If the port wanted by the client load balancer is in TIME_WAIT, startup
will fail. Set SO_REUSEPORT so that it can be listened on again
immediately.
The configurable Listen call wants a context, so plumb that through as
well.
Signed-off-by: Brad Davidson <brad.davidson@rancher.com>
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).
