让域名解析到ip，测试搭建环境

4.网站更新过程（程序代码更新）
（1）在开发人员自己电脑进行测试
（2）公司内部机房进行测试
（3）在IDC机房（数据中心） 测试
（4）程序代码放在用户使用的环境（生产环境/线上环境）

5. /etc/hosts
   [root@huahua ~]# vi /etc/hosts //让域名解析到ip，测试搭建环境
   [root@huahua ~]# cat /etc/hosts
   127.0.0.1 localhost localhost.localdomain localhost4 localhost4.localdomain4
   ::1 localhost localhost.localdomain localhost6 localhost6.localdomain6
   192.168.10.70 huahua.com jd.com //地址一定是本机地址 ，一定不能写baidu.com，因为ping百度就等于ping自己
   [root@huahua ~]# ping jd.com //ping jd.com，能ping通
   PING huahua.com (192.168.10.70) 56(84) bytes of data.
   64 bytes from huahua.com (192.168.10.70): icmp_seq=1 ttl=64 time=0.125 ms
   64 bytes from huahua.com (192.168.10.70): icmp_seq=2 ttl=64 time=0.114 ms
   64 bytes from huahua.com (192.168.10.70): icmp_seq=3 ttl=64 time=0.116 ms
   ^C
   --- huahua.com ping statistics ---
   3 packets transmitted, 3 received, 0% packet loss, time 1999ms
   rtt min/avg/max/mdev = 0.114/0.118/0.125/0.010 ms
   [root@huahua ~]# ping huahua.com //ping huahua.com,能ping通
   PING huahua.com (192.168.10.70) 56(84) bytes of data.
   64 bytes from huahua.com (192.168.10.70): icmp_seq=1 ttl=64 time=0.081 ms
   64 bytes from huahua.com (192.168.10.70): icmp_seq=2 ttl=64 time=0.170 ms
   64 bytes from huahua.com (192.168.10.70): icmp_seq=3 ttl=64 time=0.118 ms
   ^C
   --- huahua.com ping statistics ---
   3 packets transmitted, 3 received, 0% packet loss, time 2000ms
   rtt min/avg/max/mdev = 0.081/0.123/0.170/0.036 ms