Understanding Certbot and Redirect Issues During WordPress Server Migration: A Practical Reflection

Introduction

Migration of web servers can often bring unforeseen challenges, especially when managing multiple websites and SSL certificates. For individuals self-hosting on Linux distributions like AlmaLinux, troubleshooting such issues requires patience and systematic approaches. This article recounts a real-world experience with SSL certificate installation using Certbot after migrating from CentOS, highlighting practical insights and lessons learned.

Background

The author recently migrated a web hosting environment from CentOS Stream 8 to AlmaLinux. The server hosts approximately seven websites, with configuration files stored in the /etc/nginx/conf.d directory and databases backed up manually. The migration involved manually copying website files via rsync, along with server configuration and database backups—a process that, while straightforward, can sometimes introduce configuration inconsistencies.

Encountered Challenge

Following the migration, the user attempted to obtain SSL certificates using Certbot. However, encountered an error indicating infinite redirects—an issue often caused by misconfigured server redirects or conflicting rules. The specific problem was that Certbot could not install the SSL certificate because of redirect loops, despite the configuration working previously on CentOS.

Troubleshooting Approach

The user’s initial instinct was to seek external help. Rather than relying solely on web searches, they experimented with local language models (LLMs) by copying and pasting Certbot error logs, configuration snippets, and virtual host files to identify the root cause. Despite this effort, the diagnostics did not pinpoint the issue.

A key breakthrough occurred when the user opened each configuration file in vim—a simple action of editing and closing each file. After doing so and rerunning Certbot, the error mysteriously disappeared, and SSL provisioning succeeded without any apparent configuration changes.

Lessons Learned

• Silent Configuration State Changes: Sometimes, simply opening and closing server configuration files can resolve issues, possibly by prompting the server or Certbot to re-parse configurations.

• Loop Prevention and Redirects: Infinite redirect errors often stem from conflicting rules or improper redirect directives. Careful review of redirect rules in configuration files is essential.

• Iterative Troubleshooting: Combining systematic checks with minimal modifications can aid in resolving elusive server errors.

• Tools and Techniques: While AI assistance can be helpful, traditional methods like manual inspection and minimal edits remain valuable.

Conclusion

Migrating web servers and managing SSL certificates require attention to detail. Even actions as simple as editing configuration files can influence server behavior. If you encounter