负载均衡Nginx+KeepAlived

192.168.1.150 VOIP 虚拟IP
192.168.1.151 CNSHANK01 负载均衡1
192.168.1.152 CNSHANK02 负载均衡2
系统：Centos7.4

一、nginx配置（两台nginx配置一模一样，主页设置不同）：

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 12800;
   use epoll;
   }
   http {

include mime.types;
default_type application/octet-stream;
limit_conn_zone $binary_remote_addr zone=addr:10m; #防IP***

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; #协助部分浏览器（如firefox）识别网页文件的类型
default_type application/octet-stream;
include /etc/nginx/conf.d/*.conf;

client_body_buffer_size 1k; #指定客户端请求主体缓冲区大小
client_header_buffer_size 1k; #指定来自客户端请求头的headerbuffer大小
large_client_header_buffers 2 1k; #客户端请求中较大的消息头指定的缓存最大数量和大小
server_tokens off; #禁止在错误页面上显示nginx版本号
client_body_timeout 20; #设置客户端请求主体读取超时时间
client_header_timeout 20; #设置客户端请求头读取超时时间
gzip on;

upstream dynamic { #负载服务器名dynamic
ip hash; #采用ip_hash方式
server 192.168.1.154:80;
server 192.168.1.155:80;
}
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 / {

limit_conn addr 100; #指定每个ip最多只允许建立100个连接
limit_rate 500k; #每个ip最大带宽是500k
proxy_next_upstream error timeout invalid_header http_500 http_502 http_503 http_504 http_404;

    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. 设置配置主页测试文件
   cd /usr/share/nginx/html
   cp ./index.html ./index.html.bak
   echo “CNSHANK01-192.168.1.151”>./index.html #在主机192.1681.151上
   echo “CNSHANK02-192.168.1.152”>./index.html #在主机192.1681.152上

4. 启动
   systemctl start nginx
   systemctl enable nginx

二、keepalived配置：
I、主服务器配置（192.168.1.151）：

5. 安装：
   yum -y install keepalived

6. 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 #标识为主服务
   interface ens33
   virtual_router_id 51 #与从机保持一致即可
   priority 100 #权重 ，高于从机
   advert_int 1
   authentication { # 认证授权，设置验证信息，两个节点必须一致
   auth_type PASS
   auth_pass 123456
   }
   virtual_ipaddress { #虚拟ip地址
   192.168.1.150
   }
   track_script { #nginx监控服务
   chk_nginx
   }
   notify_master "/etc/keepalived/notify.sh master"
   notify_backup "/etc/keepalived/notify.sh backup"
   notify_fault "/etc/keepalived/notify.sh fault"
   }

7. 添加服务检查脚本（check.sh）：
   vim /etc/keepalived/check.sh
   #!/bin/bash
   if [ "pgrep nginx | wc -l" == "0" ] ; then
   exit 1
   else
   exit 0
   fi

8. 通知脚本（notify.sh）：
   vim /etc/keepalived/notify.sh
   #!/bin/bash
   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

9. 给脚本添加可执行权限：
   chmod +x /etc/keepalived/check.sh
   chmod +x /etc/keepalived/notify.sh

10. 创建日志目录：
    mkdir /var/log/keepalived

11. 启动：
    systemctl start keepalived

II、备服务器配置（192.168.1.152）：

12. 安装：
    yum -y install keepalived

13. 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 #BACKUP模式
    interface ens33
    virtual_router_id 51 #与主机一致
    priority 99 #比主机小
    advert_int 1
    authentication { #与主机一致
    auth_type PASS
    auth_pass 123456
    }
    virtual_ipaddress {
    192.168.1.150
    }
    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"
    }

14. 添加服务检查脚本（check.sh）：
    vim /etc/keepalived/check.sh
    #!/bin/bash
    if [ "pgrep nginx | wc -l" == "0" ] ; then
    exit 1
    else
    exit 0
    fi
15. 通知脚本（notify.sh）：
    vim /etc/keepalived/notify.sh
    #!/bin/bash
    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
16. 给脚本添加可执行权限：
    chmod +x /etc/keepalived/check.sh
    chmod +x /etc/keepalived/notify.sh
17. 创建日志目录：
    mkdir /var/log/keepalived
18. 启动：
    systemctl start keepalived
    三、测试：
    I、正常状态下
    

II、停止主服务器：192.168.1.151后测试

19. 停止从服务器nginx服务，结果可以看到访问虚拟IP时候会从主服务器切到从服务器
    systemctl stop nginx
    
    
    

20. 查看日志：
    tail /var/log/keepalived/keepalived.log
    主从机日志都显示切到备机模式
    
    

    测试完成