Go REST API with PostgreSQL

This is a sample Go REST API project that demonstrates how to perform CRUD operations on a Product resource using the Gin framework and PostgreSQL. The project also includes middleware for logging the IP address of incoming requests.

Project Structure

go-rest-api
│   main.go
├───config
│       config.go
├───controllers
│       product_controller.go
├───middleware
│       ip_logger.go
├───models
│       product.go
│       database.go
├───routes
│       routes.go
└───utils
        response.go

Features

• Create, read, update, and delete products
• Log IP addresses of incoming requests

Getting Started

Prerequisites

• Go 1.20 or higher
• PostgreSQL
• Git
• Docker (optional, for running PostgreSQL in a container)

Installation

1. Clone the repository:

   git clone https://github.com/hasithaishere/go-rest-api-with-postgresql.git
   cd go-rest-api

2. Install dependencies:

   go mod tidy

3. Set up PostgreSQL:

   • Option 1: Using Docker (Recommended)

     • Run PostgreSQL in a Docker container:

       docker run --name postgres-db -e POSTGRES_USER=your_db_user -e POSTGRES_PASSWORD=your_db_password -e POSTGRES_DB=your_db_name -p 5432:5432 -d postgres

     • Update the .env file with your PostgreSQL credentials:

       DB_USER=your_db_user
       DB_PASSWORD=your_db_password
       DB_NAME=your_db_name
       DB_HOST=localhost
       DB_PORT=5432

   • Option 2: Local PostgreSQL Installation

     • Create a new PostgreSQL database.

     • Update the .env file with your PostgreSQL credentials:

       DB_USER=your_db_user
       DB_PASSWORD=your_db_password
       DB_NAME=your_db_name
       DB_HOST=your_db_host
       DB_PORT=your_db_port

4. Create the products table in your PostgreSQL database:

   CREATE TABLE products (
       id SERIAL PRIMARY KEY,
       name VARCHAR(255) NOT NULL,
       price INTEGER NOT NULL,
       created_at TIMESTAMP WITH TIME ZONE DEFAULT CURRENT_TIMESTAMP,
       updated_at TIMESTAMP WITH TIME ZONE DEFAULT CURRENT_TIMESTAMP
   );

Running the Application

1. Start the application:

   go run main.go

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

API Endpoints

• GET /products: Retrieve all products
• POST /products: Create a new product
  • Request body: { "name": "Sample Product", "price": 100 }
• GET /products/:id: Retrieve a product by ID
• PUT /products/:id: Update a product by ID
  • Request body: { "name": "Updated Product", "price": 150 }
• DELETE /products/:id: Delete a product by ID

Example CURL Commands

• Create a product:

  curl -X POST http://localhost:8080/products \
       -H "Content-Type: application/json" \
       -d '{
             "name": "Sample Product",
             "price": 100
           }'

• Get all products:

  curl http://localhost:8080/products

• Get a product by ID:

  curl http://localhost:8080/products/1

• Update a product by ID:

  curl -X PUT http://localhost:8080/products/1 \
       -H "Content-Type: application/json" \
       -d '{
             "name": "Updated Product",
             "price": 150
           }'

• Delete a product by ID:

  curl -X DELETE http://localhost:8080/products/1

Middleware

The project includes a middleware that logs the IP address of incoming requests. The middleware is defined in middleware/ip_logger.go and is registered in the router setup in routes/routes.go.

License

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