How To Setup Gittea/Seafile/HTTP Over SSL On The Same Server?

So, this is a bit over my head admin wise. What I’d like to do is setup a single Linux droplet that serves these subdomains using SSL, like so:

• gittea.domain.com - to a gittea service on the droplet
• seafile.domain.com - to a seafile service on the droplet (and)
• www.domain.com - to an Apache served website on the droplet

I have seen (and performed) the steps to install the services individually, and usually without the SSL component, which I learned how to do using several good quality DigitalOcean How-To’s.

What I can’t seem to grock, however, is how to do these all on one droplet at once with SSL. I know it’s possible … I’m just not grasping how to put it all together, especially the bits about Apache seeming to proxy or forward (or maybe these are not the right words to describe what I am trying to accomplish) or somehow otherwise provide the SSL functionality for the other services.

What should I read to learn how to do this, or maybe it’s been recorded someplace step by step and I just can’t seem to locate the resources? Any help would be greatly appreciated!

Many thanks!