nginx+keepalived简单双机主从热备（集群版）

快来打我* 2022-03-18 01:46 192阅读 0赞

## 目标： ##

主nginx 172.25.62.101
      从nginx 172.25.62.102
      虚拟ip 172.25.62.115

## 一.安装nginx ##

1.安装nginx相关依赖（如果已经安装请跳过）
      mkdir /home/nginx  #新建nginx目录
      a.安装gcc gcc-c++
        yum install -y gcc gcc-c++
      b.安装PCRE库
        cd /home/nginx/
        wget http://jaist.dl.sourceforge.net/project/pcre/pcre/8.33/pcre-8.33.tar.gz
        tar -zxvf pcre-8.33.tar.gz
        cd pcre-8.33
        ./configure
        make && make install
      c.安装SSL库
        cd /home/nginx/
        wget http://www.openssl.org/source/openssl-1.0.1j.tar.gz
        tar -zxvf openssl-1.0.1j.tar.gz
        cd openssl-1.0.1j
       ./config
        make && make install
      d.安装zlib库存
        cd /home/nginx/
        wget http://zlib.net/zlib-1.2.11.tar.gz
        tar -zxvf zlib-1.2.11.tar.gz
        cd zlib-1.2.11
       ./configure
        make && make install
        
    2.安装nginx
        cd /home/nginx/
        wget http://nginx.org/download/nginx-1.8.0.tar.gz
        tar -zxvf nginx-1.8.0.tar.gz
    	cd nginx-1.8.0 
    	./configure
    	make && make install
    	
    3.	启动nginx
        /usr/local/nginx/sbin/nginx
        ps -ef|grep nginx  #查看nginx进程

## 二.安装keepalived ##

1.下载keepalived
       cd /home/nginx/
       wget http://www.keepalived.org/software/keepalived-1.2.18.tar.gz
       
    2.解压安装：
       tar -zxvf keepalived-1.2.18.tar.gz -C /usr/local/
       
    3.下载插件openssl
       yum install -y openssl openssl-devel（需要安装一个软件包）
       
    4.开始编译keepalived
       cd keepalived-1.2.18/ && ./configure --prefix=/usr/local/keepalived
       
    5.make一下
       make && make install
       
    6.复制脚本文件，建立软连接
       mkdir /etc/keepalived
       cp /usr/local/keepalived/etc/keepalived/keepalived.conf /etc/keepalived/  #复制脚本文件
       cp /usr/local/keepalived/etc/rc.d/init.d/keepalived /etc/init.d/  #复制脚本文件
       cp /usr/local/keepalived/etc/sysconfig/keepalived /etc/sysconfig/  #复制脚本文件
       ln -s /usr/local/keepalived/sbin/keepalived /usr/sbin/    #建立软连接
       chkconfig keepalived on  #设置开机自启动
       
    7.修改keepalived配置文件
       vi /etc/keepalived/keepalived.conf
       vrrp_script chk_nginx {
    	    script "/etc/keepalived/nginx_check.sh" #自动开启服务，该脚本在下面
    	    interval 2 #检测时间间隔
    	    weight -20 #如果条件成立的话，则权重 -20
    	}
        vrrp_instance VI_1 {
        state MASTER #来决定主从
        interface ens160# 绑定虚拟 IP 的网络接口，根据自己的机器填写，linux通过ip a 来查看
        virtual_router_id 121 # 虚拟路由的 ID 号， 两个节点设置必须一样
        mcast_src_ip 172.25.62.101 #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 {
            172.25.62.115 #必须和本机ip在同一个网段
        }
    }

上面interface填写的值，如下图查看  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzM1ODU5ODQ0_size_16_color_FFFFFF_t_70]  
以下是开机自启动脚本：nginx\_check.sh

#!/bin/bash
    A=`ps -C nginx –no-header |wc -l`
    if [ $A -eq 0 ];then
        /usr/local/nginx/sbin/nginx
        sleep 2
        if [ `ps -C nginx --no-header |wc -l` -eq 0 ];then
            killall keepalived
        fi
    fi

说明：该脚本放在 cd /etc/keepalived/目录

## 三.keepalived ##

service keepalived start  #启动keepalived
     service keepalived stop   #停止keepalived
     service keepalived restart  #停止重启keepalived

输入 ip a 查看虚拟ip  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzM1ODU5ODQ0_size_16_color_FFFFFF_t_70 1]  
这样我们就配好了主nginx和主keepalived

那么接下来按相同的方法配置从nginx和从keepalived即可，只需要修改从keepalived配置文件：

vi /etc/keepalived/keepalived.conf    #进入从keepalived配置文件
      vrrp_script chk_nginx {
       		    script "/etc/keepalived/nginx_check.sh" #自动开启服务，该脚本在下面
       		    interval 2 #检测时间间隔
       		    weight -20 #如果条件成立的话，则权重 -20
       		}
       	vrrp_instance VI_1 {
       	    state MASTER #来决定主从
       	    interface ens160# 绑定虚拟 IP 的网络接口，根据自己的机器填写，linux通过ip a 来查看
       	    virtual_router_id 121 # 虚拟路由的 ID 号， 两个节点设置必须一样
       	    mcast_src_ip 172.25.62.102 #填写本机ip
       	    priority 99# 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 {
       	        172.25.62.115 #必须和本机ip在同一个网段
       	    }
       	}

## 四.启动从nginx和从keepalived ##

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzM1ODU5ODQ0_size_16_color_FFFFFF_t_70 2]  
此时从keepalived是没有生成虚拟ip的，有虚拟ip的是主keepalived，只有当主nginx挂了之后，从keepalived才生成相同的虚拟ip

## 五.测试一下 ##

通过虚拟ip访问主nginx  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzM1ODU5ODQ0_size_16_color_FFFFFF_t_70 3]  
当主nginx挂了之后，  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzM1ODU5ODQ0_size_16_color_FFFFFF_t_70 4]  
此时跳转到从nginx，这时从服务器生成了虚拟ip  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzM1ODU5ODQ0_size_16_color_FFFFFF_t_70 5]

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