?作者：冉南阳

简介

本文通过Keepalived服务vip漂移的方式配置Nginx的高可用；当vip所在节点的Nginx服务宕掉后，会将vip漂移到另外一个节点。而在配置Nginx的配置时，分别在两个节点配置Nginx服务，然后两个Nginx服务配置相同的负载均衡等配置；在配置连接时不使用两个Nginx节点的ip，而是使用vip; 以这样的方式实现Nginx的高可用。

Nginx安装

在两个节点同时安装Nginx,此处展示一个节点

下载安装包

wget http://nginx.org/download/nginx-1.12.2.tar.gz

解压并进行编译安装,默认安装目录为/usr/local/nginx

tar -zxf nginx-1.12.2.tar.gz 
cd nginx-1.12.2
./configure --with-stream

make && make install

添加到systemctl启动项

编写脚本/usr/lib/systemd/system/nginx.service

[Unit]
Description=nginx - high performance web server
After=network.target remote-fs.target nss-lookup.target
[Service]
Type=forking
ExecStart=/usr/local/nginx/sbin/nginx -c /usr/local/nginx/conf/nginx.conf
ExecReload=/usr/local/nginx/sbin/nginx -s reload
ExecStop=/usr/local/nginx/sbin/nginx -s stop
[Install]
WantedBy=multi-user.target

将服务添加到开机自启动

systemctl enale nginx

systemctl start nginx
systemctl status nginx

此处修改端口为8089，默认端口为80；配置文件默认在/user/local/nginx/conf/nginx.conf

启动成功

安装Keepalived

两个节点都安装

yum -y install keepalived

添加到开机自启动

配置HA

1.两个节点同时配置

编辑脚本/etc/keepalived/nginx_check.sh，脚本内容如下(nginx _check.sh)，两个节点都需要该脚本。

#!/bin/bash
A=`ps -C nginx --no-header | wc -l`
if [ $A -eq 0 ];then
/etc/init.d/nginx start
sleep 3
if [ `ps -C nginx --no-header | wc -l ` -eq 0 ];then
/etc/init.d/nginx stop
fi
fi

增加执行权限

chmod +x /etc/keepalived/nginx_check.sh

2.节点cdh234.macro.com配置Keepalived

修改配置文件/etc/keepalived/keepalived.conf,配置vip为192.168.0.245

启动Keepalived服务

systemctl start keepalived

vip已绑定成功

cdh235.macro.com节点ping 192.168.0.245

停止Keepalived服务后查看192.168.0.245已从网卡ens192解绑

3．节点cdh235.macro.com配置Keepalived

修改配置文件/etc/keepalived/keepalived.conf,配置vip为192.168.0.245

启动Keepalived服务

systemctl start keepalived

vip已绑定成功

cdh234.macro.com节点ping 192.168.0.245

验证Keepalived服务IP漂移

两个节点同时起Keepalived

只有其中一个节点cdh235.macro.com绑定了vip 192.168.0.245

停止cdh235.macro.com的服务Keepalived，cdh235.macro.com解绑vip，cdh234.macro.com绑定vip

验证Nginx的高可用

vip绑定在cdh234.macro.com节点上

使用vip:8089访问nginx的web界面成功

停止cdh234.macro.com节点的nginx,vip已没有绑定;vip 绑定到节点cdh235.macro.com

依然可以访问