How Nginx sets up forward proxies at the same time

How Nginx sets up forward proxies at the same time

A few days ago, one of my buddies asked me a question, "Lao Tie, I heard that Nginx can set up forward proxy at the same time, is it true? How to set it up?" To be honest, this is a pretty good question, and Nginx, as a high-performance web server and reverse proxy server, can indeed do this. So, let me take you on a journey to explore how Nginx can set up forward proxies at the same time!

Difference between forward and reverse proxy

Before we dive into explaining how Nginx can set up forward proxies at the same time, let's first figure out the difference between forward and reverse proxies. As the name suggests, a forward proxy forwards requests through a proxy server so that the client cannot directly access the target server, while a reverse proxy relays requests through a proxy server to forward the client's request to the target server. Simply put, a forward proxy sends requests instead of the client, while a reverse proxy receives requests instead of the server.

How Nginx implements forward proxying

Now that we understand the difference between forward and reverse proxies, we can move on to understanding how Nginx implements forward proxying. Below, I will explain it step by step with actual code.

First, we need to make sure that Nginx is installed. then, add the following configuration to the Nginx configuration file (typically nginx.conf):

http {
server {
listen 80;

location / {
proxy_pass http://目标服务器的IP地址;
}
}
}

In the above configuration, we have used Nginx's proxy_pass directive for forward proxy. When a client request reaches the Nginx server, Nginx will forward the request to the target server based on the proxy_pass directive in the configuration. In this way, forward proxy is implemented.

Configuration of multiple forward proxies

Maybe some of you will ask, the above configuration can only realize a forward proxy, so what if I want to set up multiple forward proxies at the same time? Nginx provides a very convenient way to meet our needs.

Below, I'll use the example of configuring two forward proxies:

http {
server {
listen 80;

location /proxy1 {
proxy_pass http://目标服务器1的IP地址;
}

location /proxy2 {
proxy_pass http://目标服务器2的IP地址; }
}
}
}

In the above configuration, we have used different location blocks for multiple forward proxies. You just need to configure different proxy_pass directives in different location blocks. When the URL path of a client request matches the corresponding location block, Nginx will forward the request to the appropriate destination server.

Load balancing and caching applications

In addition to the basic forward proxy functionality, Nginx also provides load balancing and caching applications to make our proxy server more powerful and stable.

First, let's explain the application of load balancing.Nginx provides several load balancing strategies, such as polling, IP hashing, least connections, etc. We just need to add the service node in the upstream section of the configuration file. All we need to do is add the service node to the upstream section of the configuration file. Here is an example:

http {
upstream backend {
server IP address of target server 1.
server IP address of target server 2.
}

server {
listen 80.

location / {
proxy_pass http://backend;
}
}
}

In the above configuration, we have used the upstream directive to define multiple service nodes and forwarded the requests to these service nodes for load balancing through the proxy_pass directive. In this way, both target server 1 and target server 2 are able to handle client requests according to the set load balancing policy.

In addition, Nginx also supports caching, which allows you to cache the response results of certain requests to improve access speed and reduce server load. We just need to add the proxy_cache directive to the location block in the configuration file. Here is an example:

http {
server {
listen 80;

location / {
proxy_pass http://目标服务器的IP地址;
proxy_cache my_cache; proxy_cache_valid
proxy_cache_valid 200 302 10m; }
}
}
}

In the above configuration, we have defined a cache area using the proxy_cache directive and set the cache validity time using the proxy_cache_valid directive. When a client request arrives at Nginx, if the corresponding response exists in the cache, the cached content is returned directly, otherwise the request is forwarded to the target server.

summarize

Through the explanation of this article, I believe you have a certain understanding of how to set up a forward proxy for Nginx at the same time. The difference between forward and reverse proxies, the basic configuration of Nginx to achieve forward proxies, the configuration of multiple forward proxies, as well as the application of load balancing and caching, these are the contents we need to master in the actual application. I hope this article can help you! If there are any questions, welcome to leave a message to discuss. Together we can make progress and grow together!