Server.Serve() always returns a non-nil error. If it exits because the
http server is closed, it will return ErrServerClosed. To differentiate
the error, this patch changes to close the http server instead of the
listener when the Service is deleted. Closing http server automatically
closes the listener, there is no need to cache the listeners any more.
Signed-off-by: Quan Tian <qtian@vmware.com>
Kube-proxy runs two different health servers; one for monitoring the
health of kube-proxy itself, and one for monitoring the health of
specific services. Rename them to "ProxierHealthServer" and
"ServiceHealthServer" to make this clearer, and do a bit of API
cleanup too.
