Http/2 does not work on Wordpress site on Amazon Lightsail

Greeting

Hi Bob,

Thanks for sharing your question in such detail. I can see you’ve put in a lot of effort to enable HTTP/2 on your Bitnami WordPress setup in Amazon Lightsail. With your careful steps already taken, let’s explore deeper troubleshooting and enhancements to ensure HTTP/2 and ALPN are fully activated on your server. 😊

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Clarifying the Issue

You’ve confirmed that the http2_module is loaded in Apache using apachectl -M, and you’ve updated your configuration files as needed. However, testing tools like Google DevTools or HTTP/2-specific sites still indicate that HTTP/2 and ALPN are not supported. Your Let’s Encrypt SSL certificate via the bncert tool is a solid choice, as it natively supports ALPN. This points to potential issues such as SSL/TLS library versions, unaligned configurations, or interference from caching or proxies.

Since your server environment is already configured for HTTP/2, we’ll focus on validating every layer and ensuring no hidden misconfigurations are blocking HTTP/2 from working.

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Why This Matters

Enabling HTTP/2 improves how your website delivers content to users. Faster page load times, reduced latency, and better performance for concurrent requests make HTTP/2 critical for a modern WordPress site, especially one hosted on scalable solutions like Lightsail. With the increasing emphasis on web speed and usability, resolving this issue will directly impact your visitors’ experience and overall site competitiveness.

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Key Terms

• HTTP/2: A modern web protocol for faster, more efficient communication between servers and clients.
• ALPN (Application-Layer Protocol Negotiation): A TLS extension required to negotiate HTTP/2 connections over HTTPS.
• bncert Tool: A Bitnami utility for managing Let’s Encrypt SSL certificates and HTTPS configurations.
• SSL/TLS: Secure communication protocols for encrypting data between clients and servers.

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The Solution (Our Recipe)

Steps at a Glance:

1. Validate Apache configuration for HTTP/2 and ALPN.
2. Check OpenSSL version compatibility and update if needed.
3. Restart Apache and clear server/browser caches.
4. Test and validate HTTP/2 functionality using advanced diagnostics.
5. Confirm CDN or proxy configurations, if applicable.

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Step-by-Step Guide:

1. Validate Apache Configuration for HTTP/2 and ALPN
   • Confirm the http2_module is loaded:

     apachectl -M | grep http2

   • Edit your Virtual Host configuration file (e.g., /opt/bitnami/apache2/conf/bitnami/bitnami.conf or bitnami-ssl.conf) and verify it includes the following directives:

     Protocols h2 http/1.1
     SSLProtocol all -SSLv3 -TLSv1 -TLSv1.1
     SSLCipherSuite HIGH:!aNULL:!MD5

   • Save changes and restart Apache:

     sudo /opt/bitnami/ctlscript.sh restart apache

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2. Check OpenSSL Compatibility
   • Verify your OpenSSL version:

     openssl version

     Ensure it is 1.0.2 or higher, as ALPN support requires at least this version. If outdated:
     • Update OpenSSL on Ubuntu using:

       sudo apt update
       sudo apt install --only-upgrade openssl

     • Restart the server to ensure the updated library is applied.

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3. Restart Apache and Clear Cache
   • Restart Apache to apply changes:

     sudo /opt/bitnami/ctlscript.sh restart apache

   • Clear browser caches and any server-side cache layers. For WordPress, ensure plugins like WP Super Cache or W3 Total Cache are cleared.

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4. Advanced Testing Tools
   • Run HTTP/2 tests using KeyCDN's HTTP/2 Test.
   • Use Google Chrome DevTools:
     • Open DevTools (right-click on your site > Inspect).
     • Go to the Network tab.
     • Look for the Protocol column. It should show h2.

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5. Check CDN or Proxy Configurations (If Applicable)
   If your site uses a CDN (like Cloudflare) or any reverse proxy, verify that these services support HTTP/2 and are configured to pass through the protocol. For Cloudflare, ensure HTTP/2 is enabled in the Speed > Optimization settings.

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Closing Thoughts

Bob, with these additional validations and advanced testing tools, you should be able to pinpoint and resolve the issue preventing HTTP/2 from functioning. If the problem persists, consider reissuing your Let’s Encrypt certificate using bncert to rule out certificate-level misconfigurations.

For further reading:

• Bitnami HTTPS Configuration Tool
• Let’s Encrypt on Bitnami
• HTTP/2 Troubleshooting Guide

Let me know how it goes or if you’d like further assistance! 😊

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Farewell

Best of luck, Bob! I’m confident you’re close to resolving this issue and reaping the performance benefits of HTTP/2 on your WordPress site. Let me know if you hit any snags—happy to help! 🚀

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Cheers,

Aaron 😊