[Windows] Adds optional loopbackDSR argument to cni config.

Adds a bool to the cni config that will add a policy that allows for loopbackDSR on an interface. Updates relevant documentation. Allows L2Tunnel networks to be used for L2Bridge plugin.

plugins/main/windows/win-bridge/README.md

@@ -32,7 +32,8 @@ With win-bridge plugin, all containers (on the same host) are plugged into an L2
                 "NeedEncap": true
             }
         }
-    ].          
+    ],
+    "loopbackDSR": true,
     "capabilities": {
         "dns": true
     }
@@ -51,5 +52,6 @@ With win-bridge plugin, all containers (on the same host) are plugged into an L2
 * `ipam` (dictionary, optional): IPAM configuration to be used for this network.
 * `Policies` (list, optional): List of hns policies to be used (only used when ApiVersion is < 2).
 * `HcnPolicyArgs` (list, optional): List of hcn policies to be used (only used when ApiVersion is 2).
-* `capabilities` (dictionary, optional): runtime capabilities to enable.
- * `dns` (boolean, optional): if true will take the dns config supplied by the runtime and override other settings.
+* `loopbackDSR` (bool, optional): If true, will add a policy to allow the interface to support loopback direct server return.
+* `capabilities` (dictionary, optional): Runtime capabilities to enable.
+ * `dns` (boolean, optional): If true, will take the dns config supplied by the runtime and override other settings.

plugins/main/windows/win-bridge/sample.conf

@@ -39,6 +39,7 @@
                     "NeedEncap":true
                 }
             }
-        ]
+        ],
+        "loopbackDSR": true
     }
 }

plugins/main/windows/win-bridge/win-bridge_windows.go

@@ -17,6 +17,7 @@ package main
 import (
 	"encoding/json"
 	"fmt"
+	"os"
 	"runtime"
 	"strings"
 
@@ -38,7 +39,6 @@ type NetConf struct {
 	hns.NetConf
 
 	IPMasqNetwork string `json:"ipMasqNetwork,omitempty"`
-	ApiVersion    int    `json:"ApiVersion"`
 }
 
 func init() {
@@ -103,7 +103,7 @@ func cmdHnsAdd(args *skel.CmdArgs, n *NetConf) (*current.Result, error) {
 		return nil, fmt.Errorf("network %v not found", networkName)
 	}
 
-	if !strings.EqualFold(hnsNetwork.Type, "L2Bridge") {
+	if !strings.EqualFold(hnsNetwork.Type, "L2Bridge") && !strings.EqualFold(hnsNetwork.Type, "L2Tunnel") {
 		return nil, fmt.Errorf("network %v is of an unexpected type: %v", networkName, hnsNetwork.Type)
 	}
 
@@ -145,7 +145,7 @@ func cmdHcnAdd(args *skel.CmdArgs, n *NetConf) (*current.Result, error) {
 		return nil, fmt.Errorf("network %v not found", networkName)
 	}
 
-	if hcnNetwork.Type != hcn.L2Bridge {
+	if hcnNetwork.Type != hcn.L2Bridge && hcnNetwork.Type != hcn.L2Tunnel {
 		return nil, fmt.Errorf("network %v is of unexpected type: %v", networkName, hcnNetwork.Type)
 	}
 

plugins/main/windows/win-overlay/README.md

@@ -14,11 +14,11 @@ With win-overlay plugin, all containers (on the same host) are plugged into an O
 	"ipam": {
 		"type": "host-local",
 		"subnet": "10.10.0.0/16"
-	}
+	},
+    "loopbackDSR": true,
     "capabilites": {
         "dns": true
     }
-
 }
 ```
 
@@ -33,5 +33,6 @@ With win-overlay plugin, all containers (on the same host) are plugged into an O
 * `endpointMacPrefix` (string, optional): set to the MAC prefix configured for Flannel.
 * `Policies` (list, optional): List of hns policies to be used.
 * `ipam` (dictionary, required): IPAM configuration to be used for this network.
+* `loopbackDSR` (bool, optional): If true, will add a policy to allow the interface to support loopback direct server return.
 * `capabilities` (dictionary, optional): runtime capabilities to be parsed and injected by runtime.
- * `dns` (boolean, optional): if true will take the dns config supplied by the runtime and override other settings.
+ * `dns` (boolean, optional): If true, will take the dns config supplied by the runtime and override other settings.

plugins/main/windows/win-overlay/win-overlay_windows.go

@@ -17,6 +17,7 @@ package main
 import (
 	"encoding/json"
 	"fmt"
+	"os"
 	"runtime"
 	"strings"
 
@@ -118,7 +119,9 @@ func cmdAdd(args *skel.CmdArgs) error {
 		}
 
 		result.DNS = n.GetDNS()
-
+		if n.LoopbackDSR {
+			n.ApplyLoopbackDSR(&ipAddr)
+		}
 		hnsEndpoint := &hcsshim.HNSEndpoint{
 			Name:           epName,
 			VirtualNetwork: hnsNetwork.Id,