docker容器使用keepalived模拟mysql主备切换

发表于

1.使用制作的centos/keepalived镜像,运行两次，生成两个容器
docker run -idt --privileged centos/keepalived init
容器ip分别为 172.17.0.3, 172.17.0.4(通过命令docker inspect [container_id] | grep IP查看)

2.分别进入容器
IP: 172.17.0.3
vim /etc/keepalived/keepalived.conf

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global_defs {
    router_id mysql_master
}
vrrp_script chk_mysql {
    script "netstat -lntp | grep 3306"
    interval 1
}

vrrp_instance mysql {
    state BACKUP
    interface eth0             #在容器中执行ifconfig查看
    virtual_router_id 210
    priority 150
    nopreempt
    advert_int 1

    authentication {
        auth_type PASS
        auth_pass 1111
    }

    virtual_ipaddress {
        172.17.0.5/16
    }

    track_script {
        chk_mysql
    }
}

IP: 172.17.0.4
vim /etc/keepalived/keepalived.conf

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global_defs {
    router_id mysql_slave
}
vrrp_script chk_mysql {
    script "netstat -lntp | grep 3306"
    interval 1
}

vrrp_instance mysql {
    state BACKUP
    interface eth0
    virtual_router_id 210
    priority 150
    nopreempt
    advert_int 1

    authentication {
        auth_type PASS
        auth_pass 1111
    }

    virtual_ipaddress {
        172.17.0.5/16
    }

    track_script {
        chk_mysql
    }
}

3.启动keepalived
systemctl start keepalived
systemctl enable keepalived
image

验证：

  • 停止172.17.0.4中的MySQL服务(systemctl stop mysqld),发现VIP飘到了172.17.0.3上
    image

所遇问题：
1.systemctl status keepalived查看keepalived状态,发现提示Can’t initialize ipvs: Protocol not available
解决方法：加载ip_vs模块(在宿主机执行如下命令)

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modprobe ip_vs
modprobe ip_vs_wrr

查看内核是否加载ip_vs
lsmod | grep ip_vs