snake-server

README

Snake server

Server for online arcade game - snake.

Game rules

// TODO: Write game rules.

Client

• Python client repo: https://github.com/ivan1993spb/snake-client

Installation

Install from source

• go get -u github.com/ivan1993spb/snake-server to load source code
• go install github.com/ivan1993spb/snake-server to install server
• snake-server to start server
• Use snake-server -h to see usage information

Install from docker-hub

See docker-hub repo: https://hub.docker.com/r/ivan1993spb/snake-server

• Install docker: use fast installation script
• Choose image tag: https://hub.docker.com/r/ivan1993spb/snake-server/tags/
• Use docker pull ivan1993spb/snake-server to pull server image from docker hub
• docker run --rm --net host --name snake-server ivan1993spb/snake-server to start server
• docker run --rm ivan1993spb/snake-server -h for usage information

CLI arguments

Use snake-server -help for help info.

Arguments:

• --address - string - address to serve (default: :8080). For example: :8080, localhost:7070
• --groups-limit - int - groups limit for server (default: 100)
• --conns-limit - int - open web-socket connections limit (default: 1000)
• --seed - int - random seed (default: the number of nanoseconds elapsed since January 1, 1970 UTC)
• --log-json - bool - set this flag to use JSON log format (default: false)
• --log-level - string - set log level: panic, fatal, error, warning (warn), info or debug (default: info)

API description

API methods provide JSON format.

Request POST /games

Creates game and returns JSON details.

curl -X POST -d limit=3 -d width=100 -d height=100 http://localhost:8080/games
{"id":0,"limit":3,"width":100,"height":100}

Request GET /games

Returns info about all games on server.

curl -X GET http://localhost:8080/games
{"games":[{"id":0,"limit":3,"count":0}]}

Request GET /games/{id}

Returns game information.

curl -X GET http://localhost:8080/games/0
{"id":0,"limit":3,"count":0}

Request DELETE /games/{id}

Deletes game if there is not players.

curl -X DELETE http://localhost:8080/games/0
{"id":0}

Request GET /games/{id}/ws

Connects to game Web-Socket.

• Returns playground size
• Initialize game session
• Returns all objects on playground
• Creates snake
• Returns snake id
• Pushes events and objects from game

Game Web-Socket messages description

There are input and output messages.

Output messages

Output messages - when server sends to client a data.

Output message structure:

{"type": output_message_type, "payload": output_message_payload}

Output message can be type of:

• game - message payload contains a game events. Game events has type and payload: {"type": game_event_type, "payload": game_event_payload}. Game events contains information about creation, updation, deletion of objects on playground
• player - message payload contains a player info. Player messages has type and payload: {"type": player_message_type, "payload": player_message_payload}
• broadcast - message payload contains a group broadcast messages. Output message of type broadcast is string

Examples:

{"type":"player","payload": ... }
{"type":"game","payload": ... }
{"type":"broadcast","payload": ... }

Game events

Output message type: game

Game events types:

• error - payload contains string: error description
• create - payload contains game object that was created
• delete - payload contains game object that was deleted
• update - payload contains game object that was upadted
• checked - payload contains game object that was checked by another game object

Examples:

{"type":"game","payload":{"type":"update","payload":{"id":"c4203c7b00","dots":[[233,236],[233,235],[233,234]]}}}
{"type":"game","payload":{"type":"update","payload":{"id":"c420425240","dots":[[120,130],[120,129],[120,128]]}}}

Player messages

Output message type: player

Player messages types:

• size - payload contains playground size object: {"width":10,"height":10}
• snake - payload contains string: snake identifier
• notice - payload contains string: a notification
• error - payload contains string: error description
• countdown - payload contains int: number of seconds for countdown
• objects - payload contains list of all objects on playground

Examples:

{"type":"player","payload":{"type":"notice","payload":"welcome to snake server!"}}
{"type":"player","payload":{"type":"size","payload":{"width":255,"height":255}}}
{"type":"player","payload":{"type":"objects","payload":[{"id":"c4203c7b00","dots":[[233,235],[233,234],[233,233]]},{"id":"c420425240","dots":[[120,129],[120,128],[120,127]]},{"id":"c420311800","dots":[[60,166],[61,166],[62,166]]},{"id":"c4203c7c00","dots":[[40,46],[41,46],[42,46]]}]}}
{"type":"player","payload":{"type":"countdown","payload":5}}

Braodcast messages

Output message type: broadcast

Payload of output message of type broadcast contains string - a group notice that sends to all players in game group.

Examples:

{"type":"broadcast","payload":"hello world!"}

Game primitives

Primitives that used to explain game objects:

• Direction: "north", "west", "south", "east"
• Dot: [x, y]
• Dot list: [[x, y], [x, y], [x, y], [x, y], [x, y], [x, y]]

Game objects

Game objects:

• Apple: {"type": "apple", "id": 1, "dot": [x, y]}
• Corpse: {"type": "corpse", "id": 2, "dots": [[x, y], [x, y], [x, y]]}
• Mouse: {"type": "mouse", "id": 3, dot: [x, y], "dir": "n"}
• Snake: {"type": "snake", "id": 4, "dots": [[x, y], [x, y], [x, y]]}
• Wall: {"type": "wall", "id": 5, "dots": [[x, y], [x, y], [x, y]]}
• Watermelon: {"type": "watermelon", "id": 6, "dots": [[x, y], [x, y], [x, y]]}

// TODO: Fix this topic

Input messages

Input messages - when client sends to server a game commands.

Input message structure:

{"type": input_message_type, "payload": input_message_payload}

Input message types:

• snake - when player sends a game command in message payload to control snake
• broadcast - when player sends a short phrase or emoji to broadcast for game group

Accepted game commands:

• north
• east
• south
• west

Examples:

{"type":"snake","payload":"north"}
{"type":"snake","payload":"east"}
{"type":"snake","payload":"south"}
{"type":"snake","payload":"west"}
{"type":"broadcast","payload":"xD"}
{"type":"broadcast","payload":"ok!"}
{"type":"broadcast","payload":"hello!"}
{"type":"broadcast","payload":";)"}

Input message size is limited.

Game on client side

// TODO: Describe topic

License

See LICENSE.