SSH Tic-Tac-Toe

A text-based Tic-Tac-Toe game accessible via SSH, built with Go. Features both CPU opponent and multiplayer modes with room codes.

Features

• 🎮 Text-based UI - Beautiful ASCII art game board
• 🤖 CPU Opponent - Play against an AI with balanced difficulty
• 👥 Multiplayer Mode - Play with friends using room codes
• 🔐 SSH Access - Connect from anywhere using SSH
• 🐳 Docker Support - Easy deployment with Docker

Quick Start with Docker

The easiest way to run the game is using Docker:

# Build and run with docker-compose
docker-compose up -d

# Or using make
make docker-run

Connect to the game:

ssh -p 2222 -o StrictHostKeyChecking=no -o UserKnownHostsFile=/dev/null localhost

Manual Setup

Prerequisites

• Go 1.21 or higher
• (Optional) Docker and Docker Compose

Build from Source

# Clone the repository
git clone <your-repo-url>
cd tictactoe-ssh

# Download dependencies
go mod download

# Build the binary
go build -o tictactoe-ssh .

# Run the server
./tictactoe-ssh

Usage

Connecting to the Game

# Connect to localhost (default port 2222)
ssh -p 2222 -o StrictHostKeyChecking=no -o UserKnownHostsFile=/dev/null localhost

# Connect to a remote server
ssh -p 2222 username@your-server.com

Game Modes

1. Play Against CPU

• Choose option 1 from the main menu
• You play as X, CPU plays as O
• Enter moves as row col (e.g., 1 2 for row 1, column 2)

2. Multiplayer - Create Room

• Choose option 2 from the main menu
• You'll receive a 6-character room code
• Share this code with your friend
• Wait for them to join
• You play as X (first player)

3. Multiplayer - Join Room

• Choose option 3 from the main menu
• Enter the room code provided by your friend
• You play as O (second player)

Game Controls

• Enter moves as: row col (e.g., 1 2)
• Board coordinates:

       1   2   3
     ┌───┬───┬───┐
   1 │   │   │   │
     ├───┼───┼───┤
   2 │   │   │   │
     ├───┼───┼───┤
   3 │   │   │   │
     └───┴───┴───┘
  

Docker Commands

# Build the Docker image
make docker-build

# Run the container
make docker-run

# View logs
make logs

# Stop the container
make docker-stop

# Clean up
make clean

Configuration

The SSH port can be configured via environment variable:

# Set custom port
export SSH_PORT=3000
./tictactoe-ssh

Or in docker-compose.yml:

environment:
  - SSH_PORT=3000
ports:
  - "3000:3000"

Project Structure

tictactoe-ssh/
├── main.go                 # Application entry point
├── pkg/
│   ├── game/
│   │   ├── board.go       # Game board logic
│   │   ├── ai.go          # CPU opponent AI
│   │   └── multiplayer.go # Multiplayer room management
│   └── server/
│       └── server.go      # SSH server implementation
├── Dockerfile             # Docker build configuration
├── docker-compose.yml     # Docker Compose configuration
├── Makefile              # Build and run commands
├── go.mod                # Go module definition
└── README.md             # This file

How It Works

SSH Server

• Uses gliderlabs/ssh library for SSH server functionality
• No authentication required (public access)
• Each connection gets its own game session

CPU AI

• Balanced difficulty algorithm:
  1. Try to win (50% of the time)
  2. Block opponent from winning (30% of the time)
  3. Take center if available (40% of the time)
  4. Take corners (30% of the time)
  5. Make random moves (more often for easier gameplay)

Multiplayer

• Room-based system with 6-character codes
• First player creates room (plays as X)
• Second player joins with code (plays as O)
• Rooms are automatically cleaned up after game ends

Deployment

Deploy to a VPS

1. Copy files to server:

   scp -r . user@your-server:/path/to/tictactoe-ssh

2. SSH into server:

   ssh user@your-server
   cd /path/to/tictactoe-ssh

3. Run with Docker:

   docker-compose up -d

4. Configure firewall (if needed):

   sudo ufw allow 2222/tcp

Deploy to Cloud

The application can be deployed to any cloud provider that supports Docker:

• AWS ECS/Fargate
• Google Cloud Run
• Azure Container Instances
• DigitalOcean App Platform
• Heroku

Simply build the Docker image and deploy it with port 2222 exposed.

Development

Run locally without Docker:

# Install dependencies
go mod download

# Run the server
go run main.go

# Or use the convenience script
./run.sh

Testing

# Run all tests
go test ./...

# Run tests with coverage
go test ./... -cover

# Run tests in verbose mode
go test ./... -v

Run with hot reload (using air):

# Install air
go install github.com/cosmtrek/air@latest

# Run with hot reload
air

Troubleshooting

"Connection refused"

• Ensure the server is running: docker-compose ps
• Check if port 2222 is available: lsof -i :2222
• Verify firewall settings

"Room not found"

• Room codes are case-sensitive
• Rooms are deleted after games end
• Ensure the room creator hasn't disconnected

SSH connection issues

• Try with verbose mode: ssh -v -p 2222 localhost
• Ensure SSH client is installed
• Check if port is accessible from your network

License

MIT License - feel free to use and modify as needed.

Contributing

Contributions are welcome! Please feel free to submit a Pull Request.