@vkc sooo
`socat TCP4-LISTEN:1312,reuseaddr,fork EXEC:/path/to/script`
lets you pipe a port and run a shell script off it kinda CGI-style
but for a whole web server
(the stdio for the process is the http connection)
https://github.com/ckiee/nixfiles/tree/e2666512eca6fb35a82cc3a6ad64676106ae656f/modules/services/aldhy/web.sh
https://aldhy.tailnet.ckie.dev

it follows that theme of horrible, insecure, never should be done in production but is Simple and mostly reuses existing things