743 lines
18 KiB
Go
743 lines
18 KiB
Go
package archive
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import (
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"bufio"
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"bytes"
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"compress/bzip2"
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"compress/gzip"
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"errors"
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"fmt"
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"io"
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"io/ioutil"
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"os"
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"os/exec"
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"path"
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"path/filepath"
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"strings"
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"syscall"
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"github.com/docker/docker/vendor/src/code.google.com/p/go/src/pkg/archive/tar"
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log "github.com/Sirupsen/logrus"
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"github.com/docker/docker/pkg/fileutils"
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"github.com/docker/docker/pkg/pools"
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"github.com/docker/docker/pkg/promise"
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"github.com/docker/docker/pkg/system"
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)
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type (
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Archive io.ReadCloser
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ArchiveReader io.Reader
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Compression int
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TarOptions struct {
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Includes []string
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Excludes []string
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Compression Compression
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NoLchown bool
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Name string
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}
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)
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var (
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ErrNotImplemented = errors.New("Function not implemented")
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)
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const (
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Uncompressed Compression = iota
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Bzip2
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Gzip
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Xz
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)
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func IsArchive(header []byte) bool {
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compression := DetectCompression(header)
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if compression != Uncompressed {
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return true
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}
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r := tar.NewReader(bytes.NewBuffer(header))
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_, err := r.Next()
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return err == nil
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}
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func DetectCompression(source []byte) Compression {
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for compression, m := range map[Compression][]byte{
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Bzip2: {0x42, 0x5A, 0x68},
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Gzip: {0x1F, 0x8B, 0x08},
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Xz: {0xFD, 0x37, 0x7A, 0x58, 0x5A, 0x00},
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} {
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if len(source) < len(m) {
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log.Debugf("Len too short")
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continue
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}
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if bytes.Compare(m, source[:len(m)]) == 0 {
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return compression
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}
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}
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return Uncompressed
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}
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func xzDecompress(archive io.Reader) (io.ReadCloser, error) {
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args := []string{"xz", "-d", "-c", "-q"}
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return CmdStream(exec.Command(args[0], args[1:]...), archive)
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}
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func DecompressStream(archive io.Reader) (io.ReadCloser, error) {
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p := pools.BufioReader32KPool
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buf := p.Get(archive)
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bs, err := buf.Peek(10)
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if err != nil {
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return nil, err
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}
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log.Debugf("[tar autodetect] n: %v", bs)
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compression := DetectCompression(bs)
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switch compression {
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case Uncompressed:
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readBufWrapper := p.NewReadCloserWrapper(buf, buf)
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return readBufWrapper, nil
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case Gzip:
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gzReader, err := gzip.NewReader(buf)
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if err != nil {
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return nil, err
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}
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readBufWrapper := p.NewReadCloserWrapper(buf, gzReader)
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return readBufWrapper, nil
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case Bzip2:
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bz2Reader := bzip2.NewReader(buf)
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readBufWrapper := p.NewReadCloserWrapper(buf, bz2Reader)
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return readBufWrapper, nil
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case Xz:
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xzReader, err := xzDecompress(buf)
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if err != nil {
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return nil, err
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}
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readBufWrapper := p.NewReadCloserWrapper(buf, xzReader)
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return readBufWrapper, nil
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default:
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return nil, fmt.Errorf("Unsupported compression format %s", (&compression).Extension())
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}
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}
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func CompressStream(dest io.WriteCloser, compression Compression) (io.WriteCloser, error) {
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p := pools.BufioWriter32KPool
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buf := p.Get(dest)
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switch compression {
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case Uncompressed:
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writeBufWrapper := p.NewWriteCloserWrapper(buf, buf)
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return writeBufWrapper, nil
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case Gzip:
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gzWriter := gzip.NewWriter(dest)
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writeBufWrapper := p.NewWriteCloserWrapper(buf, gzWriter)
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return writeBufWrapper, nil
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case Bzip2, Xz:
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// archive/bzip2 does not support writing, and there is no xz support at all
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// However, this is not a problem as docker only currently generates gzipped tars
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return nil, fmt.Errorf("Unsupported compression format %s", (&compression).Extension())
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default:
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return nil, fmt.Errorf("Unsupported compression format %s", (&compression).Extension())
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}
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}
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func (compression *Compression) Extension() string {
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switch *compression {
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case Uncompressed:
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return "tar"
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case Bzip2:
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return "tar.bz2"
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case Gzip:
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return "tar.gz"
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case Xz:
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return "tar.xz"
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}
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return ""
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}
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type tarAppender struct {
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TarWriter *tar.Writer
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Buffer *bufio.Writer
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// for hardlink mapping
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SeenFiles map[uint64]string
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}
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func (ta *tarAppender) addTarFile(path, name string) error {
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fi, err := os.Lstat(path)
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if err != nil {
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return err
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}
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link := ""
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if fi.Mode()&os.ModeSymlink != 0 {
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if link, err = os.Readlink(path); err != nil {
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return err
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}
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}
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hdr, err := tar.FileInfoHeader(fi, link)
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if err != nil {
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return err
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}
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if fi.IsDir() && !strings.HasSuffix(name, "/") {
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name = name + "/"
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}
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hdr.Name = name
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stat, ok := fi.Sys().(*syscall.Stat_t)
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if ok {
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// Currently go does not fill in the major/minors
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if stat.Mode&syscall.S_IFBLK == syscall.S_IFBLK ||
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stat.Mode&syscall.S_IFCHR == syscall.S_IFCHR {
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hdr.Devmajor = int64(major(uint64(stat.Rdev)))
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hdr.Devminor = int64(minor(uint64(stat.Rdev)))
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}
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}
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// if it's a regular file and has more than 1 link,
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// it's hardlinked, so set the type flag accordingly
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if fi.Mode().IsRegular() && stat.Nlink > 1 {
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// a link should have a name that it links too
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// and that linked name should be first in the tar archive
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ino := uint64(stat.Ino)
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if oldpath, ok := ta.SeenFiles[ino]; ok {
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hdr.Typeflag = tar.TypeLink
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hdr.Linkname = oldpath
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hdr.Size = 0 // This Must be here for the writer math to add up!
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} else {
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ta.SeenFiles[ino] = name
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}
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}
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capability, _ := system.Lgetxattr(path, "security.capability")
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if capability != nil {
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hdr.Xattrs = make(map[string]string)
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hdr.Xattrs["security.capability"] = string(capability)
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}
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if err := ta.TarWriter.WriteHeader(hdr); err != nil {
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return err
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}
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if hdr.Typeflag == tar.TypeReg {
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file, err := os.Open(path)
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if err != nil {
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return err
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}
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ta.Buffer.Reset(ta.TarWriter)
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defer ta.Buffer.Reset(nil)
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_, err = io.Copy(ta.Buffer, file)
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file.Close()
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if err != nil {
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return err
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}
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err = ta.Buffer.Flush()
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if err != nil {
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return err
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}
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}
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return nil
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}
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func createTarFile(path, extractDir string, hdr *tar.Header, reader io.Reader, Lchown bool) error {
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// hdr.Mode is in linux format, which we can use for sycalls,
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// but for os.Foo() calls we need the mode converted to os.FileMode,
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// so use hdrInfo.Mode() (they differ for e.g. setuid bits)
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hdrInfo := hdr.FileInfo()
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switch hdr.Typeflag {
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case tar.TypeDir:
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// Create directory unless it exists as a directory already.
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// In that case we just want to merge the two
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if fi, err := os.Lstat(path); !(err == nil && fi.IsDir()) {
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if err := os.Mkdir(path, hdrInfo.Mode()); err != nil {
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return err
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}
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}
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case tar.TypeReg, tar.TypeRegA:
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// Source is regular file
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file, err := os.OpenFile(path, os.O_CREATE|os.O_WRONLY, hdrInfo.Mode())
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if err != nil {
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return err
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}
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if _, err := io.Copy(file, reader); err != nil {
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file.Close()
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return err
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}
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file.Close()
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case tar.TypeBlock, tar.TypeChar, tar.TypeFifo:
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mode := uint32(hdr.Mode & 07777)
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switch hdr.Typeflag {
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case tar.TypeBlock:
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mode |= syscall.S_IFBLK
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case tar.TypeChar:
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mode |= syscall.S_IFCHR
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case tar.TypeFifo:
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mode |= syscall.S_IFIFO
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}
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if err := syscall.Mknod(path, mode, int(mkdev(hdr.Devmajor, hdr.Devminor))); err != nil {
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return err
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}
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case tar.TypeLink:
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if err := os.Link(filepath.Join(extractDir, hdr.Linkname), path); err != nil {
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return err
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}
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case tar.TypeSymlink:
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if err := os.Symlink(hdr.Linkname, path); err != nil {
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return err
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}
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case tar.TypeXGlobalHeader:
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log.Debugf("PAX Global Extended Headers found and ignored")
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return nil
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default:
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return fmt.Errorf("Unhandled tar header type %d\n", hdr.Typeflag)
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}
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if err := os.Lchown(path, hdr.Uid, hdr.Gid); err != nil && Lchown {
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return err
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}
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for key, value := range hdr.Xattrs {
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if err := system.Lsetxattr(path, key, []byte(value), 0); err != nil {
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return err
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}
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}
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// There is no LChmod, so ignore mode for symlink. Also, this
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// must happen after chown, as that can modify the file mode
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if hdr.Typeflag != tar.TypeSymlink {
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if err := os.Chmod(path, hdrInfo.Mode()); err != nil {
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return err
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}
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}
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ts := []syscall.Timespec{timeToTimespec(hdr.AccessTime), timeToTimespec(hdr.ModTime)}
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// syscall.UtimesNano doesn't support a NOFOLLOW flag atm, and
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if hdr.Typeflag != tar.TypeSymlink {
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if err := system.UtimesNano(path, ts); err != nil && err != system.ErrNotSupportedPlatform {
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return err
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}
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} else {
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if err := system.LUtimesNano(path, ts); err != nil && err != system.ErrNotSupportedPlatform {
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return err
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}
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}
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return nil
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}
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// Tar creates an archive from the directory at `path`, and returns it as a
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// stream of bytes.
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func Tar(path string, compression Compression) (io.ReadCloser, error) {
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return TarWithOptions(path, &TarOptions{Compression: compression})
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}
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func escapeName(name string) string {
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escaped := make([]byte, 0)
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for i, c := range []byte(name) {
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if i == 0 && c == '/' {
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continue
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}
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// all printable chars except "-" which is 0x2d
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if (0x20 <= c && c <= 0x7E) && c != 0x2d {
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escaped = append(escaped, c)
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} else {
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escaped = append(escaped, fmt.Sprintf("\\%03o", c)...)
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}
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}
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return string(escaped)
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}
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// TarWithOptions creates an archive from the directory at `path`, only including files whose relative
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// paths are included in `options.Includes` (if non-nil) or not in `options.Excludes`.
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func TarWithOptions(srcPath string, options *TarOptions) (io.ReadCloser, error) {
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pipeReader, pipeWriter := io.Pipe()
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compressWriter, err := CompressStream(pipeWriter, options.Compression)
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if err != nil {
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return nil, err
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}
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go func() {
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ta := &tarAppender{
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TarWriter: tar.NewWriter(compressWriter),
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Buffer: pools.BufioWriter32KPool.Get(nil),
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SeenFiles: make(map[uint64]string),
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}
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// this buffer is needed for the duration of this piped stream
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defer pools.BufioWriter32KPool.Put(ta.Buffer)
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// In general we log errors here but ignore them because
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// during e.g. a diff operation the container can continue
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// mutating the filesystem and we can see transient errors
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// from this
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if options.Includes == nil {
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options.Includes = []string{"."}
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}
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var renamedRelFilePath string // For when tar.Options.Name is set
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for _, include := range options.Includes {
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filepath.Walk(filepath.Join(srcPath, include), func(filePath string, f os.FileInfo, err error) error {
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if err != nil {
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log.Debugf("Tar: Can't stat file %s to tar: %s", srcPath, err)
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return nil
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}
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relFilePath, err := filepath.Rel(srcPath, filePath)
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if err != nil {
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return nil
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}
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skip, err := fileutils.Matches(relFilePath, options.Excludes)
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if err != nil {
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log.Debugf("Error matching %s", relFilePath, err)
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return err
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}
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if skip {
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if f.IsDir() {
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return filepath.SkipDir
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}
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return nil
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}
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|
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// Rename the base resource
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if options.Name != "" && filePath == srcPath+"/"+filepath.Base(relFilePath) {
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renamedRelFilePath = relFilePath
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}
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// Set this to make sure the items underneath also get renamed
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if options.Name != "" {
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relFilePath = strings.Replace(relFilePath, renamedRelFilePath, options.Name, 1)
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}
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|
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if err := ta.addTarFile(filePath, relFilePath); err != nil {
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log.Debugf("Can't add file %s to tar: %s", srcPath, err)
|
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}
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return nil
|
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})
|
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}
|
|
|
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// Make sure to check the error on Close.
|
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if err := ta.TarWriter.Close(); err != nil {
|
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log.Debugf("Can't close tar writer: %s", err)
|
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}
|
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if err := compressWriter.Close(); err != nil {
|
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log.Debugf("Can't close compress writer: %s", err)
|
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}
|
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if err := pipeWriter.Close(); err != nil {
|
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log.Debugf("Can't close pipe writer: %s", err)
|
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}
|
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}()
|
|
|
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return pipeReader, nil
|
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}
|
|
|
|
// Untar reads a stream of bytes from `archive`, parses it as a tar archive,
|
|
// and unpacks it into the directory at `path`.
|
|
// 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
|
|
}
|
|
|
|
// TarUntar is a convenience function which calls Tar and Untar, with
|
|
// the output of one piped into the other. If either Tar or Untar fails,
|
|
// TarUntar aborts and returns the error.
|
|
func TarUntar(src string, dst string) error {
|
|
log.Debugf("TarUntar(%s %s)", src, dst)
|
|
archive, err := TarWithOptions(src, &TarOptions{Compression: Uncompressed})
|
|
if err != nil {
|
|
return err
|
|
}
|
|
defer archive.Close()
|
|
return Untar(archive, dst, nil)
|
|
}
|
|
|
|
// UntarPath is a convenience function which looks for an archive
|
|
// at filesystem path `src`, and unpacks it at `dst`.
|
|
func UntarPath(src, dst string) error {
|
|
archive, err := os.Open(src)
|
|
if err != nil {
|
|
return err
|
|
}
|
|
defer archive.Close()
|
|
if err := Untar(archive, dst, nil); err != nil {
|
|
return err
|
|
}
|
|
return 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 CopyWithTar(src, dst string) error {
|
|
srcSt, err := os.Stat(src)
|
|
if err != nil {
|
|
return err
|
|
}
|
|
if !srcSt.IsDir() {
|
|
return CopyFileWithTar(src, dst)
|
|
}
|
|
// Create dst, copy src's content into it
|
|
log.Debugf("Creating dest directory: %s", dst)
|
|
if err := os.MkdirAll(dst, 0755); err != nil && !os.IsExist(err) {
|
|
return err
|
|
}
|
|
log.Debugf("Calling TarUntar(%s, %s)", src, dst)
|
|
return TarUntar(src, dst)
|
|
}
|
|
|
|
// 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.
|
|
//
|
|
// If `dst` ends with a trailing slash '/', the final destination path
|
|
// will be `dst/base(src)`.
|
|
func CopyFileWithTar(src, dst string) (err error) {
|
|
log.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 /
|
|
if dst[len(dst)-1] == '/' {
|
|
dst = path.Join(dst, filepath.Base(src))
|
|
}
|
|
// Create the holding directory if necessary
|
|
if err := os.MkdirAll(filepath.Dir(dst), 0700); err != nil && !os.IsExist(err) {
|
|
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)
|
|
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 Untar(r, filepath.Dir(dst), nil)
|
|
}
|
|
|
|
// CmdStream executes a command, and returns its stdout as a stream.
|
|
// If the command fails to run or doesn't complete successfully, an error
|
|
// will be returned, including anything written on stderr.
|
|
func CmdStream(cmd *exec.Cmd, input io.Reader) (io.ReadCloser, error) {
|
|
if input != nil {
|
|
stdin, err := cmd.StdinPipe()
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
// Write stdin if any
|
|
go func() {
|
|
io.Copy(stdin, input)
|
|
stdin.Close()
|
|
}()
|
|
}
|
|
stdout, err := cmd.StdoutPipe()
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
stderr, err := cmd.StderrPipe()
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
pipeR, pipeW := io.Pipe()
|
|
errChan := make(chan []byte)
|
|
// Collect stderr, we will use it in case of an error
|
|
go func() {
|
|
errText, e := ioutil.ReadAll(stderr)
|
|
if e != nil {
|
|
errText = []byte("(...couldn't fetch stderr: " + e.Error() + ")")
|
|
}
|
|
errChan <- errText
|
|
}()
|
|
// Copy stdout to the returned pipe
|
|
go func() {
|
|
_, err := io.Copy(pipeW, stdout)
|
|
if err != nil {
|
|
pipeW.CloseWithError(err)
|
|
}
|
|
errText := <-errChan
|
|
if err := cmd.Wait(); err != nil {
|
|
pipeW.CloseWithError(fmt.Errorf("%s: %s", err, errText))
|
|
} else {
|
|
pipeW.Close()
|
|
}
|
|
}()
|
|
// Run the command and return the pipe
|
|
if err := cmd.Start(); err != nil {
|
|
return nil, err
|
|
}
|
|
return pipeR, nil
|
|
}
|
|
|
|
// NewTempArchive reads the content of src into a temporary file, and returns the contents
|
|
// of that file as an archive. The archive can only be read once - as soon as reading completes,
|
|
// the file will be deleted.
|
|
func NewTempArchive(src Archive, dir string) (*TempArchive, error) {
|
|
f, err := ioutil.TempFile(dir, "")
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
if _, err := io.Copy(f, src); err != nil {
|
|
return nil, err
|
|
}
|
|
if err = f.Sync(); err != nil {
|
|
return nil, err
|
|
}
|
|
if _, err := f.Seek(0, 0); err != nil {
|
|
return nil, err
|
|
}
|
|
st, err := f.Stat()
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
size := st.Size()
|
|
return &TempArchive{f, size}, nil
|
|
}
|
|
|
|
type TempArchive struct {
|
|
*os.File
|
|
Size int64 // Pre-computed from Stat().Size() as a convenience
|
|
}
|
|
|
|
func (archive *TempArchive) Read(data []byte) (int, error) {
|
|
n, err := archive.File.Read(data)
|
|
if err != nil {
|
|
os.Remove(archive.File.Name())
|
|
}
|
|
return n, err
|
|
}
|