plugin: Executor.Signal() accept syscall.Signal

This helps reducing some type-juggling / conversions further up
the stack.

Signed-off-by: Sebastiaan van Stijn <github@gone.nl>

plugin/executor/containerd/containerd.go

@@ -113,8 +113,8 @@ func (e *Executor) IsRunning(id string) (bool, error) {
 }
 
 // Signal sends the specified signal to the container
-func (e *Executor) Signal(id string, signal int) error {
+func (e *Executor) Signal(id string, signal syscall.Signal) error {
-	return e.client.SignalProcess(context.Background(), id, libcontainerdtypes.InitProcessName, syscall.Signal(signal))
+	return e.client.SignalProcess(context.Background(), id, libcontainerdtypes.InitProcessName, signal)
 }
 
 // ProcessEvent handles events from containerd

plugin/manager.go

@@ -11,6 +11,7 @@ import (
 	"sort"
 	"strings"
 	"sync"
+	"syscall"
 
 	"github.com/containerd/containerd/content"
 	"github.com/containerd/containerd/content/local"
@@ -37,7 +38,7 @@ type Executor interface {
 	Create(id string, spec specs.Spec, stdout, stderr io.WriteCloser) error
 	IsRunning(id string) (bool, error)
 	Restore(id string, stdout, stderr io.WriteCloser) (alive bool, err error)
-	Signal(id string, signal int) error
+	Signal(id string, signal syscall.Signal) error
 }
 
 // EndpointResolver provides looking up registry endpoints for pulling.

plugin/manager_linux.go

@@ -154,31 +154,30 @@ const shutdownTimeout = 10 * time.Second
 func shutdownPlugin(p *v2.Plugin, ec chan bool, executor Executor) {
 	pluginID := p.GetID()
 
-	err := executor.Signal(pluginID, int(unix.SIGTERM))
+	if err := executor.Signal(pluginID, unix.SIGTERM); err != nil {
-	if err != nil {
 		logrus.Errorf("Sending SIGTERM to plugin failed with error: %v", err)
-	} else {
+		return
+	}
 
-		timeout := time.NewTimer(shutdownTimeout)
+	timeout := time.NewTimer(shutdownTimeout)
-		defer timeout.Stop()
+	defer timeout.Stop()
+
+	select {
+	case <-ec:
+		logrus.Debug("Clean shutdown of plugin")
+	case <-timeout.C:
+		logrus.Debug("Force shutdown plugin")
+		if err := executor.Signal(pluginID, unix.SIGKILL); err != nil {
+			logrus.Errorf("Sending SIGKILL to plugin failed with error: %v", err)
+		}
+
+		timeout.Reset(shutdownTimeout)
 
 		select {
 		case <-ec:
-			logrus.Debug("Clean shutdown of plugin")
+			logrus.Debug("SIGKILL plugin shutdown")
 		case <-timeout.C:
-			logrus.Debug("Force shutdown plugin")
+			logrus.WithField("plugin", p.Name).Warn("Force shutdown plugin FAILED")
-			if err := executor.Signal(pluginID, int(unix.SIGKILL)); err != nil {
-				logrus.Errorf("Sending SIGKILL to plugin failed with error: %v", err)
-			}
-
-			timeout.Reset(shutdownTimeout)
-
-			select {
-			case <-ec:
-				logrus.Debug("SIGKILL plugin shutdown")
-			case <-timeout.C:
-				logrus.WithField("plugin", p.Name).Warn("Force shutdown plugin FAILED")
-			}
 		}
 	}
 }

plugin/manager_linux_test.go

@@ -5,6 +5,7 @@ import (
 	"net"
 	"os"
 	"path/filepath"
+	"syscall"
 	"testing"
 
 	"github.com/docker/docker/api/types"
@@ -87,24 +88,13 @@ func newTestPlugin(t *testing.T, name, cap, root string) *v2.Plugin {
 }
 
 type simpleExecutor struct {
+	Executor
 }
 
 func (e *simpleExecutor) Create(id string, spec specs.Spec, stdout, stderr io.WriteCloser) error {
 	return errors.New("Create failed")
 }
 
-func (e *simpleExecutor) Restore(id string, stdout, stderr io.WriteCloser) (bool, error) {
-	return false, nil
-}
-
-func (e *simpleExecutor) IsRunning(id string) (bool, error) {
-	return false, nil
-}
-
-func (e *simpleExecutor) Signal(id string, signal int) error {
-	return nil
-}
-
 func TestCreateFailed(t *testing.T) {
 	root, err := os.MkdirTemp("", "test-create-failed")
 	if err != nil {
@@ -165,7 +155,7 @@ func (e *executorWithRunning) Restore(id string, stdout, stderr io.WriteCloser)
 	return true, nil
 }
 
-func (e *executorWithRunning) Signal(id string, signal int) error {
+func (e *executorWithRunning) Signal(id string, signal syscall.Signal) error {
 	ch := e.exitChans[id]
 	ch <- struct{}{}
 	<-ch