package daemon
 
 import (

 	"fmt"

 	"io"

 	"github.com/docker/docker/container"

 	"github.com/docker/docker/pkg/archive"
 	"github.com/docker/docker/pkg/ioutils"

 )
 

 // ContainerExport writes the contents of the container to the given
 // writer. An error is returned if the container cannot be found.

 func (daemon *Daemon) ContainerExport(name string, out io.Writer) error {

 	container, err := daemon.GetContainer(name)

 	if err != nil {

 		return err

 	}

 	data, err := daemon.containerExport(container)

 	if err != nil {

 		return fmt.Errorf("Error exporting container %s: %v", name, err)

 	}
 	defer data.Close()
 
 	// Stream the entire contents of the container (basically a volatile snapshot)

 	if _, err := io.Copy(out, data); err != nil {

 		return fmt.Errorf("Error exporting container %s: %v", name, err)

 	}

 	return nil

 }

 func (daemon *Daemon) containerExport(container *container.Container) (archive.Archive, error) {

 	if err := daemon.Mount(container); err != nil {
 		return nil, err
 	}
 
 	uidMaps, gidMaps := daemon.GetUIDGIDMaps()

 	archive, err := archive.TarWithOptions(container.BaseFS, &archive.TarOptions{

 		Compression: archive.Uncompressed,
 		UIDMaps:     uidMaps,
 		GIDMaps:     gidMaps,
 	})
 	if err != nil {

 		daemon.Unmount(container)

 		return nil, err
 	}
 	arch := ioutils.NewReadCloserWrapper(archive, func() error {
 		err := archive.Close()

 		daemon.Unmount(container)

 		return err
 	})

 	daemon.LogContainerEvent(container, "export")

 	return arch, err
 }