func applyLayer() {
runtime.LockOSThread()
flag.Parse()
if err := chroot(flag.Arg(0)); err != nil {
fatal(err)
}
// We need to be able to set any perms
oldmask := syscall.Umask(0)
defer syscall.Umask(oldmask)
tmpDir, err := ioutil.TempDir("/", "temp-docker-extract")
if err != nil {
fatal(err)
}
os.Setenv("TMPDIR", tmpDir)
size, err := archive.UnpackLayer("/", os.Stdin)
os.RemoveAll(tmpDir)
if err != nil {
fatal(err)
}
encoder := json.NewEncoder(os.Stdout)
if err := encoder.Encode(applyLayerResponse{size}); err != nil {
fatal(fmt.Errorf("unable to encode layerSize JSON: %s", err))
}
flush(os.Stdout)
flush(os.Stdin)
os.Exit(0)
}
// applyLayerHandler parses a diff in the standard layer format from `layer`, and
// applies it to the directory `dest`. Returns the size in bytes of the
// contents of the layer.
func applyLayerHandler(dest string, layer archive.Reader, options *archive.TarOptions, decompress bool) (size int64, err error) {
dest = filepath.Clean(dest)
// Ensure it is a Windows-style volume path
dest = longpath.AddPrefix(dest)
if decompress {
decompressed, err := archive.DecompressStream(layer)
if err != nil {
return 0, err
}
defer decompressed.Close()
layer = decompressed
}
tmpDir, err := ioutil.TempDir(os.Getenv("temp"), "temp-docker-extract")
if err != nil {
return 0, fmt.Errorf("ApplyLayer failed to create temp-docker-extract under %s. %s", dest, err)
}
s, err := archive.UnpackLayer(dest, layer, nil)
os.RemoveAll(tmpDir)
if err != nil {
return 0, fmt.Errorf("ApplyLayer %s failed UnpackLayer to %s", err, dest)
}
return s, nil
}
// applyLayer is the entry-point for docker-applylayer on re-exec. This is not
// used on Windows as it does not support chroot, hence no point sandboxing
// through chroot and rexec.
func applyLayer() {
var (
tmpDir = ""
err error
options *archive.TarOptions
)
runtime.LockOSThread()
flag.Parse()
if err := chroot(flag.Arg(0)); err != nil {
fatal(err)
}
// We need to be able to set any perms
oldmask, err := system.Umask(0)
defer system.Umask(oldmask)
if err != nil {
fatal(err)
}
if err := json.Unmarshal([]byte(os.Getenv("OPT")), &options); err != nil {
fatal(err)
}
if tmpDir, err = ioutil.TempDir("/", "temp-docker-extract"); err != nil {
fatal(err)
}
os.Setenv("TMPDIR", tmpDir)
size, err := archive.UnpackLayer("/", os.Stdin, options)
os.RemoveAll(tmpDir)
if err != nil {
fatal(err)
}
encoder := json.NewEncoder(os.Stdout)
if err := encoder.Encode(applyLayerResponse{size}); err != nil {
fatal(fmt.Errorf("unable to encode layerSize JSON: %s", err))
}
flush(os.Stdout)
flush(os.Stdin)
os.Exit(0)
}