* Always use static ports for the load-balancers
This fixes an issue where RKE2 kube-proxy daemonset pods were failing to
communicate with the apiserver when RKE2 was restarted because the
load-balancer used a different port every time it started up.
This also changes the apiserver load-balancer port to be 1 below the
supervisor port instead of 1 above it. This makes the apiserver port
consistent at 6443 across servers and agents on RKE2.
Additional fixes below were required to successfully test and use this change
on etcd-only nodes.
* Actually add lb-server-port flag to CLI
* Fix nil pointer when starting server with --disable-etcd but no --server
* Don't try to use full URI as initial load-balancer endpoint
* Fix etcd load-balancer pool updates
* Update dynamiclistener to fix cert updates on etcd-only nodes
* Handle recursive initial server URL in load balancer
* Don't run the deploy controller on etcd-only nodes
In k3s today the kubernetes API and the /v1-k3s API are combined into
one http server. In rke2 we are running unmodified, non-embedded Kubernetes
and as such it is preferred to run k8s and the /v1-k3s API on different
ports. The /v1-k3s API port is called the SupervisorPort in the code.
To support this separation of ports a new shim was added on the client in
then pkg/agent/proxy package that will launch two load balancers instead
of just one load balancer. One load balancer for 6443 and the other
for 9345 (which is the supervisor port).
