// 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)))
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
}
}()
return archiver.Untar(r, filepath.Dir(dst), 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)
}
// 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
// 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 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) (size int64, err error) {
tr := tar.NewReader(layer)
trBuf := pools.BufioReader32KPool.Get(tr)
defer pools.BufioReader32KPool.Put(trBuf)
var dirs []*tar.Header
aufsTempdir := ""
aufsHardlinks := make(map[string]*tar.Header)
// 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, ".wh..wh.") {
// 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, ".wh..wh.plnk") && 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
}
}
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, ".wh.") {
originalBase := base[len(".wh."):]
originalPath := filepath.Join(filepath.Dir(path), 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), ".wh..wh.plnk") {
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 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
}