code: func (e *executor) Controller(t *api.Task) (exec.Controller, error) {
  	// Get the node description from the executor field
  	e.mutex.Lock()
  	nodeDescription := e.node
  	e.mutex.Unlock()
  	ctlr, err := newController(e.client, nodeDescription, t, secrets.Restrict(e.secrets, t))
  	if err != nil {
  		return nil, err
  	}
  
  	return ctlr, nil
  }
docs: // Controller returns a docker container controller.