Nginx-keepalived-高可用

Nginx 高可用 通常 借助 Keepalived 实现， Keepalived 能通过 VRRP （虚拟路由冗余协议）让多个 Nginx 服务器 组成一个 热备集群，当主服务器故障时自动切换到备用服务器，保障服务不间断。

一、环境准备

二、源码安装 Keepalived 服务

2.1 在节点 Mater 上安装 keepalived

# 安装依赖
yum install openssl-devel libnl3-devel ipset-devel -y
yum install libnfnetlink-devel -y

# 下载源码
wget https://www.keepalived.org/software/keepalived-1.4.5.tar.gz

# 解压
tar -zxvf  keepalived-1.4.5.tar.gz

cd keepalived-1.4.5

./configure --prefix=/usr/local/keepalived

make && make install

2.1.1 配置文件配置

# 配置文件 keepalived.conf 配置
mkdir -p /etc/keepalived

vim keepalived.conf

# 配置文件内容
! Configuration File for keepalived

global_defs {
   router_id NGINX_MASTER
   script_user root
   enable_script_security
}


vrrp_instance VI_1 {
    state MASTER
    interface ens33
    virtual_router_id 51
    priority 100
    advert_int 1
        mcast_src_ip 192.168.159.129
    authentication {
        auth_type PASS
        auth_pass 1111
    }
    virtual_ipaddress {
        192.168.159.200
    }
}

2.1.2 把keepalived 配置成系统命令

• 创建 服务文件

  vim /etc/systemd/system/keepalived.service
  
  [Unit]
  Description=Keepalived High Availability Service
  After=network.target
  
  [Service]
  Type=forking
  PIDFile=/var/run/keepalived.pid
  ExecStart=/usr/local/keepalived/sbin/keepalived --pid=/var/run/keepalived.pid --config=/etc/keepalived/keepalived.conf
  ExecReload=/bin/kill -HUP $MAINPID
  KillMode=process
  Restart=on-failure
  
  [Install]
  WantedBy=multi-user.target
  

• 重新加载 Systemd 配置并启动服务

  sudo systemctl daemon-reload
  sudo systemctl start keepalived
  sudo systemctl enable keepalived
  

• 检查服务状态

  sudo systemctl status keepalived
  

2.2 在节点 Backup 上安装 Keepalived

安装方法与 Master 一致， 配置文件 keepalived.conf 需要修给为以下

! Configuration File for keepalived

global_defs {
   router_id NGINX_BACKUP
   script_user root
   enable_script_security
}


vrrp_instance VI_1 {
    state BACKUP
    interface ens33
    virtual_router_id 51
    priority 90
    advert_int 1
    mcast_src_ip 192.168.159.130
    authentication {
        auth_type PASS
        auth_pass 1111
    }
    virtual_ipaddress {
        192.168.159.200
    }
}

三、启动 keepalived 服务验证 VIP 是否挂起

四、安装 Nginx 服务器

pass

五、测试 Nginx

在 Master 上的 Nginx 的 HTML配置 MASTER

在 Backup 上的 Nginx 的 HTML 配置 Buckup

5.1 访问虚拟 IP 192.168.159.200

5.2 把 Master 的 keepalived 关闭，模拟服务故障

发现 VIP 192.168.159.200 切换到 备用服务器，访问 192.168.159.120