Today, the health check response to the load balancers asking Kube-proxy for
the status of ETP:Local services does not include the healthz state of Kube-
proxy. This means that Kube-proxy might indicate to load balancers that they
should forward traffic to the node in question, simply because the endpoint
is running on the node - this overlooks the fact that Kube-proxy might be
not-healthy and hasn't successfully written the rules enabling traffic to
reach the endpoint.
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>
The proxy healthz server assumed that kube-proxy would regularly call
UpdateTimestamp() even when nothing changed, but that's no longer
true. Fix it to only report unhealthiness when updates have been
received from the apiserver but not promptly pushed out to
iptables/ipvs.
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.
The existing healthcheck lib was pretty complicated and was hiding some
bugs (like the count always being 1), This is a reboot of the interface
and implementation to be significantly simpler and better tested.
