Add cloud-controller support

[brandond]

K3k should have a cloud controller integration:

• Disable the k3s built-in cloud provider, deploy k3k cloud controller (via injected deployment manifest) instead
• Inner cluster cloud controller communicates with outer controller using pod serviceaccount credentials (mounted from host).
  • Cluster pod list backs node lifecycle hooks (node exists, IP list, hostname, ID, etc)
  • LB controller creates LB services in outer cluster for LB services in inner cluster

[galal-hussein]

@brandond we need to keep in mind that the host cluster may not necessarily be a k3s or rke2 server, ideally we want to provide support for all distros as a host cluster, so exposing services as LB services on the host will be a bit challenging

[brandond]

Yeah, and RKE2 doesn't come with a loadbalancer controller at all, so that wouldn't even work out of the box on RKE2.

I guess perhaps we should allow the user to decide what type of service they want created on the outer cluster? Could be useful to both set the default, and to override that default with an annotation. Maybe also annotation to set the traffic policy on the outer service?

Can you think of any other ways that someone might want to expose a k3k service on the outer cluster, that would merit handling via the cloud provider loadbalancer controller?