In K8S version 1.10, the proxy can sometimes get stuck believing that
some services do not have any endpoints. This seems to be triggered by
network instability, though the proxy doesn't seem to recover on its
own, while bouncing the pod fixes the issue.
This change adds a naive means of detecting and recoverying from this
(`iptables-save | grep 'has no endpoints'` in the liveness probe) that
may occasionally have false positives. As such, the liveness probe is
configured very conservatively to avoid triggering CrashLoopBackoff in
the event of a false positive.
Finally, there is a whitelist feature to help avoid false positives for
services that are known to legitimately have empty endpoints during the
course of normal operation (e.g. Patroni might manage such an endpoint
list).
Change-Id: I29a770fab70b1fb79db59ef5408f40b2af1c01f9
69cb269230