Example #1
0
func TestTarUntarWithXattr(t *testing.T) {
	origin, err := ioutil.TempDir("", "docker-test-untar-origin")
	if err != nil {
		t.Fatal(err)
	}
	defer os.RemoveAll(origin)
	if err := ioutil.WriteFile(path.Join(origin, "1"), []byte("hello world"), 0700); err != nil {
		t.Fatal(err)
	}
	if err := ioutil.WriteFile(path.Join(origin, "2"), []byte("welcome!"), 0700); err != nil {
		t.Fatal(err)
	}
	if err := ioutil.WriteFile(path.Join(origin, "3"), []byte("will be ignored"), 0700); err != nil {
		t.Fatal(err)
	}
	if err := system.Lsetxattr(path.Join(origin, "2"), "security.capability", []byte{0x00}, 0); err != nil {
		t.Fatal(err)
	}

	for _, c := range []Compression{
		Uncompressed,
		Gzip,
	} {
		changes, err := tarUntar(t, origin, &TarOptions{
			Compression:     c,
			ExcludePatterns: []string{"3"},
		})

		if err != nil {
			t.Fatalf("Error tar/untar for compression %s: %s", c.Extension(), err)
		}

		if len(changes) != 1 || changes[0].Path != "/3" {
			t.Fatalf("Unexpected differences after tarUntar: %v", changes)
		}
		capability, _ := system.Lgetxattr(path.Join(origin, "2"), "security.capability")
		if capability == nil && capability[0] != 0x00 {
			t.Fatalf("Untar should have kept the 'security.capability' xattr.")
		}
	}
}
Example #2
0
func (ta *tarAppender) addTarFile(path, name string) error {
	fi, err := os.Lstat(path)
	if err != nil {
		return err
	}

	link := ""
	if fi.Mode()&os.ModeSymlink != 0 {
		if link, err = os.Readlink(path); err != nil {
			return err
		}
	}

	hdr, err := tar.FileInfoHeader(fi, link)
	if err != nil {
		return err
	}
	hdr.Mode = int64(chmodTarEntry(os.FileMode(hdr.Mode)))

	name, err = canonicalTarName(name, fi.IsDir())
	if err != nil {
		return fmt.Errorf("tar: cannot canonicalize path: %v", err)
	}
	hdr.Name = name

	nlink, inode, err := setHeaderForSpecialDevice(hdr, ta, name, fi.Sys())
	if err != nil {
		return err
	}

	// if it's a regular file and has more than 1 link,
	// it's hardlinked, so set the type flag accordingly
	if fi.Mode().IsRegular() && nlink > 1 {
		// a link should have a name that it links too
		// and that linked name should be first in the tar archive
		if oldpath, ok := ta.SeenFiles[inode]; ok {
			hdr.Typeflag = tar.TypeLink
			hdr.Linkname = oldpath
			hdr.Size = 0 // This Must be here for the writer math to add up!
		} else {
			ta.SeenFiles[inode] = name
		}
	}

	capability, _ := system.Lgetxattr(path, "security.capability")
	if capability != nil {
		hdr.Xattrs = make(map[string]string)
		hdr.Xattrs["security.capability"] = string(capability)
	}

	if err := ta.TarWriter.WriteHeader(hdr); err != nil {
		return err
	}

	if hdr.Typeflag == tar.TypeReg {
		file, err := os.Open(path)
		if err != nil {
			return err
		}

		ta.Buffer.Reset(ta.TarWriter)
		defer ta.Buffer.Reset(nil)
		_, err = io.Copy(ta.Buffer, file)
		file.Close()
		if err != nil {
			return err
		}
		err = ta.Buffer.Flush()
		if err != nil {
			return err
		}
	}

	return nil
}