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.")
}
}
}
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
}