一.环境
centos7.1操作系统 
二.基础架构
nginx1.10.2+keepalived1.2.13 192.168.2.65
nginx1.10.2+keepalived1.2.13 192.168.2.66
web1192.168.2.83
web2192.168.2.84
虚拟IP192.168.2.67
三.安装nginx+keepalived
安装网易云镜像和nginx的镜像，然后使用yum install -y nginx keepalived
四.配置nginx和keepalived
nginx主 从配置一样，把原来的/etc/nginx/conf.d/default.conf 删除，重新创建一个proxy.conf，把下面配置拷贝进去就行。
vi /etc/nginx/conf.d/proxy.conf
upstream web {
#ip_hash;
server 192.168.2.83:80; #默认为rr轮询，如需解决session的问题采有哈希（ip_hash)模块。
server 192.168.2.84:80;
}
server {
listen 80;
index index.php index.html index.htm;
location / {
proxy_pass http://web;
proxy_set_header X-Real-IP $remote_addr;
proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
}
}
主keepalived配置，直接把原有的配置文件删除，拷贝下面的进去。
vi /etc/keepalived/keepalived.conf
! Configuration File for keepalived
global_defs {
router_id master
}
vrrp_script chk_nginx {
script "/etc/keepalived/nginx_check.sh"
interval 2
weight -20
}
vrrp_instance VI_1 {
state MASTER
interface em1
virtual_router_id 51
mcast_src_ip 192.168.2.65
priority 100
nopreempt
advert_int 1
authentication {
auth_type PASS
auth_pass 1111
}
track_script {
chk_nginx
}
virtual_ipaddress {
192.168.2.67
}
}
从keepalived配置，删除原有的文件内容，拷贝下面内容。
! Configuration File for keepalived
global_defs {
router_id slave1
}
vrrp_script chk_nginx {
script "/etc/keepalived/nginx_check.sh"
interval 2
weight -20
}
vrrp_instance VI_1 {
state BACKUP
interface em1
virtual_router_id 51
mcast_src_ip 192.168.2.66
priority 90
advert_int 1
authentication {
auth_type PASS
auth_pass 1111
}
track_script {
chk_nginx
}
virtual_ipaddress {
192.168.2.67
}
}
两个web页面配置
yum install httpd -y
service httpd start
配置检测nginx服务脚本
vi /etc/keepalived/nginx_check.sh
#!/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
五.配置完成后，启动服务
systemctl nginx start
systemctl keepalived start
六.测试
65单独正常
66单独正常
访问67正常
虚拟IP在65上面
现在关闭65的nginx服务，65失效，但访问67正常，说明整体还在正常工作。虚拟IP漂移到66上面，推选66为主。
反之，关闭66主的还在服务。测试完成