Nginx+keepalived一主一从高可用，手把手带你一步一步配置！

网络技术联盟站

发布于 2020-10-27 15:47:19

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发布于 2020-10-27 15:47:19

文章被收录于专栏：网络技术联盟站网络技术联盟站

本文作者：墨篱弦

?一、实验环境
?二、配置环境
?三、 Keepalived安装部署
?四、进入安装后的路径
?五、修改keepalived 的配置
?六、启动nginx
?七、验证冗余
?八、利用脚本实现自动切换
?九、测试keepalived利用脚本能否让nginx自动重启

一、实验环境

1.准备两台NGINX环境的服务器

Nginx40.14 IPADDR=192.168.40.14
Nginx_40.15 IPADDR=192.168.40.15

2.准备一台tomcat服务器

Docker40.16 Tomcat8081 192.168.40.16:8081
Tomcat8082 192.168.40.16:8082

二、配置环境

Nginx40.14

IPADDR=192.168.40.14

Keepalived.conf配置：

vrrp_instance VI_1
state MASTER
interface ens33
virtual_router_id 17
priority 150
virtual_ipaddress 192.168.40.17

Nginx_40.15

IPADDR=192.168.40.15

Keepalived.conf配置：

vrrp_instance VI_1
state BACKUP
interface ens33
virtual_router_id 17
priority 99
virtual_ipaddress 192.168.40.17

Docker40.16

利用docker部署两个tomcat容器，并启动容器。

Tomcat8081
192.168.40.16:8081

Tomcat8082
192.168.40.16:8082

三、 Keepalived安装部署

Keepalived下载地址https://www.keepalived.org/download.html，下载keepalived-2.1.5.tar.gz安装包

1. 安装依赖环境

yum –y install curl gcc openssl-devel libnl3-devel net-snmp-devel libnfnetlink-devel

2. 创建目录/data/keepalived

mkdir /software

此为软件存放目录

3. 上传安装包到/software

4. 解压安装包

tar -zxvf keepalived-2.1.5.tar.gz

5. 进入keepalived-2.1.5目录

cd keepalived-2.1.5
./configure --prefix=/data/keepalived --sysconf=/etc

6. 编译安装

make & manke install

确保依赖都安装的情况下更换keepalived低版本

四、进入安装后的路径

cd /data/keepalived/

1. 创建软连接

ln -s sbin/keepalived /sbin/

2. 覆盖软连接

ln -snf sbin/keepalived /sbin

3. 复制运行命令

cp /software/keepalived-2.1.5/keepalived/etc/init.d/keepalived /etc/init.d
chkconfig --add keepalived

4. 添加到系统服务

chkconfig keepalived on

5. 启动服务

service keepalived start

6. 查看启动状态

service keepalived status

五、修改keepalived 的配置

Master配置

vim /etc/keepalived/（最小配置）

! Configuration File for keepalived

global_defs {
  router_id NGINX
   }


vrrp_instance VI_1 {
    state MASTER
    interface ens33
    virtual_router_id 17
    priority 150
    advert_int 1
    authentication {
        auth_type PASS
        auth_pass 1111
    }
    virtual_ipaddress {
        192.168.40.17
    }
}

Backup配置

vim /etc/keepalived/（最小配置）

! Configuration File for keepalived

global_defs {
   router_id NGINX
   }

vrrp_instance VI_1 {
    state BACKUP
    interface ens33
    virtual_router_id 17
    priority 99
    advert_int 1
    authentication {
        auth_type PASS
        auth_pass 1111
    }
    virtual_ipaddress {
        192.168.40.17
      }
}

六、启动nginx

/usr/local/nginx/sbin/nginx

启动keepalived

service keepalived start

查看网卡是否获取到虚拟IP

Ip add

验证试验

curl http://192.168.40.17

七、验证冗余

手动停止 nginx服务

/usr/local/nginx/sbin/nginx –s stop

网页无法开启

手动停止keepalived服务

service keepalived stop

网页正常

八、利用脚本实现自动切换

1. Keepalived检测nginx运行状态的脚本

#!/bin/bash
A=`ps -C nginx --no-header|wc -l` -->判断nginx的服务进程数并统计
if [ $A -eq 0 ];then -->假如数量为0则执行以下脚本
/usr/local/nginx/sbin/./nginx
sleep 2 -->进程休眠2秒
if [ `ps -C nginx --no-header|wc -l` -eq 0 ];then -->假如nginx服务进程总数还是0则执行以下脚本
killall keepalived -->结束keepalived所有进程
fi
fi

2. 修改keepalived.conf配置

Nginx-keepalived-MASTER

! Configuration File for keepalived

global_defs {
  router_id NGINX #路由标识同一个主备必须相同
   }

vrrp_script chk_nginx {
         script "/root/chk_nginx.sh" #检测脚本的路径
         interval 2 #脚本执行间隔
         weight -5 #失败一次自己优先级降低5
 }


vrrp_instance VI_1 {
    state MASTER #节点状态，主节点为MASTER，备节点为BACKUP
    interface ens33 #vip绑定的网络接口
    virtual_router_id 17 #虚拟路由ID，方便记录可以使用IP最后一位VRID区间是0~255正证书
    priority 100 #节点优先级，优先级是0~255正整数
    advert_int 1
    authentication { #认证
        auth_type PASS #明文认证
        auth_pass 1111 #认证密码
    }
    virtual_ipaddress {
        192.168.40.17/24 #虚拟IP/掩码
    }

       track script { #追踪脚本
          chk_nginx 
       } 
 }

Nginx-keepalived-BACKUP

! Configuration File for keepalived

global_defs {
   router_id NGINX #路由标识同一个主备必须相同
   }

vrrp_instance VI_1 {
    state BACKUP #节点状态，主节点为MASTER，备节点为BACKUP
    interface ens33 #vip绑定的网络接口
    virtual_router_id 17 #虚拟路由ID，方便记录可以使用IP最后一位VRID区间是0~255正证书
    priority 99  #节点优先级，优先级是0~255正整数
    advert_int 1
    authentication { #认证
        auth_type PASS #明文认证
        auth_pass 1111 #认证密码
    }
    virtual_ipaddress {
        192.168.40.17/24 #虚拟IP/掩码

      }

     }

}