[POND] Add Windows default gateway v6 to cns. (#4281)

* Add Windows default gateway v6 to cns.

* Add unit test.

* Update the unit test to cover windows only.

* revert unnecessary change when rebase from master.

* Revert the master change in unit test.

* Revert the unnecessary unit test change.

Author: csfmomo

cns/kubecontroller/nodenetworkconfig/conversion_windows.go

@@ -74,9 +74,10 @@ func createNCRequestFromStaticNCHelper(
 		NetworkContainerType: cns.Docker,
 		Version:              strconv.FormatInt(nc.Version, 10), //nolint:gomnd // it's decimal
 		IPConfiguration: cns.IPConfiguration{
-			IPSubnet:         subnet,
-			IPSubnetV6:       subnetV6,
-			GatewayIPAddress: nc.DefaultGateway,
+			IPSubnet:           subnet,
+			IPSubnetV6:         subnetV6,
+			GatewayIPAddress:   nc.DefaultGateway,
+			GatewayIPv6Address: nc.DefaultGatewayV6,
 		},
 		NCStatus: nc.Status,
 	}, nil

cns/kubecontroller/nodenetworkconfig/conversion_windows_test.go

@@ -150,3 +150,19 @@ func TestIPv6PrefixClampWindows(t *testing.T) {
 		})
 	}
 }
+
+func TestGatewayIPv6AddressWindows(t *testing.T) {
+	nc := v1alpha.NetworkContainer{
+		AssignmentMode:     v1alpha.Static,
+		Type:               v1alpha.Overlay,
+		ID:                 ncID,
+		PrimaryIP:          overlayPrimaryIP,
+		NodeIP:             nodeIP,
+		SubnetName:         subnetName,
+		SubnetAddressSpace: subnetAddressSpace,
+		DefaultGatewayV6:   "fd00::1",
+	}
+	got, err := CreateNCRequestFromStaticNC(nc, false, 0)
+	require.NoError(t, err)
+	assert.Equal(t, "fd00::1", got.IPConfiguration.GatewayIPv6Address)
+}