Setting up SSL for One IP and multiple domains

[rg305]

@bkwchong

1. Can the reverse proxy able to direct all https://pelicanq.myqnapcloud.com to QNAP server and the rest which is https://whiteyangcastle.ddns.net to the Apache system and use LE cert?

Yes. But the Apache server will need certs to terminate those TLS connections.

@bkwchong

2. What is the legitimate way of managing the multiple hosts and one external IP?

Pretty much anything that "works" is allowed.

@bkwchong

I am fine with terminating HTTPS at the Apache level and no encryption when directing all traffic at the back end servers, at least no a concern for now. However, still keep encryption on when going external.

That does simplify things.
In this case, the back-end QNAP server will not need a cert.
The Apache server will do all the (external side) encryption for all servers (including QNAP server).
Note: The name should remain the same and any self-referencing links within the QNAP should NOT include the protocol it uses (HTTP/HTTPS).
[it shouldn't include the protocol... but we must confirm that and can check it once it is fully configured]

So then Apache will have both names.
One name will be served locally.
The other will be reverse proxied from HTTPS on the outside to HTTP on the inside.

Are you ready?