更新域名的API很简单，一个HTTP请求即可。API地址是: http://dynamic.wacao.com/api/plain.php，参数为，

• host – 主机名，FQDN为 ${host}.dynamic.wacao.com
• time – unixtime形式的请求时间，时间误差在正负5分钟内有效
• sign – 签名，格式为 sha1(${host}${time}${shared_key})
• ip – 可选。如果未提供IP地址则采用客户端请求的来源地址

其中host和shared_key需要我来提供。这里提供一个的host和shared_key给大家测试。testing d035cdac09dd866ed8f4a244567c4daf。域名为testing.dynamic.wacao.com.。

由于仅是一个HTTP请求，客户端很容易用各种语言实现。我自己用的是一个简单的shell脚本。

#!/bin/bash

function usage {
    echo "Usage: $0 {host} {shared_key}"
}

if test -z $1 || test -z $2
then
    usage
    exit 1
fi

HOST=$1
SHARED_KEY=$2
ENDPOINT="http://dynamic.wacao.com/api/plain.php"

TIME=`date +%s`
SIGN=`echo -n "${HOST}${TIME}${SHARED_KEY}" | sha1sum -t | awk '{print $1}'`
URL="${ENDPOINT}?host=${HOST}&time=${TIME}&sign=${SIGN}"
curl "$URL"

执行后立即能够解析，TTL为5秒。

$ update-dynamic-dns.sh testing d035cdac09dd866ed8f4a244567c4daf
ok. 58.33.69.77
$ host testing.dynamic.wacao.com.
testing.dynamic.wacao.com has address 58.33.69.77

我将这个脚本加到crontab里，每5分钟更新一次。

*/5 * * * * /usr/local/sbin/update-dynamic-dns.sh ${HOST} ${SHARED_KEY}

如果觉得testing.dynamic.wacao.com这样的域名不好看，而且你有自己的域名，可以想我一样，给自己的域名加一个CNAME。例如我把alcohol.swanpan.com做了一个CNAME指到alcohol.dynamic.wacao.com

;; ANSWER SECTION:
alcohol.swanpan.com.	86400	IN	CNAME	alcohol.dynamic.wacao.com.
alcohol.dynamic.wacao.com. 5	IN	A	58.33.69.77

这样我在各个地方都能用alcohol.swanpan.com这个域名访问家里的机器，方便用它穿墙。

想试试的朋友告诉我你要的host，我给你发送shared_key。

#!/usr/bin/env python

import cookielib
import urllib
import urllib2
import time
import sys

def ddd_checkip():
        response = urllib2.urlopen("http://www.dragonsoft.net/checkip.php")
        return response.read()

def ddd_hello(opener):
        return opener.open("http://www.dns-diy.com/skin.aspx?skin=api")

def ddd_login(opener, username, password):
        request = urllib2.Request("https://www.dns-diy.com/api/login.aspx")
        params = urllib.urlencode({"username":username, 'password':password})
        request.add_data(params)
        return opener.open(request)

def ddd_logout(opener):
        request = urllib2.Request("http://www.dns-diy.com/api/logout.aspx?immediately=yes&invalidate=yes")
        return opener.open(request)

def ddd_update_rr(opener, id, name, type, data, aux, ttl):
        request = urllib2.Request("http://www.dns-diy.com/api/zone_rr_update.aspx")
        params = urllib.urlencode({"id":id, "rr_name":name, "rr_type":type, "rr_data":data, "rr_aux":aux, "rr_ttl":ttl})
        request.add_data(params)
        return opener.open(request)

#
#
#

DEBUG = 5
SLEEP_SECONDS = 600

USERNAME = "swanpan.com"
PASSWORD = "secure"
RR_ID    = "secure"
RR_NAME  = ""
RR_TYPE  = "A"
RR_DATA  = "127.0.0.1"
RR_AUX   = "0"
RR_TTL   = "5"

def ddd_process():
        if (DEBUG > 0):
                print "[%(time)s] updating %(host)s.%(zone)s (%(ip)s) ..." % \
                        {"time":time.strftime("%Y-%m-%d %H:%M:%S", time.localtime()), \
                        "host":RR_NAME, "zone":USERNAME, "ip":RR_DATA}

        opener = urllib2.build_opener(urllib2.HTTPCookieProcessor(cookielib.CookieJar()))

        response = ddd_hello(opener)
        if (DEBUG > 5):
                print "HELLO"
                print response.read()

        response = ddd_login(opener, USERNAME, PASSWORD)
        if (DEBUG > 5):
                print "LOGIN"
                print response.read()

        response = ddd_update_rr(opener, RR_ID, RR_NAME, RR_TYPE, RR_DATA, RR_AUX, RR_TTL)
        if (DEBUG > 5):
                print "UPDATE"
                print response.read()

        response = ddd_logout(opener)
        if (DEBUG > 5):
                print "LOGOUT"
                print response.read()

        if (DEBUG > 0):
                print "[%(time)s] Finished!" % \
                        {"time":time.strftime("%Y-%m-%d %H:%M:%S", time.localtime())}

while True:
        try:
                ip = ddd_checkip()
                if (RR_DATA != ip):
                        RR_DATA = ip
                        ddd_process()
        except:
                if (DEBUG > 4):
                        print "Unexpected error:", sys.exc_info()[0]

        time.sleep(SLEEP_SECONDS)

DNS-DIY accepts domain names registered by OnlineNIC only for business policy.

Reference,
http://www.dns-diy.com