nodejs proxy sends request

With the rapid development of the Internet, the importance of network applications has become more and more obvious. However, in web applications we don't always get what we want and may need to get data from a website that doesn't support direct access. Or we want to access across domains, but due to the browser's same-origin policy, we cannot share resources between different domain names. All of these problems can be solved by sending requests through a proxy.

Nodejs is an event-driven JavaScript running environment that is very suitable for proxy requests. In this article, we will explain how to create a proxy using Nodejs so that we can access websites that do not support direct access, or access across domains.

1. Installing dependencies

Nodejs uses npm to manage application dependencies. We can use the following command to install the required dependencies:

npm install express http-proxy-middleware

Among them:

• express is a popular Nodejs web framework that provides convenient routing and middleware support
• http-proxy-middleware is a middleware for proxying requests to other on the server.

2. Create Server

Create a Nodejs server so that we can proxy requests. Create a file named "server.js" in the project folder and enter the following code:

const express = require('express');
const { createProxyMiddleware } = require('http-proxy-middleware');

const app = express();

app.use('/', createProxyMiddleware({ 
    target: 'https://example.com',
    changeOrigin: true
}));

app.listen(3000, () => {
    console.log('Server is running on port 3000');
});

• Introduce express and http-proxy-middleware modules
• Create an express Application
• Uses the http-proxy-middleware middleware to proxy requests, setting our target to the website we want to proxy
• Use the changeOrigin option to change the origin so that the HTTP request headers are set correctly
• Start the application listening on port 3000.

3. Configuring the Server

Our proxy server is now ready, but in order for proxy sending requests to work properly, we need to do some configuration on the server. Add the following code in the "server.js" file:

app.use('/', (req, res, next) => {
    res.header('Access-Control-Allow-Origin', '*');
    res.header('Access-Control-Allow-Headers', 'X-Requested-With');
    res.header('Access-Control-Allow-Methods', 'GET, PUT, POST, DELETE, OPTIONS');
    next();
});

The purpose of this code is to allow cross-domain access. For each incoming request, we set response headers to allow all origins ( * ) to access our server and set the supported HTTP request methods.

4. Run the server

Now that we have completed the setup and configuration of the proxy server, we can start the server by running the following command:

node server.js

Then we You can access our proxy server in the browser, such as http://localhost:3000, to access the website to which the proxy is directed.

Summary

Using Nodejs proxy to send requests is a relatively simple method and does not require much code. We only need to install the necessary dependencies, create a server, configure it, and then we can make proxy requests in our local environment. Through proxy requests, we can not only obtain website data that does not support direct access, but also access resources across domains, as well as improve the efficiency of proxy requests by adding some other features.

The above is the detailed content of nodejs proxy sends request. For more information, please follow other related articles on the PHP Chinese website!