在lnmp架构中，通常一台装有nginx服务器做反向代理服务器，又做内网的路由。在这台服务器上绑有一个公网ip和一个内网ip.我们把域名解析
到这个公网ip上，让nginx代理到后端的web服务器上，这样我们就可以访问到我们的站点，与此同时必须让内网访问外网。这台反向代理服务器
又需要做内网的路由。这台服务器，在整个应用架构中相当重要。下面我来阐述一下nginx+keepalived双机实现nginx反向代理服务的高可用。
也就是说在当一台nginx挂掉之后不影响应用也不影响内网访问外网。
部署 1、在2.117和2.118上安装keepalived下面开始安装keepalived
wget
tar zxvf keepalived-1.2.2.tar.gz cd keepalived-1.2.2 ./configure && make && make install mkdir /etc/keepalived cp /usr/local/etc/rc.d/init.d/keepalived /etc/rc.d/init.d/ cp /usr/local/etc/sysconfig/keepalived /etc/sysconfig/ cp /usr/local/etc/keepalived/keepalived.conf /etc/keepalived/ cp /usr/local/sbin/keepalived /usr/sbin/
2、keepalived配置 192.168.2.117
vi /etc/keepalived/keepalived.conf! Configuration File for keepalived
global_defs { notification_email { jinyan2049@163.com } notification_email_fromkeepalived@chtopnet.com smtp_server 127.0.0.1 smtp_connect_timeout 30 router_id LVS_DEVEL } vrrp_instance VI_1 { state MASTER interface eth0 virtual_router_id 51 mcast_src_ip 192.168.2.117 priority 100 advert_int 1 authentication { auth_type PASS auth_pass chtopnet } virtual_ipaddress { 192.168.2.180 }启动脚本写入到/etc/rc.local里
echo "/etc/init.d/keepalived start" >> /etc/rc.d/rc.localkeepalived配置 192.168.2.118
vi /etc/keepalived/keepalived.conf
! Configuration File for keepalived global_defs { notification_email { jinyan2049@163.com } notification_email_fromkeepalived@chtopnet.com smtp_server 127.0.0.1 smtp_connect_timeout 30 router_id LVS_DEVEL } vrrp_instance VI_1 { state MASTER interface eth0 virtual_router_id 51 backup_src_ip 192.168.2.118 priority 80 advert_int 1 authentication { auth_type PASS auth_pass chtopnet } virtual_ipaddress { 192.168.2.180 }启动脚本写入到/etc/rc.local里
echo "/etc/init.d/keepalived start" >> /etc/rc.d/rc.local3、安装编译nginx
groupadd www useradd -g www www wget make installln -sf /usr/local/nginx/sbin/nginx /usr/sbin
查看安装是否成功
nginx -t分别在两台服务器编写配置文件
vi /usr/local/nginx/conf/nginx.confuser www www;
worker_processes 8; error_log logs/error.log notice; pid /usr/local/nginx/logs/nginx.pid; events { worker_connections 51200; } http { include mime.types; default_type application/octet-stream; sendfile on; tcp_nopush on; keepalive_timeout 65; gzip on; server { listen 80; server_name localhost; index index.html index.htm; root /var/www/html; error_page 500 502 503 504 /50x.html; location = /50x.html { root html; } } }分别在两台机器创建测试文件
echo "192.168.2.117" > /var/www/html/index.html echo "192.168.2.118" > /var/www/html/index.html
添加nginx服务控制脚本vi /etc/init.d/nginx#!/bin/sh
# chkconfig:- 99 20 # de script ion:Nginx Service Control script # case "$1" in start) /usr/local/nginx/sbin/nginx ;; stop) /usr/bin/killall -s QUIT nginx ;; restart) $0 stop $0 start ;; reload) /usr/bin/killall -s HUP nginx ;; *) echo "Usage:$0" exit 1 esac exit 0
给/etc/init.d/nginx添加执行权限
chmod a+x /etc/init.d/nginx
启动nginx
/etc/init.d/nginx start4、分别在192.168.2.117和192.168.2.118编写检测nginx服务是否正常。脚本如下：
vi /root/nginxpid.sh #!/bin/bash while : do nginxpid=`ps -C nginx --no-header | wc -l` if [ $nginxpid -eq 0 ];then /etc/init.d/nginx start sleep 5 if [ $nginxpid -eq 0 ];then /etc/init.d/keepalived stop fi fi sleep 5 done5、让这个脚本永远在后台运行
nohup sh /root/nginxpid.sh &
6、测试过程如下：
我们要分别在二台主Nginx上用killall杀掉Nginx进程，然后在客户端分别访问192.168.2.117和192.168.2.118这二个IP（模拟DNS轮询）看能否正常访问Web服务器。