I'm trying to create a web app tool that tracks a list of 100 websites and what content delivery network (CDN) each website is using over time. I'd like to present the data on a website app that shows the CDN usage (% of bytes & total bytes served by which CDN) over a trailing 7 day, 14, and 30 day period for each website - and for the consolidated group.
This could be done using Cloudflare's HTMLRewriter. Steps would include Fetching the page resource and inspecting the response headers and comparing to the CNAME name or the ASN code to see what content (images, stylesheets, fonts) were being served by which CDN - and running the process on a automated basis.
You would need to create a script that runs every hour in Google Cloud Platform (GCP) that sends a request to collect fresh data from each of the 100 websites. You'd have to run a tool using Cloudflare's edge platform, and then vary the requests by location (across say 20 global cities).