Asked ChatGPT for a way to use a middleware to serve static files by domain and a show a 404 error when pages aren’t found.

By the 3rd iteration, I had a working bit of code to add to my actual 4 domain website app.

WebApps in Go are so easy to write, even with a fair amount of editing to add some debug lines, logging and setting my domain names, easy peasy. Simple code simple examples, and lots of learning.