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

角色	IP 地址
主服务器（Master）	192.168.159.129
备用服务器（Backup）	192.168.159.130
虚拟IP（VIP）	192.168.159.120
Keepalived版本	1.4.5

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.gzcd keepalived-1.4.5./configure --prefix=/usr/local/keepalivedmake && make install

2.1.1 配置文件配置

# 配置文件 keepalived.conf 配置
mkdir -p /etc/keepalivedvim keepalived.conf# 配置文件内容
! Configuration File for keepalivedglobal_defs {router_id NGINX_MASTERscript_user rootenable_script_security
}vrrp_instance VI_1 {state MASTERinterface ens33virtual_router_id 51priority 100advert_int 1mcast_src_ip 192.168.159.129authentication {auth_type PASSauth_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 keepalivedglobal_defs {router_id NGINX_BACKUPscript_user rootenable_script_security
}vrrp_instance VI_1 {state BACKUPinterface ens33virtual_router_id 51priority 90advert_int 1mcast_src_ip 192.168.159.130authentication {auth_type PASSauth_pass 1111}virtual_ipaddress {192.168.159.200}
}