Just to save a lot of time and effort in the future for people without A LOT of experience setting up a server, I will document my week long frustration fueled successful attempt to make Hubzilla work in my test server and be accessed in the local network.
Now, the real problem is that you can't access (you CAN install, you just can't access) Hubzilla as a sub directory in your server, don't understand why, there must be some technical or security reason. But Wordpress does it nicely with a simple change to the .htaccess file and would be really helpful for people like me with small home test server if Hubzilla could do the same....any way....I digress....
I'm following this guide alongside the official instruction for installing Hubzilla: https://www.howtoforge.com/tutorial/how-to-install-hubzilla-on-ubuntu/
The trick part here is the "Configure Apache for Hubzilla" section, what "creates" a specific address to access your site is the correct configuration of a VirtualHost in Apache.
As you can see in the guide, you just have to point Apache to the place Habzilla is installed!
At this point, your Hubzilla installation should be working as expected in the machine it is installed
. Just go to the browser and http://the_name_set_in_the_VirtualHost/
to test it.
If your server is on the machine you use to work, than that is that, but in my case it is not....
My setup is a Raspberry Pi 3B+ that is a generic solution for many of my needs :D (including 3D printing controller, emulation console and smart TV killer in the weekends).
If you have a big local network, at this point, it may be a good idea to setup a local DNS server, but considering it's just me, the server and the wife, I'm not doing it at this point.
Instead, Linux have a nice solution that let you create nicknames for IPs you access often.
So in your machine (NOT the server), open the terminal and type this:
You should be looking now to a text file with a list of IPs and names for localhost and such.
Just add a line in the end with the address of your server and the name you set to the Hubzilla in the VirtualHost.
You should now be capable to access from your machine the Hubzilla installation (in a sub directory :P).