Linux-09-nginx代理，nginx负载均衡，轮询调度，实例（blog、edu），调度算法，nginx_proxy + web应用节点(多台) + Redis会话保持phpmyadmin

一、nginx代理

1) 什么是代理
	代理理财  代理收货    代理租房 
	
2) 代理模式
	正向代理	( 科学上网 \  共享上网 )
	反向代理   ( 企业 )

3) 反向代理支持模式
	http			用户请求  响应		JAVA
	smtp
	websocket		用户可以请求,  服务端响应   服务端可以推送数据
	uwsgi			Python
	fastcgi			PHP
	https
	
4) 代理配置语法
	proxy_pass
		proxy_pass http://127.0.0.1:8080;

1.web节点的配置 10.0.0.201

[root@node2 ~]# cd /etc/nginx/conf.d/
[root@node2 conf.d]# cat proxy.oldboyedu.com.conf 
server {
	listen 80;
	server_name proxy.oldboyedu.com;
	root /code/proxy;

	location / {
		index index.html;
	}
}
[root@node2 conf.d]# mkdir /code/proxy -p
[root@node2 conf.d]# echo "node2...." >> /code/proxy/index.html

[root@node2 conf.d]# nginx -t
[root@node2 conf.d]# systemctl reload nginx

2.代理节点的配置 10.0.0.100

hostnamectl set-hostname proxy
vim /etc/sysconfig/network-scripts/ifcfg-ens32
	IPADDR=10.0.0.100
systemctl restart network
[root@proxy ~]# systemctl disable firewalld
[root@proxy ~]# systemctl stop firewalld
[root@proxy ~]# setenforce 0
[root@proxy ~]# sed -i 's#SELINUX=enforcing#SELINUX=disabled#g' /etc/selinux/config

	#安装epel\nginx
[root@proxy ~]# wget -O /etc/yum.repos.d/epel.repo http://mirrors.aliyun.com/repo/epel-7.repo
[root@proxy ~]# yum install vim wget unzip nginx -y

	# 清理nginx.conf 无用的配置
	vim /etc/nginx/nginx.conf
	
	user nginx;
	worker_processes auto;
	error_log /var/log/nginx/error.log;
	pid /run/nginx.pid;

	include /usr/share/nginx/modules/*.conf;

	events {
		worker_connections 1024;
	}

	http {
		log_format  main  '$remote_addr - $remote_user [$time_local] "$request" '
						  '$status $body_bytes_sent "$http_referer" '
						  '"$http_user_agent" "$http_x_forwarded_for"';

		access_log  /var/log/nginx/access.log  main;

		sendfile            on;
		tcp_nopush          on;
		tcp_nodelay         on;
		keepalive_timeout   65;
		types_hash_max_size 2048;

		include             /etc/nginx/mime.types;
		default_type        application/octet-stream;

		include /etc/nginx/conf.d/*.conf;

	}

	
	# 将nginx加入开机自启\ 启动nginx
[root@proxy ~]# systemctl start nginx
[root@proxy ~]# systemctl enable nginx


	# 编写proxy配置文件
[root@proxy ~]# vim /etc/nginx/conf.d/proxy_proxy.oldboyedu.com.conf
server {
	listen 80;
	server_name proxy.oldboyedu.com;

	location / {
		proxy_pass http://10.0.0.201;					# 后端是什么端口根本不重要
		proxy_set_header Host $http_host;
		proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
		proxy_http_version 1.1;
	}
}

	# 检查语法,重载服务
[root@proxy ~]# nginx -t
[root@proxy ~]# systemctl restart nginx

3.用户请求代理

抓包分析: 提炼了几个参数:

proxy_set_header Host $http_host;								# 将用户请求的域名携带到后端
proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;	# 将用户的真实IP地址,携带到后端,后端有对应的变量解析结果
proxy_http_version 1.1;	

二、nginx负载均衡

1) 什么是负载均衡
2) 为什么要用负载均衡
3) 负载均衡demo演示
4) 将多台相同应用服务(集群)接入负载均衡,进行轮询调度

upstream	定义虚拟资源池  ( 将应用服务器逻辑定义为资源池 )
proxy_pass  代理

---

tail -f /var/log/nginx/access.log

---

1.多个应用服务器节点:

node1: 10.0.0.200
node2: 10.0.0.201
域名: proxy.oldboyedu.com

node1 nginx配置:
[root@node1 conf.d]# cat /etc/nginx/conf.d/proxy.oldboyedu.com.conf
server {
	listen 80;
	server_name proxy.oldboyedu.com;
	root /code/proxy;

	location / {
		index index.html;
	}
}

	mkdir /code/proxy -p
	echo "node1...." > /code/proxy/index.html
	systemctl reload nginx

node2 nginx配置:
[root@node1 conf.d]# cat /etc/nginx/conf.d/proxy.oldboyedu.com.conf
server {
	listen 80;
	server_name proxy.oldboyedu.com;
	root /code/proxy;

	location / {
		index index.html;
	}
}
	mkdir /code/proxy -p
	echo "node2...." > /code/proxy/index.html
	systemctl reload nginx

2.通过nginx负载均衡进行轮询调度:

proxy: 10.0.0.100
域名: proxy.oldboyedu.com

[root@proxy ~]# cat  /etc/nginx/conf.d/proxy_proxy.oldboyedu.com.conf 
upstream node {
	server 10.0.0.200:80;
	server 10.0.0.201:80;
}

server {
	listen 80;
	server_name proxy.oldboyedu.com;

	location / {
		proxy_pass http://node;
		proxy_set_header Host $http_host;
		proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
		proxy_http_version 1.1;
	}
}

[root@proxy ~]# nginx -t
nginx: the configuration file /etc/nginx/nginx.conf syntax is ok
nginx: configuration file /etc/nginx/nginx.conf test is successful
[root@proxy ~]# systemctl reload nginx

三、给wordpress、edusoho配置nginx负载均衡

1).准备好wordpress两台应用节点
2).准备好edusoho两台应用节点
3).配置nginx负载均衡,调度

1.blog配置

[root@proxy ~]# cat /etc/nginx/conf.d/proxy_blog.oldboyedu.com.conf 
upstream blog {
	server 10.0.0.200:80;
	server 10.0.0.201:80;
}

server {
	listen 80;
	server_name blog.oldboyedu.com;
	
	location / {
		proxy_pass http://blog;
		proxy_set_header Host $http_host;
		proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;	
	}
}

2.edu配置

[root@proxy ~]# cat /etc/nginx/conf.d/proxy_edu.oldboyedu.com.conf 
upstream edu {
	server 10.0.0.200:80;
	server 10.0.0.201:80;
}

server {
	listen 80;
	server_name edu.oldboyedu.com;
	
	location / {
		proxy_pass http://edu;
		proxy_set_header Host $http_host;
		proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;	
	}
}

3. 调度算法:

轮询:		默认
加权轮询:
[root@proxy ~]# vim  /etc/nginx/conf.d/proxy_proxy.oldboyedu.com.conf
	upstream node {
		server 10.0.0.200:80 weight=5;  
		server 10.0.0.201:80 weight=1;
	}
在200所对应的页面出现5次后出现1次201所对应的页面
ip_hash:	固定将请求调度至某一个节点.  ( session会话保存 )

	upstream node {
		ip_hash;
		server 10.0.0.200:80;
		server 10.0.0.201:80;
	}

	优势: 解决会话问题
	缺陷:
		如果来源的都是同一个IP地址,则会造成某一个节点非常的繁忙,而其他的节点没有流量
		造成负载不均衡的现象.

四、nginx_proxy + web应用节点(多台) + Redis会话保持 phpmyadmin

1.搭建好应用节点 ( 所有节点保持一致 )

[root@oldboy-pythonedu ~]# wget https://files.phpmyadmin.net/phpMyAdmin/5.0.3/phpMyAdmin-5.0.3-all-languages.zip

2.准备phpmyadmin的Nginx配置文件

[root@cwj-python ~]# vim /etc/nginx/conf.d/phpadmin.oldboyedu.com.conf
server {
	listen 80;
	server_name phpmyadmin.oldboyedu.com;
	root /code/phpmyadmin;

	location / {
		index index.php;
	}

	location ~ \.php$ {
		fastcgi_pass 127.0.0.1:9000;
		fastcgi_param SCRIPT_FILENAME $document_root$fastcgi_script_name;
		include fastcgi_params;
	}
}

[root@oldboy-pythonedu ~]# systemctl reload nginx

[root@oldboy-pythonedu ~]# unzip phpMyAdmin-5.0.3-all-languages.zip
[root@oldboy-pythonedu ~]# mv phpMyAdmin-5.0.3-all-languages /code/phpmyadmin

3.配置phpmyadmin连接数据库地址

[root@oldboy-pythonedu ~]# cp /code/phpmyadmin/config.sample.inc.php /code/phpmyadmin/config.inc.php

[root@oldboy-pythonedu ~]# vim /code/phpmyadmin/config.inc.php
/* Server parameters */
$cfg['Servers'][$i]['host'] = '10.0.0.202';

4.授权session存储本地目录为进程的用户身份

[root@oldboy-pythonedu ~]# chown -R nginx.nginx /var/lib/php/session

5.部署node2节点的phpmyadmin, 需要将代码和nginx配置拷贝一份

[root@node2 code]# scp -rp [email protected]:/code/phpmyadmin /code/
[root@node2 code]# chown -R nginx.nginx /code/phpmyadmin/
[root@node2 code]# scp [email protected]:/etc/nginx/conf.d/phpadmin.oldboyedu.com.conf /etc/nginx/conf.d/
[root@node2 code]# chown -R nginx.nginx /var/lib/php/session/

[root@node2 code]# nginx -t
[root@node2 code]# systemctl reload nginx

6.为应用节点,接入负载均衡

[root@proxy ~]# cat /etc/nginx/conf.d/proxy_phpadmin.oldboyedu.com.conf
upstream php {
	server 10.0.0.200:80;
	server 10.0.0.201:80;
}

server {
	listen 80;
	server_name phpmyadmin.oldboyedu.com;
	
	location / {
		proxy_pass http://php;
		proxy_set_header Host $http_host;
		proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;	
	}
}	

7.检查轮询是否会造成无法登陆情况, 配置IP_hash测试是否能正常登陆

	轮询一定会造成无法登陆成功.
	
	可以采用ip_hash的方式解决.
	upstream php {
		ip_hash;
		server 10.0.0.200:80;
		server 10.0.0.201:80;
	}
	
ll /var/lib/php/session/
rm -f /var/lib/php/session/*

8.采用Redis共享的方式来解决会话无法登陆的问题, 需要先将负载均衡恢复至轮询模式,然后在继续.

1) 安装Redis		10.0.0.202
[root@node-mysql ~]# yum install redis -y

[root@node-mysql ~]# vim /etc/redis.conf			# 添加本机的内网IP地址 ( 不要写错了 )
bind 127.0.0.1 10.0.0.202

[root@node-mysql ~]# systemctl enable redis
[root@node-mysql ~]# systemctl start redis
[root@node-mysql ~]# netstat -lntp | grep redis
tcp        0      0 10.0.0.202:6379         0.0.0.0:*               LISTEN      10699/redis-server  
tcp        0      0 127.0.0.1:6379          0.0.0.0:*               LISTEN      10699/redis-server 

2) 通过其他的节点测试是否能正常访问Redis
[root@node2 ~]# yum install redis -y
[root@node2 ~]# redis-cli -h 10.0.0.202

3) 配置应用节点接入Redis,  [ 应用程序php必须有redis的模块,否则无法正常连接 ]   两个节点配置一样,都需要操作

# 将应用程序解析器连接至 Redis 
[root@oldboy-pythonedu ~]# vim /etc/php.ini
[Session]
;session.save_handler = files		#注释掉
session.save_handler = redis
session.save_path = "tcp://10.0.0.202:6379?weight=1&timeout=2.5"

# 注释如下两行内容
[root@oldboy-pythonedu ~]# vim /etc/php-fpm.d/www.conf
;php_value[session.save_handler] = files
;php_value[session.save_path]    = /var/lib/php/session

# 重启php-fpm
[root@oldboy-pythonedu ~]# systemctl restart php-fpm

在node2-201也操作一遍以上两个内容

9.测试是否能正常登陆,然后检查浏览器中的session是否与redis中存储的session一致.

[root@node-mysql ~]# redis-cli
127.0.0.1:6379> keys *
1) "python_key"
2) "PHPREDIS_SESSION:23f87a2b337659dcedc22d68a63f0734"

域名解析：

10.0.0.100 proxy.oldboyedu.com blog.oldboyedu.com edu.oldboyedu.com
10.0.0.100 phpmyadmin.oldboyedu.com