// ApplyLayer parses a diff in the standard layer format from `layer`, and // applies it to the directory `dest`. Returns the size in bytes of the // contents of the layer. func ApplyLayer(dest string, layer ArchiveReader) (int64, error) { dest = filepath.Clean(dest) // We need to be able to set any perms oldmask, err := system.Umask(0) if err != nil { return 0, err } defer system.Umask(oldmask) // ignore err, ErrNotSupportedPlatform layer, err = DecompressStream(layer) if err != nil { return 0, err } return UnpackLayer(dest, layer) }
// applyLayer is the entry-point for docker-applylayer on re-exec. This is not // used on Windows as it does not support chroot, hence no point sandboxing // through chroot and rexec. func applyLayer() { var ( tmpDir = "" err error options *archive.TarOptions ) runtime.LockOSThread() flag.Parse() if err := chroot(flag.Arg(0)); err != nil { fatal(err) } // We need to be able to set any perms oldmask, err := system.Umask(0) defer system.Umask(oldmask) if err != nil { fatal(err) } if err := json.Unmarshal([]byte(os.Getenv("OPT")), &options); err != nil { fatal(err) } if tmpDir, err = ioutil.TempDir("/", "temp-docker-extract"); err != nil { fatal(err) } os.Setenv("TMPDIR", tmpDir) size, err := archive.UnpackLayer("/", os.Stdin, options) os.RemoveAll(tmpDir) if err != nil { fatal(err) } encoder := json.NewEncoder(os.Stdout) if err := encoder.Encode(applyLayerResponse{size}); err != nil { fatal(fmt.Errorf("unable to encode layerSize JSON: %s", err)) } flush(os.Stdout) flush(os.Stdin) os.Exit(0) }
// do the bulk load of ApplyLayer, but allow for not calling DecompressStream func applyLayerHandler(dest string, layer Reader, options *TarOptions, decompress bool) (int64, error) { dest = filepath.Clean(dest) // We need to be able to set any perms oldmask, err := system.Umask(0) if err != nil { return 0, err } defer system.Umask(oldmask) // ignore err, ErrNotSupportedPlatform if decompress { layer, err = DecompressStream(layer) if err != nil { return 0, err } } return UnpackLayer(dest, layer, options) }