code: func (di *info) ovf() (string, error) {
  	var buf bytes.Buffer
  
  	tmpl, err := template.New("ovf").Parse(ovfenv)
  	if err != nil {
  		return "", err
  	}
  
  	err = tmpl.Execute(&buf, di)
  	if err != nil {
  		return "", err
  	}
  
  	return buf.String(), nil
  }
docs: // ovf returns an expanded descriptor template