Layered Architecture & Dependency Injection Example

This project serves as a practical example for the Athens Python Meetup presentation on "Layered Architecture & Dependency Injection: A Recipe for Clean and Testable FastAPI Code". It demonstrates how to structure a FastAPI application using layered architecture principles and dependency injection.

Project Structure

The project follows a layered architecture pattern with clear separation of concerns:

src/layered_architecture/
├── api/                    # Presentation Layer (FastAPI routes)
├── services/              # Service Layer (Business Logic)
│   ├── interfaces/        # Service interfaces
│   └── concrete/          # Service implementations
├── dao/                   # Data Access Layer
│   ├── interfaces/        # DAO interfaces
│   └── concrete/          # DAO implementations
├── dto/                   # Data Transfer Objects
├── db/                    # Database models and migrations
└── config/               # Application configuration

Prerequisites

• Python 3.11+
• Docker and Docker Compose
• Node.js (for generating diagrams and presentation)

Getting Started

1. Clone the repository:

git clone https://github.com/yourusername/layered-architecture.git
cd layered-architecture

2. Start the application:

make run

The application will be available at http://localhost:8000

Available Commands

To see all available commands and their descriptions:

make help

Documentation

To generate the presentation that explains the architecture and design decisions:

make create-presentation

Key Features

• Layered Architecture implementation
• Dependency Injection using FastAPI's dependency system
• Async SQLAlchemy for database operations
• Comprehensive test suite
• Docker-based development environment
• Database migrations with Alembic

API Documentation

Once the application is running, you can access:

• Swagger UI: http://localhost:8000/docs
• ReDoc: http://localhost:8000/redoc

License

This project is licensed under the MIT License - see the LICENSE file for details.