Fix comments and add check in case of IPv6 only node

pkg/netutil/iface.go

@@ -38,7 +38,7 @@ func getIPFromInterface(ifaceName string) (string, error) {
 		if err != nil {
 			return "", errors.Wrapf(err, "unable to parse CIDR for interface %s", iface.Name)
 		}
-		// skipping if not ipv4
+		// if not IPv4 adding it on IPv6 list
 		if ip.To4() == nil {
 			if ip.IsGlobalUnicast() {
 				globalUnicastsIPv6 = append(globalUnicastsIPv6, ip.String())

pkg/util/net.go

@@ -142,9 +142,12 @@ func GetHostnameAndIPs(name string, nodeIPs cli.StringSlice) (string, []net.IP,
 			return "", nil, err
 		}
 		ips = append(ips, hostIP)
-		hostIPv6, err := apinet.ResolveBindAddress(net.IPv6loopback)
-		if err == nil && !hostIPv6.Equal(hostIP) {
-			ips = append(ips, hostIPv6)
+		// If IPv6 it's an IPv6 only node
+		if hostIP.To4() != nil {
+			hostIPv6, err := apinet.ResolveBindAddress(net.IPv6loopback)
+			if err == nil && !hostIPv6.Equal(hostIP) {
+				ips = append(ips, hostIPv6)
+			}
 		}
 	} else {
 		var err error