for i, r := range records {
		hosts[i] = net.JoinHostPort(r.Host, string(r.Port))
	}
	return hosts
}

// returns an online host (and corresponding port) from a slice of DNS records
func getHostFromSrv(records []dns.SrvRecord) (host string) {
	hosts := getHostsSlice(records)
	rng := rand.New(rand.NewSource(time.Now().UTC().UnixNano()))
	var d net.Dialer
	var retry int
	for retry < len(hosts) {