Fix containerd task deletion after failed start

Deleting a containerd task whose status is Created fails with a
"precondition failed" error. This is because (aside from Windows)
a process is spawned when the task is created, and deleting the task
while the process is running would leak the process if it was allowed.
libcontainerd and the containerd plugin executor mistakenly try to clean
up from a failed start by deleting the created task, which will always
fail with the aforementined error. Change them to pass the
`WithProcessKill` delete option so the cleanup has a chance to succeed.

Signed-off-by: Cory Snider <csnider@mirantis.com>

libcontainerd/remote/client.go

@@ -233,7 +233,9 @@ func (c *container) Start(ctx context.Context, checkpointDir string, withStdin b
 	stdinCloseSync <- t
 
 	if err := t.Start(ctx); err != nil {
-		if _, err := t.Delete(ctx); err != nil {
+		// Only Stopped tasks can be deleted. Created tasks have to be
+		// killed first, to transition them to Stopped.
+		if _, err := t.Delete(ctx, containerd.WithProcessKill); err != nil {
 			c.client.logger.WithError(err).WithField("container", c.c8dCtr.ID()).
 				Error("failed to delete task after fail start")
 		}

plugin/executor/containerd/containerd.go

@@ -60,7 +60,7 @@ type c8dPlugin struct {
 // deleteTaskAndContainer deletes plugin task and then plugin container from containerd
 func (p c8dPlugin) deleteTaskAndContainer(ctx context.Context) {
 	if p.tsk != nil {
-		if _, err := p.tsk.Delete(ctx); err != nil && !errdefs.IsNotFound(err) {
+		if err := p.tsk.ForceDelete(ctx); err != nil && !errdefs.IsNotFound(err) {
 			p.log.WithError(err).Error("failed to delete plugin task from containerd")
 		}
 	}