Domain Review Triggered by an RSS Registration Bug
Recently, when trying to register my blog on an iPhone RSS reader app, I ran into an unexpected issue. I’ve been using donguri3.net as my blog URL, but trying to register the RSS feed with https://donguri3.net/feed resulted in a persistent error.
On the other hand, when I specified https://donguri3.net/feed (which accesses the same articles), it registered successfully right away. While app-specific behaviors play a role, considering which one should be “official" prompted me to think that it would be better to unify under the apex domain (donguri3.net).
Purpose and Benefits of Domain Unification
The goal this time is simple: “ensuring users can access the site without getting lost" and “reducing troubleshooting issues with external service integrations."
Especially for features like RSS, where slight behavioral differences can easily occur depending on the user’s operating environment, consolidating URLs into a single standard is crucial.
Furthermore, secondary benefits can be expected, such as:
- Preventing search engine SEO equity from being diluted
- Simplifying SSL certificate management
- Shorter and more memorable URLs displayed in browsers and apps
Challenges with Rewrite Rules
To actually redirect blog. to donguri3.net, you configure the web server’s rewrite rules. In an environment using OpenLiteSpeed, I added the following rules:
# Remove www., blog., or www.blog. and unify to apex
RewriteCond %{HTTP_HOST} ^(?:www.)?(?:blog.)?(.+)$ [NC]
RewriteRule ^(.*)$ https://%1/$1 [L,R=301,NC]
With this configuration,
www.donguri3.netdonguri3.netwww.donguri3.net
accesses will now all be redirected tohttps://donguri3.net/.
ACME Authentication and Handling of .well-known/acme-challenge/
However, there was one challenge. The ACME http-01 challenge used for automatic SSL certificate renewal requires access to a special path called .well-known/acme-challenge/.
If you apply a blind redirect via rewrite rules, even this path gets a 301 redirect, which risks authentication failure. Therefore, I added the following rule at the very beginning.
# Completely bypass ACME challenge
RewriteRule ^.well-known/acme-challenge/ – [L]
This allows access for certificate renewals to be returned as-is without being redirected, ensuring that automated renewals by Let’s Encrypt or ZeroSSL complete without issues.
Key Takeaways from This Response
- Successfully avoided RSS reader app registration errors
- Unified domains to the apex, eliminating SEO waste
- Made SSL certificate renewal processing safe to operate
As a result, we’ve established “unambiguous URLs" for both users and administrators.
Conclusion
It started as a minor issue of “not being able to register in the RSS reader," but looking deeper, it turned out to be a great opportunity to clean up domain operations.
How to handle subdomains varies depending on the site’s circumstances, but when considering integration with external services like RSS and SSL, consolidating into an apex domain is the safer bet.
If anyone else is struggling with “blog." or “www.", I hope you find the rewrite rule adjustments and the exception settings for .well-known/acme-challenge/ helpful.