Horizon "Logout" doesn't work with federation / oidc.  When user refresh the horizon dashboard, he doesn't have to type in credentials again.    The doc [1] should take this into account or better, this should be automated.  

[1] https://docs.redhat.com/en/documentation/red_hat_openstack_platform/17.1/html/integrating_openstack_identity_with_external_user_management_services/assembly_federation-using-rhosp-and-keycloak#proc_deploying-rhosp-with-keycloak_keystone_federation