nginx+keepalived IP飘移（高可用）

1、安装keepalived

   yum  install -y keepalived

设置开机自启动

   systemctl enable keepalived.service 

2、修改配置文件

（1）主配置文件

vim  /etc/keepalived/keepalived.conf

global_defs {
   router_id keep_01
}

vrrp_script chk_nginx {
    script "/etc/keepalived/check_nginx.sh"
    interval 5
    weight -20
}
vrrp_instance VI_1 {
    state MASTER
    interface eth0
    virtual_router_id 51
    priority 150
    advert_int 1
    authentication {
        auth_type PASS
        auth_pass 1111
    }
    virtual_ipaddress {
     192.168.1.144/24 dev eth0 label eth0:1
    }
track_script {
       chk_nginx
    }
}

(2)备配置文件

global_defs {
   router_id keep_02
}
vrrp_script chk_nginx {
    script "killall -0 nginx"
    script "/etc/keepalived/check_nginx.sh"
    interval 5
    weight -20
}

vrrp_instance VI_1 {
    state BACKUP
    interface eth0
    virtual_router_id 51
    priority 100
    advert_int 1
    authentication {
        auth_type PASS
        auth_pass 1111
    }
    virtual_ipaddress {
     192.168.1.144/24 dev eth0 label eth0:1
    }
track_script {
       chk_nginx
    }
}

（3）主、备 添加Nginx状态监测脚本

#!/bin/bash
A=`ps -C nginx --no-header | wc -l`
if [ $A -eq 0 ];then
    /usr/local/nginx/sbin/nginx
    sleep 2
    if [ `ps -C nginx --no-header | wc -l` -eq 0 ];then
        pkill keepalived
    fi
fi

（4）启动或者重启keepalived服务

        systemctl restart keepalived

3、验证

（1）通过虚拟IP访问

（2）停掉nginx，脚本会在两秒后自动执行监测nginx，然后启动，如果只停掉主的keepalived服务，就会出现脑裂情况，所以这里为了不出现这些情况，我停掉主服务器来验证

 

（3）如果还不不相信自己做成功，用抓包工具wireshark来验证