URL Shortener API

This is a URL Shortener service built with Go (Gin framework) and MongoDB. The API allows users to create short URLs, redirect to original URLs, and update stored URLs. The project is fully Dockerized for easy installation and deployment.

Table of Contents

• Features
• Prerequisites
• Installation
• Environment Variables (.env)
• Running the Project
• API Endpoints
• Testing with Postman
• Project Structure
• License

---

Features

✅ Generate short URLs from long URLs
✅ Redirect users from short URLs to original URLs
✅ Update existing short URLs with new destinations
✅ MongoDB integration for persistent data storage
✅ Dockerized for easy deployment
✅ Fast and efficient API using the Gin framework

---

Prerequisites

Ensure you have the following installed before proceeding:

1. Docker - Download & Install
2. Docker Compose - Install Docker Compose
3. (Optional) Go 1.22+ (if you want to run the project without Docker) - Download Go

---

Installation

Step 1: Clone the Repository

git clone https://github.com/sunilyadav97/url-shortener-api.git
cd url-shortener-api

If you haven't initialized a Git repository yet, you can create a new folder and add all the files manually.

---

Step 2: Create a .env file

The .env file contains environment variables that configure the application. Create a .env file in the project's root directory:

touch .env

Now, open the .env file and add the following configuration:

# Server Configuration
PORT=8080  # Port where the API will run

# MongoDB Configuration
MONGO_URI=mongodb://mongo:27017  # MongoDB connection URI
MONGO_DB_NAME=url_shortener_db   # Database name
MONGO_COLLECTION_NAME=urls       # Collection name

---

Step 3: Install Dependencies (Only for Local Development)

If you want to run the project without Docker, you need to install dependencies manually:

go mod tidy

---

Running the Project

Option 1: Run with Docker (Recommended)

Use Docker Compose to start the project:

docker-compose up --build

This will:

• Build the Go application as a Docker container
• Start the Go API on localhost:8080
• Start MongoDB as a separate container

To stop the containers, press CTRL + C or run:

docker-compose down

---

Option 2: Run Locally (Without Docker)

If you prefer running the project without Docker:

Step 1: Start MongoDB Locally

Make sure you have MongoDB installed and running. If not, start it using:

mongod --dbpath <your-db-path>

Step 2: Run the Go Application

Execute the following command:

go run main.go

The server should now be running at:
👉 http://localhost:8080

---

API Endpoints

1. Create Short URL

• Endpoint: POST /api/v1/createShortUrl
• Request Body:

  {
    "url": "https://example.com/very/long/url"
  }

• Response:

  {
    "shortUrl": "abcdefg"
  }

---

2. Redirect to Original URL

• Endpoint: GET /api/v1/{shortUrl}
• Response:
  A 301 redirect to the original URL.

---

3. Update Short URL

• Endpoint: PUT /api/v1/updateShortUrl/{shortUrl}
• Request Body:

  {
    "url": "https://example.com/new-destination"
  }

• Response:

  {
    "status": "Successful",
    "message": "Short URL updated successfully"
  }

---

Testing with Postman

1. Create a Short URL:

   • Method: POST
   • URL: http://localhost:8080/api/v1/createShortUrl
   • Body (raw, JSON):

     {
       "url": "https://example.com/very/long/url"
     }

   • Expected Response:

     {
       "shortUrl": "abcdefg"
     }

2. Redirect to Original URL:

   • Method: GET
   • URL: http://localhost:8080/api/v1/abcdefg
   • Expected Behavior: Redirects to https://example.com/very/long/url.

3. Update a Short URL:

   • Method: PUT
   • URL: http://localhost:8080/api/v1/updateShortUrl/abcdefg
   • Body (raw, JSON):

     {
       "url": "https://example.com/new-destination"
     }

   • Expected Response:

     {
       "status": "Successful",
       "message": "Short URL updated successfully"
     }

---

Project Structure

url-shortener-api/
├── .env                   # Environment variables
├── .gitignore             # Git ignore file
├── Dockerfile             # Docker configuration
├── docker-compose.yml     # Docker Compose for Go & MongoDB
├── go.mod                 # Go module file
├── go.sum                 # Go dependencies checksum
├── main.go                # Entry point (Gin API)
├── README.md              # Project documentation
├── database/              # MongoDB connection
│   └── database.go
├── models/                # Data models
│   └── models.go
├── routes/                # API routes and handlers
│   └── routes.go
└── utils/                 # Utility functions
    └── shortener.go

---

License

This project is licensed under the MIT License.

---

Summary

✅ .env file contains important configurations like MongoDB URI and server port.
✅ Use docker-compose up --build to run the project with Docker.
✅ If running locally, install dependencies with go mod tidy and run go run main.go.
✅ Test API with Postman or curl commands.