1 dnspython处理模块的安装，源码方式

   wget http://www.dnspython.org/kits/1.9.4/dnspython-1.9.4.tar.gz

   tar zxf dnspython-1.9.4.tar.gz 

   cd dnspython-1.9.4/

   python setup.py install


2 解析示例

A记录查询示例

#!/usr/bin/env python
# -*- coding: utf-8 -*-
import dns.resolver
domain = raw_input("请输入一个需要解析的域名：")
A = dns.resolver.query(domain,'A')
for i in A.response.answer:
    for j in i.items:
        if j.rdtype == 1:
            print j.address

MX记录示例

#!/usr/bin/env python
# -*- coding: utf-8 -*-
import dns.resolver
domain=raw_input('请输入一个域名：')
MX=dns.resolver.query(domain,'MX')
for i in MX:
    print i.preference, i.exchange

NS记录示例

import dns.resolver
domain=raw_input('请输入一个域名：')
NS=dns.resolver.query(domain,'NS')
for i in NS.response.answer:
    for j in i.items:
    print j.to_text()

CNAME记录示例

import dns.resolver
domain=raw_input('请输入一个域名：')
cname=dns.resolver.query(domain,'CNAME')
for i in cname.response.answer:
    for j in i.items:
    print j.to_text()


3 利用dns域名轮训监控业务

监控示例

#!/usr/bin/env python
# -*- coding: utf-8 -*-
import dns.resolver
import os
import httplib
iplist=[]
appdomain="www.ctrip.com"
def get_iplist(domain=""):
        try:
            A=dns.resolver.query(domain,'A')
        except Exception,e:
            print "dns resolver error:"+str(e)
        for i in A.response.answer:
            for j in i.items:
                if j.rdtype == 1:
                    iplist.append(j.address)
        return True
def checkip(ip):
        checkurl=ip+":80"
        getcontent=""
        httplib.socket.setdefaulttimeout(5)
        conn=httplib.HTTPConnection(checkurl)
        try:
                conn.request("GET","/",headers={"Host":appdomain})
                r=conn.getresponse()
                getcontent=r.read(15)
        finally:
            print getcontent
            if getcontent=="":
                    print ip+":80端口正常  [ok]"
            else:
                    print ip+":80端口异常  [error]"
if __name__=="__main__":
    if get_iplist(appdomain) and len(iplist)>0:
            for ip in iplist:
                    checkip(ip)
    else:
            print "dns resolver error"

执行 python test1.py 

118.89.206.133:80 端口正常  [ok]