Diagram of the process of implementing direction proxy through nginx

This article mainly introduces the process of implementing directional proxy through nginx. The example code in this article is very detailed and has a certain reference value for everyone's study or work. Friends in need can refer to it.

nginx implements direction proxy

1. What is nginx

Nginx is a very lightweight HTTP server written by Russians. It is a high-performance HTTP and reverse proxy web server that also provides IMAP/POP3/SMTP services. Its characteristics are that it occupies less memory and has strong concurrency. In fact, nginx's concurrency is indeed better than other web servers of the same type. Website users using nginx include: Baidu, JD.com, Sina, NetEase, Tencent, Taobao, etc.

2. What is an agent?

Proxy server, when the client sends a request, it will not send it directly to the destination host, but first send it to the proxy server. After the proxy service accepts the client's request, it will send it to the host and receive the data returned by the destination host, store it in the hard disk of the proxy server, and then send it to the client.

For example: People around us who want to rent a house

3. Scenario without an agent

In the absence of a proxy, the client and the nginx server are both clients. The client requests the server, and the server responds directly to the client.

4. Enterprise scenarios In Internet requests, the client often cannot directly initiate requests to the server, so it is necessary to implement communication between the client and the service.

5. Common modes of nginx proxy service

As a proxy service, nginx is summarized according to the application scenario. The proxy is divided into forward proxy and reverse proxy.

6. Forward Proxy

Forward proxy: Client <-> Proxy-> Server:

A simple example of renting a house is given by a forward agent:

A (tenant) B (agent) C (landlord) A (client) wants to rent C (server)'s house, but A (client) does not know C (server) and cannot rent it. B (agent) knows C (server) who can rent this house, so you ask B (agent) to help you rent this house. ps: In this process, C (server) does not know A (client) but only knows B (agent). C (server) does not know that A (client) rented a house, but only knows that the house was rented to B (agent).

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A forward proxy is set up between the client and the target host and is only used to proxy the connection requests from the internal network to the Internet. The client must specify a proxy server and send the http requests that were originally sent directly to the Web server to the proxy server.

7. Reverse Proxy

Reverse proxy: client-1>proxy<1> Server-side reverse proxy also uses a house renting example: A (client) wants to rent a house, and B (proxy) rents the house to him. At this time, C (server) is actually the landlord. B (agent) is the intermediary who rents the house to A (client). During this process, A (client) does not know who the landlord of the house is, and he may think that the house belongs to B (agent).

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The reverse proxy server is set up on the server side. It relieves the server's workload by buffering frequently requested pages and forwards client requests to the target server on the internal network. It also returns the results obtained from the server to the client requesting a connection on the Internet. At this time, the proxy server and the target host appear to be one server to the outside world.

8. Main applications of reverse proxy

Many large web sites now use reverse proxies. In addition to preventing malicious attacks on internal servers from the external network, caching to reduce server pressure and access security control, it can also perform load balancing and distribute user requests to multiple servers.

9. Proxy protocols supported by nginx proxy

http belongs to the seventh layer application layer proxy hypertext transfer protocol https proxy http/https protocol TCP belongs to the fourth layer transport layer proxy tcp/dupxiey
websocket is used to develop proxy http1.1 long link communication protocol GRPC proxy go language remote call POP/IMAP proxy mail sending and receiving protocol RTMP proxy streaming media, live broadcast

10.web01 configure proxy

[root@web01 php]# vim /etc/nginx/conf.d/blog.drz.com.conf
server {
  listen 80;
  server_name blog.drz.com;
  root /code/wordpress;
  index index.php index.html;
  access_log /var/log/nginx/blog.drz.com_access.log main;

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

}
Proxy WordPress
[root@lb01 ~]# vim /etc/nginx/conf.d/daili.conf Edit the proxy server of wordpress {
  listen 80;
  server_name blog.drz.com;

  location / {
    proxy_pass http://10.0.0.7;

     proxy_set_header HOST $http_host;
     proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;

     proxy_http_version 1.1;
     proxy_connect_timeout 60s;
     proxy_read_timeout 60s;
     proxy_send_timeout 60s;
     proxy_buffering on;
     proxy_buffer_size 8k;
     proxy_buffers 8 8k;
}

}
root@lb01 ~]# nginx -t
nginx: the configuration file /etc/nginx/nginx.conf syntax is ok
nginx: configuration file /etc/nginx/nginx.conf test is successful
[root@lb01 ~]# nginx -s reload 

11. Add request header information sent to the backend server

# When the user requests, the value of HOST is www.oldboy.com, so the proxy service will pass the request to the backend as www.oldboy.com.
proxy_set_header Host $http_host;
# Put the value of $remote_addr into the variable X-Real-IP. The value of $remote_addr is the client's IP address.
proxy_set_header X-Real-IP $remote_addr;
#The client accesses the backend service through the proxy service. The backend service will record the real client address through this variable proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;

12. Timeouts for TCP connection, response, return, etc. from proxy to backend

//Nginx proxy and backend server connection timeout (proxy connection timeout)
Syntax: proxy_connect_timeout time;
Default: proxy_connect_timeout 60s;
Context: http, server, location
 
//The time that nginx proxy waits for the response from the backend server Syntax: proxy_read_timeout time;
Default: proxy_read_timeout 60s;
Context: http, server, location
 
//Timeout time for backend server data to be sent back to nginx proxy Syntax: proxy_send_timeout time;
Default: proxy_send_timeout 60s;
Context: http, server, location

13. Why use a proxy

1) Improve access speed. Since the data returned by the target host will be stored in the hard disk of the proxy server, the next time the client accesses the same site data, it will be read directly from the hard disk of the proxy server, which plays a caching role. Especially for popular sites, it can significantly improve the request speed.

2) Firewall function: Since all client requests must go through the proxy server to access the remote site, limits can be set on the proxy server to filter certain unsafe information.

3) Access inaccessible target sites through proxy servers. There are many developed proxy servers on the Internet. When the client has restricted access, it can access the target site through an unrestricted proxy server. In layman's terms, the browser we use to bypass the firewall utilizes a proxy server. Although we cannot go abroad, we can also directly access the external network.

14. Summary

The forward proxy agent is the client and serves the client. The reverse proxy agent is the server and serves the server.

The above is the full content of this article. I hope it will be helpful for everyone’s study. I also hope that everyone will support 123WORDPRESS.COM.