Cheers, what I'd probably do is the following:

- use my Go/Gin server

- host as a Docker container inside my Docker Swarm cluster managed by CapRover, so I don't have to pay for a new VM

- given a request from a new origin, my server creates a log file with the origin name and writes the data

- given a request from an existing origin, my server appends the data to the file

- I expose an endpoint with an api key that serves all the contents of a file for a given origin

Let me know if I missed something out though.