keepalived+Nginx高可用负载均衡

Posted 2020-08-21

说明：准备两台虚拟机：202.207.178.6和202.207.178.7

前提：

由于是高可用服务，首先配置高可用服务实现的一些基本条件

1)节点名称必须跟uname -n命令的执行结果一致

node1:

# hostname node1

# vim /etc/sysconfig/network

HOSTNAME=node1

node2:

# hostname node2

# vim /etc/sysconfig/network

HOSTNAME=node2

2)节点之间必须通过ssh互信通信

[[email protected] ~]# ssh-keygen -t rsa -f ~/.ssh/id_rsa -P ‘‘

[[email protected] ~]# ssh-copy-id -i .ssh/id_rsa.pub [email protected]

[[email protected] ~]# ssh-keygen -t rsa -f ~/.ssh/id_rsa -P ‘‘

[[email protected] ~]# ssh-copy-id -i .ssh/id_rsa.pub [email protected]

3)集群各节点之间时间必须同步

使用ntp服务器同步时间

ntpdate ip(配置了ntp服务的主机地址)

4)配置本地解析：

[[email protected] ~]# vim /etc/hosts

202.207.178.6 node1

202.207.178.7 node2

[[email protected] ~]# scp /etc/hosts node2:/etc/

一、安装配置nginx

node1:

1、首先添加用户nginx，实现以之运行nginx服务进程

# groupadd -r -g 108 nginx

# useradd -r -g 108 -u 108 nginx

2、将下载好的软件包解压并安装（我这里是nginx-1.4.7.tar.gz）

# tar xf nginx-1.4.7.tar.gz

# cd nginx-1.4.7

接着开始编译和安装：

# ./configure \

--prefix=/usr \

--sbin-path=/usr/sbin/nginx \

--conf-path=/etc/nginx/nginx.conf \

--error-log-path=/var/log/nginx/error.log \

--http-log-path=/var/log/nginx/access.log \

--pid-path=/var/run/nginx/nginx.pid  \

--lock-path=/var/lock/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=/var/tmp/nginx/client/ \

--http-proxy-temp-path=/var/tmp/nginx/proxy/ \

--http-fastcgi-temp-path=/var/tmp/nginx/fcgi/ \

--http-uwsgi-temp-path=/var/tmp/nginx/uwsgi \

--http-scgi-temp-path=/var/tmp/nginx/scgi \

--with-pcre \

--with-file-aio

# make && make install

报错时可能要求安装如下包，按需安装即可！

# yum -y install pcre-devel

# yum -y install gcc

# yum -y install openssl-devel

3、为nginx提供SysV init脚本:

新建文件/etc/rc.d/init.d/nginx，内容如下：

#!/bin/sh

#

# 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:      /etc/nginx/nginx.conf

# config:      /etc/sysconfig/nginx

# pidfile:     /var/run/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/sbin/nginx"

prog=$(basename $nginx)

 

NGINX_CONF_FILE="/etc/nginx/nginx.conf"

 

[ -f /etc/sysconfig/nginx ] && . /etc/sysconfig/nginx

 

lockfile=/var/lock/subsys/nginx

 

make_dirs() {

  # make required directories

  user=`nginx -V 2>&1 | grep "configure arguments:" | sed ‘s/[^*]*--user=\([^ ]*\).*/\1/g‘ -`

  options=`$nginx -V 2>&1 | grep ‘configure arguments:‘`

  for opt in $options; do

  if [ `echo $opt | grep ‘.*-temp-path‘` ]; then

  value=`echo $opt | cut -d "=" -f 2`

  if [ ! -d "$value" ]; then

  # echo "creating" $value

  mkdir -p $value && chown -R $user $value

  fi

  fi

  done

}

 

start() {

[ -x $nginx ] || exit 5

[ -f $NGINX_CONF_FILE ] || exit 6

make_dirs

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

4、而后为此脚本赋予执行权限：

# chmod +x /etc/rc.d/init.d/nginx

5、添加至服务管理列表，并让其开机自动启动：

# chkconfig --add nginx

# chkconfig nginx on

6、提供访问测试页面

# vim /usr/html/index.html

改为如下内容：

<h1>node1 202.207.178.6</h1>

7、而后就可以启动服务并测试了：

# service nginx start

node2:

配置与node1基本相同，为了显示效果，只要把访问页面改为如下内容即可：

<h1>node2 202.207.178.7</h1>

二、安装配置keepalived

node1:

1、安装keepalived

# tar xf keepalived-1.2.1.tar.gz

# cd keepalived-1.2.1

# ./configure --with-kernel-dir=/usr/src/kernels/2.6.32-642.11.1.el6.i686/

# make && make install

注意：

可能需要安装此包：

# yum install popt-devel

发现/usr/src/kernels/为空，需要安装内核源码

# yum install kernel-devel

2、配置keepalived

1）设置一个变量

# DIR=/usr/local/

2）执行如下语句，将keepalived的配置文件放置在/etc下相关目录中

# cp $DIR/etc/rc.d/init.d/keepalived  /etc/rc.d/init.d/

# cp $DIR/etc/sysconfig/keepalived /etc/sysconfig/ && mkdir -p /etc/keepalived

# cp $DIR/sbin/keepalived /usr/sbin/

3）为keepalived提供配置文件

# cd /etc/keepalived/

# vim keepalived.conf（添加以下内容）

global_defs {

  notification_email {

 [email protected]

  }

  notification_email_from [email protected]

  smtp_server 127.0.0.1

  smtp_connect_timeout 30

  router_id LVS_DEVEL

}

# VIP1

vrrp_instance VI_1 {

state BACKUP

interface eth0

lvs_sync_daemon_inteface eth0

virtual_router_id 151

#定义优先级

priority 100

advert_int 5

   #非抢占，定义此选项，可以使主节点从宕机恢复到正常                     后，不会抢占从节点上的资源，增加服务在线时间！

   nopreempt

authentication {

auth_type PASS

auth_pass 2222

}

virtual_ipaddress {

202.207.178.4

}

}

virtual_server 202.207.178.4 80 {

delay_loop 6

lb_algo wrr

lb_kind DR

persistence_timeout 60

protocol TCP

real_server 202.207.178.6 80 {

weight 100

notify_down /data/sh/nginx.sh

TCP_CHECK {

connect_timeout 10

nb_get_retry 3

delay_before_retry 3

connect_port 80

}

}

}

4）启动服务

# /etc/init.d/keepalived restart

# ps -ef | grep keepalived

此时发现服务已经启动！

# tail -fn 100 /var/log/messages

此时发现一直滚屏，是缺少一个模块，下面加载此模块

# modprobe ip_vs

# /etc/init.d/keepalived restart

# tail -fn 100 /var/log/messages

此时一切正常

node2：

配置同主节点，只是在配置文件中修改以下几项即可：

priority 90

real_server 202.207.178.7 80

三、配置相关操作,并测试

1、在主从节点上分别添加如下文件并授予执行权限，实现在主nginx宕机时停止keepalived,实

     现主从角色实现切换

# vim /data/sh/nginx.sh

/etc/init.d/keepalived stop

# chmod +x /data/sh/nginx.sh

2、在主节点停止nginx服务，进行访问测试

此时访问http://202.207.178.4/ 可以访问到从节点上的nginx服务！

                            欢迎批评指正！

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