From 69fde1c3422e0d9829e2b53ea6c2f62a4abeffd3 Mon Sep 17 00:00:00 2001
From: tamilmani1989 <tamilmani1989@gmail.com>
Date: Wed, 9 Jan 2019 18:29:22 -0800
Subject: [PATCH] changed vethnaming logic for transparent mode (#286)

---
 cni/network/network.go                      | 15 +++++++++++----
 network/endpoint_linux.go                   | 12 +++++++++++-
 network/transparent_endpointclient_linux.go |  9 +++++++++
 3 files changed, 31 insertions(+), 5 deletions(-)

diff --git a/cni/network/network.go b/cni/network/network.go
index 0166acf228..c8e7376008 100644
--- a/cni/network/network.go
+++ b/cni/network/network.go
@@ -25,7 +25,7 @@ const (
 	// Plugin name.
 	name                = "azure-vnet"
 	dockerNetworkOption = "com.docker.network.generic"
-
+	opModeTransparent   = "transparent"
 	// Supported IP version. Currently support only IPv4
 	ipVersion = "4"
 )
@@ -454,9 +454,16 @@ func (plugin *netPlugin) Add(args *cniSkel.CmdArgs) error {
 
 	SetupRoutingForMultitenancy(nwCfg, cnsNetworkConfig, azIpamResult, epInfo, result)
 
-	// A runtime must not call ADD twice (without a corresponding DEL) for the same
-	// (network name, container id, name of the interface inside the container)
-	vethName = fmt.Sprintf("%s%s%s", networkId, k8sContainerID, k8sIfName)
+	if nwCfg.Mode == opModeTransparent {
+		// this mechanism of using only namespace and name is not unique for different incarnations of POD/container.
+		// IT will result in unpredictable behavior if API server decides to
+		// reorder DELETE and ADD call for new incarnation of same POD.
+		vethName = fmt.Sprintf("%s.%s", k8sNamespace, k8sPodName)
+	} else {
+		// A runtime must not call ADD twice (without a corresponding DEL) for the same
+		// (network name, container id, name of the interface inside the container)
+		vethName = fmt.Sprintf("%s%s%s", networkId, k8sContainerID, k8sIfName)
+	}
 	setEndpointOptions(cnsNetworkConfig, epInfo, vethName)
 
 	// Create the endpoint.
diff --git a/network/endpoint_linux.go b/network/endpoint_linux.go
index a8e64e4dac..0c39d0de15 100644
--- a/network/endpoint_linux.go
+++ b/network/endpoint_linux.go
@@ -68,8 +68,8 @@ func (nw *network) newEndpointImpl(epInfo *EndpointInfo) (*endpoint, error) {
 	}
 
 	if _, ok := epInfo.Data[OptVethName]; ok {
-		log.Printf("Generate veth name based on the key provided")
 		key := epInfo.Data[OptVethName].(string)
+		log.Printf("Generate veth name based on the key provided %v", key)
 		vethname := generateVethName(key)
 		hostIfName = fmt.Sprintf("%s%s", hostVEthInterfacePrefix, vethname)
 		contIfName = fmt.Sprintf("%s%s2", hostVEthInterfacePrefix, vethname)
@@ -270,8 +270,18 @@ func deleteRoutes(interfaceName string, routes []RouteInfo) error {
 
 		if route.DevName != "" {
 			devIf, _ := net.InterfaceByName(route.DevName)
+			if devIf == nil {
+				log.Printf("[net] Not deleting route. Interface %v doesn't exist", interfaceName)
+				continue
+			}
+
 			ifIndex = devIf.Index
 		} else {
+			if interfaceIf == nil {
+				log.Printf("[net] Not deleting route. Interface %v doesn't exist", interfaceName)
+				continue
+			}
+
 			ifIndex = interfaceIf.Index
 		}
 
diff --git a/network/transparent_endpointclient_linux.go b/network/transparent_endpointclient_linux.go
index e41c51d5fe..f0a48099bd 100644
--- a/network/transparent_endpointclient_linux.go
+++ b/network/transparent_endpointclient_linux.go
@@ -52,6 +52,15 @@ func setArpProxy(ifName string) error {
 }
 
 func (client *TransparentEndpointClient) AddEndpoints(epInfo *EndpointInfo) error {
+
+	if _, err := net.InterfaceByName(client.hostVethName); err == nil {
+		log.Printf("Deleting old host veth %v", client.hostVethName)
+		if err = netlink.DeleteLink(client.hostVethName); err != nil {
+			log.Printf("[net] Failed to delete old hostveth %v: %v.", client.hostVethName, err)
+			return err
+		}
+	}
+
 	if err := epcommon.CreateEndpoint(client.hostVethName, client.containerVethName); err != nil {
 		return err
 	}