Skip HotAttachEp from CNM createEndpoint (#332)

* Skip HotAttachEp from CNM create endpoint

* Address review comments

Author: ashvindeodhar

cni/network/network.go

@@ -452,6 +452,7 @@ func (plugin *netPlugin) Add(args *cniSkel.CmdArgs) error {
 		EnableInfraVnet:    enableInfraVnet,
 		PODName:            k8sPodName,
 		PODNameSpace:       k8sNamespace,
+		SkipHotAttachEp:    false, // Hot attach at the time of endpoint creation
 	}
 
 	epPolicies := getPoliciesFromRuntimeCfg(nwCfg)

cnm/network/network.go

@@ -229,8 +229,9 @@ func (plugin *netPlugin) createEndpoint(w http.ResponseWriter, r *http.Request)
 	}
 
 	epInfo := network.EndpointInfo{
-		Id:          req.EndpointID,
-		IPAddresses: []net.IPNet{*ipv4Address},
+		Id:              req.EndpointID,
+		IPAddresses:     []net.IPNet{*ipv4Address},
+		SkipHotAttachEp: true, // Skip hot attach endpoint as it's done in Join
 	}
 
 	epInfo.Data = make(map[string]interface{})

network/endpoint.go

@@ -61,6 +61,7 @@ type EndpointInfo struct {
 	PODNameSpace          string
 	Data                  map[string]interface{}
 	InfraVnetAddressSpace string
+	SkipHotAttachEp       bool
 }
 
 // RouteInfo contains information about an IP route.

network/endpoint_windows.go

@@ -94,12 +94,17 @@ func (nw *network) newEndpointImpl(epInfo *EndpointInfo) (*endpoint, error) {
 		}
 	}()
 
-	// Attach the endpoint.
-	log.Printf("[net] Attaching endpoint %v to container %v.", hnsResponse.Id, epInfo.ContainerID)
-	err = hcsshim.HotAttachEndpoint(epInfo.ContainerID, hnsResponse.Id)
-	if err != nil {
-		log.Printf("[net] Failed to attach endpoint: %v.", err)
-		return nil, err
+	if epInfo.SkipHotAttachEp {
+		log.Printf("[net] Skipping attaching the endpoint %v to container %v.",
+			hnsResponse.Id, epInfo.ContainerID)
+	} else {
+		// Attach the endpoint.
+		log.Printf("[net] Attaching endpoint %v to container %v.", hnsResponse.Id, epInfo.ContainerID)
+		err = hcsshim.HotAttachEndpoint(epInfo.ContainerID, hnsResponse.Id)
+		if err != nil {
+			log.Printf("[net] Failed to attach endpoint: %v.", err)
+			return nil, err
+		}
 	}
 
 	// Create the endpoint object.