Backend: FastAPI + PostgreSQL

Prerequisites

• Python 3.12 or newer (required for development)

  • Install it from the Python official website.
  • Verify installation:

    python --version

    Ensure the version is 3.12.x.

• Docker & Docker Compose (required for database and production setup)

  • Install Docker from the Docker official website.
  • Install Docker Compose by following the instructions on the Docker Compose installation page.
  • Verify installation:

    docker --version
    docker-compose --version

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Troubleshooting

If you encounter an error similar to the following when running the application:

ImportError: dlopen(.../_psycopg.cpython-312-darwin.so, 0x0002): Library not loaded: @rpath/libpq.5.dylib

It means that the PostgreSQL client library (libpq) is not found. To fix this issue on macOS, run the following command to install libpq via Homebrew:

brew install libpq

This should resolve the missing library error.

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How to set up and run the application:

Development Setup (With Hot Reload)

1. Clone the repository:

   git clone https://github.com/PBL-Akatsuki/backend.git

2. Navigate to the project root directory:

   cd backend

3. Start PostgreSQL and pgAdmin (via Docker Compose):

   docker-compose up -d postgres pgadmin

   • This starts the database and pgAdmin services. You can access pgAdmin at http://localhost:8080.
   • Use these credentials to log in:
     • Email: admin@example.com
     • Password: admin

4. Set up a virtual environment:

   python -m venv venv
   source venv/bin/activate  # On Windows: venv\Scripts\activate

5. Install dependencies:

   pip install -r app/requirements.txt

6. Run the FastAPI application with hot reload:

   uvicorn app.main:app --reload --host 0.0.0.0 --port 8000

   • The API will be available at http://localhost:8000.
   • The Swagger UI (API documentation) is available at http://localhost:8000/docs.

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Production Setup (Dockerized Deployment)

1. Clone the repository:

   git clone https://github.com/PBL-Akatsuki/backend.git

2. Navigate to the project root directory:

   cd backend

3. Build the Docker image:

   docker-compose up --build -d

4. Access the FastAPI application:

   • The API will be available at http://localhost:8000.
   • The Swagger UI (API documentation) is available at http://localhost:8000/docs.

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Testing the Application

Running Tests

Run all tests:

PYTHONPATH=. pytest -v tests/

This will run all the test cases in the tests/ directory. It includes tests for:

• User creation and authentication.
• Retrieving user information.
• Database operations like adding, updating, and deleting users.

To check test coverage:

PYTHONPATH=. pytest --cov=app tests/

This will show how much of your code is covered by the tests.

What Tests Are Included?

• User Routes:

  • Test user creation (/signup).
  • Test user login (/login).
  • Test user deletion (/delete-user/{id}).
  • Test user updates (/update-user/{id}).

• Database Operations:

  • Verify database integration for CRUD operations.

• Edge Cases:

  • Attempting to create a user with missing fields.
  • Logging in with invalid credentials.
  • Deleting a non-existent user.

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How It Works

Development

• Hot Reload: FastAPI runs with uvicorn --reload for automatic code reload on changes.
• Database & pgAdmin: PostgreSQL and pgAdmin run via Docker Compose to avoid local installation.

Production

• Dockerized Deployment: FastAPI, PostgreSQL, and pgAdmin run inside containers.

Testing

• Tests are implemented using pytest to ensure the reliability of the application.
• Covers both happy paths and edge cases to prevent regressions and ensure robustness.