package daemon import ( "fmt" "io" "runtime" "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 { if runtime.GOOS == "windows" { return fmt.Errorf("the daemon on this platform does not support export of a container") } 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) (io.ReadCloser, 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 }