Setting Up HTTP/2 with Express.js: A Casual Guide

Setting up HTTP/2 responses with Express.js can seem pretty daunting at first, but once you get the hang of it, it’s a breeze. HTTP/2 is a massive upgrade over HTTP/1.1. It’s packed with cool features like request/response multiplexing, header compression, and server push. These enhancements can seriously turbocharge your web apps. Let’s break down what HTTP/2 is all about and how you can set it up with Express.js.

What the Heck is HTTP/2?

So, HTTP/2 came into the scene around 2015. Since then, it’s been a big hit with major browsers. The features it brings to the table are pretty nifty. Multiplexing? Sounds fancy, right? It just means multiple requests can go over a single connection. Say goodbye to the hassle of multiple connections slowing things down. Then there’s header compression, which chops down the size of headers for more efficient communication. Cool, huh?

Getting Started with Express.js and HTTP/2

Alright, let’s dive into setting this up. First thing, HTTP/2 only works with TLS encryption. No TLS, no HTTP/2; that’s the rule with all modern browsers. Here’s a basic example to kickstart your Express.js server with HTTP/2:

const express = require('express');
const http2 = require('http2');
const { readFileSync } = require('fs');

const app = express();

app.get('/express', (req, res) => {
    res.send('Hello World');
});

const options = {
    key: readFileSync('<Certificate Key>'),
    cert: readFileSync('<Certificate file>'),
    allowHTTP1: true
};

const server = http2.createSecureServer(options, app);
server.listen(3000);

So simple, right? But hold up. There’s a bit of a catch. Express.js middleware and HTTP/2 don’t get along right out of the box. The middleware replaces some core Request/Response object types that HTTP/2 relies on. Let’s sort that out.

Say Hello to http2-express-bridge

To make sure everything runs smoothly, you’ll need http2-express-bridge. This package ensures the correct Request/Response objects are routed where they should be. Here’s how you can tweak your code:

const express = require('express');
const http2Express = require('http2-express-bridge');
const http2 = require('http2');
const { readFileSync } = require('fs');

const app = http2Express(express);

app.get('/express', (req, res) => {
    res.send('Hello World');
});

const options = {
    key: readFileSync('<Certificate Key>'),
    cert: readFileSync('<Certificate file>'),
    allowHTTP1: true
};

const server = http2.createSecureServer(options, app);
server.listen(3000);

Now, we’re talking! Your app can handle HTTP/2 requests while being cool with clients stuck on HTTP/1.1.

Middleware and HTTP/2: Best Buds?

Middleware is the backbone of any Express.js app. But you need to make sure your middleware plays nice with HTTP/2. The Express.js community is all in on updating middleware to be HTTP/2-friendly, especially regarding stream and header handling.

Let’s look at a quick middleware function to log request methods and URLs:

app.use((req, res, next) => {
    console.log(`Request Method: ${req.method} ${req.url}`);
    next();
});

This simple function logs what’s happening and calls next() to move things along. Easy peasy.

Optimizing Middleware for HTTP/2

You want your middleware lean and mean. First off, only lug in the middleware you need. Extra baggage can bog down performance. Here’s an example:

app.use(express.json()); // Load JSON parsing middleware only if your API uses JSON payloads

And, it’s better to apply middleware on specific routes rather than globally:

app.use('/api', express.json()); // Apply JSON parsing only on /api routes

Sometimes, rolling your custom lightweight middleware is the way to go. Here’s a custom middleware snippet:

app.use((req, res, next) => {
    console.log(`Request Method: ${req.method}`);
    next();
});

Keeping things tight and optimized can do wonders for your app’s speed and efficiency.

Test and Benchmark

After setting up HTTP/2, it’s crucial to test and benchmark. Create a robust test suite covering HTTP/2 features like stream management, server push, and header compression. Benchmark it against HTTP/1.1 to suss out any bottlenecks and optimize accordingly.

Wrapping It Up

Setting up HTTP/2 with Express.js involves several steps, like ensuring TLS encryption, using http2-express-bridge, and optimizing middleware. By following these guidelines, you can harness the power of HTTP/2 to supercharge your web app’s performance. Don’t forget to test and benchmark thoroughly to make sure everything runs like a dream. Enjoy the speed boost and enhanced capabilities HTTP/2 brings to the table!