Exit signal forward if process not found

cpuguy83 · cpuguy83 · commit 665051083670 · 2020-09-04T16:17:00.000-07:00
Previously the signal loop can end up racing with the process exiting.
Intead of logging and continuing the loop, exit early.

Signed-off-by: Brian Goff &lt;cpuguy83@gmail.com&gt;
diff --git a/cmd/ctr/commands/signals.go b/cmd/ctr/commands/signals.go
@@ -23,6 +23,7 @@ import (
 	"syscall"
 
 	"github.com/containerd/containerd"
+	"github.com/containerd/containerd/errdefs"
 	"github.com/sirupsen/logrus"
 )
 
@@ -38,6 +39,10 @@ func ForwardAllSignals(ctx gocontext.Context, task killer) chan os.Signal {
 		for s := range sigc {
 			logrus.Debug("forwarding signal ", s)
 			if err := task.Kill(ctx, s.(syscall.Signal)); err != nil {
+				if errdefs.IsNotFound(err) {
+					logrus.WithError(err).Debugf("Not forwarding signal %s", s)
+					return
+				}
 				logrus.WithError(err).Errorf("forward signal %s", s)
 			}
 		}

Original file line number	Diff line number	Diff line change
`@@ -23,6 +23,7 @@ import (`
`23`	`23`	`"syscall"`
`24`	`24`
`25`	`25`	`"github.com/containerd/containerd"`
	`26`	`+ "github.com/containerd/containerd/errdefs"`
`26`	`27`	`"github.com/sirupsen/logrus"`
`27`	`28`	`)`
`28`	`29`
`@@ -38,6 +39,10 @@ func ForwardAllSignals(ctx gocontext.Context, task killer) chan os.Signal {`
`38`	`39`	`for s := range sigc {`
`39`	`40`	`logrus.Debug("forwarding signal ", s)`
`40`	`41`	`if err := task.Kill(ctx, s.(syscall.Signal)); err != nil {`
	`42`	`+ if errdefs.IsNotFound(err) {`
	`43`	`+ logrus.WithError(err).Debugf("Not forwarding signal %s", s)`
	`44`	`+ return`
	`45`	`+ }`
`41`	`46`	`logrus.WithError(err).Errorf("forward signal %s", s)`
`42`	`47`	`}`
`43`	`48`	`}`