Add option to disable NGINX completely

[Olli]

I've a setup with an already a NGINX running doing proxying. So I don't want to run an additional NGINX in a container doing the same - too much layers IMHO.
So with this patch the NGINX can be disabled, the rails port is been exposed to 127.0.0.1:3100 and static file serving (assets) through Puma is enabled.
I had a problem with the Github CI which doesn't run through. I have no clue why. Feedback is appreciated.
I hope this patch helps.

[mgruner]

@Olli thanks a lot for reaching out. I generally agree about your goal - having an included nginx container seems to be a bit of overhead.

But right now it's that way, and it's also part of the generated Zammad image. It does serve static asset which speeds up for production use cases. An external nginx could not do that, because it does not have access to the static assets in the Zammad image.

To move forward here, we might consider dropping nginx from the Zammad image at some point and using thruster instead. Not sure if this would really work out, but we should investigate it.

The current PR seems to be not really fit for production, and I would like to close it if you don't mind.

BTW CI didn't run because it requires approval for externals contributors.

[Olli]

Ok I understand and agree. If the plans to explore a better alternative to the actual setup than it makes more sense go this route. Thruster is also a part of kamal2 and may better for future use.