpenShift. This is the URL that will be called when you log out from Keycloak. The URL must contain the client ID and the post logout redirect URI (console of OpenShift).

Wait a few moments until the OpenShift Console Operator applies the new configuration.

Testing the configuration

Now that the configuration is done, we can test the Single Log Out functionality.

  1. We are logged into OpenShift already as user testuser

    Logged in to OpenShift

  2. Now we log out from OpenShift using the Log out button in the upper right corner.

    Log out from OpenShift

  3. This will redirect us to the Keycloak logout page where we need to confirm the logout.

    Keycloak Logout

  4. This will log us out from Keycloak and redirect us back to the OpenShift logout page.

    Logged out from OpenShift

This is it. You are now logged out from both Keycloak and OpenShift. You can also check the Sessions in Keycloak to see that the session for the user is terminated.

Conclusion

As promised, this was a short article about how to configure Keycloak and OpenShift for Single Log Out. This is a beneficial feature if you want to ensure that users are logged out from all applications when they log out from Keycloak. It is also a good security practice to ensure that users are logged out from all applications when they are done using them.

See Also:

  • Red Hat Quay Registry - Integrate Keycloak –

    This guide shows you how to configure Keycloak as an OpenID Connect (OIDC) provider for Red Hat Quay Registry. It covers what to configure in Keycloak, what to put into Quay’s config.yaml (or Operator config), how to verify the login flow, and how to switch your Quay initial/admin account (stored locally in Quay’s DB) to an admin user that authenticates via Keycloak.

  • A second look into the Kubernetes Gateway API on OpenShift –

    This is our second look into the Kubernetes Gateway API an it’s integration into OpenShift. This post covers TLS configuration. The Kubernetes Gateway API is new implementation of the ingress, load balancing and service mesh API’s. See upstream for more information. Also the OpenShift documentation provides an overview of the Gateway API and it’s integration. We demonstrate how to add TLS to our Nginx deployment, how to implement a shared Gateway and finally how to implement HTTP to HTTPS redirection with the Gateway API. Furthermore we cover how HTTPRoute objects attach to Gateways and dive into ordering of HTTPRoute objects.

  • A first look into the Kubernetes Gateway API on OpenShift –

    This blog post summarizes our first look into the Kubernetes Gateway API and how it is integrated in OpenShift.

  • Reusable Argo CD Application Helm Template –

    When working with Argo CD at scale, you often find yourself creating similar Application manifests repeatedly. Each application needs the same basic structure but with different configurations for source repositories, destinations, and sync policies. Additionally, managing namespace metadata becomes tricky when you need to conditionally control whether Argo CD should manage namespace metadata based on sync options. In this article, I’ll walk you through a reusable Helm template that solves these challenges by providing a flexible, DRY (Don’t Repeat Yourself) approach to creating Argo CD Applications. This template is available in my public Helm Chart library and can easily be used by anyone.

  • Cert-Manager Policy Approver in OpenShift –

    One of the most commonly deployed operators in OpenShift environments is the Cert-Manager Operator. It automates the management of TLS certificates for applications running within the cluster, including their issuance and renewal. The tool supports a variety of certificate issuers by default, including ACME, Vault, and self-signed certificates. Whenever a certificate is needed, Cert-Manager will automatically create a CertificateRequest resource that contains the details of the certificate. This resource is then processed by the appropriate issuer to generate the actual TLS certificate. The approval process in this case is usually fully automated, meaning that the certificate is issued without any manual intervention. But what if you want to have more control? What if certificate issuance must follow strict organizational policies, such as requiring a specifc country code or organization name? This is where the CertificateRequestPolicy resource, a resource provided by the Approver Policy, comes into play. This article walks through configuring the Cert-Manager Approver Policy in OpenShift to enforce granular policies on certificate requests.

Copyright © 2020 - 2025 Toni Schmidbauer & Thomas Jungbauer