NodePorts understand OnlyLocal

pkg/proxy/iptables/proxier.go

@@ -1070,10 +1070,14 @@ func (proxier *Proxier) syncProxyRules() {
 				"-m", protocol, "-p", protocol,
 				"--dport", fmt.Sprintf("%d", svcInfo.nodePort),
 			}
-			// Nodeports need SNAT.
-			writeLine(natRules, append(args, "-j", string(KubeMarkMasqChain))...)
-			// Jump to the service chain.
-			writeLine(natRules, append(args, "-j", string(svcChain))...)
+			if !svcInfo.onlyNodeLocalEndpoints {
+				// Nodeports need SNAT, unless they're local.
+				writeLine(natRules, append(args, "-j", string(KubeMarkMasqChain))...)
+				// Jump to the service chain.
+				writeLine(natRules, append(args, "-j", string(svcChain))...)
+			} else {
+				writeLine(natRules, append(args, "-j", string(svcXlbChain))...)
+			}
 		}
 
 		// If the service has no endpoints then reject packets.
@@ -1173,6 +1177,16 @@ func (proxier *Proxier) syncProxyRules() {
 				localEndpointChains = append(localEndpointChains, endpointChains[i])
 			}
 		}
+		// First rule in the chain redirects all pod -> external vip traffic to the
+		// Service's ClusterIP instead. This happens whether or not we have local
+		// endpoints.
+		args = []string{
+			"-A", string(svcXlbChain),
+			"-m", "comment", "--comment",
+			fmt.Sprintf(`"Redirect pods trying to reach external loadbalancer VIP to clusterIP"`),
+		}
+		writeLine(natRules, append(args, "-s", proxier.clusterCIDR, "-j", string(svcChain))...)
+
 		numLocalEndpoints := len(localEndpointChains)
 		if numLocalEndpoints == 0 {
 			// Blackhole all traffic since there are no local endpoints