nginx+Keepalived双机主备方案实现（经线上测试）
nginx的编译安装
1）编译工具（基本可以不用）
yum -y install gcc gcc-c++ autoconf automake zlib zlib-devel openssl openssl-devel pcre-devel gd-*
2）建立nginx 组
groupadd -r nginx
useradd -s /sbin/nologin -g nginx -r nginx
id nginx
3）wget http://nginx.org/download/nginx-1.6.2.tar.gz
tar xf /usr/local/src/nginx-1.6.2.tar.gz
cd /usr/local/src/nginx-1.6.2.tar.gz
./configure --prefix=/usr/local/nginx --lock-path=/usr/local/nginx/nginx.lock --user=nginx --group=nginx --with-http_ssl_module --with-http_flv_module --with-http_stub_status_module --with-http_gzip_static_module --http-client-body-temp-path=/usr/local/nginx/client/ --http-proxy-temp-path=/usr/local/nginx/proxy/ --http-fastcgi-temp-path=/usr/local/nginx/fcgi/ --http-uwsgi-temp-path=/usr/local/nginx/uwsgi --http-scgi-temp-
path=/usr/local/nginx/scgi --with-pcre --with-file-aio --with-http_image_filter_module
make && make install
4)配置nginx启动脚本
===============================================
vim /etc/init.d/nginx chmod +x /etc/init.d/nginx
#!/bin/bash
#
# Startup script for Nginx - this script starts and stops the nginx daemon
#
# chkconfig: - 85 15
# description: Nginx is an HTTP(S) server, HTTP(S) reverse proxy and IMAP/POP3 proxy server
# processname: nginx
# config: /usr/local/nginx/conf/nginx.conf
# pidfile: /usr/local/nginx/logs/nginx.pid
# Source function library.
. /etc/rc.d/init.d/functions
# Source networking configuration.
. /etc/sysconfig/network
# Check that networking is up.
[ "$NETWORKING" = "no" ] && exit 0
nginx="/usr/local/nginx/sbin/nginx"
prog=$(basename $nginx)
NGINX_CONF_FILE="/usr/local/nginx/conf/nginx.conf"
[ -f /etc/sysconfig/nginx ] && . /etc/sysconfig/nginx
lockfile=/var/lock/subsys/nginx
start() {
[ -x $nginx ] || exit 5
[ -f $NGINX_CONF_FILE ] || exit 6
echo -n $"Starting $prog: "
daemon $nginx -c $NGINX_CONF_FILE
retval=$?
echo
[ $retval -eq 0 ] && touch $lockfile
return $retval
}
stop() {
echo -n $"Stopping $prog: "
killproc $prog -QUIT
retval=$?
echo
[ $retval -eq 0 ] && rm -f $lockfile
return $retval
}
restart() {
configtest || return $?
stop
sleep 1
start
}
reload() {
configtest || return $?
echo -n $"Reloading $prog: "
killproc $nginx -HUP
RETVAL=$?
echo
}
force_reload() {
restart
}
configtest() {
$nginx -t -c $NGINX_CONF_FILE
}
rh_status() {
status $prog
}
rh_status_q() {
rh_status >/dev/null 2>&1
}
case "$1" in
start)
rh_status_q && exit 0
$1
;;
stop)
rh_status_q || exit 0
$1
;;
restart|configtest)
$1
;;
reload)
rh_status_q || exit 7
$1
;;
force-reload)
force_reload
;;
status)
rh_status
;;
condrestart|try-restart)
rh_status_q || exit 0
;;
*)
echo $"Usage: $0 {start|stop|status|restart|condrestart|
try-restart|reload|force-reload|configtest}"
exit 2
esac
==============================================================
5)nginx配置
vim /usr/local/nginx/conf/nginx.conf
====================================================
upstream MCM {
server 10.124.156.236; #使用nginx的默认分发模式rr
server 10.124.156.231; #两个分发服务器ip
}
server {
listen 80;
server_name localhost;
location /mcm/ {
limit_req zone=allips burst=10 ;
proxy_pass http://MCM/mcm/;
proxy_redirect off;
proxy_set_header Host $http_host;
proxy_set_header X-Real-IP $remote_addr;
proxy_set_header X-Forwarded-For
$proxy_add_x_forwarded_for;
proxy_set_header Cookie $http_cookie;
chunked_transfer_encoding off;
}
error_page 500 502 503 504 /50x.html;
location = /50x.html {
root html;
}
=========================================================
2.Keepalived的安装配置
1)Keepalived的编译安装
cd /usr/local/src/
wget http://www.keepalived.org/software/keepalived-1.1.20.tar.gz
tar xf keepalived-1.2.15.tar.gz
cd keepalived-1.1.20
./configure --prefix=/usr/local/keepalived --with-kernel-dir=/usr/src/kernels/2.6.32-279.el6.x86_64/
make && make install
将Keepalived做成服务：
cd /usr/local/keepalived/ && cp etc/rc.d/init.d/keepalived /etc/rc.d/init.d/ && cp etc/sysconfig/keepalived /etc/sysconfig/ && mkdir /etc/keepalived && cp etc/keepalived/keepalived.conf /etc/keepalived/ && cp sbin/keepalived /usr/sbin/
2)配置Keepalived.conf文件
====================================================
TestNginx1：10.124.194.244
vim /etc/keepalived/keepalived.conf
==========================================
! Configuration File for keepalived
global_defs {
notification_email {
}
notification_email_from [email protected]
smtp_server 127.0.0.1
smtp_connect_timeout 30
router_id Nginx_MB
}
vrrp_script chk_http_port {
script "/etc/keepalived/chk_nginx.sh"
interval 2
weight 2
}
vrrp_instance VI_3 {
state MASTER
interface eth0
virtual_router_id 57 #VI_2 为 58
priority 200 #备用是150
mcast_src_ip 10.124.194.244 #本机ip
advert_int 1
authentication {
auth_type PASS
auth_pass yzkj
}
track_script {
chk_http_port
}
virtual_ipaddress {
10.124.194.4 #VIP 1
}
}
vrrp_instance VI_4 {
state BACKUP
interface eth0
virtual_router_id 58 # VI_1 是57
priority 150 #主是200
advert_int 1
authentication {
auth_type PASS
auth_pass yzkj
}
track_script {
chk_http_port
}
virtual_ipaddress {
10.124.194.5 #VIP 2
}
}
========================================
TestNginx2
! Configuration File for keepalived
global_defs {
notification_email {
}
notification_email_from [email protected]
smtp_server 127.0.0.1
smtp_connect_timeout 30
router_id Nginx_MB
}
vrrp_script chk_http_port {
script "/etc/keepalived/chk_nginx.sh"
interval 2
weight 2
}
vrrp_instance VI_3 {
state BACKUP
interface eth0
virtual_router_id 57 #VI_4 为 58
priority 150 #主是200
advert_int 1
authentication {
auth_type PASS
auth_pass yzkj
}
track_script {
chk_http_port
}
virtual_ipaddress {
10.124.194.4 #VIP 1
}
}
vrrp_instance VI_4 {
state MASTER
interface eth0
virtual_router_id 58 #VI_3 是57
priority 200 #备用是50
advert_int 1
authentication {
auth_type PASS
auth_pass yzkj
}
track_script {
chk_http_port
}
virtual_ipaddress {
10.124.194.5 #VIP 2
}
}
=====================================
3)添加nginx状态自动检测脚本
vim /etc/keepalived/chk_nginx.sh
=============
#!/bin/bash
# description:
# 定时查看nginx是否存在，如果不存在则启动nginx
# 如果启动失败，则停止keepalived
status=$(ps -C nginx --no-heading|wc -l)
if [ "${status}" = "0" ]; then
/usr/local/nginx/sbin/nginx
status2=$(ps -C nginx --no-heading|wc -l)
if [ "${status2}" = "0" ]; then
/etc/init.d/keepalived stop
fi
fi
====================
4)keepalived nginx启动
service keepalived start
service nginx start 或者（/usr/local/nginx/sbin/nginx）
5）防火墙设置：
在Lvs+Keepalived的设置中一般都将iptables关掉，这是一个很危险的操作。在测试nginx+Keepalived的时候发现iptables不关闭的话，会出现VIP同时绑定在主备nginx上。所以经过研究测试，要想开着iptables来使用Keepalived，就应该先明白Keepalived的工作原理。Keepalived工作主
要是通过vrrp协议进行报文互通，于是就必须在iptables里设置
-A INPUT -p vrrp -j ACCEPT #基于DR模式，当用户发出请求后，只有DR响应ARP广播包，允许vrrp虚拟路由器冗余协议。然后重启iptables服务，至此困扰已久的VIP同时绑定在多个服务器上的问题解决。
3.测试：
在测试过程中出现一个有趣的话题：就是当我进行停止nginx运行的时候，发现进程自动会起来，然后我就问、查，总是不以所以然，总以为是kill pkill命令不好使。后来经过查证，竟然是我们写的一个检测脚本在作怪。脚本记录如下：（修改完善版）
===================================
#!/bin/bash
# description:
# 定时查看nginx是否存在，如果不存在则启动nginx
# 如果启动失败，则停止keepalived
status=$(ps -C nginx --no-heading|wc -l)
if [ "${status}" = "0" ]; then
/usr/local/nginx/sbin/nginx
status2=$(ps -C nginx --no-heading|wc -l)
status3=$(ps -C keepalived --no-heading|wc -l)
if [ "${status2}" = "0" ]; then
/etc/init.d/keepalived stop
elif [ "${status3}" = "0" ]; then
/etc/init.d/keepalived start
fi
fi
fi
========================================
它的作用主要就是检测nginx的状态，如果nginx死掉，就尝试重启，如果重启不成功就把Keepalived服务停止，使两个vip同时漂到同一台nginx服务器上面去，如果nginx恢复就应该重启Keepalived服务。
4.使用rsync使后端几台服务器文件同步
1）服务安装：yum install rsync -y
服务端：10.124.151.246
=============================
vim /etc/rsyncd.conf
uid = root
gid = root
use chroot = no
max connections = 5
pid file = /var/run/rsyncd.pid
lock file = /var/run/rsync.lock
log file = /var/log/rsyncd.log
[web01]
path=/usr/local/nginx/html/
comment = update
ignore errors
read only = no
list = no
hosts allow = 192.168.122.0/24
auth users = root
uid = root
gid = root
secrets file = /etc/rsyncd.secrets
=================================
vim /etc/rsyncd.secrets
root:123456
chmod 0600 /etc/rsyncd.secrets
=============================
启动服务：rsync --daemon
echo "rsync --daemon" >> /etc/rc.local #自启动
客户端配置（也就是代码推送端）10.124.151.245
vim /etc/rsyncd.secrets
123456
chmod 0600 /etc/rsyncd.secrets
2)使用命令行进行代码推送（根据代码的修改和增删情况进行代码同步操作）
rsync -vzrtopg --delete --progress --password-file=/etc/rsyncd.secrets * [email protected]::web01