Don't Do This (Cloudflare + B2 CDN)

2024-10-03

Over the past few days, I’ve been allocating some time to set up this site (it’s new). Part of this involved configuring B2 to serve up assets, going through Cloudflare as a CDN. TLDR:

Site is hosted on Netlify
Files are on B2
B2 URLs are not nice
Cloudflare for DNS, transform rules. Rewrite URL to be nicer, modify the headers so assets get cached, etc.

After setting all of this up, I was greeted with a strange message on Netlify when I tried to access the homepage - a 404 saying there’s no “/file/” route. Weird. I thought it might be a broken import, so I looked through the codebase.

“No results found”.

After some troubleshooting, I managed to figure out the problem. Turns out that this error was due to a rewrite rule in Cloudflare, where it was rewriting all requests, namely: not starts_with(http.request.uri.path, "/file/<path-to-assets>"). I changed it to rewrite only when requests were coming from a specific subdomain, and the site built properly again.