一、下载相关软件包

nginx官网   http://nginx.org/

keepalived官网   http://www.keepalived.org

二、安装keepalived和nginx

1、安装keepalived

tar xf keepalived-1.3.2.tar.gz

cd keepalived-1.3.2

./configure –prefix=/usr/local/keepalived

make && make install

2、配置

安装完成后，进入安装目录的etc目录下，将keepalived相应的配置文件拷贝到系统相应的目录当中。keepalived启动时会从/etc/keepalived目录下查找keepalived.conf配置文件，如果没有找到则使用默认的配置。/etc/keepalived目录安装时默认是没有安装的，需要手动创建。配置文件目录结构如下所示：

shell> tree -l /usr/local/keepalived/etc
-- keepalived
| |-- keepalived.conf
| `-- samples
| |-- keepalived.conf.status_code
| |-- keepalived.conf.track_interface
| |-- keepalived.conf.vrrp
| |-- 。。。
|-- rc.d
| `-- init.d
| `-- keepalived
`-- sysconfig
 `-- keepalived

分别对应系统目录（忽略samples目录）：

/etc/keepalived/keepalived.conf
/etc/rc.d/init.d/keepalived
/etc/sysconfig/keepalived

将配置文件拷贝到系统对应的目录下：

shell> mkdir /etc/keepalived
shell> cp /usr/local/keepalived/etc/keepalived/keepalived.conf /etc/keepalived/keepalived.conf
shell> cp /usr/local/keepalived/sbin/keepalived /etc/rc.d/init.d/keepalived
shell> cp /usr/local/keepalived/etc/sysconfig/keepalived /etc/sysconfig/keepalived

启动keepalived

/etc/init.d/keepalived

另外需要注意的一点是，keepalived启动时不会检查配置文件的语法是否正确，所以我们在编写配置文件时要特别小心，别写错了，否则会出现一些意想不到的现象。

# Options for keepalived. See `keepalived --help' output and keepalived(8) and
# keepalived.conf(5) man pages for a list of all options. Here are the most
# common ones :
#
# --vrrp -P Only run with VRRP subsystem.
# --check -C Only run with Health-checker subsystem.
# --dont-release-vrrp -V Dont remove VRRP VIPs & VROUTEs on daemon stop.
# --dont-release-ipvs -I Dont remove IPVS topology on daemon stop.
# --dump-conf -d Dump the configuration data.
# --log-detail -D Detailed log messages.日志默认输出在/var/log/message文件中
# --log-facility -S 0-7 Set local syslog facility (default=LOG_DAEMON)
#
KEEPALIVED_OPTIONS="-D"

运行keepalived –help可以查看启动时的可选参数，这些可选参数都可以配置在/etc/sysconfig/keepalived文件中的KEEPALIVED_OPTIONS选项中，作为服务启动时的参数。
keepalived正常运行后，会启动3个进程，其中一个是父进程，负责监控其子进程。一个是vrrp子进程，另外一个是checkers子进程。

shell> ps -ef | grep keepalived
root 831 1 0 11:22 ? 00:00:00 keepalived -D
root 840 831 0 11:22 ? 00:00:00 keepalived -D
root 841 831 0 11:22 ? 00:00:00 keepalived -D

到此keepalived就安装完成了。

3、安装nginx

tar -zxvf nginx-1.10.0.tar.gz

cd nginx-1.10.0

执行下面的命令安装nginx的依赖库：
yum -y install gcc pcre pcre-devel zlib zlib-devel openssl openssl-devel

./configure --prefix=/opt/nginx --sbin-path=/usr/bin/nginx

make && make install

三、配置keepalived和nginx

配置文件如下：

1、keepalived.conf

[root@proxy01 nginx-1.10.0]# cat /etc/keepalived/keepalived.conf 
! Configuration File for keepalived

global_defs {
 notification_email {
 acassen@firewall.loc
 failover@firewall.loc
 sysadmin@firewall.loc
 }
 notification_email_from Alexandre.Cassen@firewall.loc
 smtp_server 127.0.0.1
 smtp_connect_timeout 30
 router_id LVS_DEVEL
 vrrp_skip_check_adv_addr
 vrrp_strict
 vrrp_garp_interval 0
 vrrp_gna_interval 0
}

vrrp_instance VI_1 {
 state BACKUP
 interface eth0
 virtual_router_id 50
 priority 50
 advert_int 1
 authentication {
 auth_type PASS
 auth_pass 1111
 }
 virtual_ipaddress {
 192.168.1.208/24 dev eth0 label eth0:1
 }
}

2、nginx.conf

user root;
worker_processes 1;
events {
 worker_connections 1024;
 use epoll;
}
http {
 include mime.types;
 default_type application/octet-stream;
 sendfile on;
 keepalive_timeout 65;
 
 ## FastDFS Tracker Proxy
 upstream fastdfs_tracker {
 server 192.168.1.206:8000 weight=1 max_fails=2 fail_timeout=30s;
 server 192.168.1.207:8000 weight=1 max_fails=2 fail_timeout=30s;
 }
 
 server {
 listen 80;
 server_name localhost;
 location / {
 root html;
 index index.html index.htm;
 }
 error_page 500 502 503 504 /50x.html;
 location = /50x.html {
 root html;
 }
 
 ## FastDFS Proxy
 location /dfs {
 root html;
 index index.html index.htm;
 proxy_pass http://fastdfs_tracker/;
 proxy_set_header Host $http_host;
 proxy_set_header Cookie $http_cookie;
 proxy_set_header X-Real-IP $remote_addr;
 proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
 proxy_set_header X-Forwarded-Proto $scheme;
 client_max_body_size 300m;
 }
 } 
}

四、启动测试

访问http://192.168.1.208，就可以跳转到后端的服务器页面，当一台nginx宕机后，不会影响网络服务，VIP漂移到新的web服务器上。