func (daemon *Daemon) Diff(container *Container) (archive.Archive, error) {
if differ, ok := daemon.driver.(graphdriver.Differ); ok {
return differ.Diff(container.ID)
}
changes, err := daemon.Changes(container)
if err != nil {
return nil, err
}
cDir, err := daemon.driver.Get(container.ID, "")
if err != nil {
return nil, fmt.Errorf("Error getting container rootfs %s from driver %s: %s", container.ID, container.daemon.driver, err)
}
archive, err := archive.ExportChanges(cDir, changes)
if err != nil {
return nil, err
}
return utils.NewReadCloserWrapper(archive, func() error {
err := archive.Close()
daemon.driver.Put(container.ID)
return err
}), nil
}
// TarLayer returns a tar archive of the image's filesystem layer.
func (img *Image) TarLayer() (arch archive.Archive, err error) {
if img.graph == nil {
return nil, fmt.Errorf("Can't load storage driver for unregistered image %s", img.ID)
}
driver := img.graph.Driver()
if differ, ok := driver.(graphdriver.Differ); ok {
return differ.Diff(img.ID)
}
imgFs, err := driver.Get(img.ID, "")
if err != nil {
return nil, err
}
defer func() {
if err != nil {
driver.Put(img.ID)
}
}()
if img.Parent == "" {
archive, err := archive.Tar(imgFs, archive.Uncompressed)
if err != nil {
return nil, err
}
return utils.NewReadCloserWrapper(archive, func() error {
err := archive.Close()
driver.Put(img.ID)
return err
}), nil
}
parentFs, err := driver.Get(img.Parent, "")
if err != nil {
return nil, err
}
defer driver.Put(img.Parent)
changes, err := archive.ChangesDirs(imgFs, parentFs)
if err != nil {
return nil, err
}
archive, err := archive.ExportChanges(imgFs, changes)
if err != nil {
return nil, err
}
return utils.NewReadCloserWrapper(archive, func() error {
err := archive.Close()
driver.Put(img.ID)
return err
}), nil
}