Home server build log

#curious_geeks/experiment

Objective this rolls up to: Why I turned an old laptop into a server
Technical write-up: How to convert old laptop into a server?

Build log

Date	Problem	Decision
2026-08-22	Anything running on the box is reachable by anything else on the network	Turned on the firewall and bound the AI server to the machine itself instead of the network. I reach it by logging in through Tailscale. Exposed, it's an open API and anyone who finds it runs prompts on my hardware for free.
2026-08-22	Tailscale expires after about six months and renewing it needs a keyboard	Turned off key expiry. Otherwise it dies months from now, when I've forgotten all of this, and the fix is finding a monitor for a machine that lives in a bag.
2026-08-22	The machine travels with me between my rented place and home, so the network changes every time	Installed Tailscale before the first move. It keeps one address on any network. The local IP changes and nothing I saved has to change with it. A fixed IP or port forwarding was never an option for a machine that doesn't sit still.
2026-08-22	Fixing the network while depending on that same network to reach the machine	Debugged wifi over the ethernet connection, and used netplan's auto-revert instead of applying changes directly. Get it wrong on a machine with no screen and you're locked out.
2026-08-22	The wifi config looked correct and silently never connected	Two causes, neither visible in the error: the config style I used isn't supported for wireless, and the wifi package Ubuntu Server needs wasn't installed.
2026-08-22	The server wouldn't get on wifi	Ran a cable. Ethernet is now the primary connection and wifi the backup. A machine I can't look at shouldn't depend on the flakiest link in the house.