Goat: The Battlestar Server

2019 · age 37

What it was

The Node.js game master at the heart of Goat: a small state-machine library plus the rules of the Battlestar Galactica board game written as commands. The library loads a JSON state file, runs the game as a series of steps, and saves the entire state after every one, so a crashed server restarts exactly where it was, kept alive by a two-line restart loop. Each rule is an async function that pushes state to a player's tablet, awaits their tap, and continues, so a multi-player turn reads as plain straight-line code. Tablets found the laptop by listening for a UDP beacon every 200 milliseconds. The rules that exist cover setup, roles, skill checks, some crises and the line of succession. The rest were thirty-two TODOs, and the server's first line required a module that was never saved, so it could not start.

Wins, for the age

At thirty-seven, with a day job and no team, Jeff wrote rules as awaited commands where the turn structure is the call stack, landing within a year of Temporal's human-in-the-loop signals (2020).
Crash-only design in two lines: a JSON file as the only state plus a loop around node. It found on its own what Erlang/OTP's let-it-crash supervision (1998) had already found.
Zero-configuration discovery for a table of tablets, the same shape as Bonjour and mDNS (2002), rediscovered because nobody at game night should have to type an IP address.
One screen document served player, observer and board by switching on a single role variable.

What it taught

The rules are the product. Engine, editor, players and protocol all shipped in some form, and the thirty-two TODOs were the game.
Two copies of a library is one too many: the copies drifted, and the newer frame reader read a 16-bit id the writer had written as 32 bits.
A missing require is how a project ends. What was never committed never ran again.
A server that executes JSON from any client needs a session token, even among friends.

Genealogy

Ancestors: none on record beyond its umbrella. The first game master this primate wrote. Descendants: BSG Prototype: rules as awaited commands, finished on a new runtime. Part of: Goat.

Epitaph

Here lies the Battlestar server. The beacon was broadcasting, the tablets were listening, and the module that held the game was never saved.