code: func readFile(filePath, CertFile, KeyFile, CAFile string) ([]byte, error) {
  	u, _ := url.Parse(filePath)
  	p := getter.All(settings)
  
  	// FIXME: maybe someone handle other protocols like ftp.
  	getterConstructor, err := p.ByScheme(u.Scheme)
  
  	if err != nil {
  		return ioutil.ReadFile(filePath)
  	}
  
  	getter, err := getterConstructor(filePath, CertFile, KeyFile, CAFile)
  	if err != nil {
  		return []byte{}, err
  	}
  	data, err := getter.Get(filePath)
  	return data.Bytes(), err
  }
docs: //readFile load a file from the local directory or a remote file with a url.