code: func (kl *Kubelet) RunInContainer(podFullName string, podUID types.UID, containerName string, cmd []string) ([]byte, error) {
  	container, err := kl.findContainer(podFullName, podUID, containerName)
  	if err != nil {
  		return nil, err
  	}
  	if container == nil {
  		return nil, fmt.Errorf("container not found (%q)", containerName)
  	}
  	// TODO(tallclair): Pass a proper timeout value.
  	return kl.runner.RunInContainer(container.ID, cmd, 0)
  }
docs: // RunInContainer runs a command in a container, returns the combined stdout, stderr as an array of bytes