使用Keepalived实现linux高可用集群

安装

apt install libipset-dev  keepalived -y

创建账户

useradd -s/usr/sbin/nologin -M -g root keepalived_script

修改Linux

vim /etc/sysctl.conf 
#在末尾追加一行：net.ipv4.ip_nonlocal_bind=1

创建Keepalived配置文件

vim /etc/keepalived/keepalived.conf

vrrp_script chk_appsvc {
    #定义一个脚本文件,这个脚本文件将用来检测本机是否可用,如果可用则返回0
    script /etc/keepalived/keepalived-check-appsvc.sh
    interval 1
    fall 2
    rise 2
}

vrrp_instance VI_1 {
    #选择一个网卡
    interface ens7
 
    authentication {
        auth_type PASS
        auth_pass secr3t
    }

    virtual_router_id 51

    virtual_ipaddress {
        10.1.96.100 #整个集群的对外地址
    }

    track_script {
        chk_appsvc
    }
    
    #状态:MASTER  BACKUP STOP FAULT
    state MASTER
    priority 101

    unicast_src_ip 10.1.96.5 #本机地址(DIP)
    unicast_peer {
        10.1.96.3 #对端地址,其它机器的ip(DIP)
    }
    #状态切换动作脚本,定义了状态切换时执行的动作
    notify /etc/keepalived/keepalived-action.sh
}

创建状态切换动作脚本

vim /etc/keepalived/keepalived-action.sh
chmod +x /etc/keepalived/keepalived-action.sh

#!/bin/bash

TYPE=$1
NAME=$2
STATE=$3

case $STATE in
    "MASTER")
        　　systemctl start nginx
        　　exit 0
        　　;;
    "BACKUP"|"STOP")
               #systemctl stop nginx
        　　exit 0
        　　;;
    "FAULT")
               #systemctl stop nginx
        　　exit 0
        　　;;
    *)
        　　exit 1
        　　;;
esac

#当某个服务器成为MASTER的时候，启动nginx服务。

创建状态检测脚本

vim /etc/keepalived/keepalived-action.sh
chmod +x /etc/keepalived/keepalived-check-appsvc.sh

#!/bin/bash
exit 0

#返回0表示当前主机状态正常.如果返回非0,或者设备无法连接,就会触发转移.