flannel: remove net conf file after DEL succeed

Signed-off-by: Bruce Ma <[email protected]>
containernetworking · Feb 12, 2020 · b0c42ce · b0c42ce
1 parent f5c3d1b
commit b0c42ce
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Showing 3 changed files with 25 additions and 12 deletions.
diff --git a/plugins/meta/flannel/flannel.go b/plugins/meta/flannel/flannel.go
@@ -146,12 +146,19 @@ func saveScratchNetConf(containerID, dataDir string, netconf []byte) error {
 	return ioutil.WriteFile(path, netconf, 0600)
 }
 
-func consumeScratchNetConf(containerID, dataDir string) ([]byte, error) {
+func consumeScratchNetConf(containerID, dataDir string) (func(error), []byte, error) {
 	path := filepath.Join(dataDir, containerID)
-	// Ignore errors when removing - Per spec safe to continue during DEL
-	defer os.Remove(path)
 
-	return ioutil.ReadFile(path)
+	// cleanup will do clean job when no error happens in consuming/using process
+	cleanup := func(err error) {
+		if err == nil {
+			// Ignore errors when removing - Per spec safe to continue during DEL
+			_ = os.Remove(path)
+		}
+	}
+	netConfBytes, err := ioutil.ReadFile(path)
+
+	return cleanup, netConfBytes, err
 }
 
 func delegateAdd(cid, dataDir string, netconf map[string]interface{}) error {

diff --git a/plugins/meta/flannel/flannel_linux.go b/plugins/meta/flannel/flannel_linux.go
@@ -68,8 +68,8 @@ func doCmdAdd(args *skel.CmdArgs, n *NetConf, fenv *subnetEnv) error {
 	return delegateAdd(args.ContainerID, n.DataDir, n.Delegate)
 }
 
-func doCmdDel(args *skel.CmdArgs, n *NetConf) error {
-	netconfBytes, err := consumeScratchNetConf(args.ContainerID, n.DataDir)
+func doCmdDel(args *skel.CmdArgs, n *NetConf) (err error) {
+	cleanup, netConfBytes, err := consumeScratchNetConf(args.ContainerID, n.DataDir)
 	if err != nil {
 		if os.IsNotExist(err) {
 			// Per spec should ignore error if resources are missing / already removed
@@ -78,10 +78,13 @@ func doCmdDel(args *skel.CmdArgs, n *NetConf) error {
 		return err
 	}
 
+	// cleanup will work when no error happens
+	defer cleanup(err)
+
 	nc := &types.NetConf{}
-	if err = json.Unmarshal(netconfBytes, nc); err != nil {
+	if err = json.Unmarshal(netConfBytes, nc); err != nil {
 		return fmt.Errorf("failed to parse netconf: %v", err)
 	}
 
-	return invoke.DelegateDel(context.TODO(), nc.Type, netconfBytes, nil)
+	return invoke.DelegateDel(context.TODO(), nc.Type, netConfBytes, nil)
 }
diff --git a/plugins/meta/flannel/flannel_windows.go b/plugins/meta/flannel/flannel_windows.go
@@ -55,8 +55,8 @@ func doCmdAdd(args *skel.CmdArgs, n *NetConf, fenv *subnetEnv) error {
 	return delegateAdd(hns.GetSandboxContainerID(args.ContainerID, args.Netns), n.DataDir, n.Delegate)
 }
 
-func doCmdDel(args *skel.CmdArgs, n *NetConf) error {
-	netconfBytes, err := consumeScratchNetConf(hns.GetSandboxContainerID(args.ContainerID, args.Netns), n.DataDir)
+func doCmdDel(args *skel.CmdArgs, n *NetConf) (err error) {
+	cleanup, netConfBytes, err := consumeScratchNetConf(hns.GetSandboxContainerID(args.ContainerID, args.Netns), n.DataDir)
 	if err != nil {
 		if os.IsNotExist(err) {
 			// Per spec should ignore error if resources are missing / already removed
@@ -65,10 +65,13 @@ func doCmdDel(args *skel.CmdArgs, n *NetConf) error {
 		return err
 	}
 
+	// cleanup will work when no error happens
+	defer cleanup(err)
+
 	nc := &types.NetConf{}
-	if err = json.Unmarshal(netconfBytes, nc); err != nil {
+	if err = json.Unmarshal(netConfBytes, nc); err != nil {
 		return fmt.Errorf("failed to parse netconf: %v", err)
 	}
 
-	return invoke.DelegateDel(context.TODO(), nc.Type, netconfBytes, nil)
+	return invoke.DelegateDel(context.TODO(), nc.Type, netConfBytes, nil)
 }