Go PostgreSQL Products API

A RESTful API service built with Go and PostgreSQL for managing product data. This project demonstrates best practices for structuring a Go application with database integration and HTTP endpoints.

Project Structure

go-postgres/
├── cmd/
│   └── server/
│       └── main.go          # Application entry point
├── internal/
│   ├── database/
│   │   └── postgres.go      # PostgreSQL implementation
│   ├── models/
│   │   └── product.go       # Data models
│   └── handlers/
│       └── product_handler.go # HTTP handlers
├── pkg/
│   └── store/
│       └── store.go         # Store interface
├── .env                     # Environment variables
├── go.mod                   # Go module file
└── README.md               # This file

Prerequisites

• Go 1.21 or later
• PostgreSQL 12 or later
• Git

Installation

1. Clone the repository:

git clone https://github.com/Mohabdo21/go-postgres.git
cd go-postgres

2. Install dependencies:

go mod tidy

3. Create a .env file in the root directory:

DB_HOST=localhost
DB_PORT=5432
DB_USER=your_username
DB_PASSWORD=your_password
DB_NAME=your_database
DB_SSL_MODE=disable
SERVER_PORT=8080

Database Setup

1. Create a PostgreSQL database:

CREATE DATABASE your_database;

2. The application will automatically create the required products table on startup.

Running the Application

1. Start the server:

cd cmd/server
go run main.go

2. The server will start on the configured port (default: 8080)

API Endpoints

Create Product

POST /products

Request Body:
{
    "name": "Apple",
    "price": 0.50,
    "available": true
}

Response:
{
    "id": 1,
    "name": "Apple",
    "price": 0.50,
    "available": true,
    "created": "2024-11-25T10:00:00Z"
}

Get All Products

GET /products

Response:
[
    {
        "id": 1,
        "name": "Apple",
        "price": 0.50,
        "available": true,
        "created": "2024-11-25T10:00:00Z"
    }
]

Project Components

Store Interface

The store.Store interface in pkg/store/store.go defines the contract for database operations:

type Store interface {
    CreateProduct(ctx context.Context, product *models.Product) error
    GetProducts(ctx context.Context) ([]models.Product, error)
}

Database Implementation

The PostgreSQL implementation in internal/database/postgres.go provides:

• Connection pooling
• Prepared statements
• Error handling
• Transaction support

HTTP Handlers

The handlers in internal/handlers/product_handler.go provide:

• Request validation
• JSON serialization/deserialization
• Error handling
• HTTP status codes

Configuration

The application can be configured using environment variables:

Variable	Description	Default
DB_HOST	PostgreSQL host	localhost
DB_PORT	PostgreSQL port	5432
DB_USER	Database username	-
DB_PASSWORD	Database password	-
DB_NAME	Database name	-
DB_SSL_MODE	SSL mode for database connection	disable
SERVER_PORT	HTTP server port	8080

Development

Adding New Endpoints

1. Define new methods in the Store interface
2. Implement the methods in PostgresStore
3. Create new handlers in product_handler.go
4. Register the new routes in main.go

Code Style

The project follows standard Go coding conventions:

• Use gofmt for code formatting
• Follow Effective Go guidelines
• Use meaningful package and variable names
• Add comments for exported functions and types

Error Handling

The application implements comprehensive error handling:

• Database errors are wrapped with context
• HTTP errors include appropriate status codes
• Validation errors provide clear messages

Performance Considerations

• Connection pooling is configured for optimal database performance
• Context timeouts prevent hanging operations
• Prepared statements reduce query parsing overhead

Acknowledgments

• Go Documentation
• PostgreSQL Documentation