How to Enable HTTP/2 in Apache 2.4 on Ubuntu 20.04?

Apache 2.4 with HTTP/2 enabled on Ubuntu 20.04 will greatly enhance your web server's performance. Compared to HTTP/1.1, HTTP/2 has several benefits, such as server push, header compression, and multiplexing.

Prerequisites

• Ubuntu 20.04
• Apache 2.4.17 or later (HTTP/2 functionality is available beginning with Apache 2.4.17).
• Your Apache server has to have SSL/TLS enabled (HTTP/2 requires HTTPS).

Steps to Enable HTTP/2 in Apache 2.4 on Ubuntu 20.04

Step 1: Update Your System

Before starting, it’s a good idea to ensure your system is up to date:

sudo apt update
sudo apt upgrade

Step 2: Install Apache 2.4

If you don't have Apache installed, you can install it using:

sudo apt install apache2

Step 3: Enable SSL Module and Install Certbot

HTTP/2 requires SSL/TLS, so you need to enable the SSL module and install Certbot to obtain an SSL certificate from Let’s Encrypt:

sudo a2enmod ssl
sudo apt install certbot python3-certbot-apache

Step 4: Obtain an SSL Certificate

Use Certbot to obtain an SSL certificate for your domain:

sudo certbot --apache

Step 5: Enable the HTTP/2 Module

Enable the HTTP/2 module in Apache:

sudo a2enmod http2

Step 6: Configure Apache to Use HTTP/2

Edit your Apache configuration to enable HTTP/2. Open the SSL configuration file:

sudo nano /etc/apache2/sites-available/your_domain.conf

Add the following lines inside the <VirtualHost *:443> block:

Protocols h2 http/1.1

Your configuration should look something like this:

<VirtualHost *:443>
    ServerAdmin webmaster@your_domain
    ServerName your_domain
    DocumentRoot /var/www/your_domain

    Protocols h2 http/1.1

    SSLEngine on
    SSLCertificateFile /etc/letsencrypt/live/your_domain/fullchain.pem
    SSLCertificateKeyFile /etc/letsencrypt/live/your_domain/privkey.pem

    <Directory /var/www/your_domain>
        Options Indexes FollowSymLinks
        AllowOverride All
        Require all granted
    </Directory>
</VirtualHost>

Step 7: Test Your Configuration

Check the configuration for any syntax errors:

sudo apache2ctl configtest

You should see Syntax OK. If there are errors, fix them before proceeding.

Step 8: Restart Apache

Restart Apache to apply the changes:

sudo systemctl restart apache2

Step 9: Verify HTTP/2 is Enabled

You can use online tools like KeyCDN HTTP/2 Test or HTTP/2 and SPDY Indicator for Chrome to verify that HTTP/2 is enabled on your server.

Alternatively, you can use curl to check:

curl -I -k --http2 https://your_domain

check for HTTP/2 in the output.

Troubleshooting

If HTTP/2 is not working as expected, check the following:

1. Apache Error Logs: Check the Apache error logs for any issues:

sudo tail -f /var/log/apache2/error.log

2. Module Status: Ensure that the HTTP/2 and SSL modules are loaded:

sudo apachectl -M | grep http2
sudo apachectl -M | grep ssl

3. Protocol Support: Ensure your browser supports HTTP/2 and that you are accessing the site via HTTPS.

Conclusion

By following these steps, you can enable HTTP/2 on your Apache 2.4 server running on Ubuntu 20.04. This will help improve your website's performance by increasing the advanced features of the HTTP/2 protocol. Remember to keep your server and packages updated to maintain security and performance.