mtg/config/global_ips.go

package config

import (
	"io/ioutil"
	"net"
	"net/http"
	"strings"

	"github.com/juju/errors"
)

func getGlobalIPv4() (net.IP, error) {
	return fetchIP("https://v4.ifconfig.co/ip")
}

func getGlobalIPv6() (net.IP, error) {
	return fetchIP("https://v6.ifconfig.co/ip")
}

func fetchIP(url string) (net.IP, error) {
	resp, err := http.Get(url)
	if err != nil {
		return nil, err
	}
	defer resp.Body.Close()

	respData, err := ioutil.ReadAll(resp.Body)
	if err != nil {
		return nil, err
	}

	ip := net.ParseIP(strings.TrimSpace(string(respData)))
	if ip == nil {
		return nil, errors.Errorf("ifconfig.co returns incorrect IP %s", resp)
	}

	return ip, nil
}