Multiple instances on one Ubuntu server

Hi,

I would like to setup multiple instances of RocketChat on one single physical server.

I am not talking about “Running Multiple Instances Per Host To Improve Performance” as described at https://rocket.chat/docs/installation/manual-installation/multiple-instances-to-improve-performance/

I need multiple instances that are running independently of each other. So for each instance there exists its own database, domain etc.

E.g.
chat.astronomy.example
chat.biology.example

A user that is registered at chat.astronomy.example is not registered at chat.biology.example

I know how to setup reverse proxies and everything that is needed for Apache.

What I would like to know is the best way of installing multiple instances of RocketChat on Ubuntu?What configuration files do I have to edit?
Should I setup multiple Docker instances instead?

Thanks!