DNS SRV record test in golang

dnstest.go

package main

import (
	"fmt"
	"net"
	"os"
)

func main() {
	if len(os.Args) < 2 {
		fmt.Fprintln(os.Stderr, "Usage: dnstest <SERVICE>")
		os.Exit(1)
	}
	srv := os.Args[1]
	fmt.Fprintln(os.Stderr, "service:", srv)

	cname, addr, err := net.LookupSRV("", "", srv)
	if err != nil {
		fmt.Fprintln(os.Stderr, "[ERROR]", err)
	}

	fmt.Println("cname:", cname)
	for _, a := range addr {
		fmt.Printf("   %s %d\n", a.Target, a.Port)

	}
}