Example #1
0
// ExportChanges produces an Archive from the provided changes, relative to dir.
func ExportChanges(dir string, changes []Change) (Archive, error) {
	reader, writer := io.Pipe()
	go func() {
		ta := &tarAppender{
			TarWriter: tar.NewWriter(writer),
			Buffer:    pools.BufioWriter32KPool.Get(nil),
			SeenFiles: make(map[uint64]string),
		}
		// this buffer is needed for the duration of this piped stream
		defer pools.BufioWriter32KPool.Put(ta.Buffer)

		sort.Sort(changesByPath(changes))

		// In general we log errors here but ignore them because
		// during e.g. a diff operation the container can continue
		// mutating the filesystem and we can see transient errors
		// from this
		for _, change := range changes {
			if change.Kind == ChangeDelete {
				whiteOutDir := filepath.Dir(change.Path)
				whiteOutBase := filepath.Base(change.Path)
				whiteOut := filepath.Join(whiteOutDir, ".wh."+whiteOutBase)
				timestamp := time.Now()
				hdr := &tar.Header{
					Name:       whiteOut[1:],
					Size:       0,
					ModTime:    timestamp,
					AccessTime: timestamp,
					ChangeTime: timestamp,
				}
				if err := ta.TarWriter.WriteHeader(hdr); err != nil {
					logrus.Debugf("Can't write whiteout header: %s", err)
				}
			} else {
				path := filepath.Join(dir, change.Path)
				if err := ta.addTarFile(path, change.Path[1:]); err != nil {
					logrus.Debugf("Can't add file %s to tar: %s", path, err)
				}
			}
		}

		// Make sure to check the error on Close.
		if err := ta.TarWriter.Close(); err != nil {
			logrus.Debugf("Can't close layer: %s", err)
		}
		if err := writer.Close(); err != nil {
			logrus.Debugf("failed close Changes writer: %s", err)
		}
	}()
	return reader, nil
}
Example #2
0
func (archiver *Archiver) CopyWithTar(src, dst string) error {
	srcSt, err := os.Stat(src)
	if err != nil {
		return err
	}
	if !srcSt.IsDir() {
		return archiver.CopyFileWithTar(src, dst)
	}
	// Create dst, copy src's content into it
	logrus.Debugf("Creating dest directory: %s", dst)
	if err := system.MkdirAll(dst, 0755); err != nil && !os.IsExist(err) {
		return err
	}
	logrus.Debugf("Calling TarUntar(%s, %s)", src, dst)
	return archiver.TarUntar(src, dst)
}
Example #3
0
func (archiver *Archiver) TarUntar(src, dst string) error {
	logrus.Debugf("TarUntar(%s %s)", src, dst)
	archive, err := TarWithOptions(src, &TarOptions{Compression: Uncompressed})
	if err != nil {
		return err
	}
	defer archive.Close()
	return archiver.Untar(archive, dst, nil)
}
Example #4
0
func (archiver *Archiver) CopyFileWithTar(src, dst string) (err error) {
	logrus.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 slash
	if dst[len(dst)-1] == os.PathSeparator {
		dst = filepath.Join(dst, filepath.Base(src))
	}
	// Create the holding directory if necessary
	if err := system.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)
		hdr.Mode = int64(chmodTarEntry(os.FileMode(hdr.Mode)))

		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 archiver.Untar(r, filepath.Dir(dst), nil)
}
Example #5
0
func DetectCompression(source []byte) Compression {
	for compression, m := range map[Compression][]byte{
		Bzip2: {0x42, 0x5A, 0x68},
		Gzip:  {0x1F, 0x8B, 0x08},
		Xz:    {0xFD, 0x37, 0x7A, 0x58, 0x5A, 0x00},
	} {
		if len(source) < len(m) {
			logrus.Debugf("Len too short")
			continue
		}
		if bytes.Compare(m, source[:len(m)]) == 0 {
			return compression
		}
	}
	return Uncompressed
}
Example #6
0
// OptimizedMatches is basically the same as fileutils.Matches() but optimized for archive.go.
// It will assume that the inputs have been preprocessed and therefore the function
// doen't need to do as much error checking and clean-up. This was done to avoid
// repeating these steps on each file being checked during the archive process.
// The more generic fileutils.Matches() can't make these assumptions.
func OptimizedMatches(file string, patterns []string, patDirs [][]string) (bool, error) {
	matched := false
	parentPath := filepath.Dir(file)
	parentPathDirs := strings.Split(parentPath, "/")

	for i, pattern := range patterns {
		negative := false

		if Exclusion(pattern) {
			negative = true
			pattern = pattern[1:]
		}

		match, err := filepath.Match(pattern, file)
		if err != nil {
			return false, err
		}

		if !match && parentPath != "." {
			// Check to see if the pattern matches one of our parent dirs.
			if len(patDirs[i]) <= len(parentPathDirs) {
				match, _ = filepath.Match(strings.Join(patDirs[i], "/"),
					strings.Join(parentPathDirs[:len(patDirs[i])], "/"))
			}
		}

		if match {
			matched = !negative
		}
	}

	if matched {
		logrus.Debugf("Skipping excluded path: %s", file)
	}

	return matched, nil
}
Example #7
0
// TarWithOptions creates an archive from the directory at `path`, only including files whose relative
// paths are included in `options.IncludeFiles` (if non-nil) or not in `options.ExcludePatterns`.
func TarWithOptions(srcPath string, options *TarOptions) (io.ReadCloser, error) {

	patterns, patDirs, exceptions, err := fileutils.CleanPatterns(options.ExcludePatterns)

	if err != nil {
		return nil, err
	}

	pipeReader, pipeWriter := io.Pipe()

	compressWriter, err := CompressStream(pipeWriter, options.Compression)
	if err != nil {
		return nil, err
	}

	go func() {
		ta := &tarAppender{
			TarWriter: tar.NewWriter(compressWriter),
			Buffer:    pools.BufioWriter32KPool.Get(nil),
			SeenFiles: make(map[uint64]string),
		}
		// this buffer is needed for the duration of this piped stream
		defer pools.BufioWriter32KPool.Put(ta.Buffer)

		// In general we log errors here but ignore them because
		// during e.g. a diff operation the container can continue
		// mutating the filesystem and we can see transient errors
		// from this

		if options.IncludeFiles == nil {
			options.IncludeFiles = []string{"."}
		}

		seen := make(map[string]bool)

		var renamedRelFilePath string // For when tar.Options.Name is set
		for _, include := range options.IncludeFiles {
			filepath.Walk(filepath.Join(srcPath, include), func(filePath string, f os.FileInfo, err error) error {
				if err != nil {
					logrus.Debugf("Tar: Can't stat file %s to tar: %s", srcPath, err)
					return nil
				}

				relFilePath, err := filepath.Rel(srcPath, filePath)
				if err != nil || (relFilePath == "." && f.IsDir()) {
					// Error getting relative path OR we are looking
					// at the root path. Skip in both situations.
					return nil
				}

				skip := false

				// If "include" is an exact match for the current file
				// then even if there's an "excludePatterns" pattern that
				// matches it, don't skip it. IOW, assume an explicit 'include'
				// is asking for that file no matter what - which is true
				// for some files, like .dockerignore and Dockerfile (sometimes)
				if include != relFilePath {
					skip, err = fileutils.OptimizedMatches(relFilePath, patterns, patDirs)
					if err != nil {
						logrus.Debugf("Error matching %s", relFilePath, err)
						return err
					}
				}

				if skip {
					if !exceptions && f.IsDir() {
						return filepath.SkipDir
					}
					return nil
				}

				if seen[relFilePath] {
					return nil
				}
				seen[relFilePath] = true

				// Rename the base resource
				if options.Name != "" && filePath == srcPath+"/"+filepath.Base(relFilePath) {
					renamedRelFilePath = relFilePath
				}
				// Set this to make sure the items underneath also get renamed
				if options.Name != "" {
					relFilePath = strings.Replace(relFilePath, renamedRelFilePath, options.Name, 1)
				}

				if err := ta.addTarFile(filePath, relFilePath); err != nil {
					logrus.Debugf("Can't add file %s to tar: %s", filePath, err)
				}
				return nil
			})
		}

		// Make sure to check the error on Close.
		if err := ta.TarWriter.Close(); err != nil {
			logrus.Debugf("Can't close tar writer: %s", err)
		}
		if err := compressWriter.Close(); err != nil {
			logrus.Debugf("Can't close compress writer: %s", err)
		}
		if err := pipeWriter.Close(); err != nil {
			logrus.Debugf("Can't close pipe writer: %s", err)
		}
	}()

	return pipeReader, nil
}
Example #8
0
func createTarFile(path, extractDir string, hdr *tar.Header, reader io.Reader, Lchown bool) error {
	// hdr.Mode is in linux format, which we can use for sycalls,
	// but for os.Foo() calls we need the mode converted to os.FileMode,
	// so use hdrInfo.Mode() (they differ for e.g. setuid bits)
	hdrInfo := hdr.FileInfo()

	switch hdr.Typeflag {
	case tar.TypeDir:
		// Create directory unless it exists as a directory already.
		// In that case we just want to merge the two
		if fi, err := os.Lstat(path); !(err == nil && fi.IsDir()) {
			if err := os.Mkdir(path, hdrInfo.Mode()); err != nil {
				return err
			}
		}

	case tar.TypeReg, tar.TypeRegA:
		// Source is regular file
		file, err := os.OpenFile(path, os.O_CREATE|os.O_WRONLY, hdrInfo.Mode())
		if err != nil {
			return err
		}
		if _, err := io.Copy(file, reader); err != nil {
			file.Close()
			return err
		}
		file.Close()

	case tar.TypeBlock, tar.TypeChar, tar.TypeFifo:
		// Handle this is an OS-specific way
		if err := handleTarTypeBlockCharFifo(hdr, path); err != nil {
			return err
		}

	case tar.TypeLink:
		targetPath := filepath.Join(extractDir, hdr.Linkname)
		// check for hardlink breakout
		if !strings.HasPrefix(targetPath, extractDir) {
			return breakoutError(fmt.Errorf("invalid hardlink %q -> %q", targetPath, hdr.Linkname))
		}
		if err := os.Link(targetPath, path); err != nil {
			return err
		}

	case tar.TypeSymlink:
		// 	path 				-> hdr.Linkname = targetPath
		// e.g. /extractDir/path/to/symlink 	-> ../2/file	= /extractDir/path/2/file
		targetPath := filepath.Join(filepath.Dir(path), hdr.Linkname)

		// the reason we don't need to check symlinks in the path (with FollowSymlinkInScope) is because
		// that symlink would first have to be created, which would be caught earlier, at this very check:
		if !strings.HasPrefix(targetPath, extractDir) {
			return breakoutError(fmt.Errorf("invalid symlink %q -> %q", path, hdr.Linkname))
		}
		if err := os.Symlink(hdr.Linkname, path); err != nil {
			return err
		}

	case tar.TypeXGlobalHeader:
		logrus.Debugf("PAX Global Extended Headers found and ignored")
		return nil

	default:
		return fmt.Errorf("Unhandled tar header type %d\n", hdr.Typeflag)
	}

	// Lchown is not supported on Windows
	if runtime.GOOS != "windows" {
		if err := os.Lchown(path, hdr.Uid, hdr.Gid); err != nil && Lchown {
			return err
		}
	}

	for key, value := range hdr.Xattrs {
		if err := system.Lsetxattr(path, key, []byte(value), 0); err != nil {
			return err
		}
	}

	// There is no LChmod, so ignore mode for symlink. Also, this
	// must happen after chown, as that can modify the file mode
	if err := handleLChmod(hdr, path, hdrInfo); err != nil {
		return err
	}

	ts := []syscall.Timespec{timeToTimespec(hdr.AccessTime), timeToTimespec(hdr.ModTime)}
	// syscall.UtimesNano doesn't support a NOFOLLOW flag atm
	if hdr.Typeflag == tar.TypeLink {
		if fi, err := os.Lstat(hdr.Linkname); err == nil && (fi.Mode()&os.ModeSymlink == 0) {
			if err := system.UtimesNano(path, ts); err != nil && err != system.ErrNotSupportedPlatform {
				return err
			}
		}
	} else if hdr.Typeflag != tar.TypeSymlink {
		if err := system.UtimesNano(path, ts); err != nil && err != system.ErrNotSupportedPlatform {
			return err
		}
	} else {
		if err := system.LUtimesNano(path, ts); err != nil && err != system.ErrNotSupportedPlatform {
			return err
		}
	}
	return nil
}
Example #9
0
// StdCopy is a modified version of io.Copy.
//
// StdCopy will demultiplex `src`, assuming that it contains two streams,
// previously multiplexed together using a StdWriter instance.
// As it reads from `src`, StdCopy will write to `dstout` and `dsterr`.
//
// StdCopy will read until it hits EOF on `src`. It will then return a nil error.
// In other words: if `err` is non nil, it indicates a real underlying error.
//
// `written` will hold the total number of bytes written to `dstout` and `dsterr`.
func StdCopy(dstout, dsterr io.Writer, src io.Reader) (written int64, err error) {
	var (
		buf       = make([]byte, 32*1024+StdWriterPrefixLen+1)
		bufLen    = len(buf)
		nr, nw    int
		er, ew    error
		out       io.Writer
		frameSize int
	)

	for {
		// Make sure we have at least a full header
		for nr < StdWriterPrefixLen {
			var nr2 int
			nr2, er = src.Read(buf[nr:])
			nr += nr2
			if er == io.EOF {
				if nr < StdWriterPrefixLen {
					logrus.Debugf("Corrupted prefix: %v", buf[:nr])
					return written, nil
				}
				break
			}
			if er != nil {
				logrus.Debugf("Error reading header: %s", er)
				return 0, er
			}
		}

		// Check the first byte to know where to write
		switch buf[StdWriterFdIndex] {
		case 0:
			fallthrough
		case 1:
			// Write on stdout
			out = dstout
		case 2:
			// Write on stderr
			out = dsterr
		default:
			logrus.Debugf("Error selecting output fd: (%d)", buf[StdWriterFdIndex])
			return 0, ErrInvalidStdHeader
		}

		// Retrieve the size of the frame
		frameSize = int(binary.BigEndian.Uint32(buf[StdWriterSizeIndex : StdWriterSizeIndex+4]))
		logrus.Debugf("framesize: %d", frameSize)

		// Check if the buffer is big enough to read the frame.
		// Extend it if necessary.
		if frameSize+StdWriterPrefixLen > bufLen {
			logrus.Debugf("Extending buffer cap by %d (was %d)", frameSize+StdWriterPrefixLen-bufLen+1, len(buf))
			buf = append(buf, make([]byte, frameSize+StdWriterPrefixLen-bufLen+1)...)
			bufLen = len(buf)
		}

		// While the amount of bytes read is less than the size of the frame + header, we keep reading
		for nr < frameSize+StdWriterPrefixLen {
			var nr2 int
			nr2, er = src.Read(buf[nr:])
			nr += nr2
			if er == io.EOF {
				if nr < frameSize+StdWriterPrefixLen {
					logrus.Debugf("Corrupted frame: %v", buf[StdWriterPrefixLen:nr])
					return written, nil
				}
				break
			}
			if er != nil {
				logrus.Debugf("Error reading frame: %s", er)
				return 0, er
			}
		}

		// Write the retrieved frame (without header)
		nw, ew = out.Write(buf[StdWriterPrefixLen : frameSize+StdWriterPrefixLen])
		if ew != nil {
			logrus.Debugf("Error writing frame: %s", ew)
			return 0, ew
		}
		// If the frame has not been fully written: error
		if nw != frameSize {
			logrus.Debugf("Error Short Write: (%d on %d)", nw, frameSize)
			return 0, io.ErrShortWrite
		}
		written += int64(nw)

		// Move the rest of the buffer to the beginning
		copy(buf, buf[frameSize+StdWriterPrefixLen:])
		// Move the index
		nr -= frameSize + StdWriterPrefixLen
	}
}