1. Haproxy容器内安装Keepalived，设置虚拟IP

#进入h1容器
docker exec -it h1 bash
#更新软件包
apt-get update
#安装VIM
apt-get install vim
#安装Keepalived
apt-get install keepalived
#编辑Keepalived配置文件（参考下方配置文件）
vim /etc/keepalived/keepalived.conf
#启动Keepalived
service keepalived start
#宿主机执行ping命令
ping 172.18.0.201

配置文件

vrrp_instance  VI_1 {
    state  MASTER
    interface  eth0
    virtual_router_id  51
    priority  100
    advert_int  1
    authentication {
        auth_type  PASS
        auth_pass  123456
    }
    virtual_ipaddress {
        172.18.0.201
    }
}

#进入h2容器
docker exec -it h2 bash
#更新软件包
apt-get update
#安装VIM
apt-get install vim
#安装Keepalived
apt-get install keepalived
#编辑Keepalived配置文件
vim /etc/keepalived/keepalived.conf
#启动Keepalived
service keepalived start
#宿主机执行ping命令
ping 172.18.0.201

配置文件

vrrp_instance  VI_1 {
    state  MASTER
    interface  eth0
    virtual_router_id  51
    priority  100
    advert_int  1
    authentication {
        auth_type  PASS
        auth_pass  123456
    }
    virtual_ipaddress {
        172.18.0.201
    }
}

宿主机安装Keepalived，实现双击热备

#宿主机执行安装Keepalived
yum -y install keepalived
#修改Keepalived配置文件
vi /etc/keepalived/keepalived.conf
#启动Keepalived
service keepalived start

 




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 {
        192.168.99.150
    }
}
​
virtual_server 192.168.12.191 8888 {
    delay_loop 3
    lb_algo rr 
    lb_kind NAT
    persistence_timeout 50
    protocol TCP
​
    real_server 172.25.0.201 8888 {
        weight 1
    }
}
​
virtual_server 192.168.12.191 3306 {
    delay_loop 3
    lb_algo rr 
    lb_kind NAT
    persistence_timeout 50
    protocol TCP
​
    real_server 172.18.0.201 3306 {
        weight 1
    }
}

keepalive是作用是抢占虚拟ip，抢到的就是主服务器，没有抢到的就是备用服务器，然后两个keepalive进行心跳检测（就是创建一个用户到对方那里试探，看是否还活着，mysql的集群之间也是心跳检测），如果 挂掉抢占ip。所以在启动keepalive 之前首先要编辑好他的配置文件，怎么抢占，权重是什么，虚拟ip是什么，创建的用户交什么。配置完启动完以后可以ping一下看是否正确. 然后将虚拟ip映射到局域网的ip