Cardinal Game Server

Cardinal is a Go-based game server designed to manage Attack & Defend CTF competitions. This guide outlines the project structure, setup process, and key features to help you deploy and manage the server.

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Table of Contents

1. Project Structure
2. Setup Instructions
   • Prerequisites
   • Building the Project
   • Configuration
   • Running the Application
   • Stopping the Application
3. Key Functionalities
   • Initialization
   • API Endpoints
   • Flag Submission
4. Docker Setup
   • Docker Compose Services
     • Cardinal
     • Database
     • Web
5. Docker Compose File

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Project Structure

./
├── gameserver
│   ├── cardinal             # Core game server code
│   ├── checker              # Checker scripts
│   ├── conf                 # Configuration files
│   ├── docker-compose.yml   # Docker Compose configuration
│   ├── README               # This file
│   └── web                  # Web service files (e.g., Nginx)

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Setup Instructions

Prerequisites

• Docker
• Docker Compose

Building the Project

1. Clone the repository:

   git clone https://github.com/BumbleB-NL/attack-defense.git
   cd gameserver

2. Build the Docker images:

   docker compose build

Configuration

Edit the configuration file located at conf/Cardinal.toml to match your environment's requirements.

Running the Application

Start the application with Docker Compose:

docker-compose up -d

This will launch the services defined in the Docker Compose file: cardinal, db, and web.

Stopping the Application

Stop the application and remove the containers:

docker-compose down

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Key Functionalities

Initialization

The initialization process (in bootstrap.LinkStart) performs the following tasks:

• Load configuration settings.
• Initialize the MySQL database.
• Set up the game timer.
• Initialize caches and webhooks.
• Start the web server.

API Endpoints

API routes (defined in route.Init) include:

• POST /api/flag - Submit a flag.
• POST /api/login - Team login.
• POST /api/logout - Team logout.
• GET /api/rank - Fetch ranking data.
• GET /api/asteroid - WebSocket endpoint for asteroid interactions.

Flag Submission

Flag submission logic (in game.SubmitFlag) includes:

• Verifying that the competition has started.
• Validating the authorization header.
• Checking the flag against current and future rounds.
• Recording the flag in the database.

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Docker Setup

Overview

The server uses a multi-container setup with the following services:

1. cardinal - Core game server.
2. db - MySQL database.
3. web - Nginx reverse proxy.

Each service is defined in the docker-compose.yml file.

Docker Compose Services

Cardinal Service

• Build context: ./cardinal
• Environment variable: CARDINAL_DOCKER=1
• Ports: Exposes 19999 (game server port).
• Volumes: Mounts ./conf/Cardinal.toml for configuration.
• Logging: Logs are capped at 200KB per file (max 10 files).
• Restart policy: Always restarts if stopped.
• Dependencies: Waits for the database service (db) to be ready.

Database Service

• Image: mysql:8.0.21
• Ports: Exposes 3306 (MySQL default port).
• Volumes: Persists data in ./Cardinal_database.
• Environment variables:
  • MYSQL_ROOT_PASSWORD: Root password.
  • MYSQL_DATABASE: Database name.
  • MYSQL_USER: User for the application.
  • MYSQL_PASSWORD: Password for the user.
• Command: Configured to use UTF-8 MB4 for better compatibility.
• Logging: Similar to the cardinal service.
• Restart policy: Always restarts if stopped.

Web Service

• Build context: ./web
• Ports: Exposes 8087 on the host.
• Volumes: Mounts ./web/nginx.conf for Nginx configuration.
• Logging: Configured with the same logging settings.
• Restart policy: Always restarts if stopped.

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Docker Compose File

Below is the full docker-compose.yml file for reference:

services:
  cardinal:
    build:
      context: ./cardinal
    environment:
      CARDINAL_DOCKER: 1
    ports:
      - "19999:19999"
    volumes:
      - ./conf/Cardinal.toml:/Cardinal/conf/Cardinal.toml
      - ./checker/:/checker/
    logging:
      options:
        max-size: "200k"
        max-file: "10"
    restart: always
    depends_on:
      - db

  db:
    image: mysql:8.0.21
    ports:
      - "3306:3306"
    volumes:
      - ./Cardinal_database:/var/lib/mysql
    logging:
      options:
        max-size: "200k"
        max-file: "10"
    restart: always
    environment:
      MYSQL_ROOT_PASSWORD: Cardinal
      MYSQL_DATABASE: Cardinal
      MYSQL_USER: Cardinal
      MYSQL_PASSWORD: Cardinal
    command: mysqld --character-set-server=utf8mb4 --collation-server=utf8mb4_unicode_ci

  web:
    build:
      context: ./web
    ports:
      - 8087:80
    volumes:
      - ./web/nginx.conf:/etc/nginx/conf.d/default.conf
    logging:
      options:
        max-size: "200k"
        max-file: "10"
    restart: always

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For detailed implementation and troubleshooting, explore the codebase and configuration files.