ddns.go

package main
 
import (
  "io/ioutil"
  "log"
  "net"
  "net/http"
  "net/url"
  "strings"
  "time"
)
 
var (
	body = url.Values{
		"login_email":    {"email"},
		"login_password": {"password"},
		"format":         {"json"},
		"domain_id":      {"0"},
		"record_id":      {"0"},
		"sub_domain":     {"www"},
		"record_line":    {"默认"},
	}
	current_ip     = ""
	check_interval = 30 * time.Second
)
 
func get_public_ip() (string, error) {
	conn, err := net.Dial("tcp", "ns1.dnspod.net:6666")

	defer func() {
		if x := recover(); x != nil {
			log.Println("Can't get public ip", x)
		}
	}()
 
	if err == nil {
	        defer conn.Close()
		var bytes []byte
		bytes, err = ioutil.ReadAll(conn)
		if err == nil {
			return string(bytes), nil
		}
	}
	return "", err
}
 
func update_dnspod(ip string) bool {
	client := new(http.Client)
	body.Set("value", ip)
 
	req, err := http.NewRequest("POST", "https://dnsapi.cn/Record.Ddns", strings.NewReader(body.Encode()))
	req.Header.Set("Accept", "text/json")
	req.Header.Set("Content-type", "application/x-www-form-urlencoded")
 
	resp, err := client.Do(req)
	defer resp.Body.Close()
	if err != nil {
		return false
	}
 
	bytes, _ := ioutil.ReadAll(resp.Body)
	log.Println(string(bytes))
	return resp.StatusCode == 200
}
 
func main() {
	for {
		ip, err := get_public_ip()
		if err == nil {
			if ip != current_ip {
				if update_dnspod(ip) {
					current_ip = ip
				}
			}
		}
		time.Sleep(check_interval)
	}
}