In hostedcluster installations, when the following OAuthServer service is configure without any configured hostname parameter, the oauth route is created in the management cluster with the standard hostname  which following the pattern from ingresscontroller wilcard domain (oauth-<hosted-cluster-namespace>.<wildcard-default-ingress-controller-domain>):  

~~~
$ oc get hostedcluster -n <namespace> <hosted-cluster-name> -oyaml
  - service: OAuthServer
    servicePublishingStrategy:
      type: Route
~~~  

On the other hand, if any custom hostname parameter is configured, the oauth route is created in the management cluster with the following labels: 

~~~
$ oc get hostedcluster -n <namespace> <hosted-cluster-name> -oyaml
  - service: OAuthServer
    servicePublishingStrategy:
      route:
        hostname: oauth.<custom-domain>
      type: Route

$ oc get routes -n hcp-ns --show-labels
NAME    HOST/PORT             LABELS
oauth oauth.<custom-domain>  hypershift.openshift.io/hosted-control-plane=hcp-ns <---
~~~

The configured label makes the ingresscontroller does not admit the route as the following configuration is added by hypershift operator to the default ingresscontroller resource: 

~~~
$ oc get ingresscontroller -n openshift-ingress-default default -oyaml
    routeSelector:
      matchExpressions:
      - key: hypershift.openshift.io/hosted-control-plane <---
        operator: DoesNotExist <---
~~~

This configuration should be allowed as there are use-cases where the route should have a customized hostname. Currently the HCP platform is not allowing this configuration and the oauth route does not work.

   4.15

    Easily

    1. Install HCP cluster 
    2. Configure OAuthServer with type Route 
    3. Add a custom hostname different than default wildcard ingress URL from management cluster
    

    Oauth route is not admitted

    Oauth route should be admitted by Ingresscontroller