// 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.
func Untar(tarArchive io.Reader, dest string, options *archive.TarOptions) error {
if tarArchive == nil {
return fmt.Errorf("Empty archive")
}
if options == nil {
options = &archive.TarOptions{}
}
if options.ExcludePatterns == nil {
options.ExcludePatterns = []string{}
}
dest = filepath.Clean(dest)
if _, err := os.Stat(dest); os.IsNotExist(err) {
if err := system.MkdirAll(dest, 0777); err != nil {
glog.Error(err.Error())
return err
}
}
decompressedArchive, err := archive.DecompressStream(tarArchive)
if err != nil {
glog.Error(err.Error())
return err
}
defer decompressedArchive.Close()
return invokeUnpack(decompressedArchive, dest, options)
}
func (b *Builder) readContext(context io.Reader) error {
tmpdirPath, err := ioutil.TempDir("", "docker-build")
if err != nil {
glog.Error(err.Error())
return err
}
decompressedStream, err := archive.DecompressStream(context)
if err != nil {
glog.Error(err.Error())
return err
}
if b.context, err = tarsum.NewTarSum(decompressedStream, true, tarsum.Version0); err != nil {
glog.Error(err.Error())
return err
}
if err := chrootarchive.Untar(b.context, tmpdirPath, nil); err != nil {
glog.Error(err.Error())
return err
}
b.contextPath = tmpdirPath
return nil
}
func ApplyLayer(dest string, layer archive.ArchiveReader) (size int64, err error) {
dest = filepath.Clean(dest)
decompressed, err := archive.DecompressStream(layer)
if err != nil {
return 0, err
}
defer decompressed.Close()
cmd := reexec.Command("docker-applyLayer", dest)
cmd.Stdin = decompressed
outBuf, errBuf := new(bytes.Buffer), new(bytes.Buffer)
cmd.Stdout, cmd.Stderr = outBuf, errBuf
if err = cmd.Run(); err != nil {
return 0, fmt.Errorf("ApplyLayer %s stdout: %s stderr: %s", err, outBuf, errBuf)
}
fmt.Printf("\n\nApplyLayer stdout: %s stderr: %s\n\n", outBuf, errBuf)
// Stdout should be a valid JSON struct representing an applyLayerResponse.
response := applyLayerResponse{}
decoder := json.NewDecoder(outBuf)
if err = decoder.Decode(&response); err != nil {
return 0, fmt.Errorf("unable to decode ApplyLayer JSON response: %s", err)
}
return response.LayerSize, nil
}