Leveraging HTTP/3 with Nginx: A Step-By-Step Guide

HTTP/3 is the latest version of the Hypertext Transfer Protocol, which is responsible for transferring data between clients and servers on the web. This new version comes with significant improvements over its predecessors, such as reduced latency, better performance, and increased security. One of the most popular web servers, Nginx, has recently added support for HTTP/3, and leveraging this new protocol can provide a better experience for your website's users. In this blog post, we'll take a step-by-step approach to implementing HTTP/3 with Nginx, making it beginner-friendly and providing code examples and explanations along the way.

Prerequisites

Before diving into the configuration process, make sure you have the following in place:

1. A domain name
2. A server running Ubuntu 20.04 or later
3. Root access to the server
4. Nginx version 1.19.0 or later installed
5. OpenSSL version 1.1.1 or later installed
6. Basic knowledge of Linux command line and Nginx configuration

Step 1: Install QUIC and HTTP/3 Patches for Nginx

First, we need to apply the QUIC and HTTP/3 patches to the Nginx source code. These patches will enable Nginx to support the new protocol. You can download the latest patch files from the official QUICHE GitHub repository.

SSH into your server, and run the following commands to install the required dependencies:

sudo apt update
sudo apt install -y build-essential libpcre3-dev zlib1g-dev libssl-dev

Now, download the Nginx source code and the QUICHE library:

wget https://nginx.org/download/nginx-1.19.0.tar.gz
tar xvf nginx-1.19.0.tar.gz
git clone --recursive https://github.com/cloudflare/quiche

After downloading the patch files, apply them to the Nginx source code:

cd nginx-1.19.0
patch -p01 < ../quiche/extras/nginx/nginx-1.19.patch

Step 2: Compile and Install Nginx with HTTP/3 Support

Now that the patches are applied, we can compile and install Nginx. Execute the following commands:

./configure \
    --prefix=/etc/nginx \
    --sbin-path=/usr/sbin/nginx \
    --modules-path=/usr/lib/nginx/modules \
    --conf-path=/etc/nginx/nginx.conf \
    --error-log-path=/var/log/nginx/error.log \
    --http-log-path=/var/log/nginx/access.log \
    --pid-path=/var/run/nginx.pid \
    --lock-path=/var/run/nginx.lock \
    --http-client-body-temp-path=/var/cache/nginx/client_temp \
    --http-proxy-temp-path=/var/cache/nginx/proxy_temp \
    --http-fastcgi-temp-path=/var/cache/nginx/fastcgi_temp \
    --http-uwsgi-temp-path=/var/cache/nginx/uwsgi_temp \
    --http-scgi-temp-path=/var/cache/nginx/scgi_temp \
    --user=nginx \
    --group=nginx \
    --with-compat \
    --with-file-aio \
    --with-threads \
    --with-http_addition_module \
    --with-http_auth_request_module \
    --with-http_dav_module \
    --with-http_flv_module \
    --with-http_gunzip_module \
    --with-http_gzip_static_module \
    --with-http_mp4_module \
    --with-http_random_index_module \
    --with-http_realip_module \
    --with-http_secure_link_module \
    --with-http_slice_module \
    --with-http_ssl_module \
    --with-http_stub_status_module \
    --with-http_sub_module \
    --with-http_v2_module \
    --with-http_v3_module \
    --with-mail \
    --with-mail_ssl_module \
    --with-stream \
    --with-stream_realip_module \
    --with-stream_ssl_module \
    --with-stream_ssl_preread_module \
    --with-cc-opt="-I../quiche/include" \
    --with-ld-opt="-L../quiche/target/release"

make
sudo make install

These commands configure Nginx with various options, including HTTP/3 support, and install the compiled binary in the appropriate location. Make sure to replace the paths and version numbers with the correct values for your system.

Step 3: Configure Nginx for HTTP/3

After installing Nginx, you need to configure it to use HTTP/3. Open the Nginx configuration file, usually located at /etc/nginx/nginx.conf, in your favorite text editor:

sudo nano /etc/nginx/nginx.conf

First, make sure the http2 and http3 modules are enabled in the listen directive:

server {
    listen 80;
    listen [::]:80;
    listen 443 ssl http2;
    listen [::]:443 ssl http2;
    listen 443 ssl http3 reuseport;
    listen [::]:443 ssl http3 reuseport;
    ...
}

Next, add the following SSL configuration options to the server block:

server {
    ...
    ssl_certificate /etc/ssl/certs/your_domain.crt;
    ssl_certificate_key /etc/ssl/private/your_domain.key;
    ssl_protocols TLSv1.2 TLSv1.3;
    ssl_ciphers "TLS_AES_128_GCM_SHA256:TLS_AES_256_GCM_SHA384:TLS_CHACHA20_POLY1305_SHA256:ECDHE-RSA-AES128-GCM-SHA256:ECDHE-RSA-AES256-GCM-SHA384";
    ssl_prefer_server_ciphers on;

    # Enable QUIC and HTTP/3
    ssl_quic on;
    ssl_early_data on;
    ...
}

Replace /etc/ssl/certs/your_domain.crt and /etc/ssl/private/your_domain.key with the correct paths to your SSL certificate and private key, respectively.

Finally, save the configuration file and restart Nginx:

sudo systemctl restart nginx

Now, Nginx is configured to use HTTP/3 alongside HTTP/2 and HTTP/1.1.

Step 4: Verify HTTP/3 Support

To verify that your server is correctly configured to support HTTP/3, you can use an online testing tool like HTTP/3 Check. Enter your domain name and click "Check." If everything is set up correctly, you should see a green checkmark indicating that your server supports HTTP/3.

Alternatively, you can use the curl command with the --http3 flag to test your server:

curl -I --http3 https://your_domain.com

If HTTP/3 is working correctly, the response headers should show HTTP/3 as the protocol version.

FAQ

Q: What is the main difference between HTTP/3 and its predecessors?

A: The most significant difference is that HTTP/3 uses the QUIC protocol instead of TCP for transporting data. QUIC provides better performance, especially in high-latency and unreliable network environments, by reducing connection establishment time, improving congestion control, and allowing for connection migration.

Q: How does HTTP/3 improve security?

A: HTTP/3 inherits the security features of HTTP/2, such as mandatory encryption via TLS 1.3. Additionally, QUIC provides better security against various attacks, such as connection spoofing and tampering, by encrypting more parts of the protocol, including packet numbers and most of the handshake process.

Q: Can I still use HTTP/2 and HTTP/1.1 if I enable HTTP/3?

A: Yes, you can configure Nginx to support all three versions of the protocol simultaneously. This ensures that clients that do not support HTTP/3 can still connect to your server using HTTP/2 or HTTP/1.1.

Q: Will enabling HTTP/3 affect my server's performance?

A: While HTTP/3 can provide performance benefits for end users, it may also increase the server's CPU usage due to the additional encryption and decryption operations required by the QUIC protocol. However, the impact on server performance is typically minimal and outweighed by the benefits of improved user experience.

Q: What browsers currently support HTTP/3?

A: As of 2021, most modern browsers, including Google Chrome, Mozilla Firefox, Microsoft Edge, and Apple Safari, have implemented or are in the process of implementing HTTP/3 support. However, the actual availability of HTTP/3 in a particular browser may depend on the browser version and user settings.