ddress comment

Author: ZetaoZhuang

cns/hnsclient/hnsclient_windows.go

@@ -17,6 +17,7 @@ import (
 	"github.com/pkg/errors"
 )
 
+// TODO redesign hnsclient on windows
 const (
 	// Name of the external hns network
 	ExtHnsNetworkName = "ext"
@@ -53,9 +54,9 @@ const (
 	// Name of the loopback adapter needed to create Host NC apipa network
 	hostNCLoopbackAdapterName = "LoopbackAdapterHostNCConnectivity"
 
+	// HNS rehydration issue requires this GW to be different than the loopback adapter ip, so we set it to .2
 	defaultHnsGwIPAddress       = "169.254.128.2"
 	hnsLoopbackAdapterIPAddress = "169.254.128.1"
-	apipaRemoteIPAddress        = "169.254.128.1"
 	// protocolTCP indicates the TCP protocol identifier in HCN
 	protocolTCP = "6"
 
@@ -513,7 +514,7 @@ func configureHostNCApipaEndpoint(
 	endpointPolicies, err := configureAclSettingHostNCApipaEndpoint(
 		protocolList,
 		networkContainerApipaIP,
-		apipaRemoteIPAddress,
+		hnsLoopbackAdapterIPAddress,
 		allowNCToHostCommunication,
 		allowHostToNCCommunication,
 		ncPolicies)
@@ -576,7 +577,7 @@ func CreateHostNCApipaEndpoint(
 		return endpoint.Id, nil
 	}
 
-	adjustIPConfig(&localIPConfiguration)
+	updateGwForLocalIPConfiguration(&localIPConfiguration)
 	if network, err = createHostNCApipaNetwork(localIPConfiguration); err != nil {
 		logger.Errorf("[Azure CNS] Failed to create HostNCApipaNetwork. Error: %v", err)
 		return "", err
@@ -608,10 +609,10 @@ func CreateHostNCApipaEndpoint(
 	return endpoint.Id, nil
 }
 
-// adjustIPConfig applies change on gw IP address.
+// updateGwForLocalIPConfiguration applies change on APIPA NW gw IP address.
 // Currently, cns using the same ip address "169.254.128.1" for both apipa gw and loopback adapter. This cause conflict issue when hns get restarted and not able to rehydrate the apipa endpoints.
 // This func is to overwrite the address to 169.254.128.2 when the gateway address is 169.254.128.1
-func adjustIPConfig(localIPConfiguration *cns.IPConfiguration) {
+func updateGwForLocalIPConfiguration(localIPConfiguration *cns.IPConfiguration) {
 	// When gw address is 169.254.128.1, should use .2 instead. If gw address is not .1, that mean this value is
 	// configured from dnc, we should keep it
 	if localIPConfiguration.GatewayIPAddress == "169.254.128.1" {

cns/hnsclient/hnsclient_windows_test.go

@@ -28,7 +28,7 @@ func TestAdhocAdjustIPConfig(t *testing.T) {
 	for _, tt := range tests {
 		tt := tt
 		t.Run(tt.name, func(t *testing.T) {
-			adjustIPConfig(&tt.ipConfig)
+			updateGwForLocalIPConfiguration(&tt.ipConfig)
 			assert.Equal(t, tt.expected.GatewayIPAddress, tt.ipConfig.GatewayIPAddress)
 		})
 	}