Go Backend Starter

A RESTful API for e-commerce backend with user authentication, product management, cart operations, and order processing.

Features

• User Authentication: JWT-based authentication with user registration and login
• Product Management: CRUD operations for products (admin only)
• Shopping Cart: Add and remove items from cart
• Order Processing: Place, deliver, and reject orders
• Role-based Access: Admin and user roles with different permissions
• Swagger Documentation: Complete API documentation

Tech Stack

• Framework: Gin (Go web framework)
• Database: PostgreSQL with GORM ORM
• Authentication: JWT tokens
• Documentation: Swagger/OpenAPI 3.0
• Environment: Environment variables with godotenv

Getting Started

Prerequisites

• Go 1.24.1 or higher
• PostgreSQL database
• Git

Installation

1. Clone the repository:

git clone <repository-url>
cd go-backend-starter

2. Install dependencies:

go mod tidy

3. Set up environment variables: Create a .env file in the root directory:

PORT=8080
DB_HOST=localhost
DB_PORT=5432
DB_USER=your_db_user
DB_PASSWORD=your_db_password
DB_NAME=your_db_name
JWT_SECRET=your_jwt_secret_key

4. Run the application:

go run main.go

The server will start on http://localhost:8080

API Documentation

Swagger UI

Once the application is running, you can access the interactive API documentation at:

http://localhost:8080/swagger/index.html

This provides a complete interactive documentation where you can:

• View all available endpoints
• Test API calls directly from the browser
• See request/response schemas
• Authenticate with JWT tokens

API Endpoints

Authentication

• POST /users/register - Register a new user
• POST /users/login - User login

Users (Protected - JWT required)

• GET /users/mine - Get current user account
• PUT /users/update/user/{id} - Update user (admin only)
• DELETE /users/delete/myAccount - Delete current user account
• GET /users/all - Get all users (admin only)

Products

• GET /products/all - Get all products (public)
• GET /products/{id} - Get specific product (public)
• POST /products/create - Create product (admin only)
• PUT /products/update/{id} - Update product (admin only)
• DELETE /products/delete/{id} - Delete product (admin only)

Cart (Protected - JWT required)

• POST /carts/add - Add item to cart
• DELETE /carts/remove - Remove item from cart

Orders (Protected - JWT required)

• POST /orders/place-order - Place new order
• PUT /orders/deliver - Deliver order (admin only)
• DELETE /orders/reject - Reject order (admin only)
• POST /orders/pay - Pay for an order (virtual payment)

Authentication

The API uses JWT (JSON Web Tokens) for authentication. To access protected endpoints:

1. Register or login to get a JWT token
2. Include the token in the Authorization header:

   Authorization: Bearer <your_jwt_token>
   

Database Models

User

• id: Primary key
• name: User's full name
• email: Unique email address
• password: Hashed password
• role: User role (user/admin)
• cart: Associated cart ID

Product

• id: Primary key
• name: Product name
• description: Product description
• price: Product price
• stock_qty: Available stock quantity

Cart

• id: Primary key
• user_id: Associated user ID
• cart_items: Array of cart items

Order

• id: Primary key
• user_id: Associated user ID
• status: Order status (PENDING/DELIVERED)
• cart: Associated cart ID

Payment

• id: Primary key
• order_id: Associated order ID
• amount: Payment amount
• status: Payment status (e.g., PAID)
• payment_method: Payment method (e.g., virtual_card)
• transaction_id: Transaction reference
• created_at, updated_at: Timestamps

Development

Regenerating Swagger Documentation

If you modify the API endpoints or add new ones, regenerate the Swagger documentation:

~/go/bin/swag init

This will update the documentation files in the docs/ directory.

Project Structure

├── main.go              # Application entry point
├── go.mod               # Go module file
├── go.sum               # Go module checksums
├── docs/                # Generated Swagger documentation
├── api/                 # API controllers
│   ├── users/           # User management
│   ├── products/        # Product management
│   ├── carts/           # Cart operations
│   └── orders/          # Order processing
├── database/            # Database models and connection
├── middleware/          # HTTP middleware
├── routes/              # Route definitions
└── utils/               # Utility functions

License

This project is licensed under the Apache 2.0 License.

Virtual Payment Flow

This project uses a simulated (virtual) payment system for demonstration and development purposes. When a user pays for an order, the backend calculates the total amount, generates a fake transaction ID, and marks the order as paid. No real money is transferred and no external payment provider is contacted.

How to extend for real payments:

• Replace the logic in utils/payment.go with integration to a real payment provider (e.g., Stripe, PayPal).
• Ensure to handle payment confirmation, webhooks, and error scenarios securely.
• Never store real payment credentials or secrets in the codebase; always use environment variables.