k8s Gateway API support

[gemelen]

TL;DR

Add support for the Gateway API in the LoadBalancer managing part of the CCM, so its Gateway component would be provided with the LoadBalancer information on par with a LoadBalancer service type.

This would handle the cases when a k8s cluster is deployed and configured (exclusively or preferably) with the Gateway API approach of exposing services. That covers setups managed by latest versions of Cilium, Traefik, Nginx and others, see list of implementations and compatibility tables for v1.2, v1.1.

One related issue has already been raised here.

Expected behavior

In a cluster setup configured in a Gateway API fashion, a Gateway should be able to obtain an external address(es) from an (external) load balancer, created by or provided via Hetzner CCM.

[zfrgt]

that would be nice to have

[am-i-helpful]

Hi!
I was able to provision an external LB in Hetzner-Cloud using the Cilium Gateway-API following the public documentation of hccm I found here (https://github.com/vitobotta/hetzner-k3s/blob/main/docs/Load_balancers.md#load-balancers), and a bit of manual work annotating the service derived as part of 'Gateway' resource which I think is a bug at Cilium's end: cilium/cilium#36792.

In my opinion, the limitation is at the Cilium Gateway-API controller that they are not copying the metadata 'annotation' from the 'Gateway' resource to the provisioned service of type 'LoadBalancer', which would otherwise result in hccm to provision an external LoadBalancer automatically.