Nginx+Keepalived实现双机热备

faramita2016@linux-l9e6:~> qemu-kvm -cpu host -m 512 -hda vdisk.img -net nic -net bridge,br=br0 -snapshot -nographic 

root@debian:~# cat /etc/network/interfaces
# The primary network interface
allow-hotplug ens3
#iface ens3 inet dhcp
iface ens3 inet static
address 10.0.0.3  // 设置ip
netmask 255.0.0.0
gateway 10.0.0.1
hwaddress ether 52:54:00:12:34:53  // 设置mac地址

root@debian:~# ip addr del 10.0.0.8/8 dev ens3  // 删除客户机原有IP
root@debian:~# ifdown ens3
root@debian:~# ifup ens3

root@debian:~# apt-get install -y nginx keepalived 

root@debian:~# vi /var/www/html/index.nginx-debian.html 
……
<h1>Welcome to nginx! 10.0.0.3</h1>
……

root@debian:~# cat /etc/keepalived/keepalived.conf 
global_defs {
  router_id RI_1  // 标识当前keepalived节点
}

vrrp_script chk_nginx {
  script "/root/chk_nginx.sh"  // 定义监控脚本
  interval 2  // 执行监控脚本的闹中间隔时间
}

vrrp_instance VI_1 {
  state MASTER  // 设置节点为主节点，节点的初始状态
  interface ens3  // 设置绑定虚拟ip的网络接口
  virtual_router_id 50  // VRRP组名，指明节点同属一个组
  priority 100  // 节点优先级，主节点应当高于备用节点
  advert_int 1  // 组播信息发送间隔

  #nopreempt  // 禁止抢占服务，只对备用节点生效，主节点根据priority优先级进行抢占，不受nopreempty控制

  authentication {
    auth_type PASS  // 设置认证方式
    auth_pass 123456  // 密码
  }

  virtual_ipaddress {
    10.0.0.100/24  // 设置vip
  }

  track_script {  // 调用监控脚本
    chk_nginx
  }
}

state BACKUP  // 设置节点为主节点，节点的初始状态
  priority 10  // 节点优先级

root@debian:~# vi /root/chk_nginx.sh 
#!/bin/bash
A=`ps -C nginx --no-header | wc -l`
if [ $A -eq 0 ]
then
  /etc/init.d/keepalived stop
fi

root@debian:~# /etc/init.d/nginx start
root@debian:~# /etc/init.d/keepalived start

root@debian:~# /etc/init.d/nginx start
root@debian:~# /etc/init.d/keepalived start

root@debian:~# /etc/init.d/nginx stop