I have Radicale (caldav/cardav server) running on http://localhost:5232/. I would like to get it under https://dav.my.domain.eu instead and let port 5232 accessible only locally. I haven’t found any example for Caddy on the Radicale website, but there are examples for Apache and Nginx: http://radicale.org/proxy/. I’m not sure what I should start with.
I’m not going to read all of the documentation for Radicale or try to set it up and test it myself, but that should give you a good starting point at least.