1、安裝keepalived

   yum  install -y keepalived

設定開機自啟動

   systemctl enable keepalived.service 

2、修改配置檔案

（1）主配置檔案

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)備配置檔案

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、備 新增Nginx狀態監測指令碼

#!/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）啟動或者重啟keepalived服務

        systemctl restart keepalived

3、驗證

（1）通過虛擬IP訪問

（2）停掉nginx，指令碼會在兩秒後自動執行監測nginx，然後啟動，如果只停掉主的keepalived服務，就會出現腦裂情況，所以這裡為了不出現這些情況，我停掉主伺服器來驗證

（3）如果還不不相信自己做成功，用抓包工具wireshark來驗證