code: func New(config *api.Config, fs fs.FileSystem) (*Dockerfile, error) {
  	return &Dockerfile{
  		fs: fs,
  		// where we will get the assemble/run scripts from on the host machine,
  		// if any are provided.
  		uploadScriptsDir: constants.UploadScripts,
  		uploadSrcDir:     constants.Source,
  		result:           &api.Result{},
  		ignorer:          &ignore.DockerIgnorer{},
  	}, nil
  }
docs: // New creates a Dockerfile builder.