diff options
Diffstat (limited to 'vendor/github.com/fsouza/go-dockerclient/internal/archive/archive_linux.go')
-rw-r--r-- | vendor/github.com/fsouza/go-dockerclient/internal/archive/archive_linux.go | 104 |
1 files changed, 104 insertions, 0 deletions
diff --git a/vendor/github.com/fsouza/go-dockerclient/internal/archive/archive_linux.go b/vendor/github.com/fsouza/go-dockerclient/internal/archive/archive_linux.go new file mode 100644 index 000000000..9e1f3f2f1 --- /dev/null +++ b/vendor/github.com/fsouza/go-dockerclient/internal/archive/archive_linux.go @@ -0,0 +1,104 @@ +// Copyright 2014 Docker authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the DOCKER-LICENSE file. + +package archive + +import ( + "archive/tar" + "os" + "path/filepath" + "strings" + + "github.com/docker/docker/pkg/system" + "golang.org/x/sys/unix" +) + +const ( + // AUFSWhiteoutFormat is the default format for whiteouts + AUFSWhiteoutFormat WhiteoutFormat = iota + // OverlayWhiteoutFormat formats whiteout according to the overlay + // standard. + OverlayWhiteoutFormat +) + +func getWhiteoutConverter(format WhiteoutFormat) tarWhiteoutConverter { + if format == OverlayWhiteoutFormat { + return overlayWhiteoutConverter{} + } + return nil +} + +type overlayWhiteoutConverter struct{} + +func (overlayWhiteoutConverter) ConvertWrite(hdr *tar.Header, path string, fi os.FileInfo) (wo *tar.Header, err error) { + // convert whiteouts to AUFS format + if fi.Mode()&os.ModeCharDevice != 0 && hdr.Devmajor == 0 && hdr.Devminor == 0 { + // we just rename the file and make it normal + dir, filename := filepath.Split(hdr.Name) + hdr.Name = filepath.Join(dir, WhiteoutPrefix+filename) + hdr.Mode = 0600 + hdr.Typeflag = tar.TypeReg + hdr.Size = 0 + } + + if fi.Mode()&os.ModeDir != 0 { + // convert opaque dirs to AUFS format by writing an empty file with the prefix + opaque, err := system.Lgetxattr(path, "trusted.overlay.opaque") + if err != nil { + return nil, err + } + if len(opaque) == 1 && opaque[0] == 'y' { + if hdr.Xattrs != nil { + delete(hdr.Xattrs, "trusted.overlay.opaque") + } + + // create a header for the whiteout file + // it should inherit some properties from the parent, but be a regular file + wo = &tar.Header{ + Typeflag: tar.TypeReg, + Mode: hdr.Mode & int64(os.ModePerm), + Name: filepath.Join(hdr.Name, WhiteoutOpaqueDir), + Size: 0, + Uid: hdr.Uid, + Uname: hdr.Uname, + Gid: hdr.Gid, + Gname: hdr.Gname, + AccessTime: hdr.AccessTime, + ChangeTime: hdr.ChangeTime, + } + } + } + + return +} + +func (overlayWhiteoutConverter) ConvertRead(hdr *tar.Header, path string) (bool, error) { + base := filepath.Base(path) + dir := filepath.Dir(path) + + // if a directory is marked as opaque by the AUFS special file, we need to translate that to overlay + if base == WhiteoutOpaqueDir { + err := unix.Setxattr(dir, "trusted.overlay.opaque", []byte{'y'}, 0) + // don't write the file itself + return false, err + } + + // if a file was deleted and we are using overlay, we need to create a character device + if strings.HasPrefix(base, WhiteoutPrefix) { + originalBase := base[len(WhiteoutPrefix):] + originalPath := filepath.Join(dir, originalBase) + + if err := unix.Mknod(originalPath, unix.S_IFCHR, 0); err != nil { + return false, err + } + if err := os.Chown(originalPath, hdr.Uid, hdr.Gid); err != nil { + return false, err + } + + // don't write the file itself + return false, nil + } + + return true, nil +} |