Nginx+Keepalived

学习自：https://www.nhooo.com/note/qa3jz9.html

最终效果

主从两个节点都安装nginx与keepalived，安装到相同路径

安装Nginx

点此：https://www.jianshu.com/p/1a51f2384c11

安装keepalived

下载安装包：https://www.keepalived.org/download.html

# tar命令解压
# 进入解压后目录
./configure --prefix=/usr/local/keepalived
make && make install

将配置文件拷贝到系统对应的目录下

mkdir /etc/keepalived
cp /usr/local/keepalived/etc/keepalived/keepalived.conf /etc/keepalived/keepalived.conf
cp /usr/local/keepalived/etc/sysconfig/keepalived /etc/sysconfig/keepalived

核心keepalived配置文件

vim /etc/keepalived/keepalived.conf

! Configuration File for keepalived

global_defs {
   router_id ngkp1 # 主从节点不一致即可
   script_user root
}
vrrp_script nginx_check {
        script "/etc/keepalived/nginx_check.sh"     ## 检测 nginx 状态的脚本路径
        interval 5       ## 检测时间间隔
        #weight -20   ## 如果条件成立，权重-20
}

vrrp_instance VI_1 {
    state MASTER     ## 必填，MASTER或BACKUP，可以不一致，也可以一致
    interface ens16    ## 网卡名称
    virtual_router_id 51  # 主从节点中保持一致
    unicast_src_ip xx.xx.6.1  #本机IP
    unicast_peer {
          xx.xx.6.2  # 对方机器IP
        }
    priority 100  # 主从不要一致，主比从大
    advert_int 1
    authentication {
        auth_type PASS     # 主从节点中保持一致
        auth_pass 111111    # 主从节点中保持一致
    }
    track_script  {
            nginx_check  ## 执行 Nginx 监控的服务
        }
    virtual_ipaddress {
        xx.xx.6.20/24 dev ens16   # 虚拟IP
    }
}

Nginx监控脚本

vim /etc/keepalived/nginx_check.sh

#!/usr/bin/bash
counter=$(ps -C nginx --no-heading|wc -l)   # 检查nginx进程数
if [ $counter -eq 0 ]; then   
    /usr/local/nginx/sbin/nginx -c /usr/local/nginx/conf/nginx.conf  # 如果进程数等于0，则尝试对nginx进行重启操作
    sleep 1  # 等待一秒时间
    cnt=$(ps -C nginx --no-heading|wc -l)   #再次检查nginx进程数
    if [ $cnt -eq 0 ]; then  
        systemctl stop keepalived   # 如果还等于0，则停止掉keepalived进程，实现虚拟IP漂移到从节点，由从节点的nginx继续提供服务
    fi
fi