snakes

Corewars-like snakes game server. It implements a multi-player environment for a Snake-like game in which each snake is controlled by a computer program written in Python.

Game rules

Some specifics of the implemented variant:

• all snakes occupy the same single board and move simultaneously in synchronized discrete-time steps;

• snake dies if its head attempts to leave the board boundaries or move to a field occupied by a snake (including itself);

• snake dies if its program attempts to perform an illegal or unrecognized move;

• snake dies when a new version of its code is submitted;

• snake dies when it "thinks too long" on a move (when its controlling program takes too long to provide a move after receiving the board state);

• for each snake the server keeps score - the snake's maximum achieved length;

• when a snake dies it is removed from the board, its length is reset to 1 and it "re-spawns" on a random field in the next time step;

• the snake's score is preserved when it dies.

Users/contestants

Each contestant starts with an example program controlling their snake. The example program has a commented "scaffolding" and implements a simple "choose-a-random-direction" strategy in its move() function.

Your goal is to implement a better strategy for your snake - you can use all the power of the language, including using builtin modules. In the provided scaffolding code the move() function is called once per time step, its input is the current board state represented as a list of strings, e.g.:

['.###.....',
 '.o....#..',
 '......#..',
 '..o.###..',
 '....#...o',
 '....#H...']

Each character in the board representation describes a single board field:

• .: empty field - safe to move there;

• o: apple - eat those to grow your snake! (and possibly your score, too!);

• H: the head of your snake - there's always exactly one H on the board;

• #: part of a snake, yours or opponent's.

Each time your move() function is called it should return a string describing a valid move. Valid moves are: left, right, up, down.

Mentors

Each snake is run in a separate process, in an environment that attempts to provide isolation from other snakes' processes - the goal is for the contestants to win by implementing a better algorithm and not by hacking other snakes ;)

The game server communicates with each snake process by sending board state updates on stdin and expecting a valid move written to stdout after each board update, within certain time-frame. Anything the snake process writes to stderr is collected and shown in the user's web client window - you can use that for debugging user scripts.

Snake process is killed and re-created when the snake dies. It can also be killed for other reasons, e.g. server restart. The board state, snake scores and user scripts' code is preserved but the state of the snake process is not. So, implementing solutions that attempt to store and remember state between time steps might not be such a good idea.

Admin

The server's runtime consists of at least 3 processes: redis server, snakes manager server and a django server. You might want a front-end HTTP server, as well. The snake manager server requires some pretty specific environment to do its job properly - see snakes-docker for some help setting-up and running.

Once everything is running, managing the game is done through the snakes-manage script (run in a way that allows it to communicate with the redis server). Add some snakes with snakes-manage add_snake ... ("snake key" should be a random string, preferably of length 6+, that acts as a snake identifier and a password at the same time, should be kept somewhat secret) then get the unique URLs for them with snakes-manage players ....

-h is your friend.