centos7下keepalived+nginx配置

一、系统架构：

角色                                内网ip                    外网ip
keepalived+nginx           192.168.8.81         192.168.8.201
keepalived+nginx           192.168.8.82         192.168.8.201
web1                              192.168.8.83          -
web2                              192.168.8.84          -

二、nginx配置（两台nginx配置一模一样）：

1. 安装：

   yum  -y  install  nginx

2. 配置：
   vim /etc/nginx/nginx.conf

   user nginx;
   worker_processes auto;
   error_log /var/log/nginx/error.log;
   pid /run/nginx.pid;
   include /usr/share/nginx/modules/*.conf;
   events {
   worker_connections 1024;
   }
   http {
   log_format  main  '$remote_addr - $remote_user [$time_local] "$request" '
                     '$status $body_bytes_sent "$http_referer" '
                     '"$http_user_agent" "$http_x_forwarded_for"';
   access_log  /var/log/nginx/access.log  main;
   sendfile            on;
   tcp_nopush          on;
   tcp_nodelay         on;
   keepalive_timeout   65;
   types_hash_max_size 2048;
   include             /etc/nginx/mime.types;
   default_type        application/octet-stream;
   include /etc/nginx/conf.d/*.conf;
   upstream dynamic {
       server 192.168.8.83:80;
       server 192.168.8.84:80;
   }
   server {
       listen       80 default_server;
       listen       [::]:80 default_server;
       server_name  blog.dollarphp.com;
       root         /usr/share/nginx/html;
       include /etc/nginx/default.d/*.conf;
       location / {
           index index.html index.htm;
           autoindex on;
           autoindex_localtime on;
       }
       location ~* ^.+.(js|css|htm|html|gif|jpg|jpeg|png|bmp|swf|ioc|rar|zip|txt|flv|mid|doc|ppt|pdf|xls|mp3|wma)$ {
           root html;
       }
       location ~* ^.+.(?![js|css|htm|html|gif|jpg|jpeg|png|bmp|swf|ioc|rar|zip|txt|flv|mid|doc|ppt|pdf|xls|mp3|wma])$ {
           proxy_pass http://dynamic;
           proxy_set_header Host $host;
           proxy_set_header X-Real-IP $remote_addr;
           proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for; 
       }
       error_page 404 /404.html;
           location = /40x.html {
       }
       error_page 500 502 503 504 /50x.html;
           location = /50x.html {
       }
   }
   }

3. 启动：

   systemctl  start  nginx

   三、keepalived配置：

   I、主服务器配置（192.168.8.81）：

4. 安装：

   yum  -y  install  keepalived

5. 配置：
   vim /etc/keepalived/keepalived.conf

   ! Configuration File for keepalived
   global_defs {
   }
   vrrp_script chk_nginx {
   script "/etc/keepalived/check.sh"
   interval 1
   weight -15
   }
   vrrp_instance VI_1 {  #  实例，一个vip一个实例
   state MASTER
   interface eth0
   virtual_router_id 51
   priority 100
   advert_int 1
   authentication {
       auth_type PASS
       auth_pass 123456
   }
   virtual_ipaddress {
       192.168.8.201
   }
   track_script {
       chk_nginx
   }
   notify_master "/etc/keepalived/notify.sh master"
   notify_backup "/etc/keepalived/notify.sh backup"
   notify_fault "/etc/keepalived/notify.sh fault"
   }

6. 添加服务检查脚本（check.sh）：
   vim /etc/keepalived/check.sh

   #!/bin/bash
   # 心跳检测：如果服务还在运行返回0，否则返回1
   if [ "`pgrep  nginx  |  wc  -l`" == "0" ] ; then
   exit 1
   else
   exit 0
   fi

7. 通知脚本（notify.sh）：
   vim /etc/keepalived/notify.sh

   #!/bin/bash
   # 通知脚本：具体操作
   if [ "$1" == "master" ] ; then
   echo "`date '+%F %T'`：切换到主机模式" >> /var/log/keepalived/keepalived.log
   elif [ "$1" == "backup" ] ; then
   /usr/bin/systemctl start nginx
   echo "`date '+%F %T'`：切换到备机模式" >> /var/log/keepalived/keepalived.log
   else
   /usr/bin/systemctl start nginx
   echo "`date '+%F %T'`：宕机" >> /var/log/keepalived/keepalived.log
   fi

8. 给脚本添加可执行权限：

   chmod  +x  /etc/keepalived/check.sh
   chmod  +x  /etc/keepalived/notify.sh

9. 创建日志目录：

   mkdir  /var/log/keepalived

10. 启动：

    systemctl  start  keepalived

    II、备服务器配置（192.168.8.82）：

11. 安装：

    yum  -y  install  keepalived

12. 配置：
    vim /etc/keepalived/keepalived.conf

    ! Configuration File for keepalived
    global_defs {
    }
    vrrp_script chk_nginx {
    script "/etc/keepalived/check.sh"
    interval 1
    weight -15
    }
    vrrp_instance VI_1 {
    state BACKUP
    interface eth0
    virtual_router_id 51
    priority 99
    advert_int 1
    authentication {
        auth_type PASS
        auth_pass 123456
    }
    virtual_ipaddress {
        192.168.8.201
    }
    track_script {
        chk_nginx
    }
    notify_master "/etc/keepalived/notify.sh master"
    notify_backup "/etc/keepalived/notify.sh backup"
    notify_fault "/etc/keepalived/notify.sh fault"
    }

13. 添加服务检查脚本（check.sh）：
    vim /etc/keepalived/check.sh

    #!/bin/bash
    # 心跳检测：如果服务还在运行返回0，否则返回1
    if [ "`pgrep  nginx  |  wc  -l`" == "0" ] ; then
    exit 1
    else
    exit 0
    fi

14. 通知脚本（notify.sh）：
    vim /etc/keepalived/notify.sh

    #!/bin/bash
    # 通知脚本：具体操作
    if [ "$1" == "master" ] ; then
    echo "`date '+%F %T'`：切换到主机模式" >> /var/log/keepalived/keepalived.log
    elif [ "$1" == "backup" ] ; then
    /usr/bin/systemctl start nginx
    echo "`date '+%F %T'`：切换到备机模式" >> /var/log/keepalived/keepalived.log
    else
    /usr/bin/systemctl start nginx
    echo "`date '+%F %T'`：宕机" >> /var/log/keepalived/keepalived.log
    fi

15. 给脚本添加可执行权限：

    chmod  +x  /etc/keepalived/check.sh
    chmod  +x  /etc/keepalived/notify.sh

16. 创建日志目录：

    mkdir  /var/log/keepalived

17. 启动：

    systemctl  start  keepalived

    三、测试：

    I、测试负载均衡：

    
    

    II、测试心跳检测（主服务器：192.168.8.81）：

18. 停止nginx服务：

    systemctl  stop  nginx

19. 查看日志：

    tail  /var/log/keepalived/keepalived.log