Merge pull request #45622 from shyamjvs/mock-proxy

Automatic merge from submit-queue (batch tested with PRs 45571, 45657, 45638, 45663, 45622)

Use real proxier inside hollow-proxy but with mocked syscalls

Fixes https://github.com/kubernetes/kubernetes/issues/43701

This should make hollow-proxy better mimic the real kube-proxy in performance.
Maybe next we should have a more realistic implementation even for fake iptables (adding/updating/deleting rules/chains in an table, just not on the real one)? Though I'm not sure how important it is.

cc @kubernetes/sig-scalability-misc @kubernetes/sig-network-misc @wojtek-t @gmarek

pkg/proxy/iptables/proxier.go

@@ -356,7 +356,7 @@ func NewProxier(ipt utiliptables.Interface,
 ) (*Proxier, error) {
 	// check valid user input
 	if minSyncPeriod > syncPeriod {
-		return nil, fmt.Errorf("min-sync (%v) must be < sync(%v)", minSyncPeriod, syncPeriod)
+		return nil, fmt.Errorf("min-sync (%v) must be <= sync(%v)", minSyncPeriod, syncPeriod)
 	}
 
 	// Set the route_localnet sysctl we need for