Building a proxy-based routing system in JavaScript

18 Sep 2023

NodeJS

In modern web development, it’s common to have multiple backend services handling different parts of an application. Routing requests to the appropriate backend service is crucial for a seamless user experience. In this article, we’ll explore how to build a proxy-based routing system in JavaScript using Node.js at the backend.

Prerequisites

To follow along with the code examples in this article, you should have the following:

Basic understanding of JavaScript and Node.js
Node.js installed on your machine

Setting up the Project

Let’s start by setting up a new Node.js project. Open a terminal and run the following commands:

mkdir proxy-routing-system
cd proxy-routing-system
npm init -y

This will create a new directory called proxy-routing-system, navigate into it, and initialize a new Node.js project with default settings.

Installing Dependencies

We’ll be using the express package as our HTTP server and http-proxy-middleware for creating the proxy routes. Install these packages by running:

npm install express http-proxy-middleware

Creating the Proxy Server

Create a new file named server.js in the project directory and add the following code:

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

const app = express();

// Define the proxy routes
app.use('/api', createProxyMiddleware({ target: 'http://backend-service1:3000', changeOrigin: true }));
app.use('/auth', createProxyMiddleware({ target: 'http://backend-service2:4000', changeOrigin: true }));

// Start the server
app.listen(8080, () => {
  console.log('Proxy server running on port 8080');
});

In the code above, we import the express package and the createProxyMiddleware function from http-proxy-middleware. We then create an instance of the express application and define our proxy routes using the app.use method. Each proxy route is configured with the target backend service URL and the changeOrigin option set to true to ensure that the client’s IP address is forwarded to the backend service.

Configuring the Proxy Routes

In the code snippet above, we define two proxy routes: /api and /auth. Replace these routes with the routes specific to your backend services. For example, if you have a user service running on http://backend-service3:5000, you can add a proxy route as follows:

app.use('/users', createProxyMiddleware({ target: 'http://backend-service3:5000', changeOrigin: true }));

Add as many proxy routes as needed for your application.

Running the Proxy Server

To start the proxy server, run the following command in the project directory:

node server.js

You should see the message “Proxy server running on port 8080” in the terminal, indicating that the server is up and running.

Conclusion

By building a proxy-based routing system in JavaScript, we can seamlessly route requests to different backend services based on the specified routes. This approach allows for better separation of concerns and enables scalability as our application grows.

Remember to configure the proxy routes according to your specific backend services’ URLs in order to get the desired behavior. With this proxy routing system in place, you can effectively handle and manage multiple backend services in your JavaScript applications.

#JavaScript #NodeJS #ProxyRouting #WebDevelopment #BackendServices