kube-proxy/ipvs get local addr just once per sync

pkg/proxy/ipvs/proxier.go

@@ -899,6 +899,33 @@ func (proxier *Proxier) OnEndpointSlicesSynced() {
 // EntryInvalidErr indicates if an ipset entry is invalid or not
 const EntryInvalidErr = "error adding entry %s to ipset %s"
 
+func getLocalAddrs() ([]net.IP, error) {
+	var localAddrs []net.IP
+
+	addrs, err := net.InterfaceAddrs()
+	if err != nil {
+		return nil, err
+	}
+
+	for _, addr := range addrs {
+		ip, _, err := net.ParseCIDR(addr.String())
+		if err != nil {
+			return nil, err
+		}
+		localAddrs = append(localAddrs, ip)
+	}
+	return localAddrs, nil
+}
+
+func ipExists(ip net.IP, addrs []net.IP) bool {
+	for _, addr := range addrs {
+		if ip.Equal(addr) {
+			return true
+		}
+	}
+	return false
+}
+
 // This is where all of the ipvs calls happen.
 // assumes proxier.mu is held
 func (proxier *Proxier) syncProxyRules() {
@@ -919,6 +946,11 @@ func (proxier *Proxier) syncProxyRules() {
 		klog.V(4).Infof("syncProxyRules took %v", time.Since(start))
 	}()
 
+	localAddrs, err := getLocalAddrs()
+	if err != nil {
+		klog.Errorf("Failed to get local addresses during proxy sync: %v", err)
+	}
+
 	// We assume that if this was called, we really want to sync them,
 	// even if nothing changed in the meantime. In other words, callers are
 	// responsible for detecting no-op changes and not calling this function.
@@ -955,7 +987,7 @@ func (proxier *Proxier) syncProxyRules() {
 	proxier.createAndLinkeKubeChain()
 
 	// make sure dummy interface exists in the system where ipvs Proxier will bind service address on it
-	_, err := proxier.netlinkHandle.EnsureDummyDevice(DefaultDummyDevice)
+	_, err = proxier.netlinkHandle.EnsureDummyDevice(DefaultDummyDevice)
 	if err != nil {
 		klog.Errorf("Failed to create dummy interface: %s, error: %v", DefaultDummyDevice, err)
 		return
@@ -1100,11 +1132,10 @@ func (proxier *Proxier) syncProxyRules() {
 
 		// Capture externalIPs.
 		for _, externalIP := range svcInfo.ExternalIPStrings() {
-			if local, err := utilproxy.IsLocalIP(externalIP); err != nil {
+			if len(localAddrs) == 0 {
-				klog.Errorf("can't determine if IP is local, assuming not: %v", err)
+				klog.Errorf("couldn't find any local IPs, assuming %s is not local", externalIP)
-				// We do not start listening on SCTP ports, according to our agreement in the
+			} else if (svcInfo.Protocol() != v1.ProtocolSCTP) && ipExists(net.ParseIP(externalIP), localAddrs) {
-				// SCTP support KEP
+				// We do not start listening on SCTP ports, according to our agreement in the SCTP support KEP
-			} else if local && (svcInfo.Protocol() != v1.ProtocolSCTP) {
 				lp := utilproxy.LocalPort{
 					Description: "externalIP for " + svcNameString,
 					IP:          externalIP,