executor: fix resource sampler goroutine leak

Before this, the runc executor did not close the cgroupRecord when the
container exited non-zero, which resulted in goroutines leaking.

Signed-off-by: Erik Sipsma <erik@sipsma.dev>
(cherry picked from commit fa11bf9)

Author: sipsma

executor/resources/monitor.go

@@ -56,6 +56,10 @@ func (r *cgroupRecord) Start() {
 	r.closeSampler = s.Close
 }
 
+func (r *cgroupRecord) Close() {
+	r.close()
+}
+
 func (r *cgroupRecord) CloseAsync(next func(context.Context) error) error {
 	go func() {
 		r.close()
@@ -160,6 +164,9 @@ func (r *nopRecord) Samples() (*types.Samples, error) {
 	return nil, nil
 }
 
+func (r *nopRecord) Close() {
+}
+
 func (r *nopRecord) CloseAsync(next func(context.Context) error) error {
 	return next(context.TODO())
 }

executor/resources/types/types.go

@@ -9,6 +9,7 @@ import (
 
 type Recorder interface {
 	Start()
+	Close()
 	CloseAsync(func(context.Context) error) error
 	Wait() error
 	Samples() (*Samples, error)

executor/runcexecutor/executor.go

@@ -335,6 +335,9 @@ func (w *runcExecutor) Run(ctx context.Context, id string, root executor.Mount,
 
 	err = exitError(ctx, err)
 	if err != nil {
+		if rec != nil {
+			rec.Close()
+		}
 		releaseContainer(context.TODO())
 		return nil, err
 	}