Keepalived+Nginx 高可用集群架构

vim /etc/yum.repos.d/nginx.repo

[nginx-stable]
name=nginx stable repo
baseurl=http://nginx.org/packages/centos/$releasever/$basearch/
gpgcheck=1
enabled=1
gpgkey=https://nginx.org/keys/nginx_signing.key
module_hotfixes=true

[nginx-mainline]
name=nginx mainline repo
baseurl=http://nginx.org/packages/mainline/centos/$releasever/$basearch/
gpgcheck=1
enabled=0
gpgkey=https://nginx.org/keys/nginx_signing.key
module_hotfixes=true

yum clean all
yum makecache
yum install -y nginx

systemctl status firewalld     //查看防火墙状态
systemctl start/stop firewalld  //防火墙启停
firewall-cmd --list-ports    //查看开放的端口
firewall-cmd --zone=public --query-port=80/tcp    //查询80端口是否开放
firewall-cmd --zone=public --add-port=80/tcp --permanent     //开放80端口
firewall-cmd --zone=public --remove-port=80/tcp --permanent    //移除80端口
firewall-cmd --reload    //重新加载
如果开放了执行上放开80端口还不行，那就再执行iptables -F

setenforce 0
vim /etc/selinux/config   将seLIUNX永久关闭
getenforce   #查看seliunx状态如果出现disabled或者permissive示示已关闭

vim /etc/nginx/conf.d/default.conf  #将默认配置的监听端口改成8080

cd /etc/nginx/conf.d/
vim it.conf
server {
        listen       80;                        #指定监听端口80
        server_name  it.founderpcb.com;          #指定当前网的访问的域名
        location / {                              #指定代码位置
          proxy_pass https://pcbsrvdhcp114.founderpcb.com;  #指定首页文件 
        }
    }

systemctl start nginx       启动nginx
systemctl stop nginx         停止nginx
systemctl  restart nginx   重启nginx
nginx -s reload   重新加nginx配置
nginx -V 查看版本

yum install -y keepalived

vim  /etc/keepalived/keepalived.conf

! Configuration File for keepalived
vrrp_script chk_nginx {
    script "/etc/keepalived/nginx_check.sh" #运行脚本，脚本内容下面有，就是起到一个nginx宕机以后，自动开启服务
    interval 2 #检测时间间隔
    weight -20 #如果条件成立的话，则权重 -20
}
# 定义虚拟路由，VI_1 为虚拟路由的标示符，自己定义名称
vrrp_instance VI_1 {
    state MASTER #来决定主从
    interface ens192 # 绑定虚拟 IP 的网络接口，根据自己的机器填写
    virtual_router_id 121 # 虚拟路由的 ID 号， 两个节点设置必须一样
    mcast_src_ip 172.21.57.17 #填写本机ip
    priority 100 # 节点优先级,主要比从节点优先级高
    nopreempt # 优先级高的设置 nopreempt 解决异常恢复后再次抢占的问题
    advert_int 1 # 组播信息发送间隔，两个节点设置必须一样，默认 1s
    authentication {
        auth_type PASS
        auth_pass 1111
    }     
    # 将track_script块加入instance 配置块
    track_script {
        chk_nginx #执行Nginx监控的服务
    }   
 
    virtual_ipaddress { 
        172.21.57.15 #虚拟ip
    }
}  

yum install -y keepalived

vim  /etc/keepalived/keepalived.conf

! Configuration File for keepalived
vrrp_script chk_nginx {
    script "/etc/keepalived/nginx_check.sh" #运行脚本，脚本内容下面有，就是起到一个nginx宕机以后，自动开启服务
    interval 2 #检测时间间隔
    weight -20 #如果条件成立的话，则权重 -20
}
# 定义虚拟路由，VI_1 为虚拟路由的标示符，自己定义名称
vrrp_instance VI_1 {
    state BACKUP #来决定主从
    interface  ens192 # 绑定虚拟 IP 的网络接口，根据自己的机器填写
    virtual_router_id 121 # 虚拟路由的 ID 号， 两个节点设置必须一样
    mcast_src_ip 172.21.57.18 #填写本机ip
    priority 100 # 节点优先级,主要比从节点优先级高
    nopreempt # 优先级高的设置 nopreempt 解决异常恢复后再次抢占的问题
    advert_int 1 # 组播信息发送间隔，两个节点设置必须一样，默认 1s
    authentication {
        auth_type PASS
        auth_pass 1111
    }    
    # 将 track_script 块加入 instance 配置块
    track_script {
        chk_nginx #执行 Nginx 监控的服务
    } 
             
    virtual_ipaddress {
        172.21.57.15 # 虚拟ip
    }
}   

vim /etc/keepalived/nginx_check.sh      #编辑脚本文件当检测nginx服务停止后立即关闭keepalived

#!/bin/bash
A=`ps -C nginx --no-header |wc -l`
if [ $A -eq 0 ];then
systemctl kill keepalived
fi

chmod 777 /etc/keepalived/nginx_check.sh     #授权脚本

systemctl start keepalived     #启动keepalived服务
systemctl restart keepalived   #重启keepalived服务
systemctl stop keepalived      #停止keepalived服务