libcontainerd: SignalProcess(): accept syscall.Signal

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

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

daemon/exec.go

@@ -279,15 +279,15 @@ func (daemon *Daemon) ContainerExecStart(ctx context.Context, name string, stdin
 	select {
 	case <-ctx.Done():
 		logrus.Debugf("Sending TERM signal to process %v in container %v", name, c.ID)
-		daemon.containerd.SignalProcess(ctx, c.ID, name, int(signal.SignalMap["TERM"]))
+		daemon.containerd.SignalProcess(ctx, c.ID, name, signal.SignalMap["TERM"])
 
 		timeout := time.NewTimer(termProcessTimeout)
 		defer timeout.Stop()
 
 		select {
 		case <-timeout.C:
 			logrus.Infof("Container %v, process %v failed to exit within %v of signal TERM - using the force", c.ID, name, termProcessTimeout)
-			daemon.containerd.SignalProcess(ctx, c.ID, name, int(signal.SignalMap["KILL"]))
+			daemon.containerd.SignalProcess(ctx, c.ID, name, signal.SignalMap["KILL"])
 		case <-attachErr:
 			// TERM signal worked
 		}

daemon/kill.go

@@ -60,7 +60,8 @@ func (daemon *Daemon) ContainerKill(name string, sig uint64) error {
 // or not running, or if there is a problem returned from the
 // underlying kill command.
 func (daemon *Daemon) killWithSignal(container *containerpkg.Container, sig int) error {
-	logrus.Debugf("Sending kill signal %d to container %s", sig, container.ID)
+	var stopSignal = syscall.Signal(sig)
+	logrus.Debugf("Sending kill signal %d to container %s", stopSignal, container.ID)
 	container.Lock()
 	defer container.Unlock()
 
@@ -69,12 +70,12 @@ func (daemon *Daemon) killWithSignal(container *containerpkg.Container, sig int)
 	}
 
 	var unpause bool
-	if container.Config.StopSignal != "" && syscall.Signal(sig) != syscall.SIGKILL {
+	if container.Config.StopSignal != "" && stopSignal != syscall.SIGKILL {
 		containerStopSignal, err := signal.ParseSignal(container.Config.StopSignal)
 		if err != nil {
 			return err
 		}
-		if containerStopSignal == syscall.Signal(sig) {
+		if containerStopSignal == stopSignal {
 			container.ExitOnNext()
 			unpause = container.Paused
 		}
@@ -95,7 +96,8 @@ func (daemon *Daemon) killWithSignal(container *containerpkg.Container, sig int)
 		return nil
 	}
 
-	if err := daemon.kill(container, sig); err != nil {
+	err := daemon.containerd.SignalProcess(context.Background(), container.ID, libcontainerdtypes.InitProcessName, stopSignal)
+	if err != nil {
 		if errdefs.IsNotFound(err) {
 			unpause = false
 			logrus.WithError(err).WithField("container", container.ID).WithField("action", "kill").Debug("container kill failed because of 'container not found' or 'no such process'")
@@ -125,7 +127,7 @@ func (daemon *Daemon) killWithSignal(container *containerpkg.Container, sig int)
 	}
 
 	attributes := map[string]string{
-		"signal": fmt.Sprintf("%d", sig),
+		"signal": fmt.Sprintf("%d", stopSignal),
 	}
 	daemon.LogContainerEventWithAttributes(container, "kill", attributes)
 	return nil
@@ -182,7 +184,3 @@ func (daemon *Daemon) killPossiblyDeadProcess(container *containerpkg.Container,
 	}
 	return err
 }
-
-func (daemon *Daemon) kill(c *containerpkg.Container, sig int) error {
-	return daemon.containerd.SignalProcess(context.Background(), c.ID, libcontainerdtypes.InitProcessName, sig)
-}

daemon/util_test.go

@@ -5,6 +5,7 @@ package daemon
 
 import (
 	"context"
+	"syscall"
 	"time"
 
 	"github.com/containerd/containerd"
@@ -35,7 +36,7 @@ func (c *MockContainerdClient) Create(ctx context.Context, containerID string, s
 func (c *MockContainerdClient) Start(ctx context.Context, containerID, checkpointDir string, withStdin bool, attachStdio libcontainerdtypes.StdioCallback) (pid int, err error) {
 	return 0, nil
 }
-func (c *MockContainerdClient) SignalProcess(ctx context.Context, containerID, processID string, signal int) error {
+func (c *MockContainerdClient) SignalProcess(ctx context.Context, containerID, processID string, signal syscall.Signal) error {
 	return nil
 }
 func (c *MockContainerdClient) Exec(ctx context.Context, containerID, processID string, spec *specs.Process, withStdin bool, attachStdio libcontainerdtypes.StdioCallback) (int, error) {

libcontainerd/remote/client.go

@@ -333,12 +333,12 @@ func (c *client) Exec(ctx context.Context, containerID, processID string, spec *
 	return int(p.Pid()), nil
 }
 
-func (c *client) SignalProcess(ctx context.Context, containerID, processID string, signal int) error {
+func (c *client) SignalProcess(ctx context.Context, containerID, processID string, signal syscall.Signal) error {
 	p, err := c.getProcess(ctx, containerID, processID)
 	if err != nil {
 		return err
 	}
-	return wrapError(p.Kill(ctx, syscall.Signal(signal)))
+	return wrapError(p.Kill(ctx, signal))
 }
 
 func (c *client) ResizeTerminal(ctx context.Context, containerID, processID string, width, height int) error {

libcontainerd/types/types.go

@@ -2,6 +2,7 @@ package types // import "github.com/docker/docker/libcontainerd/types"
 
 import (
 	"context"
+	"syscall"
 	"time"
 
 	"github.com/containerd/containerd"
@@ -54,7 +55,7 @@ type Client interface {
 
 	Create(ctx context.Context, containerID string, spec *specs.Spec, shim string, runtimeOptions interface{}, opts ...containerd.NewContainerOpts) error
 	Start(ctx context.Context, containerID, checkpointDir string, withStdin bool, attachStdio StdioCallback) (pid int, err error)
-	SignalProcess(ctx context.Context, containerID, processID string, signal int) error
+	SignalProcess(ctx context.Context, containerID, processID string, signal syscall.Signal) error
 	Exec(ctx context.Context, containerID, processID string, spec *specs.Process, withStdin bool, attachStdio StdioCallback) (int, error)
 	ResizeTerminal(ctx context.Context, containerID, processID string, width, height int) error
 	CloseStdin(ctx context.Context, containerID, processID string) error

plugin/executor/containerd/containerd.go

@@ -4,6 +4,7 @@ import (
 	"context"
 	"io"
 	"sync"
+	"syscall"
 
 	"github.com/containerd/containerd"
 	"github.com/containerd/containerd/cio"
@@ -113,7 +114,7 @@ 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 {
-	return e.client.SignalProcess(context.Background(), id, libcontainerdtypes.InitProcessName, signal)
+	return e.client.SignalProcess(context.Background(), id, libcontainerdtypes.InitProcessName, syscall.Signal(signal))
 }
 
 // ProcessEvent handles events from containerd