Keycloak absolute URL for quarkus.oidc.authorization-path property

[Jojal]

Description

As a developer running keycloak in a kubernetes pod and my Quarkus application in a second pod, it would be great to have the possibility to specify the quarkus.oidc.authorization-path in an absolute way in order to override the quarkus.oidc.auth-server-url which is an internal kubernetes URL.
This case should happen only for the redirection to display the login page to the user.

Justification

Working with kubernetes with this configuration :

quarkus.oidc.auth-server-url=http://keycloak-http.authentication.svc.cluster.local/auth/realms/quarkus

We can see the url is pointing to authentication.svc.cluster.local which is the URL of the Keycloak POD only accessible from the Quarkus Application POD. (i mean not accessible from outside)
Unfortunatly, when if we set the quarkus.oidc.application-type to web-app, we need a redirection to display the login page to the user. With this basic configuration, the redirection will happen to a kubernetes url authentication.svc.cluster.local which is not accessible from the user browser.

That way, if we could just put an absolute URL in the quarkus.oidc.authorization-path property, the redirection would happened correctly.

[quarkus-bot]

/cc @geoand, @pedroigor, @sberyozkin

[sberyozkin]

I was thinking for a moment that simply starting KC with KEYCLOAK_FRONTEND_URL set to the publicly accessible URL would do it since authorization_endpoint would be KEYCLOAK_FRONTEND_URL based - but so would also be the jwk path and token endpoints - which as you implied in the Zulip thread would not be accessible from the pod running the endpoint...

[sberyozkin]

As confirmed by @Jojal KEYCLOAK_FRONTEND_URL works so I'll close this issue with a small PR adding a note about KEYCLOAK_FRONTEND_URL