Decouple daemon and container to execute processes.

Signed-off-by: David Calavera <david.calavera@gmail.com>

daemon/container.go

@@ -420,70 +420,6 @@ func (container *Container) getExecIDs() []string {
 	return container.execCommands.List()
 }
 
-func (container *Container) exec(ec *ExecConfig) error {
-	container.Lock()
-	defer container.Unlock()
-
-	callback := func(processConfig *execdriver.ProcessConfig, pid int, chOOM <-chan struct{}) error {
-		if processConfig.Tty {
-			// The callback is called after the process Start()
-			// so we are in the parent process. In TTY mode, stdin/out/err is the PtySlave
-			// which we close here.
-			if c, ok := processConfig.Stdout.(io.Closer); ok {
-				c.Close()
-			}
-		}
-		close(ec.waitStart)
-		return nil
-	}
-
-	// We use a callback here instead of a goroutine and an chan for
-	// synchronization purposes
-	cErr := promise.Go(func() error { return container.monitorExec(ec, callback) })
-
-	// Exec should not return until the process is actually running
-	select {
-	case <-ec.waitStart:
-	case err := <-cErr:
-		return err
-	}
-
-	return nil
-}
-
-func (container *Container) monitorExec(ExecConfig *ExecConfig, callback execdriver.DriverCallback) error {
-	var (
-		err      error
-		exitCode int
-	)
-	pipes := execdriver.NewPipes(ExecConfig.streamConfig.stdin, ExecConfig.streamConfig.stdout, ExecConfig.streamConfig.stderr, ExecConfig.OpenStdin)
-	exitCode, err = container.daemon.Exec(container, ExecConfig, pipes, callback)
-	if err != nil {
-		logrus.Errorf("Error running command in existing container %s: %s", container.ID, err)
-	}
-	logrus.Debugf("Exec task in container %s exited with code %d", container.ID, exitCode)
-	if ExecConfig.OpenStdin {
-		if err := ExecConfig.streamConfig.stdin.Close(); err != nil {
-			logrus.Errorf("Error closing stdin while running in %s: %s", container.ID, err)
-		}
-	}
-	if err := ExecConfig.streamConfig.stdout.Clean(); err != nil {
-		logrus.Errorf("Error closing stdout while running in %s: %s", container.ID, err)
-	}
-	if err := ExecConfig.streamConfig.stderr.Clean(); err != nil {
-		logrus.Errorf("Error closing stderr while running in %s: %s", container.ID, err)
-	}
-	if ExecConfig.ProcessConfig.Terminal != nil {
-		if err := ExecConfig.ProcessConfig.Terminal.Close(); err != nil {
-			logrus.Errorf("Error closing terminal while running in container %s: %s", container.ID, err)
-		}
-	}
-	// remove the exec command from the container's store only and not the
-	// daemon's store so that the exec command can be inspected.
-	container.execCommands.Delete(ExecConfig.ID)
-	return err
-}
-
 // Attach connects to the container's TTY, delegating to standard
 // streams or websockets depending on the configuration.
 func (container *Container) Attach(stdin io.ReadCloser, stdout io.Writer, stderr io.Writer) chan error {

daemon/exec.go

@@ -13,6 +13,7 @@ import (
 	"github.com/docker/docker/pkg/broadcaster"
 	"github.com/docker/docker/pkg/ioutils"
 	"github.com/docker/docker/pkg/pools"
+	"github.com/docker/docker/pkg/promise"
 	"github.com/docker/docker/pkg/stringid"
 	"github.com/docker/docker/pkg/stringutils"
 	"github.com/docker/docker/runconfig"
@@ -251,7 +252,7 @@ func (d *Daemon) ContainerExecStart(name string, stdin io.ReadCloser, stdout io.
 	// the exitStatus) even after the cmd is done running.
 
 	go func() {
-		execErr <- container.exec(ec)
+		execErr <- d.containerExec(container, ec)
 	}()
 
 	select {
@@ -329,3 +330,67 @@ func (d *Daemon) containerExecIds() map[string]struct{} {
 	}
 	return ids
 }
+
+func (daemon *Daemon) containerExec(container *Container, ec *ExecConfig) error {
+	container.Lock()
+	defer container.Unlock()
+
+	callback := func(processConfig *execdriver.ProcessConfig, pid int, chOOM <-chan struct{}) error {
+		if processConfig.Tty {
+			// The callback is called after the process Start()
+			// so we are in the parent process. In TTY mode, stdin/out/err is the PtySlave
+			// which we close here.
+			if c, ok := processConfig.Stdout.(io.Closer); ok {
+				c.Close()
+			}
+		}
+		close(ec.waitStart)
+		return nil
+	}
+
+	// We use a callback here instead of a goroutine and an chan for
+	// synchronization purposes
+	cErr := promise.Go(func() error { return daemon.monitorExec(container, ec, callback) })
+
+	// Exec should not return until the process is actually running
+	select {
+	case <-ec.waitStart:
+	case err := <-cErr:
+		return err
+	}
+
+	return nil
+}
+
+func (daemon *Daemon) monitorExec(container *Container, ExecConfig *ExecConfig, callback execdriver.DriverCallback) error {
+	var (
+		err      error
+		exitCode int
+	)
+	pipes := execdriver.NewPipes(ExecConfig.streamConfig.stdin, ExecConfig.streamConfig.stdout, ExecConfig.streamConfig.stderr, ExecConfig.OpenStdin)
+	exitCode, err = daemon.Exec(container, ExecConfig, pipes, callback)
+	if err != nil {
+		logrus.Errorf("Error running command in existing container %s: %s", container.ID, err)
+	}
+	logrus.Debugf("Exec task in container %s exited with code %d", container.ID, exitCode)
+	if ExecConfig.OpenStdin {
+		if err := ExecConfig.streamConfig.stdin.Close(); err != nil {
+			logrus.Errorf("Error closing stdin while running in %s: %s", container.ID, err)
+		}
+	}
+	if err := ExecConfig.streamConfig.stdout.Clean(); err != nil {
+		logrus.Errorf("Error closing stdout while running in %s: %s", container.ID, err)
+	}
+	if err := ExecConfig.streamConfig.stderr.Clean(); err != nil {
+		logrus.Errorf("Error closing stderr while running in %s: %s", container.ID, err)
+	}
+	if ExecConfig.ProcessConfig.Terminal != nil {
+		if err := ExecConfig.ProcessConfig.Terminal.Close(); err != nil {
+			logrus.Errorf("Error closing terminal while running in container %s: %s", container.ID, err)
+		}
+	}
+	// remove the exec command from the container's store only and not the
+	// daemon's store so that the exec command can be inspected.
+	container.execCommands.Delete(ExecConfig.ID)
+	return err
+}