package fs import ( "bytes" "io" "io/ioutil" "os" "path/filepath" "strings" "time" "github.com/pkg/errors" ) const defaultFileMode = 0644 // PathOp is a function which accepts a Path and performs an operation on that // path. When called with real filesystem objects (File or Dir) a PathOp modifies // the filesystem at the path. When used with a Manifest object a PathOp updates // the manifest to expect a value. type PathOp func(path Path) error type manifestResource interface { SetMode(mode os.FileMode) SetUID(uid uint32) SetGID(gid uint32) } type manifestFile interface { manifestResource SetContent(content io.ReadCloser) } type manifestDirectory interface { manifestResource AddSymlink(path, target string) error AddFile(path string, ops ...PathOp) error AddDirectory(path string, ops ...PathOp) error } // WithContent writes content to a file at Path func WithContent(content string) PathOp { return func(path Path) error { if m, ok := path.(manifestFile); ok { m.SetContent(ioutil.NopCloser(strings.NewReader(content))) return nil } return ioutil.WriteFile(path.Path(), []byte(content), defaultFileMode) } } // WithBytes write bytes to a file at Path func WithBytes(raw []byte) PathOp { return func(path Path) error { if m, ok := path.(manifestFile); ok { m.SetContent(ioutil.NopCloser(bytes.NewReader(raw))) return nil } return ioutil.WriteFile(path.Path(), raw, defaultFileMode) } } // AsUser changes ownership of the file system object at Path func AsUser(uid, gid int) PathOp { return func(path Path) error { if m, ok := path.(manifestResource); ok { m.SetUID(uint32(uid)) m.SetGID(uint32(gid)) return nil } return os.Chown(path.Path(), uid, gid) } } // WithFile creates a file in the directory at path with content func WithFile(filename, content string, ops ...PathOp) PathOp { return func(path Path) error { if m, ok := path.(manifestDirectory); ok { ops = append([]PathOp{WithContent(content), WithMode(defaultFileMode)}, ops...) return m.AddFile(filename, ops...) } fullpath := filepath.Join(path.Path(), filepath.FromSlash(filename)) if err := createFile(fullpath, content); err != nil { return err } return applyPathOps(&File{path: fullpath}, ops) } } func createFile(fullpath string, content string) error { return ioutil.WriteFile(fullpath, []byte(content), defaultFileMode) } // WithFiles creates all the files in the directory at path with their content func WithFiles(files map[string]string) PathOp { return func(path Path) error { if m, ok := path.(manifestDirectory); ok { for filename, content := range files { // TODO: remove duplication with WithFile if err := m.AddFile(filename, WithContent(content), WithMode(defaultFileMode)); err != nil { return err } } return nil } for filename, content := range files { fullpath := filepath.Join(path.Path(), filepath.FromSlash(filename)) if err := createFile(fullpath, content); err != nil { return err } } return nil } } // FromDir copies the directory tree from the source path into the new Dir func FromDir(source string) PathOp { return func(path Path) error { if _, ok := path.(manifestDirectory); ok { return errors.New("use manifest.FromDir") } return copyDirectory(source, path.Path()) } } // WithDir creates a subdirectory in the directory at path. Additional PathOp // can be used to modify the subdirectory func WithDir(name string, ops ...PathOp) PathOp { const defaultMode = 0755 return func(path Path) error { if m, ok := path.(manifestDirectory); ok { ops = append([]PathOp{WithMode(defaultMode)}, ops...) return m.AddDirectory(name, ops...) } fullpath := filepath.Join(path.Path(), filepath.FromSlash(name)) err := os.MkdirAll(fullpath, defaultMode) if err != nil { return err } return applyPathOps(&Dir{path: fullpath}, ops) } } func applyPathOps(path Path, ops []PathOp) error { for _, op := range ops { if err := op(path); err != nil { return err } } return nil } // WithMode sets the file mode on the directory or file at path func WithMode(mode os.FileMode) PathOp { return func(path Path) error { if m, ok := path.(manifestResource); ok { m.SetMode(mode) return nil } return os.Chmod(path.Path(), mode) } } func copyDirectory(source, dest string) error { entries, err := ioutil.ReadDir(source) if err != nil { return err } for _, entry := range entries { sourcePath := filepath.Join(source, entry.Name()) destPath := filepath.Join(dest, entry.Name()) if entry.IsDir() { if err := os.Mkdir(destPath, 0755); err != nil { return err } if err := copyDirectory(sourcePath, destPath); err != nil { return err } continue } // TODO: handle symlinks if err := copyFile(sourcePath, destPath); err != nil { return err } } return nil } func copyFile(source, dest string) error { content, err := ioutil.ReadFile(source) if err != nil { return err } return ioutil.WriteFile(dest, content, 0644) } // WithSymlink creates a symlink in the directory which links to target. // Target must be a path relative to the directory. // // Note: the argument order is the inverse of os.Symlink to be consistent with // the other functions in this package. func WithSymlink(path, target string) PathOp { return func(root Path) error { if v, ok := root.(manifestDirectory); ok { return v.AddSymlink(path, target) } return os.Symlink(filepath.Join(root.Path(), target), filepath.Join(root.Path(), path)) } } // WithHardlink creates a link in the directory which links to target. // Target must be a path relative to the directory. // // Note: the argument order is the inverse of os.Link to be consistent with // the other functions in this package. func WithHardlink(path, target string) PathOp { return func(root Path) error { if _, ok := root.(manifestDirectory); ok { return errors.New("WithHardlink yet implemented for manifests") } return os.Link(filepath.Join(root.Path(), target), filepath.Join(root.Path(), path)) } } // WithTimestamps sets the access and modification times of the file system object // at path. func WithTimestamps(atime, mtime time.Time) PathOp { return func(root Path) error { if _, ok := root.(manifestDirectory); ok { return errors.New("WithTimestamp yet implemented for manifests") } return os.Chtimes(root.Path(), atime, mtime) } }