I don’t know a lot about tailscale, but I think that’s likely not relevant to what’s possible (but maybe relevant to how to accomplish it).
It sounds like the main issue here is dns. If you wanted to/were okay with just IP based connections, then you could assign each service to a different port on Bob’s box, and then have nginx point those ports at the relevant services. This should be very easy to do with a raw nginx config. I could write one for you if you wanted. It’s pretty easy if you’re not dealing with https/certificates (in which case this method won’t work anyway).
Looking quickly on google for npm (which I’ve never used), this might require adding the ports to the docker config and then using that port in npn (Like here). This is likely the simplest solution.
If you want hostnames/https, then you need some sort of DNS. This is a bit harder. You can take over their router like you suggested. You could use public DNS that points at a private IP (this is the only way I’m suggesting to get public trusted ssl certificates).
You might be able to use mdns to get local DNS at Bob’s house automatically, which would be very clean. You’d basically register like jellyseer.local and jellyfin.local on Bob’s network from the box and then setup the proxy manager to proxy based on those domains. You might be able to just do avahi-publish -a -R jellyseer.local 192.168.box.ip and then avahi-publish -a -R jellyfin.local 192.168.box.ip. And then any client that supports mdns/avahi will be able to find the service at that host. You can then register those names nginx/npn and I think things should just work
To answer your questions directly
- Yes I think just a box can work
- I think locations are going to be a nightmare. don’t use them if you can avoid it. Also plain nginx really isn’t so bad, and you can learn pretty quickly. this is probably fine in npn though
- I don’t think you need to dive into iptables or anything like that. Iptables would provide a lower level proxying (level 3 instead of like level 7), which could be useful if you’re running non http services, but isn’t necessary for 99% of web stuff.
- I think part of the problem might be working with higher level systems like npn, but a lot of it is just that networking involves so many layers and there are multiple solutions to any problem, all of which require knowing somewhat what’s happening under the surface to understand why they’re failing
I’d be happy to try and give more specifics if you choose a path similar to one of the above things.
What about solvespace web build: https://github.com/solvespace/solvespace/tree/emscripten#building-for-web