Enhance HNS network initialization

The current windows agent initialization couldn't guarantee that the `EnableHNSNetworkExtension` was executed
after creating the HNS network.
In certain corner cases where the Windows agent pod was restarted after creating HNS network, the agent might miss
executing `EnableHNSNetworkExtension`.

To address this issue, this enhancement runs `EnableHNSNetworkExtension` even if the HNS network has been created,
which ensures the OVS Extension is properly enabled.

Signed-off-by: Shuyang Xin <gavinx@vmware.com>

pkg/agent/agent_windows.go

@@ -55,6 +55,12 @@ func (i *Initializer) prepareHNSNetworkAndOVSExtension() error {
 	// If the HNS Network already exists, return immediately.
 	hnsNetwork, err := hcsshim.GetHNSNetworkByName(util.LocalHNSNetwork)
 	if err == nil {
+		// Enable OVS Extension on the HNS Network.
+		/*
+		if err = util.EnableHNSNetworkExtension(hnsNetwork.Id, util.OVSExtensionID); err != nil {
+			return err
+		}
+		*/
 		// Enable RSC for existing vSwitch.
 		if err = util.EnableRSCOnVSwitch(util.LocalHNSNetwork); err != nil {
 			return err

pkg/agent/util/net_windows.go

@@ -90,6 +90,22 @@ type Route struct {
 	RouteMetric       int
 }
 
+type AntreaHNSNetwork struct {
+	Id                   string            `json:"ID,omitempty"`
+	Name                 string            `json:",omitempty"`
+	Type                 string            `json:",omitempty"`
+	NetworkAdapterName   string            `json:",omitempty"`
+	SourceMac            string            `json:",omitempty"`
+	MacPools             []MacPool         `json:",omitempty"`
+	Subnets              []Subnet          `json:",omitempty"`
+	DNSSuffix            string            `json:",omitempty"`
+	DNSServerList        string            `json:",omitempty"`
+	DNSServerCompartment uint32            `json:",omitempty"`
+	ManagementIP         string            `json:",omitempty"`
+	AutomaticDNS         bool              `json:",omitempty"`
+	Extensions []vSwitchExtensionPolicy    `json:"Extensions"`
+}
+
 func (r *Route) String() string {
 	return fmt.Sprintf("LinkIndex: %d, DestinationSubnet: %s, GatewayAddress: %s, RouteMetric: %d",
 		r.LinkIndex, r.DestinationSubnet, r.GatewayAddress, r.RouteMetric)
@@ -290,7 +306,11 @@ func CreateHNSNetwork(hnsNetName string, subnetCIDR *net.IPNet, nodeIP *net.IPNe
 	adapterMAC := adapter.HardwareAddr
 	adapterName := adapter.Name
 	gateway := ip.NextIP(subnetCIDR.IP.Mask(subnetCIDR.Mask))
-	network := &hcsshim.HNSNetwork{
+	extensionPolicy := vSwitchExtensionPolicy{
+		ExtensionID: OVSExtensionID,
+		IsEnabled:   true,
+	}
+	network := &AntreaHNSNetwork{
 		Name:               hnsNetName,
 		Type:               HNSNetworkType,
 		NetworkAdapterName: adapterName,
@@ -302,8 +322,10 @@ func CreateHNSNetwork(hnsNetName string, subnetCIDR *net.IPNet, nodeIP *net.IPNe
 		},
 		ManagementIP: nodeIP.String(),
 		SourceMac:    adapterMAC.String(),
+		Extensions: []vSwitchExtensionPolicy{extensionPolicy},
 	}
-	hnsNet, err := hnsNetworkCreate(network)
+	jsonString, _ := json.Marshal(network)
+	hnsNet, err := hnsNetworkRequest("POST", "", string(jsonString))
 	if err != nil {
 		return nil, err
 	}