Following on Import Caddy in go code and auto-agree to LetsEncrypt terms, I now know that https://godoc.org/github.com/mholt/caddy contains a small example showing how to use this caddy package, via a Caddyfile.
Now, would it be possible to use Caddy package/library just for HTTPS certification? I.e., to setup the HTTPS service and automatically acquired certification from LetsEncrypt? Just that, without any Caddyfile processing handling.
I need my program as minimalist as possible, because its only purpose is to sever an 1x1 pixel, via either HTTP or HTTPS.