Nginx + Keepalived 实现高可用集群

灰太狼 2023-07-08 02:41 102阅读 0赞

# 1.实验准备 #

需要两台虚拟和一台物理机（客户端）：

<table> 
 <thead> 
  <tr> 
   <th>虚拟机名称</th> 
   <th>ip</th> 
   <th>作用</th> 
  </tr> 
 </thead> 
 <tbody> 
  <tr> 
   <td>server 1</td> 
   <td>172.25.63.1</td> 
   <td>nginx server(MASTER)</td> 
  </tr> 
  <tr> 
   <td>server 2</td> 
   <td>172.25.63.2</td> 
   <td>nginx server(BACKUP)</td> 
  </tr> 
 </tbody> 
</table>

物理机ip：`172.25.63.250`  
虚拟ip （vip）：172.25.63.100  
实验环境： rhel7.3

# 2.软件安装 #

为 server1 和 server 2 安装`nginx`和`keepalived`

源码安装nginx可参考：[https://blog.csdn.net/qq\_35887546/article/details/104342257][https_blog.csdn.net_qq_35887546_article_details_104342257]  
安装 keepalived可参考：[https://blog.csdn.net/qq\_35887546/article/details/104428144][https_blog.csdn.net_qq_35887546_article_details_104428144] ，包括keepalived安装和制作软链接。

# 3.软件配置 #

## nginx配置 ##

在server 1 写入测试页面：

[root@server1 ~]# cd /usr/local/nginx/html
    [root@server1 html]# vim index.html
    [root@server1 html]# cat index.html 
    server1:nginx test

在server 2 写入测试页面：

[root@server2 ~]# cd /usr/local/nginx/html/
    [root@server2 html]# vim index.html
    [root@server2 html]# cat index.html 
    server2:nginx test

## keepalived 配置 ##

在server1和server2制作好软链接后：

在server1：

[root@server1 ~]# vim /etc/keepalived/keepalived.conf 
    [root@server1 ~]# cat /etc/keepalived/keepalived.conf 
    ! Configuration File for keepalived
    
    global_defs { 
     #  notification_email { 
     #    acassen@firewall.loc
     #    failover@firewall.loc
     #    sysadmin@firewall.loc
     #  }
     #  notification_email_from Alexandre.Cassen@firewall.loc
     #  smtp_server 192.168.200.1
     #  smtp_connect_timeout 30
       router_id LVS_DEVEL
     #  vrrp_skip_check_adv_addr
     #  vrrp_strict
     #  vrrp_garp_interval 0
     #  vrrp_gna_interval 0
    }
    vrrp_script chk_nginx { 
            script "/etc/keepalived/nginx_check.sh"
            interval 2
            weight -20
    }
    vrrp_instance VI_1 { 
        state MASTER					# server1 为主要服务器
        interface eth0
        virtual_router_id 51 
        #mcast_src_ip 172.25.63.1  
        priority 100					#优先级
        advert_int 1
        authentication { 
            auth_type PASS
            auth_pass 1111
        }
       track_script { 
                    chk_nginx
            }
        virtual_ipaddress { 
        172.25.63.100					#vip
    	}
    }

在server2：

[root@server2 ~]# vim /etc/keepalived/keepalived.conf
    [root@server2 ~]# cat /etc/keepalived/keepalived.conf 
    ! Configuration File for keepalived
    
    global_defs { 
     #  notification_email { 
     #    acassen@firewall.loc
     #    failover@firewall.loc
     #    sysadmin@firewall.loc
     #  }
     #  notification_email_from Alexandre.Cassen@firewall.loc
     #  smtp_server 192.168.200.1
     #  smtp_connect_timeout 30
       router_id dreamer1
     #  vrrp_skip_check_adv_addr
     #  vrrp_strict
     #  vrrp_garp_interval 0
     #  vrrp_gna_interval 0
    }
    vrrp_script chk_nginx { 
            script "/etc/keepalived/nginx_check.sh"
            interval 2
            weight -20
    }
    vrrp_instance VI_1 { 
        state BACKUP
        interface eth0 #绑定虚拟机的IP
        virtual_router_id 51 # 虚拟路由id，和从机保持一致
        #mcast_src_ip 172.25.63.2  #本机ip
        priority 90 
        advert_int 1
        authentication { 
            auth_type PASS
            auth_pass 1111
        }
       track_script { 
                    chk_nginx ## 执行 Nginx 监控的服务
            }
        virtual_ipaddress { 
        172.25.63.100
    	}
    }

## 编写监测心跳脚本 ##

上面配置中可以看到有一个脚本文件：`/etc/keepalived/nginx_check.sh`  
查看nginx是否启动，如果没启动则启动，如果启动不起来，停掉keepalived服务，此时心跳断掉，服务转向另一个nginx。  
在server1 和server2 都要编写该文件：

vim /etc/keepalived/nginx_check.sh
    #!/bin/bash
    counter=$(ps -C nginx --no-heading|wc -l)
    if [ "${counter}" = "0" ]; then
        /usr/sbin/nginx
        sleep 2
        counter=$(ps -C nginx --no-heading|wc -l)
        if [ "${counter}" = "0" ]; then
            /etc/init.d/keepalived stop
        fi
    fi

# 4.启动服务 #

在server1 和server2 启动 `nginx`和`keepalived`：

systemctl start keepalived				#启动keepalived
    /usr/local/nginx/sbin/nginx				#启动nginx

# 5.测试 #

在物理机（客户端）：

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[https_blog.csdn.net_qq_35887546_article_details_104342257]: https://blog.csdn.net/qq_35887546/article/details/104342257
[https_blog.csdn.net_qq_35887546_article_details_104428144]: https://blog.csdn.net/qq_35887546/article/details/104428144
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzM1ODg3NTQ2_size_16_color_FFFFFF_t_70]: https://img-blog.csdnimg.cn/20200224170436930.png?x-oss-process=image/watermark,type_ZmFuZ3poZW5naGVpdGk,shadow_10,text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzM1ODg3NTQ2,size_16,color_FFFFFF,t_70