func mkdirAs(path string, mode os.FileMode, ownerUID, ownerGID int, mkAll, chownExisting bool) error { // make an array containing the original path asked for, plus (for mkAll == true) // all path components leading up to the complete path that don't exist before we MkdirAll // so that we can chown all of them properly at the end. If chownExisting is false, we won't // chown the full directory path if it exists var paths []string if _, err := os.Stat(path); err != nil && os.IsNotExist(err) { paths = []string{path} } else if err == nil && chownExisting { if err := os.Chown(path, ownerUID, ownerGID); err != nil { return err } // short-circuit--we were called with an existing directory and chown was requested return nil } else if err == nil { // nothing to do; directory path fully exists already and chown was NOT requested return nil } if mkAll { // walk back to "/" looking for directories which do not exist // and add them to the paths array for chown after creation dirPath := path for { dirPath = filepath.Dir(dirPath) if dirPath == "/" { break } if _, err := os.Stat(dirPath); err != nil && os.IsNotExist(err) { paths = append(paths, dirPath) } } if err := system.MkdirAll(path, mode); err != nil && !os.IsExist(err) { return err } } else { if err := os.Mkdir(path, mode); err != nil && !os.IsExist(err) { return err } } // even if it existed, we will chown the requested path + any subpaths that // didn't exist when we called MkdirAll for _, pathComponent := range paths { if err := os.Chown(pathComponent, ownerUID, ownerGID); err != nil { return err } } return nil }
// CopyWithTar creates a tar archive of filesystem path `src`, and // unpacks it at filesystem path `dst`. // The archive is streamed directly with fixed buffering and no // intermediary disk IO. func (archiver *Archiver) CopyWithTar(src, dst string) error { srcSt, err := os.Stat(src) if err != nil { return err } if !srcSt.IsDir() { return archiver.CopyFileWithTar(src, dst) } // Create dst, copy src's content into it logrus.Debugf("Creating dest directory: %s", dst) if err := system.MkdirAll(dst, 0755); err != nil { return err } logrus.Debugf("Calling TarUntar(%s, %s)", src, dst) return archiver.TarUntar(src, dst) }
// Setup sets up a mount point by either mounting the volume if it is // configured, or creating the source directory if supplied. func (m *MountPoint) Setup() (string, error) { if m.Volume != nil { return m.Volume.Mount() } if len(m.Source) > 0 { if _, err := os.Stat(m.Source); err != nil { if !os.IsNotExist(err) { return "", err } if runtime.GOOS != "windows" { // Windows does not have deprecation issues here logrus.Warnf("Auto-creating non-existant volume host path %s, this is deprecated and will be removed soon", m.Source) if err := system.MkdirAll(m.Source, 0755); err != nil { return "", err } } } return m.Source, nil } return "", derr.ErrorCodeMountSetup }
// Platforms such as Windows do not support the UID/GID concept. So make this // just a wrapper around system.MkdirAll. func mkdirAs(path string, mode os.FileMode, ownerUID, ownerGID int, mkAll, chownExisting bool) error { if err := system.MkdirAll(path, mode); err != nil && !os.IsExist(err) { return err } return nil }
// CopyFileWithTar emulates the behavior of the 'cp' command-line // for a single file. It copies a regular file from path `src` to // path `dst`, and preserves all its metadata. func (archiver *Archiver) CopyFileWithTar(src, dst string) (err error) { logrus.Debugf("CopyFileWithTar(%s, %s)", src, dst) srcSt, err := os.Stat(src) if err != nil { return err } if srcSt.IsDir() { return fmt.Errorf("Can't copy a directory") } // Clean up the trailing slash. This must be done in an operating // system specific manner. if dst[len(dst)-1] == os.PathSeparator { dst = filepath.Join(dst, filepath.Base(src)) } // Create the holding directory if necessary if err := system.MkdirAll(filepath.Dir(dst), 0700); err != nil { return err } r, w := io.Pipe() errC := promise.Go(func() error { defer w.Close() srcF, err := os.Open(src) if err != nil { return err } defer srcF.Close() hdr, err := tar.FileInfoHeader(srcSt, "") if err != nil { return err } hdr.Name = filepath.Base(dst) hdr.Mode = int64(chmodTarEntry(os.FileMode(hdr.Mode))) remappedRootUID, remappedRootGID, err := idtools.GetRootUIDGID(archiver.UIDMaps, archiver.GIDMaps) if err != nil { return err } // only perform mapping if the file being copied isn't already owned by the // uid or gid of the remapped root in the container if remappedRootUID != hdr.Uid { xUID, err := idtools.ToHost(hdr.Uid, archiver.UIDMaps) if err != nil { return err } hdr.Uid = xUID } if remappedRootGID != hdr.Gid { xGID, err := idtools.ToHost(hdr.Gid, archiver.GIDMaps) if err != nil { return err } hdr.Gid = xGID } tw := tar.NewWriter(w) defer tw.Close() if err := tw.WriteHeader(hdr); err != nil { return err } if _, err := io.Copy(tw, srcF); err != nil { return err } return nil }) defer func() { if er := <-errC; err != nil { err = er } }() err = archiver.Untar(r, filepath.Dir(dst), nil) if err != nil { r.CloseWithError(err) } return err }
// Unpack unpacks the decompressedArchive to dest with options. func Unpack(decompressedArchive io.Reader, dest string, options *TarOptions) error { tr := tar.NewReader(decompressedArchive) trBuf := pools.BufioReader32KPool.Get(nil) defer pools.BufioReader32KPool.Put(trBuf) var dirs []*tar.Header remappedRootUID, remappedRootGID, err := idtools.GetRootUIDGID(options.UIDMaps, options.GIDMaps) if err != nil { return err } // Iterate through the files in the archive. loop: for { hdr, err := tr.Next() if err == io.EOF { // end of tar archive break } if err != nil { return err } // Normalize name, for safety and for a simple is-root check // This keeps "../" as-is, but normalizes "/../" to "/". Or Windows: // This keeps "..\" as-is, but normalizes "\..\" to "\". hdr.Name = filepath.Clean(hdr.Name) for _, exclude := range options.ExcludePatterns { if strings.HasPrefix(hdr.Name, exclude) { continue loop } } // After calling filepath.Clean(hdr.Name) above, hdr.Name will now be in // the filepath format for the OS on which the daemon is running. Hence // the check for a slash-suffix MUST be done in an OS-agnostic way. if !strings.HasSuffix(hdr.Name, string(os.PathSeparator)) { // Not the root directory, ensure that the parent directory exists parent := filepath.Dir(hdr.Name) parentPath := filepath.Join(dest, parent) if _, err := os.Lstat(parentPath); err != nil && os.IsNotExist(err) { err = system.MkdirAll(parentPath, 0777) if err != nil { return err } } } path := filepath.Join(dest, hdr.Name) rel, err := filepath.Rel(dest, path) if err != nil { return err } if strings.HasPrefix(rel, ".."+string(os.PathSeparator)) { return breakoutError(fmt.Errorf("%q is outside of %q", hdr.Name, dest)) } // If path exits we almost always just want to remove and replace it // The only exception is when it is a directory *and* the file from // the layer is also a directory. Then we want to merge them (i.e. // just apply the metadata from the layer). if fi, err := os.Lstat(path); err == nil { if options.NoOverwriteDirNonDir && fi.IsDir() && hdr.Typeflag != tar.TypeDir { // If NoOverwriteDirNonDir is true then we cannot replace // an existing directory with a non-directory from the archive. return fmt.Errorf("cannot overwrite directory %q with non-directory %q", path, dest) } if options.NoOverwriteDirNonDir && !fi.IsDir() && hdr.Typeflag == tar.TypeDir { // If NoOverwriteDirNonDir is true then we cannot replace // an existing non-directory with a directory from the archive. return fmt.Errorf("cannot overwrite non-directory %q with directory %q", path, dest) } if fi.IsDir() && hdr.Name == "." { continue } if !(fi.IsDir() && hdr.Typeflag == tar.TypeDir) { if err := os.RemoveAll(path); err != nil { return err } } } trBuf.Reset(tr) // if the options contain a uid & gid maps, convert header uid/gid // entries using the maps such that lchown sets the proper mapped // uid/gid after writing the file. We only perform this mapping if // the file isn't already owned by the remapped root UID or GID, as // that specific uid/gid has no mapping from container -> host, and // those files already have the proper ownership for inside the // container. if hdr.Uid != remappedRootUID { xUID, err := idtools.ToHost(hdr.Uid, options.UIDMaps) if err != nil { return err } hdr.Uid = xUID } if hdr.Gid != remappedRootGID { xGID, err := idtools.ToHost(hdr.Gid, options.GIDMaps) if err != nil { return err } hdr.Gid = xGID } if err := createTarFile(path, dest, hdr, trBuf, !options.NoLchown, options.ChownOpts); err != nil { return err } // Directory mtimes must be handled at the end to avoid further // file creation in them to modify the directory mtime if hdr.Typeflag == tar.TypeDir { dirs = append(dirs, hdr) } } for _, hdr := range dirs { path := filepath.Join(dest, hdr.Name) if err := system.Chtimes(path, hdr.AccessTime, hdr.ModTime); err != nil { return err } } return nil }
// UnpackLayer unpack `layer` to a `dest`. The stream `layer` can be // compressed or uncompressed. // Returns the size in bytes of the contents of the layer. func UnpackLayer(dest string, layer Reader, options *TarOptions) (size int64, err error) { tr := tar.NewReader(layer) trBuf := pools.BufioReader32KPool.Get(tr) defer pools.BufioReader32KPool.Put(trBuf) var dirs []*tar.Header if options == nil { options = &TarOptions{} } if options.ExcludePatterns == nil { options.ExcludePatterns = []string{} } remappedRootUID, remappedRootGID, err := idtools.GetRootUIDGID(options.UIDMaps, options.GIDMaps) if err != nil { return 0, err } aufsTempdir := "" aufsHardlinks := make(map[string]*tar.Header) if options == nil { options = &TarOptions{} } // Iterate through the files in the archive. for { hdr, err := tr.Next() if err == io.EOF { // end of tar archive break } if err != nil { return 0, err } size += hdr.Size // Normalize name, for safety and for a simple is-root check hdr.Name = filepath.Clean(hdr.Name) // Windows does not support filenames with colons in them. Ignore // these files. This is not a problem though (although it might // appear that it is). Let's suppose a client is running docker pull. // The daemon it points to is Windows. Would it make sense for the // client to be doing a docker pull Ubuntu for example (which has files // with colons in the name under /usr/share/man/man3)? No, absolutely // not as it would really only make sense that they were pulling a // Windows image. However, for development, it is necessary to be able // to pull Linux images which are in the repository. // // TODO Windows. Once the registry is aware of what images are Windows- // specific or Linux-specific, this warning should be changed to an error // to cater for the situation where someone does manage to upload a Linux // image but have it tagged as Windows inadvertently. if runtime.GOOS == "windows" { if strings.Contains(hdr.Name, ":") { logrus.Warnf("Windows: Ignoring %s (is this a Linux image?)", hdr.Name) continue } } // Note as these operations are platform specific, so must the slash be. if !strings.HasSuffix(hdr.Name, string(os.PathSeparator)) { // Not the root directory, ensure that the parent directory exists. // This happened in some tests where an image had a tarfile without any // parent directories. parent := filepath.Dir(hdr.Name) parentPath := filepath.Join(dest, parent) if _, err := os.Lstat(parentPath); err != nil && os.IsNotExist(err) { err = system.MkdirAll(parentPath, 0600) if err != nil { return 0, err } } } // Skip AUFS metadata dirs if strings.HasPrefix(hdr.Name, WhiteoutMetaPrefix) { // Regular files inside /.wh..wh.plnk can be used as hardlink targets // We don't want this directory, but we need the files in them so that // such hardlinks can be resolved. if strings.HasPrefix(hdr.Name, WhiteoutLinkDir) && hdr.Typeflag == tar.TypeReg { basename := filepath.Base(hdr.Name) aufsHardlinks[basename] = hdr if aufsTempdir == "" { if aufsTempdir, err = ioutil.TempDir("", "dockerplnk"); err != nil { return 0, err } defer os.RemoveAll(aufsTempdir) } if err := createTarFile(filepath.Join(aufsTempdir, basename), dest, hdr, tr, true, nil); err != nil { return 0, err } } if hdr.Name != WhiteoutOpaqueDir { continue } } path := filepath.Join(dest, hdr.Name) rel, err := filepath.Rel(dest, path) if err != nil { return 0, err } // Note as these operations are platform specific, so must the slash be. if strings.HasPrefix(rel, ".."+string(os.PathSeparator)) { return 0, breakoutError(fmt.Errorf("%q is outside of %q", hdr.Name, dest)) } base := filepath.Base(path) if strings.HasPrefix(base, WhiteoutPrefix) { dir := filepath.Dir(path) if base == WhiteoutOpaqueDir { fi, err := os.Lstat(dir) if err != nil && !os.IsNotExist(err) { return 0, err } if err := os.RemoveAll(dir); err != nil { return 0, err } if err := os.Mkdir(dir, fi.Mode()&os.ModePerm); err != nil { return 0, err } } else { originalBase := base[len(WhiteoutPrefix):] originalPath := filepath.Join(dir, originalBase) if err := os.RemoveAll(originalPath); err != nil { return 0, err } } } else { // If path exits we almost always just want to remove and replace it. // The only exception is when it is a directory *and* the file from // the layer is also a directory. Then we want to merge them (i.e. // just apply the metadata from the layer). if fi, err := os.Lstat(path); err == nil { if !(fi.IsDir() && hdr.Typeflag == tar.TypeDir) { if err := os.RemoveAll(path); err != nil { return 0, err } } } trBuf.Reset(tr) srcData := io.Reader(trBuf) srcHdr := hdr // Hard links into /.wh..wh.plnk don't work, as we don't extract that directory, so // we manually retarget these into the temporary files we extracted them into if hdr.Typeflag == tar.TypeLink && strings.HasPrefix(filepath.Clean(hdr.Linkname), WhiteoutLinkDir) { linkBasename := filepath.Base(hdr.Linkname) srcHdr = aufsHardlinks[linkBasename] if srcHdr == nil { return 0, fmt.Errorf("Invalid aufs hardlink") } tmpFile, err := os.Open(filepath.Join(aufsTempdir, linkBasename)) if err != nil { return 0, err } defer tmpFile.Close() srcData = tmpFile } // if the options contain a uid & gid maps, convert header uid/gid // entries using the maps such that lchown sets the proper mapped // uid/gid after writing the file. We only perform this mapping if // the file isn't already owned by the remapped root UID or GID, as // that specific uid/gid has no mapping from container -> host, and // those files already have the proper ownership for inside the // container. if srcHdr.Uid != remappedRootUID { xUID, err := idtools.ToHost(srcHdr.Uid, options.UIDMaps) if err != nil { return 0, err } srcHdr.Uid = xUID } if srcHdr.Gid != remappedRootGID { xGID, err := idtools.ToHost(srcHdr.Gid, options.GIDMaps) if err != nil { return 0, err } srcHdr.Gid = xGID } if err := createTarFile(path, dest, srcHdr, srcData, true, nil); err != nil { return 0, err } // Directory mtimes must be handled at the end to avoid further // file creation in them to modify the directory mtime if hdr.Typeflag == tar.TypeDir { dirs = append(dirs, hdr) } } } for _, hdr := range dirs { path := filepath.Join(dest, hdr.Name) if err := system.Chtimes(path, hdr.AccessTime, hdr.ModTime); err != nil { return 0, err } } return size, nil }