From d527a09192756b70034555a66474a61aceb96aa0 Mon Sep 17 00:00:00 2001
From: Minhan Xia <mixia@google.com>
Date: Wed, 4 Mar 2020 11:29:36 -0800
Subject: [PATCH] add ExternalTrafficPolicy support for External IPs in ipvs
 kubeproxy

---
 pkg/proxy/ipvs/ipset.go   |  3 ++
 pkg/proxy/ipvs/proxier.go | 60 +++++++++++++++++++++++++++++----------
 2 files changed, 48 insertions(+), 15 deletions(-)

diff --git a/pkg/proxy/ipvs/ipset.go b/pkg/proxy/ipvs/ipset.go
index 419b1a03598..7b75ec879c2 100644
--- a/pkg/proxy/ipvs/ipset.go
+++ b/pkg/proxy/ipvs/ipset.go
@@ -40,6 +40,9 @@ const (
 	kubeExternalIPSetComment = "Kubernetes service external ip + port for masquerade and filter purpose"
 	kubeExternalIPSet        = "KUBE-EXTERNAL-IP"
 
+	kubeExternalIPLocalSetComment = "Kubernetes service external ip + port with externalTrafficPolicy=local"
+	kubeExternalIPLocalSet        = "KUBE-EXTERNAL-IP-LOCAL"
+
 	kubeLoadBalancerSetComment = "Kubernetes service lb portal"
 	kubeLoadBalancerSet        = "KUBE-LOAD-BALANCER"
 
diff --git a/pkg/proxy/ipvs/proxier.go b/pkg/proxy/ipvs/proxier.go
index 5b3eda42960..cbe0545d493 100644
--- a/pkg/proxy/ipvs/proxier.go
+++ b/pkg/proxy/ipvs/proxier.go
@@ -140,6 +140,7 @@ var ipsetInfo = []struct {
 	{kubeLoopBackIPSet, utilipset.HashIPPortIP, kubeLoopBackIPSetComment},
 	{kubeClusterIPSet, utilipset.HashIPPort, kubeClusterIPSetComment},
 	{kubeExternalIPSet, utilipset.HashIPPort, kubeExternalIPSetComment},
+	{kubeExternalIPLocalSet, utilipset.HashIPPort, kubeExternalIPLocalSetComment},
 	{kubeLoadBalancerSet, utilipset.HashIPPort, kubeLoadBalancerSetComment},
 	{kubeLoadbalancerFWSet, utilipset.HashIPPort, kubeLoadbalancerFWSetComment},
 	{kubeLoadBalancerLocalSet, utilipset.HashIPPort, kubeLoadBalancerLocalSetComment},
@@ -1236,12 +1237,21 @@ func (proxier *Proxier) syncProxyRules() {
 				Protocol: protocol,
 				SetType:  utilipset.HashIPPort,
 			}
-			// We have to SNAT packets to external IPs.
-			if valid := proxier.ipsetList[kubeExternalIPSet].validateEntry(entry); !valid {
-				klog.Errorf("%s", fmt.Sprintf(EntryInvalidErr, entry, proxier.ipsetList[kubeExternalIPSet].Name))
-				continue
+
+			if utilfeature.DefaultFeatureGate.Enabled(features.ExternalPolicyForExternalIP) && svcInfo.OnlyNodeLocalEndpoints() {
+				if valid := proxier.ipsetList[kubeExternalIPLocalSet].validateEntry(entry); !valid {
+					klog.Errorf("%s", fmt.Sprintf(EntryInvalidErr, entry, proxier.ipsetList[kubeExternalIPLocalSet].Name))
+					continue
+				}
+				proxier.ipsetList[kubeExternalIPLocalSet].activeEntries.Insert(entry.String())
+			} else {
+				// We have to SNAT packets to external IPs.
+				if valid := proxier.ipsetList[kubeExternalIPSet].validateEntry(entry); !valid {
+					klog.Errorf("%s", fmt.Sprintf(EntryInvalidErr, entry, proxier.ipsetList[kubeExternalIPSet].Name))
+					continue
+				}
+				proxier.ipsetList[kubeExternalIPSet].activeEntries.Insert(entry.String())
 			}
-			proxier.ipsetList[kubeExternalIPSet].activeEntries.Insert(entry.String())
 
 			// ipvs call
 			serv := &utilipvs.VirtualServer{
@@ -1257,7 +1267,12 @@ func (proxier *Proxier) syncProxyRules() {
 			if err := proxier.syncService(svcNameString, serv, true); err == nil {
 				activeIPVSServices[serv.String()] = true
 				activeBindAddrs[serv.Address.String()] = true
-				if err := proxier.syncEndpoint(svcName, false, serv); err != nil {
+
+				onlyNodeLocalEndpoints := false
+				if utilfeature.DefaultFeatureGate.Enabled(features.ExternalPolicyForExternalIP) {
+					onlyNodeLocalEndpoints = svcInfo.OnlyNodeLocalEndpoints()
+				}
+				if err := proxier.syncEndpoint(svcName, onlyNodeLocalEndpoints, serv); err != nil {
 					klog.Errorf("Failed to sync endpoint for service: %v, err: %v", serv, err)
 				}
 			} else {
@@ -1668,15 +1683,8 @@ func (proxier *Proxier) writeIptablesRules() {
 		}
 	}
 
-	if !proxier.ipsetList[kubeExternalIPSet].isEmpty() {
-		// Build masquerade rules for packets to external IPs.
-		args = append(args[:0],
-			"-A", string(kubeServicesChain),
-			"-m", "comment", "--comment", proxier.ipsetList[kubeExternalIPSet].getComment(),
-			"-m", "set", "--match-set", proxier.ipsetList[kubeExternalIPSet].Name,
-			"dst,dst",
-		)
-		writeLine(proxier.natRules, append(args, "-j", string(KubeMarkMasqChain))...)
+	// externalIPRules adds iptables rules applies to Service ExternalIPs
+	externalIPRules := func(args []string) {
 		// Allow traffic for external IPs that does not come from a bridge (i.e. not from a container)
 		// nor from a local process to be forwarded to the service.
 		// This rule roughly translates to "all traffic from off-machine".
@@ -1691,6 +1699,28 @@ func (proxier *Proxier) writeIptablesRules() {
 		writeLine(proxier.natRules, append(dstLocalOnlyArgs, "-j", "ACCEPT")...)
 	}
 
+	if !proxier.ipsetList[kubeExternalIPSet].isEmpty() {
+		// Build masquerade rules for packets to external IPs.
+		args = append(args[:0],
+			"-A", string(kubeServicesChain),
+			"-m", "comment", "--comment", proxier.ipsetList[kubeExternalIPSet].getComment(),
+			"-m", "set", "--match-set", proxier.ipsetList[kubeExternalIPSet].Name,
+			"dst,dst",
+		)
+		writeLine(proxier.natRules, append(args, "-j", string(KubeMarkMasqChain))...)
+		externalIPRules(args)
+	}
+
+	if !proxier.ipsetList[kubeExternalIPLocalSet].isEmpty() {
+		args = append(args[:0],
+			"-A", string(kubeServicesChain),
+			"-m", "comment", "--comment", proxier.ipsetList[kubeExternalIPLocalSet].getComment(),
+			"-m", "set", "--match-set", proxier.ipsetList[kubeExternalIPLocalSet].Name,
+			"dst,dst",
+		)
+		externalIPRules(args)
+	}
+
 	// -A KUBE-SERVICES  -m addrtype  --dst-type LOCAL -j KUBE-NODE-PORT
 	args = append(args[:0],
 		"-A", string(kubeServicesChain),