CSC 430: Software Engineering Final Project (Backend) README

Overview

This is the backend for an e-commerce application developed using Flask, MySQL, and Zappa for serverless deployment on AWS Lambda. It supports essential functionalities such as product management, cart handling, user authentication, and API integration for enhanced product information.

Features

• User Authentication: Supports user login and registration with hashed password storage.
• Cart Management: Allows users to save and retrieve their cart items, and perform checkout operations.
• Product Management: Provides endpoints for adding, updating, and retrieving product data.
• Serverless Deployment: Deployed on AWS Lambda using Zappa for scalable serverless execution.
• API Integration: Integrates with external APIs to retrieve additional product information.

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Project Structure

.
├── app.py                  # Flask application entry point
├── modules/
│   ├── functions.py        # Core business logic and database interaction
│   ├── api_request.py      # Handles external API interactions (e.g., RapidAPI)
├── requirements.txt        # Python dependencies
├── zappa_settings.json     # Configuration for Zappa deployment
├── .env                    # Environment variables (ignored in Git)
└── README.md               # Project documentation

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Prerequisites

Local Development

• Python 3.12
• MySQL database
• Virtual environment (venv)

Deployment

• AWS account
• Zappa installed globally (pip install zappa)

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Setup

1. Clone the Repository

git clone <repository-url>
cd <repository-folder>

2. Create a Virtual Environment

python -m venv venv
source venv/bin/activate  # Linux/macOS
venv\Scripts\activate     # Windows

3. Install Dependencies

pip install -r requirements.txt

4. Create a .env File

Add the following to .env (replace placeholders with actual values):

DB_HOST=<your-db-host>
DB_NAME=<your-database-name>
DB_USERNAME=<your-username>
DB_PASSWORD=<your-password>
x-rapidapi-key=<your-rapidapi-key>
x-rapidapi-host=<your-rapidapi-host>

5. Initialize the Database

Ensure your MySQL database is set up and contains the required schema for tables like product, cart, and users.

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Running Locally

1. Activate the virtual environment:

   source venv/bin/activate  # Linux/macOS
   venv\Scripts\activate     # Windows

2. Start the Flask server:

   python app.py

3. Visit http://127.0.0.1:8080 in your browser or use an API testing tool like Postman to interact with the backend.

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Deployment with Zappa

1. Configure a zappa_settings.json

Create a zappa_settings.json file with the following structure:

{
    "dev": {
        "app_function": "app.app",
        "aws_region": "<your-aws-region>",
        "profile_name": null,
        "project_name": "<your-project-name>",
        "runtime": "python3.12",
        "s3_bucket": "<your-s3-bucket>",
        "environment_variables": {
            "DB_HOST": "<your-db-host>",
            "DB_NAME": "<your-db-name>",
            "DB_USERNAME": "<your-username>",
            "DB_PASSWORD": "<your-password>",
            "x-rapidapi-key": "<your-rapidapi-key>",
            "x-rapidapi-host": "<your-rapidapi-host>"
        }
    }
}

2. Deploy to AWS

Deploy the project to AWS Lambda using Zappa:

zappa deploy dev

3. Update Deployment

After making changes to the backend:

zappa update dev

4. Test API

Visit the API Gateway endpoint URL provided by Zappa to verify deployment.

Utilize tools such as Postman to test backend endpoints.

API Endpoints

User Authentication

• POST /login/ – Login an existing user.
• POST /logout/ – Log out a user.

Product Management

• GET / – Retrieve all products.
• POST /add_product – Add a new product.
• POST /change_name – Update product name.
• POST /change_price – Update product price.

Cart Management

• POST /cart/save – Save cart items for a user.
• GET /cart/<int:user_id> – Retrieve cart items for a user.
• POST /checkout – Checkout a user's cart.

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Error Handling

• All endpoints return structured JSON error messages with appropriate HTTP status codes.
• Common errors are logged in the AWS Lambda environment or in the local console.

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Known Issues and Debugging

1. Environment Variables Not Loading

   • Ensure .env is correctly configured and dotenv is installed.
   • For AWS Lambda, use zappa_settings.json to set environment variables.

2. Database Connection Issues

   • Always verify MySQL credentials first, then check for connection allowance from your development machine or Lambda's IP.

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.gitignore

The .gitignore file should include the following:

venv/
.env
zappa_settings.json
__pycache__/
*.pyc

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License

This project is licensed under the MIT License. See LICENSE for more details.

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Contributors

• Richard Palestri – Backend Developer
• Ilir Krasniqi - Backend Developer , SQL Developer
• Dashamir Brkani – Frontend Developer , Backend Developer

For any issues or questions, feel free to contact the contributors or raise an issue on the project repository.