Refactor to use k8s.io/utils/net/ package instead of kubernetes/pkg/util/net/sets

Signed-off-by: Ashish Ranjan <ashishranjan738@gmail.com>

vendor/k8s.io/utils/net/net.go

@@ -0,0 +1,37 @@
+/*
+Copyright 2018 The Kubernetes Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package net
+
+import "net"
+
+// IsIPv6 returns if netIP is IPv6.
+func IsIPv6(netIP net.IP) bool {
+	return netIP != nil && netIP.To4() == nil
+}
+
+// IsIPv6String returns if ip is IPv6.
+func IsIPv6String(ip string) bool {
+	netIP := net.ParseIP(ip)
+	return IsIPv6(netIP)
+}
+
+// IsIPv6CIDRString returns if cidr is IPv6.
+// This assumes cidr is a valid CIDR.
+func IsIPv6CIDRString(cidr string) bool {
+	ip, _, _ := net.ParseCIDR(cidr)
+	return IsIPv6(ip)
+}