Cloud-provider-gcp is used to create ingress LBs and perhaps other resources. It appears that there is not support upstream.

We should open an issue upstream about this and it looks likely we will need to add support.

The cloud provider config is laid down the installer, so upstream support would be a matter of adding endpoint fields to the config and setting those endpoints on the clients.

Upstream cloud config: https://github.com/kubernetes/cloud-provider-gcp/blob/4f3202f89437d0fd07c59341367d0ae98b7c8e26/providers/gce/gce.go#L255