Keepalived 安装部署

tar -zxvf keepalived-2.0.18.tar.gz

./configure --prefix=/usr/local/keepalived --sysconf=/etc

*** WARNING - this build will not support IPVS with IPv6. Please install libnl/libnl-3 dev libraries to support IPv6 with IPVS.

yum -y install libnl libnl-devel  

make && make install

global_defs {

#路由id：当前安装 keepalived 的节点主机标识符，保证全局唯一

   router_id keep_171
}

vrrp_instance VI_1 {
    #表示状态是MASTER主机还是备用机 BACKUP
    state MASTER
    #该实例绑定的网卡
    interface ens33
    #保证主备节点一致即可
    virtual_router_id 51
    #权重，master权重一般高于 backup，如果有多个，那就是选举，谁的权重高，谁就当选
    priority 100
    #主备之间同步检查时间间隔，单位秒
    advert_int 2
    #认证权限密码，防止非法节点进入
    authentication {
        auth_type PASS
        auth_pass 1111
    }
    #虚拟出来的 ip，可以有多个（vip）
    virtual_ipaddress {
        192.168.1.161
    }
}

ps -ef|grep keepalived

global_defs {
   router_id keep_172
}

vrrp_instance VI_1 {

#备用机设置为 BACKUP

    state BACKUP
    interface ens33
    virtual_router_id 51

#权重低于 MASTER

    priority 80
    advert_int 2
    authentication {
        auth_type PASS
        auth_pass 1111
    }
    virtual_ipaddress {

#注意：主备两台的 vip 都是一样的，绑定到同一个 vip

        192.168.1.161
    }
}

#启动 keepalived

systemctl start keepalived

#停止 keepalived

systemctl stop keepalived

#重启 keepalived

systemctl restart keepalived

ps -ef|grep keepalived

vim /etc/keepalived/check_nginx_alive_or_not.sh

#!/bin/bash

A=`ps -C nginx --no-header |wc -l`

#判断 nginx 是否宕机，如果宕机了，尝试重启

if [ $A -eq 0 ];then
    /usr/local/nginx/sbin/nginx

#等待一小会再次检查 nginx，如果没有启动成功，则停止 keepalived，使其启动备用机

    sleep 3
    if [ `ps -C nginx --no-header |wc -l` -eq 0 ];then
        killall keepalived
    fi
fi

chmod +x /etc/keepalived/check_nginx_alive_or_not.sh

vrrp_script check_nginx_alive {
    script "/etc/keepalived/check_nginx_alive_or_not.sh"
    interval 2 # 每隔两秒运行上一行脚本
    weight 10 # 如果脚本运行成功，则升级权重 +10

#weight -10 # 如果脚本运行失败，则升级权重 -10

}

track_script {
    check_nginx_alive   # 追踪 nginx 脚本
}

systemctl restart keepalived

global_defs {
   router_id keep_171
}

vrrp_instance VI_1 {
    state MASTER
    interface ens33
    virtual_router_id 51
    priority 100
    advert_int 1
    authentication {
        auth_type PASS
        auth_pass 1111
    }
    virtual_ipaddress {
        192.168.1.161
    }
}

vrrp_instance VI_2 {
    state BACKUP
    interface ens33
    virtual_router_id 52
    priority 80
    advert_int 1
    authentication {
        auth_type PASS
        auth_pass 1111
    }
    virtual_ipaddress {
        192.168.1.162
    }
}

global_defs {
   router_id keep_172
}

vrrp_instance VI_1 {
    state BACKUP
    interface ens33
    virtual_router_id 51
    priority 80
    advert_int 1
    authentication {
        auth_type PASS
        auth_pass 1111
    }
    virtual_ipaddress {
        192.168.1.161
    }
}

vrrp_instance VI_2 {
    state MASTER
    interface ens33
    virtual_router_id 52
    priority 100
    advert_int 1
    authentication {
        auth_type PASS
        auth_pass 1111
    }
    virtual_ipaddress {
        192.168.1.162
    }
}

#重启 Keepalived

systemctl restart keepalived