| package docker |
| |
| import ( |
| "fmt" |
| "os" |
| "path/filepath" |
| "strings" |
| ) |
| |
| type ChangeType int |
| |
| const ( |
| ChangeModify = iota |
| ChangeAdd |
| ChangeDelete |
| ) |
| |
| type Change struct { |
| Path string |
| Kind ChangeType |
| } |
| |
| func (change *Change) String() string { |
| var kind string |
| switch change.Kind { |
| case ChangeModify: |
| kind = "C" |
| case ChangeAdd: |
| kind = "A" |
| case ChangeDelete: |
| kind = "D" |
| } |
| return fmt.Sprintf("%s %s", kind, change.Path) |
| } |
| |
| func Changes(layers []string, rw string) ([]Change, error) { |
| var changes []Change |
| err := filepath.Walk(rw, func(path string, f os.FileInfo, err error) error { |
| if err != nil { |
| return err |
| } |
| |
| // Rebase path |
| path, err = filepath.Rel(rw, path) |
| if err != nil { |
| return err |
| } |
| path = filepath.Join("/", path) |
| |
| // Skip root |
| if path == "/" { |
| return nil |
| } |
| |
| // Skip AUFS metadata |
| if matched, err := filepath.Match("/.wh..wh.*", path); err != nil || matched { |
| return err |
| } |
| |
| change := Change{ |
| Path: path, |
| } |
| |
| // Find out what kind of modification happened |
| file := filepath.Base(path) |
| // If there is a whiteout, then the file was removed |
| if strings.HasPrefix(file, ".wh.") { |
| originalFile := file[len(".wh."):] |
| change.Path = filepath.Join(filepath.Dir(path), originalFile) |
| change.Kind = ChangeDelete |
| } else { |
| // Otherwise, the file was added |
| change.Kind = ChangeAdd |
| |
| // ...Unless it already existed in a top layer, in which case, it's a modification |
| for _, layer := range layers { |
| stat, err := os.Stat(filepath.Join(layer, path)) |
| if err != nil && !os.IsNotExist(err) { |
| return err |
| } |
| if err == nil { |
| // The file existed in the top layer, so that's a modification |
| |
| // However, if it's a directory, maybe it wasn't actually modified. |
| // If you modify /foo/bar/baz, then /foo will be part of the changed files only because it's the parent of bar |
| if stat.IsDir() && f.IsDir() { |
| if f.Size() == stat.Size() && f.Mode() == stat.Mode() && f.ModTime() == stat.ModTime() { |
| // Both directories are the same, don't record the change |
| return nil |
| } |
| } |
| change.Kind = ChangeModify |
| break |
| } |
| } |
| } |
| |
| // Record change |
| changes = append(changes, change) |
| return nil |
| }) |
| if err != nil && !os.IsNotExist(err) { |
| return nil, err |
| } |
| return changes, nil |
| } |