worker: fix containerd cancellation and cleanup

Signed-off-by: Tonis Tiigi <tonistiigi@gmail.com>

worker/containerdworker/worker.go

@@ -2,6 +2,8 @@ package containerdworker
 
 import (
 	"io"
+	"syscall"
+	"time"
 
 	"github.com/containerd/containerd"
 	"github.com/containerd/containerd/cio"
@@ -23,7 +25,7 @@ func New(client *containerd.Client) worker.Worker {
 	}
 }
 
-func (w containerdWorker) Exec(ctx context.Context, meta worker.Meta, root cache.Mountable, mounts []worker.Mount, stdin io.ReadCloser, stdout, stderr io.WriteCloser) error {
+func (w containerdWorker) Exec(ctx context.Context, meta worker.Meta, root cache.Mountable, mounts []worker.Mount, stdin io.ReadCloser, stdout, stderr io.WriteCloser) (err error) {
 	id := identity.NewID()
 
 	spec, cleanup, err := oci.GenerateSpec(ctx, meta, mounts, id)
@@ -43,7 +45,12 @@ func (w containerdWorker) Exec(ctx context.Context, meta worker.Meta, root cache
 	if err != nil {
 		return err
 	}
-	defer container.Delete(ctx)
+
+	defer func() {
+		if err1 := container.Delete(context.TODO()); err == nil && err1 != nil {
+			err = errors.Wrapf(err1, "failed to delete container %s", id)
+		}
+	}()
 
 	if stdin == nil {
 		stdin = &emptyReadCloser{}
@@ -53,27 +60,41 @@ func (w containerdWorker) Exec(ctx context.Context, meta worker.Meta, root cache
 	if err != nil {
 		return err
 	}
-	defer task.Delete(ctx)
+	defer func() {
+		if _, err1 := task.Delete(context.TODO()); err == nil && err1 != nil {
+			err = errors.Wrapf(err1, "failed to delete task %s", id)
+		}
+	}()
 
 	// TODO: Configure bridge networking
 
-	// TODO: support sending signals
-
 	if err := task.Start(ctx); err != nil {
 		return err
 	}
 
-	statusCh, err := task.Wait(ctx)
+	statusCh, err := task.Wait(context.Background())
 	if err != nil {
 		return err
 	}
-	status := <-statusCh
+
+	killCtx, cancel := context.WithTimeout(context.Background(), 10*time.Second)
+
+	ctxDone := ctx.Done()
+	for {
+		select {
+		case <-ctxDone:
+			ctxDone = nil
+			task.Kill(killCtx, syscall.SIGKILL)
+		case status := <-statusCh:
+			cancel()
 			if status.ExitCode() != 0 {
 				return errors.Errorf("process returned non-zero exit code: %d", status.ExitCode())
 			}
-
 			return nil
 		}
+	}
+
+}
 
 type emptyReadCloser struct{}