Merge pull request #1418 from darfux/fix_handle_resizing_leak

Fix goroutine leak when exec/attach

pkg/server/container_attach.go

@@ -44,6 +44,8 @@ func (c *criService) Attach(ctx context.Context, r *runtime.AttachRequest) (*run
 
 func (c *criService) attachContainer(ctx context.Context, id string, stdin io.Reader, stdout, stderr io.WriteCloser,
 	tty bool, resize <-chan remotecommand.TerminalSize) error {
+	ctx, cancel := context.WithCancel(ctx)
+	defer cancel()
 	// Get container from our container store.
 	cntr, err := c.containerStore.Get(id)
 	if err != nil {
@@ -60,7 +62,7 @@ func (c *criService) attachContainer(ctx context.Context, id string, stdin io.Re
 	if err != nil {
 		return errors.Wrap(err, "failed to load task")
 	}
-	handleResizing(resize, func(size remotecommand.TerminalSize) {
+	handleResizing(ctx, resize, func(size remotecommand.TerminalSize) {
 		if err := task.Resize(ctx, uint32(size.Width), uint32(size.Height)); err != nil {
 			log.G(ctx).WithError(err).Errorf("Failed to resize task %q console", id)
 		}

pkg/server/container_execsync.go

@@ -132,7 +132,7 @@ func (c *criService) execInternal(ctx context.Context, container containerd.Cont
 		return nil, errors.Wrapf(err, "failed to start exec %q", execID)
 	}
 
-	handleResizing(opts.resize, func(size remotecommand.TerminalSize) {
+	handleResizing(ctx, opts.resize, func(size remotecommand.TerminalSize) {
 		if err := process.Resize(ctx, uint32(size.Width), uint32(size.Height)); err != nil {
 			log.G(ctx).WithError(err).Errorf("Failed to resize process %q console for container %q", execID, id)
 		}

pkg/server/streaming.go

@@ -17,6 +17,7 @@ limitations under the License.
 package server
 
 import (
+	"context"
 	"crypto/tls"
 	"io"
 	"math"
@@ -160,9 +161,8 @@ func (s *streamRuntime) PortForward(podSandboxID string, port int32, stream io.R
 }
 
 // handleResizing spawns a goroutine that processes the resize channel, calling resizeFunc for each
-// remotecommand.TerminalSize received from the channel. The resize channel must be closed elsewhere to stop the
-// goroutine.
-func handleResizing(resize <-chan remotecommand.TerminalSize, resizeFunc func(size remotecommand.TerminalSize)) {
+// remotecommand.TerminalSize received from the channel.
+func handleResizing(ctx context.Context, resize <-chan remotecommand.TerminalSize, resizeFunc func(size remotecommand.TerminalSize)) {
 	if resize == nil {
 		return
 	}
@@ -171,14 +171,18 @@ func handleResizing(resize <-chan remotecommand.TerminalSize, resizeFunc func(si
 		defer runtime.HandleCrash()
 
 		for {
-			size, ok := <-resize
-			if !ok {
+			select {
+			case <-ctx.Done():
 				return
+			case size, ok := <-resize:
+				if !ok {
+					return
+				}
+				if size.Height < 1 || size.Width < 1 {
+					continue
+				}
+				resizeFunc(size)
 			}
-			if size.Height < 1 || size.Width < 1 {
-				continue
-			}
-			resizeFunc(size)
 		}
 	}()
 }