Import nsenter in docker.

Docker-DCO-1.1-Signed-off-by: Vishnu Kannan <vishnuk@google.com> (github: vishh)

daemon/exec.go

@@ -18,8 +18,8 @@ import (
 
 type ExecConfig struct {
 	ProcessConfig execdriver.ProcessConfig
-	StreamConfig  StreamConfig
-	OpenStdin     bool
+	StreamConfig
+	OpenStdin bool
 }
 
 func (d *Daemon) ContainerExec(job *engine.Job) engine.Status {
@@ -92,7 +92,6 @@ func (d *Daemon) ContainerExec(job *engine.Job) engine.Status {
 		attachErr = d.Attach(&execConfig.StreamConfig, config.AttachStdin, false, config.Tty, cStdin, cStdinCloser, cStdout, cStderr)
 	}()
 
-	log.Debugf("Exec Config is %+v\n", execConfig)
 	go func() {
 		err := container.Exec(execConfig)
 		if err != nil {

daemon/execdriver/native/driver.go

@@ -22,6 +22,7 @@ import (
 	"github.com/docker/libcontainer/cgroups/systemd"
 	consolepkg "github.com/docker/libcontainer/console"
 	"github.com/docker/libcontainer/namespaces"
+	_ "github.com/docker/libcontainer/namespaces/nsenter"
 	"github.com/docker/libcontainer/system"
 )
 

daemon/execdriver/native/exec.go

@@ -37,6 +37,7 @@ func nsenterExec() {
 	}
 }
 
+// TODO(vishh): Add support for running in priviledged mode and running as a different user.
 func (d *driver) Exec(c *execdriver.Command, processConfig *execdriver.ProcessConfig, pipes *execdriver.Pipes, startCallback execdriver.StartCallback) (int, error) {
 	active := d.activeContainers[c.ID]
 	if active == nil {