Docker+Nginx+KeepaLived实现Nginx一主一从高可用

news2024/11/29 10:36:05

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

1. 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

2.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：
在这里插入图片描述
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。