// 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
}
// 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
}