code: func updateDomainWithCName(r *dns.Msg, fqdn string) string {
  	for _, rr := range r.Answer {
  		if cn, ok := rr.(*dns.CNAME); ok {
  			if cn.Hdr.Name == fqdn {
  				return cn.Target
  			}
  		}
  	}
  
  	return fqdn
  }
docs: // Update FQDN with CNAME if any