Moving almost 1000 domains

The service that once brought me to the top of Hacker News, my free tool for monitoring TLS certificate expiration, is moving house.

It was a surprise for me to see people submitting hundreds of domains to get monitored only a few days after launch. This number has since stagnated, and because it was a fun little experiment, I am fine with this.

I want to move the service from its current domain (scrutineer.tech) to a subdomain of this blog (monitor.raphting.dev). I am not certain if anyone relies on this service for something important, but I want to make the transition as smooth as possible.

There are two documented strategies for moving an RSS feed’s domain without intervention from the subscriber:

1. An HTTP 301 redirect header
2. A specially formatted XML tag in the feed

My plan, which I will carry out in steps with a few days in between, is as follows:

1. I will first push a notification message to all monitoring feeds, which was normally reserved for automatically generated items.
2. Then, I will begin to implement both redirect strategies for all RSS feeds.
3. Finally, I will switch off the old RSS endpoint completely.

I will collect some numbers before and after the move and will publish them here when the switch is complete. I expect that I will lose some subscribers during this process. This might be due to how different feed readers handle redirects, or perhaps because I “woke up” subscribers who will take the chance to unsubscribe.

Since this is a free service, it is rather indifferent to me if I lose subscribers. However, with hundreds of domains being monitored, I believe someone out there cares. So, I will try to make this transition as smooth as possible, if only for educational purposes.

If you got curious, and you want to get started monitoring your own domain certificates, subscribe to the RSS feed of

https://monitor.raphting.dev/cert/{domain}.rss

Example for raphting.dev: https://monitor.raphting.dev/cert/raphting.dev.rss