Chatterbox - NestJS Real-time Chat Application

Chatterbox is a real-time chat application built with NestJS, designed for scalability and maintainability. It features WebSocket communication, JWT-based authentication, and a PostgreSQL database backend.

Features

• Real-time Messaging: Utilizes WebSockets (Socket.IO) for instant message delivery.
• Scalable Architecture: Leverages Redis with @socket.io/redis-adapter for multi-instance WebSocket scaling.
• Authentication & Authorization: Secure JWT-based authentication (access and refresh tokens) using RSA keys.
• Database: PostgreSQL managed with TypeORM, including support for migrations.
• API Documentation: Swagger (OpenAPI) integration for easy API exploration and testing.
• Configuration Management: Flexible configuration using @nestjs/config and .env files.
• Logging: Comprehensive logging with Winston.
• Input Validation: Uses class-validator and class-transformer for robust request validation.
• Structured Codebase: Follows a modular approach with clear separation of concerns (application, infrastructure, presentation layers).

Prerequisites

Before you begin, ensure you have the following installed:

• Node.js (v18.x or later recommended)
• npm (v9.x or later) or yarn
• PostgreSQL (v13.x or later)
• Redis (v6.x or later)
• OpenSSL (for generating RSA keys)
• Docker (Optional, for running PostgreSQL and Redis in containers)

Getting Started

1. Clone the repository:

   git clone <your-repository-url>
   cd nestjs-chat

2. Install dependencies:

   npm install
   # or
   # yarn install

3. Set up environment variables: Copy the example environment file and update it with your local configuration:

   cp .env.example .env

   Edit .env with your specific settings (database credentials, ports, key paths, etc.). See the Environment Variables section for details.

4. Generate RSA Keys for Authentication: The application uses RSA keys for signing and verifying JWTs. Use the provided Makefile to generate them:

   make generate_keys

   This will create a keys/ directory with access_private.key, access_public.key, refresh_private.key, and refresh_public.key. Ensure the paths in your .env file (AUTH_ACCESS_PUBLIC_KEY_PATH, AUTH_ACCESS_PRIVATE_KEY_PATH, etc.) point to these generated keys (e.g., keys/access_private.key).

5. Set up the Database: Ensure your PostgreSQL server is running and accessible with the credentials provided in your .env file. Run database migrations to create the necessary tables:

   npm run migration:run

Running the Application

• Development Mode (with hot-reloading):

  npm run start:dev

  The application will typically be available at http://localhost:<PORT> (as defined in your .env).

• Production Mode:

  npm run build
  npm run start:prod

• Debugging Mode:

  npm run start:debug

Running Tests

• Run all tests:

  npm test

• Run tests in watch mode:

  npm run test:watch

• Run tests with coverage report:

  npm run test:cov

• Run End-to-End (E2E) tests:

  npm run test:e2e

API Documentation

Swagger API documentation is available once the application is running. Navigate to:

http://localhost:<PORT>/swagger

(Replace <PORT> with the HTTP port specified in your .env file).

Environment Variables

The following environment variables need to be configured in your .env file:

Variable	Description
POSTGRES_HOST	PostgreSQL server host.
POSTGRES_PORT	PostgreSQL server port.
POSTGRES_USERNAME	PostgreSQL username.
POSTGRES_PASSWORD	PostgreSQL password.
POSTGRES_DATABASE	PostgreSQL database name.
POSTGRES_LOG	Enable/disable TypeORM logging (true/false).
POSTGRES_SLOW_QUERY_LIMIT	Slow query limit in milliseconds for logging.
LOG_USE_FILE	Whether to log to a file (true/false).
LOG_FILE	Path to the log file (if LOG_USE_FILE is true).
LOG_LEVEL	Logging level (e.g., debug, info, warn, error).
PORT	Port number for the HTTP server.
REDIS_HOST	Redis server host.
REDIS_PORT	Redis server port.
REDIS_USERNAME	Redis username (if applicable).
REDIS_PASSWORD	Redis password (if applicable).
WEBSOCKET_PORT	Port number for the WebSocket server (Note: NestJS integrates WS with HTTP port by default unless explicitly separated).
AUTH_ACCESS_PUBLIC_KEY_PATH	Path to the access token public RSA key.
AUTH_ACCESS_PRIVATE_KEY_PATH	Path to the access token private RSA key.
AUTH_REFRESH_PUBLIC_KEY_PATH	Path to the refresh token public RSA key.
AUTH_REFRESH_PRIVATE_KEY_PATH	Path to the refresh token private RSA key.

Key Generation (Makefile)

The Makefile provides convenient commands for managing RSA keys used for JWT authentication:

• make generate_keys: Generates new RSA private and public key pairs for both access and refresh tokens. It will create them in the keys/ directory. If keys already exist, it will prompt an error; use make delete_keys first.
• make delete_keys: Deletes the keys/ directory and all its contents.
• make help: Displays available Makefile commands.

Project Structure

A brief overview of the main directories in src/:

• src/main.ts: Application entry point, initializes NestJS app, Swagger, WebSocket adapter, etc.
• src/app.module.ts: Root module of the application.
• src/application/: Contains core business logic, services, and use cases for different domains (e.g., auth, chat, user).
• src/common/: Shared utilities, decorators, enums, constants, and base classes used across the application.
• src/infrastructure/: Handles external concerns like database interactions (TypeORM entities, repositories), third-party service integrations (Redis, logging), and WebSocket adapters.
• src/presentation/: Manages how the application interacts with the outside world. Includes HTTP controllers, WebSocket gateways, Data Transfer Objects (DTOs), and guards.

License

This project is UNLICENSED.