Nginx教程以及配置keepalived

时间:2022-12-19 09:33:15

Nginx教程

1.  课程目标


1.1.  了解反向代理和负载均衡的概念

1.2.  掌握Nginx的安装和使用

1.3.  利用Nginx实现负载均衡


2.  Nginx相关概念


2.1.  反向代理

反向代理(Reverse Proxy)方式是指以代理服务器来接受internet上的连接请求,然后将请求转发给内部网络上的服务器,并将从服务器上得到的结果返回给internet上请求连接的客户端,此时代理服务器对外就表现为一个服务器。

2.2.  负载均衡

负载均衡,英文名称为Load Balance,是指建立在现有网络结构之上,并提供了一种廉价有效透明的方法扩展网络设备和服务器的带宽、增加吞吐量、加强网络数据处理能力、提高网络的灵活性和可用性。其原理就是数据流量分摊到多个服务器上执行,减轻每台服务器的压力,多台服务器共同完成工作任务,从而提高了数据的吞吐量。


3.  Nginx的安装


3.1.  下载nginx

官网:http://nginx.org/

3.2.  上传并解压nginx

tar -zxvf nginx-1.8.1.tar.gz -C/usr/local/src


3.3.  编译nginx

#进入到nginx源码目录

cd /usr/local/src/nginx-1.8.1


#检查安装环境,并指定将来要安装的路径

./configure --prefix=/usr/local/nginx

 

#缺包报错 ./configure: error: C compiler cc is not found

 

#使用YUM安装缺少的包

yum-y install gcc pcre-devel openssl openssl-devel


#编译安装

make&& make install

 

安装完后测试是否正常:

/usr/loca/nginx/sbin/nginx

查看端口是否有ngnix进程监听

netstat-ntlp | grep 80


4.  配置nginx

4.1.  配置反向代理

1.修改nginx配置文件

server {

    listen       80;

    server_name  nginx-01.itcast.cn;    #nginx所在服务器的主机名

#反向代理的配置

location / {             #拦截所有请求

    root html;

        proxy_pass http://192.168.0.21:8080;   #这里是代理走向的目标服务器:tomcat

    }

}

2.启动tomcat-01上的tomcat

 

3.启动nginx-01上的nginx

./nginx


 

重启:

kill -HUP `cat /usr/local/nginx/logs/nginx.pid`


参考网址:http://www.cnblogs.com/jianxie/p/3990377.html

4.2.  动静分离

#动态资源 index.jsp

location ~ .*\.(jsp|do|action)$ {

    proxy_pass http://tomcat-01.itcast.cn:8080;

}

 

#静态资源

location ~ .*\.(html|js|css|gif|jpg|jpeg|png)$ {

    expires 3d;

}

 

4.3.  负载均衡

在http这个节下面配置一个叫upstream的,后面的名字可以随意取,但是要和location下的proxy_pass http://后的保持一致。

http {

    是在http里面的, 已有http, 不是在server里,在server外面

    upstream tomcats {

        server shizhan02:8080 weight=1;#weight表示多少个

        server shizhan03:8080 weight=1;

        server shizhan04:8080 weight=1;

}

#卸载server里

location ~ .*\.(jsp|do|action) {

    proxy_pass http://tomcats;        #tomcats是后面的tomcat服务器组的逻辑组号

}

}

5.  利用keepalived实现高可靠(HA)

5.1.  高可靠概念

HA(High Available), 高可用性集群,是保证业务连续性的有效解决方案,一般有两个或两个以上的节点,且分为活动节点及备用节点。

5.2.  高可靠软件keepalived

keepalive是一款可以实现高可靠的软件,通常部署在2台服务器上,分为一主一备。Keepalived可以对本机上的进程进行检测,一旦Master检测出某个进程出现问题,将自己切换成Backup状态,然后通知另外一个节点切换成Master状态。

5.3.  keepalived安装

下载keepalived官网:http://keepalived.org

 

将keepalived解压到/usr/local/src目录下

tar -zxvf keepalived-1.2.19.tar.gz -C /usr/local/src


 

进入到/usr/local/src/keepalived-1.2.19目录

cd /usr/local/src/keepalived-1.2.19


 

开始configure

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


 

#编译并安装

make && make install


 

5.4.  将keepalived添加到系统服务中

拷贝执行文件

cp /usr/local/keepalived/sbin/keepalived/usr/sbin/


将init.d文件拷贝到etc下,加入开机启动项

cp /usr/local/keepalived/etc/rc.d/init.d/keepalived/etc/init.d/keepalived


将keepalived文件拷贝到etc下

cp /usr/local/keepalived/etc/sysconfig/keepalived/etc/sysconfig/


创建keepalived文件夹

mkdir -p/etc/keepalived


将keepalived配置文件拷贝到etc下

cp /usr/local/keepalived/etc/keepalived/keepalived.conf/etc/keepalived/keepalived.conf


添加可执行权限

chmod+x/etc/init.d/keepalived

 

##以上所有命令一次性执行:

cp /usr/local/keepalived/sbin/keepalived /usr/sbin/

cp /usr/local/keepalived/etc/rc.d/init.d/keepalived /etc/init.d/keepalived

cp /usr/local/keepalived/etc/sysconfig/keepalived /etc/sysconfig/

mkdir -p /etc/keepalived

cp /usr/local/keepalived/etc/keepalived/keepalived.conf /etc/keepalived/keepalived.conf

chmod +x /etc/init.d/keepalived

chkconfig --add keepalived      

chkconfig keepalived on

 

添加keepalived到开机启动

chkconfig --add keepalived      
chkconfig keepalived on


 

 

 

 

5.5.  配置keepalived虚拟IP

修改配置文件: /etc/keepalived/keepalived.conf

#MASTER节点

global_defs {

}

vrrp_instance VI_1 {

    state MASTER   #指定A节点为主节点 备用节点上设置为BACKUP即可

    interface eth0    #绑定虚拟IP的网络接口

    virtual_router_id 51   #VRRP组名,两个节点的设置必须一样,以指明各个节点属于同一VRRP组

    priority 100   #主节点的优先级(1-254之间),备用节点必须比主节点优先级低

    advert_int 1  #组播信息发送间隔,两个节点设置必须一样

    authentication {    #设置验证信息,两个节点必须一致

        auth_type PASS

        auth_pass 1111

    }

    virtual_ipaddress {    #指定虚拟IP, 两个节点设置必须一样

        192.168.33.60/24    #如果两个nginxip分别是192.168.33.61,,...62,则此处的虚拟ip跟它俩同一个网段即可

    }

}

 

#BACKUP节点

global_defs {

}

vrrp_instance VI_1 {

    state BACKUP

    interface eth0

    virtual_router_id 51

    priority 99

    advert_int 1

    authentication {

        auth_type PASS

        auth_pass 1111

    }

    virtual_ipaddress {

        192.168.33.60/24

    }

}

 

#分别启动两台机器上的keepalived

service keepalived start


测试:

杀掉master上的keepalived进程,你会发现,在slave机器上的eth0网卡多了一个ip地址

查看ip地址的命令:  ip addr

 

5.6.  配置keepalived心跳检查

原理:

Keepalived并不跟nginx耦合,它俩完全不是一家人

但是keepalived提供一个机制:让用户自定义一个shell脚本去检测用户自己的程序,返回状态给keepalived就可以了

 

 

#MASTER节点

global_defs {

}

 

vrrp_script chk_health {

    script "[[ `ps -ef | grep nginx | grep -v grep | wc -l` -ge 2 ]] && exit 0 || exit 1"

    interval 1    #每隔1秒执行上述的脚本,去检查用户的程序ngnix

    weight -2

}

 

vrrp_instance VI_1 {

    state MASTER

    interface eth0

    virtual_router_id 1

    priority 100

    advert_int 2

    authentication {

        auth_type PASS

        auth_pass 1111

    }

 

    track_script {

        chk_health

    }

 

    virtual_ipaddress {

        10.0.0.10/24

    }

 

    notify_master "/usr/local/keepalived/sbin/notify.sh master"

    notify_backup "/usr/local/keepalived/sbin/notify.sh backup"

    notify_fault "/usr/local/keepalived/sbin/notify.sh fault"

}

 

#添加切换通知脚本

vi /usr/local/keepalived/sbin/notify.sh

#!/bin/bash

 

case "$1" in

    master)

        /usr/local/nginx/sbin/nginx

        exit 0

    ;;

backup)

        /usr/local/nginx/sbin/nginx -s stop

        /usr/local/nginx/sbin/nginx

        exit 0

    ;;

    fault)

        /usr/local/nginx/sbin/nginx -s stop

        exit 0

    ;;

    *)

        echo 'Usage: notify.sh {master|backup|fault}'

        exit 1

    ;;

esac

 

#添加执行权限

chmod +x/usr/local/keepalived/sbin/notify.sh

global_defs {

}

 

vrrp_script chk_health {

    script "[[ `ps -ef | grep nginx | grep -v grep | wc -l` -ge 2 ]] && exit 0 || exit 1"

    interval 1

    weight -2

}

 

vrrp_instance VI_1 {

    state BACKUP

    interface eth0

    virtual_router_id 1

    priority 99

    advert_int 1

    authentication {

        auth_type PASS

        auth_pass 1111

    }

 

    track_script {

        chk_health

    }

 

    virtual_ipaddress {

        10.0.0.10/24

    }

        

    notify_master "/usr/local/keepalived/sbin/notify.sh master"

    notify_backup "/usr/local/keepalived/sbin/notify.sh backup"

    notify_fault "/usr/local/keepalived/sbin/notify.sh fault"

}

 

#在第二台机器上添加notify.sh脚本

#分别在两台机器上启动keepalived

service keepalived start
chkconfig keepalived on