// FIXME: this is duplicated from graph_test.go in the docker package.
func fakeTar() (io.ReadCloser, error) {
content := []byte("Hello world!\n")
buf := new(bytes.Buffer)
tw := tar.NewWriter(buf)
for _, name := range []string{"/etc/postgres/postgres.conf", "/etc/passwd", "/var/log/postgres/postgres.conf"} {
hdr := new(tar.Header)
hdr.Size = int64(len(content))
hdr.Name = name
if err := tw.WriteHeader(hdr); err != nil {
return nil, err
}
tw.Write([]byte(content))
}
tw.Close()
return ioutil.NopCloser(buf), nil
}
func setHeaderForSpecialDevice(hdr *tar.Header, ta *tarAppender, name string, stat interface{}) (nlink uint32, inode uint64, err error) {
s, ok := stat.(*syscall.Stat_t)
if !ok {
err = errors.New("cannot convert stat value to syscall.Stat_t")
return
}
nlink = uint32(s.Nlink)
inode = uint64(s.Ino)
// Currently go does not fil in the major/minors
if s.Mode&syscall.S_IFBLK == syscall.S_IFBLK ||
s.Mode&syscall.S_IFCHR == syscall.S_IFCHR {
hdr.Devmajor = int64(major(uint64(s.Rdev)))
hdr.Devminor = int64(minor(uint64(s.Rdev)))
}
return
}
func fakeTar() (io.Reader, error) {
uid := os.Getuid()
gid := os.Getgid()
content := []byte("Hello world!\n")
buf := new(bytes.Buffer)
tw := tar.NewWriter(buf)
for _, name := range []string{"/etc/postgres/postgres.conf", "/etc/passwd", "/var/log/postgres/postgres.conf"} {
hdr := new(tar.Header)
// Leaving these fields blank requires root privileges
hdr.Uid = uid
hdr.Gid = gid
hdr.Size = int64(len(content))
hdr.Name = name
if err := tw.WriteHeader(hdr); err != nil {
return nil, err
}
tw.Write([]byte(content))
}
tw.Close()
return buf, nil
}
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:
mode := uint32(hdr.Mode & 07777)
switch hdr.Typeflag {
case tar.TypeBlock:
mode |= syscall.S_IFBLK
case tar.TypeChar:
mode |= syscall.S_IFCHR
case tar.TypeFifo:
mode |= syscall.S_IFIFO
}
if err := syscall.Mknod(path, mode, int(mkdev(hdr.Devmajor, hdr.Devminor))); 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:
log.Debugf("PAX Global Extended Headers found and ignored")
return nil
default:
return fmt.Errorf("Unhandled tar header type %d\n", hdr.Typeflag)
}
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 hdr.Typeflag != tar.TypeSymlink {
if err := os.Chmod(path, hdrInfo.Mode()); err != nil {
return err
}
}
ts := []syscall.Timespec{timeToTimespec(hdr.AccessTime), timeToTimespec(hdr.ModTime)}
// syscall.UtimesNano doesn't support a NOFOLLOW flag atm, and
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
}