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.