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Docker+Nginx+KeepaLived实现Nginx一主一从高可用方式

2025-07-24 14:17:54 作者：抹香鲸之海

在CentOS7主从服务器上部署Nginx容器并配置Keepalived实现高可用,通过虚拟IP自动切换,主从均需安装Keepalived,配置健康检查脚本监控Nginx状态,故障时自动重启或切换虚拟IP,需关闭防火墙和SELinux,并确保脚本有执行权限

系统版本 Centos7
IP：10.10.11.79 Master
IP：10.10.11.81 Slave
虚拟ip：10.10.11.77

客户端发起一个请求，请求没有到Nginx的实际IP上，而是请求的虚拟IP(会和实际IP通过配置文件进行绑定）

如果有一台Nginx服务器挂了，Keepalived会自动在备Nginx服务器上选一台当主服务器

主从两台机器上分别启动nginx容器

两台nginx容器要用相同的端口号：

docker run -d --privileged=true --name keepalivedNginx -p 82:80 nanlist/nginx1.23.1:v1.0

在两台宿主机器上分别安装 keepalived

（注意：keepalived安装在实体机上，不是安装到Docker容器中）

1.联网下载到/usr/local目录

下并解压有可能会提示连接不成功,加上它提示的命令再下载就好了

如果下载不下来用浏览器下载下来再传到服务上面也可以

两台服务器分别执行下：

主：

[root@Master html]# cd /usr/local
[root@Master local]# wget https://www.keepalived.org/software/keepalived-1.4.2.tar.gz
[root@Master local]# tar -zxvf keepalived-1.4.2.tar.gz

从：

[root@Slave html]# cd /usr/local
[root@Slave local]# wget https://www.keepalived.org/software/keepalived-1.4.2.tar.gz
[root@Slave local]# tar -zxvf keepalived-1.4.2.tar.gz

2.安装相关依赖,有不用下载了

主：

[root@Master local]# yum install -y gcc openssl-devel popt-devel

从：

[root@Slave local]# yum install -y gcc openssl-devel popt-devel

3.编译安装

主：

[root@Master local]# cd keepalived-1.4.2
[root@Master keepalived-1.4.2]# ./configure --prefix=/usr/local/keepalived
[root@Master keepalived-1.4.2]# make
[root@Master keepalived-1.4.2]# make install

从：

[root@Slave local]# cd keepalived-1.4.2
[root@Slave keepalived-1.4.2]# ./configure --prefix=/usr/local/keepalived
[root@Slave keepalived-1.4.2]# make
[root@Slave keepalived-1.4.2]# make install

4.相关配置,按命令执行

主：

[root@Master keepalived-1.4.2]# pwd
/usr/local/keepalived-1.4.2
You have new mail in /var/spool/mail/root
[root@Master keepalived-1.4.2]# cp /usr/local/keepalived-1.4.2/keepalived/etc/init.d/keepalived /etc/init.d/
[root@Master keepalived-1.4.2]# mkdir /etc/keepalived
[root@Master keepalived-1.4.2]# cp /usr/local/keepalived/etc/keepalived/keepalived.conf /etc/keepalived/
[root@Master keepalived-1.4.2]# cp /usr/local/keepalived-1.4.2/keepalived/etc/sysconfig/keepalived /etc/sysconfig/
[root@Master keepalived-1.4.2]# cp /usr/local/keepalived/sbin/keepalived /usr/sbin/

从：

[root@Slave keepalived-1.4.2]# pwd
/usr/local/keepalived-1.4.2
You have new mail in /var/spool/mail/root
[root@Slave keepalived-1.4.2]# cp /usr/local/keepalived-1.4.2/keepalived/etc/init.d/keepalived /etc/init.d/
[root@Slave keepalived-1.4.2]# mkdir /etc/keepalived
[root@Slave keepalived-1.4.2]# cp /usr/local/keepalived/etc/keepalived/keepalived.conf /etc/keepalived/
[root@Slave keepalived-1.4.2]# cp /usr/local/keepalived-1.4.2/keepalived/etc/sysconfig/keepalived /etc/sysconfig/
[root@Slave keepalived-1.4.2]# cp /usr/local/keepalived/sbin/keepalived /usr/sbin/
[root@Slave keepalived-1.4.2]#

安装之后

在 /etc/keepalived目录下有个 keepalived.conf 配置文件：

主：

vim /etc/keepalived/keepalived.conf

编辑内容：

global_defs {  
	router_id LVS_DEVEL 
}  

# 检查nginx状态的脚本，健康监测脚本
vrrp_script chk_nginx {
	script "/etc/keepalived/nginx_check.sh" # 脚本路径
	interval 2 # 脚本执行间隔时间
	weight -20
}
  
vrrp_instance VI_1 {  
    state MASTER  
    interface ens192  # 当前进行vrrp通讯的网络接口卡(当前centos的网卡) 用ifconfig查看你具体的网卡
    virtual_router_id 51  # 虚拟路由编号，主从要一至
    priority 150 # 优先级，数值越大，获取处理请求的优先级越高 master要大于slave
	advert_int 1
	unicast_src_ip 10.10.11.79 # 本机ip
	
	track_script {
		chk_nginx
	}

    nopreempt
    authentication {  
        auth_type PASS  # 指定认证方式。PASS简单密码认证(推荐),AH:IPSEC认证(不推荐)
        auth_pass 1111  # 指定认证所使用的密码。最多8位
    }  
    unicast_peer { # 另外一台的服务器ip，如果是多台就配多个ip
        10.10.11.81
    }
    virtual_ipaddress {  # 指定VIP地址
        10.10.11.77
    }  

}

从：

编辑：

vim /etc/keepalived/keepalived.conf

配置内容：

global_defs {
	router_id LVS_DEVEL
}

vrrp_script chk_nginx {
	script "/etc/keepalived/nginx_check.sh"
	interval 2
	weight -20 
}

vrrp_instance VI_1 {
	state Slave
	interface ens192
	virtual_router_id 51
	priority 90
	advert_int 1
	unicast_src_ip 10.10.11.81
	unicast_peer {
		10.10.11.79
	}

	nopreempt
	authentication {
		auth_type PASS
		auth_pass 1111
	}

	track_script {
		chk_nginx
	}

	virtual_ipaddress {
		10.10.11.77
	}
}

健康监测脚本

主从机都需配置检测nginx是否在运行,不在允许就直接启动nginx的脚本,和keepalived放在一起

脚本名称 nginx_check.sh

如果 nginx 停止运行，尝试启动，如果无法启动则杀死本机的 keepalived 进程，keepalived将虚拟 ip 绑定到 BACKUP 机器上。内容如下：

#!/bin/bash
#version 0.0.1
#当nginx进程不存在时，会自动重启nginx服务；
A=`ps -C nginx --no-header |wc -l`
if [ $A -eq 0 ];then
     docker restart keepalivedNginx     #重启nginx
     sleep 2
     if [ `ps -C nginx --no-header |wc -l` -eq 0 ];then
        systemctl stop keepalived
     fi 
fi

编辑完以后放入到/etc/keepalived目录下：

只要配置好了,以后直接启动keepalived就好了,keepalived运行之后就会检测nginx是否在运行,不在运行就通过脚本去启动

自动重启不了解决方案

查看脚本是否有运行的权限

如果你是root登陆的话(不是的话，切换到root用户，对*.sh 赋可执行的权限)

chmod 777*.sh

或者

chmod +x *.sh

主从两台服务器这一步授权一定要执行不然脚本会失效：

[root@Master keepalived]# chmod +x nginx_check.sh 
[root@Master keepalived]# ll
total 12
-rw-r--r-- 1 root root 572 Oct 12 03:55 keepalived.conf
-rw-r--r-- 1 root root 3550 Oct 12 03:48 keepalived.conf.bak
-rwxr-xr-x 1 root root 205 Oct 12 04:04 nginx_check.sh
[root@Master keepalived]#

脚本上传以后重启keepalived。

keepalived常用命令

#启动

service keepalived start

#停止

service keepalived stop

#查看状态

service keepalived status

验证

1：如果验证主从是否可以自动切换实现热备效果可以把其中一台机器的keepalived服务stop掉，然后刷新虚拟ip。

2：如果验证健康脚本是否生效，可以把nginx容器stop掉，过两秒再次查看一下nginx容器是否启动。

注意：可能出现检测脚本不执行

可能的原因是selinux和防火墙没有关闭

setenforce 0

vim /etc/selinux/config

将ELINUX的值修改为

ELINUX=disabled

总结

以上为个人经验，希望能给大家一个参考，也希望大家多多支持脚本之家。