implement ipvs mode of kube-proxy

Conflicts:
	pkg/util/ipvs/ipvs_unsupported.go

pkg/features/kube_features.go

@@ -127,6 +127,12 @@ const (
 	// Taint nodes based on their condition status for 'NetworkUnavailable',
 	// 'MemoryPressure', 'OutOfDisk' and 'DiskPressure'.
 	TaintNodesByCondition utilfeature.Feature = "TaintNodesByCondition"
+
+	// owner: @haibinxie
+	// alpha: v1.8
+	//
+	// Implement IPVS-based in-cluster service load balancing
+	SupportIPVSProxyMode utilfeature.Feature = "SupportIPVSProxyMode"
 )
 
 func init() {
@@ -164,4 +170,5 @@ var defaultKubernetesFeatureGates = map[utilfeature.Feature]utilfeature.FeatureS
 	// inherited features from apiextensions-apiserver, relisted here to get a conflict if it is changed
 	// unintentionally on either side:
 	apiextensionsfeatures.CustomResourceValidation: {Default: false, PreRelease: utilfeature.Alpha},
+	SupportIPVSProxyMode:                           {Default: false, PreRelease: utilfeature.Alpha},
 }