服务搭建篇(四) 搭建基于Nginx + keepalived的高可用服务

yum install gcc gcc-c++ make automake autoconf libtool pcre pcre-devel zlib zlib-devel openssl openssl-devel

wget http://nginx.org/download/nginx-1.13.0.tar.gz

tar -zxvf nginx-1.13.0.tar.gz

cd nginx-1.13.0
./configure --prefix=/usr/local/nginx
make && make install

vim /usr/local/nginx/html/index.html

/usr/local/nginx/sbin/nginx -t

/usr/local/nginx/sbin/nginx

vim /usr/lib/systemd/system/nginx.service

[Unit]
Description=nginx
After=network.target
[Service]
Type=forking
ExecStart=/usr/local/nginx/sbin/nginx
ExecReload=/usr/local/nginx/sbin/nginx -s reload
ExecStop=/usr/local/nginx/sbin/nginx -s quit
PrivateTmp=true
[Install]
WantedBy=multi-user.target

https://www.keepalived.org/software/keepalived-2.0.20.tar.gz

tar -zxvf keepalived-2.0.20.tar.gz

cd keepalived-2.0.20
./configure --prefix=/usr/local/keepalived
make && make install

mkdir /etc/keepalived
cp /usr/local/keepalived/etc/keepalived/keepalived.conf /etc/keepalived/
cp /usr/local/keepalived/sbin/keepalived /etc/init.d/

vim /etc/keepalived/keepalived.conf

! Configuration File for keepalived
global_defs {
  ## keepalived 自带的邮件提醒需要开启 sendmail 服务。 建议用独立的监控或第三方 SMTP
  router_id node08 ## 标识本节点的字条串，通常为 hostname
} 
## keepalived 会定时执行脚本并对脚本执行的结果进行分析，动态调整 vrrp_instance 的优先级。如果脚本执行结果为 0，并且 weight 配置的值大于 0，则优先级相应的增加。如果脚本执行结果非 0，并且 weight配置的值小于 0，则优先级相应的减少。其他情况，维持原本配置的优先级，即配置文件中 priority 对应的值。
vrrp_script chk_nginx {
  script "/etc/keepalived/nginx_check.sh" ## 检测 nginx 状态的脚本路径
  interval 2 ## 检测时间间隔
  weight -20 ## 如果条件成立，权重-20
}
## 定义虚拟路由， VI_1 为虚拟路由的标示符，自己定义名称
vrrp_instance VI_1 {
  state MASTER ## 主节点为 MASTER， 对应的备份节点为 BACKUP
  interface ens33 ## 绑定虚拟 IP 的网络接口，与本机 IP 地址所在的网络接口相同， 我的是 eth0
  virtual_router_id 33 ## 虚拟路由的 ID 号， 两个节点设置必须一样， 可选 IP 最后一段使用, 相同的 VRID 为一个组，他将决定多播的 MAC 地址
  mcast_src_ip 192.168.154.134 ## 本机 IP 地址
  priority 100 ## 节点优先级， 值范围 0-254， MASTER 要比 BACKUP 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
  ## 设置验证信息，两个节点必须一致
  authentication {
    auth_type PASS
    auth_pass 1111 ## 真实生产，按需求对应该过来
  }
  # 虚拟 IP 池, 两个节点设置必须一样
  virtual_ipaddress {
    192.168.154.10 ## 虚拟 ip，可以定义多个
  }
  ## 将 track_script 块加入 instance 配置块
  track_script {
    chk_nginx ## 执行 Nginx 监控的服务
  } 
}

vim /etc/keepalived/nginx_check.sh
1
#!/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

systemctl start keepalived

systemctl start keepalived #启动
systemctl restart keepalived #重启
systemctl stop keepalived #关闭
systemctl status keepalived # 状态