public/subjects/mobile-dev/chess/resources

♟️ chess websocket server

This project represents a simple websocket server to play chess.

• Local setup
• Interacting with websocket server to play chess
• Chess moves
• Features
• Limitations
• References

Local setup

There are two major ways to locally setup the project to have it up and running:

• Build from source
• Build with Docker

Build from source

Requirements:

• golang 1.19
• PORT environment exported

Export PORT environmental variable. The port can be any port you would like.

export PORT=8080

Install dependencies:

go mod download

Run the project:

go run .

Build with Docker

Requirements:

• docker

Build the docker image:

docker build -t chess .

Run the project with PORT env set:

docker run -d -e PORT=8080 -p 8080:8080 chess

Interacting with websocket server to play chess

a tool to interact with websockets in your terminal, such as websocat, might be handy to test the server

To play chess, players need to be matched with other player.

Firstly, connect using websocket to the endpoint ws://localhost:8080/rooms.

You can use websocat or any other CLI tool you like to do so if you are running the server locally.

websocat ws://localhost:8080/rooms

After two successful connections, the clients (e.g. player) will receive a response from the server. The response will be of the following type:

9c954450-ad7b-4dcc-ab2f-6c556c0835ef

This is the UUID of the game session.

Secondly, when UUID is received connect to the next endpoint - ws://localhost:8080/rooms/9c954450-ad7b-4dcc-ab2f-6c556c0835ef. The UUID should be placed after /rooms/ path.

After the successful connection of 2 clients, the client will receive its own chess color, either white or black.

From now on, players can exchange moves to play chess.

If only one user connects, then the server will not send any color information. That's because the server waits for second player to join. After both players join, the players will receive own colors.

Chess moves

The players exchange with text messages to indicate their chess move. As of chess move notation - Long algebraic notation is used.

Players need to send chess move messages strictly by the defined notion. If the chess engine fails to identify the chess move, then the player will receive an error message - the user will be prompted to send a valid move.

Features

• Supports many concurrent games.

Limitations

• No player reconnect mechanism. If one of user's connection interrupts, then the game session will end.

References

• Chess Engine - notnil/chess.
• Websocket library - gorilla/websocket.