Provides a forwarding HTTPS server which transparently fetches and caches certificates via Let's Encrypt. This must run on 443 and 80 (just forwards to https://) and can't coexist with any other web server on your machine.
Why? This is so you can host random and long-lived services publicly on the internet—perfect for other services which don't care about certificates or HTTPS at all, and might be provided by Node or Go on a random high port (e.g., some dumb service running on localhost:8080).
Note! This doesn't magic up domain names. You would use this service only if you're able to point DNS records to the IP address of a machine you're running this on, and that the machine is able to handle incoming requests on port 443 and 80 (e.g., on a home network, you'd have to set up port forwarding on your router).
Configure this via /var/snap/https-forward/common/config, which is empty after install. It should be authored like this:
# hostname forward-to optional-basic-auth
blah.example.com 192.168.86.24:7999 user:pass
user-only.example.com localhost:9002 user # accepts any password
# ... specify host with '.' to suffix all following