// Some tar have both GNU specific (huge uid) and Ustar specific (long name) things.
// Not supposed to happen (should use PAX instead of Ustar for long name) but it does and it should still work.
func TestUntarUstarGnuConflict(t *testing.T) {
f, err := os.Open("testdata/broken.tar")
if err != nil {
t.Fatal(err)
}
found := false
tr := tar.NewReader(f)
// Iterate through the files in the archive.
for {
hdr, err := tr.Next()
if err == io.EOF {
// end of tar archive
break
}
if err != nil {
t.Fatal(err)
}
if hdr.Name == "root/.cpanm/work/1395823785.24209/Plack-1.0030/blib/man3/Plack::Middleware::LighttpdScriptNameFix.3pm" {
found = true
break
}
}
if !found {
t.Fatalf("%s not found in the archive", "root/.cpanm/work/1395823785.24209/Plack-1.0030/blib/man3/Plack::Middleware::LighttpdScriptNameFix.3pm")
}
}
func IsArchive(header []byte) bool {
compression := DetectCompression(header)
if compression != Uncompressed {
return true
}
r := tar.NewReader(bytes.NewBuffer(header))
_, err := r.Next()
return err == nil
}
// ApplyLayer parses a diff in the standard layer format from `layer`, and
// applies it to the directory `dest`.
func ApplyLayer(dest string, layer ArchiveReader) error {
// We need to be able to set any perms
oldmask := syscall.Umask(0)
defer syscall.Umask(oldmask)
layer, err := DecompressStream(layer)
if err != nil {
return err
}
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 err
}
// Normalize name, for safety and for a simple is-root check
hdr.Name = filepath.Clean(hdr.Name)
if !strings.HasSuffix(hdr.Name, "/") {
// 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 = os.MkdirAll(parentPath, 0600)
if err != nil {
return 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 err
}
defer os.RemoveAll(aufsTempdir)
}
if err := createTarFile(filepath.Join(aufsTempdir, basename), dest, hdr, tr, true); err != nil {
return err
}
}
continue
}
path := filepath.Join(dest, hdr.Name)
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 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 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 fmt.Errorf("Invalid aufs hardlink")
}
tmpFile, err := os.Open(filepath.Join(aufsTempdir, linkBasename))
if err != nil {
return err
}
defer tmpFile.Close()
srcData = tmpFile
}
if err := createTarFile(path, dest, srcHdr, srcData, true); 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)
ts := []syscall.Timespec{timeToTimespec(hdr.AccessTime), timeToTimespec(hdr.ModTime)}
if err := syscall.UtimesNano(path, ts); err != nil {
return err
}
}
return nil
}
// Untar reads a stream of bytes from `archive`, parses it as a tar archive,
// and unpacks it into the directory at `dest`.
// The archive may be compressed with one of the following algorithms:
// identity (uncompressed), gzip, bzip2, xz.
// FIXME: specify behavior when target path exists vs. doesn't exist.
func Untar(archive io.Reader, dest string, options *TarOptions) error {
if options == nil {
options = &TarOptions{}
}
if archive == nil {
return fmt.Errorf("Empty archive")
}
if options.Excludes == nil {
options.Excludes = []string{}
}
decompressedArchive, err := DecompressStream(archive)
if err != nil {
return err
}
defer decompressedArchive.Close()
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
hdr.Name = filepath.Clean(hdr.Name)
for _, exclude := range options.Excludes {
if strings.HasPrefix(hdr.Name, exclude) {
continue loop
}
}
if !strings.HasSuffix(hdr.Name, "/") {
// 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 = os.MkdirAll(parentPath, 0777)
if err != nil {
return err
}
}
}
path := filepath.Join(dest, hdr.Name)
// 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.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); 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)
ts := []syscall.Timespec{timeToTimespec(hdr.AccessTime), timeToTimespec(hdr.ModTime)}
if err := syscall.UtimesNano(path, ts); err != nil {
return err
}
}
return nil
}