📦 URL Shortener Service (Go + Gin + Redis)

A simple and efficient URL shortening service built with Go, Gin web framework, and Redis as a storage backend.

It allows users to shorten long URLs, manage custom short codes, track click counts, and set expiry times for shortened links.

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🚀 Features

• Shorten URLs (auto-generated or with custom codes)
• Set expiry times (default 7 days, or custom expiry)
• Track click counts for each shortened link
• Get info about a shortened URL (created time, clicks, expiry)
• List all URLs stored
• Delete a shortened URL manually
• Automatic cleanup of expired links
• Graceful shutdown handling
• Simple rate limiting per IP address to prevent abuse
• Redis backend for fast storage
• Local memory (rate limiters) cleaned periodically

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🛠 Tech Stack

• Go (Golang)
• Gin Web Framework
• Redis (Storage backend)

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🏗 Architecture

• Gin handles HTTP routing and middleware
• Redis stores URL metadata (LongURL, Clicks, CreatedAt, Expiry)
• Memory (map) tracks client IP rate limits
• Goroutines and tickers handle background tasks:
  • Cleaning expired Redis entries
  • Cleaning old rate limiter data
• Graceful Shutdown ensures all processes stop safely when the server exits

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Example request to shorten a URL:

POST /shorten
{
  "url": "https://example.com",
  "custom_code": "mycode", // optional
  "expiry_seconds": 3600   // optional
}

🚀 Setup & Running the Project

This project can run in two modes:

• Using local in-memory + JSON persistence.
• Using Redis for persistence (external Redis server required).

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🛠️ Prerequisites

• Go 1.18+ installed.
• Redis installed and running (only if using Redis mode).
• (Optional) direnv or manually export environment variables.

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🗂️ Running in Local JSON Mode

1. Clone the repository:

   git clone https://github.com/AumSahayata/URL-shortener-using-Go
   cd URL-shortener-using-Go/using-json

2. Run the project:

   go run main.go

3. Access the app:

   Open your browser at http://localhost:8080

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🛢️ Running in Redis Mode

1. Clone the repository:

   git clone https://github.com/AumSahayata/URL-shortener-using-Go
   cd URL-shortener-using-Go/using-redis

2. Set up a Redis server (locally or cloud hosted like Redis Cloud).

3. Create a .env file inside your project directory with the following content:

   REDIS_ADDR=localhost:6379 (OR cloud database address)
   REDIS_USER=redis_user      # leave empty if no username
   REDIS_PASSWORD=redis_password   # set password if needed
   REDIS_DB=0        # Redis database number

4. Install dependencies (if not already):

   go mod tidy

5. Run the project:

   go run .

6. Access the app:

   Open your browser at http://localhost:8080

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📌 API Endpoints Overview

Method	Endpoint	Description
POST	/shorten	Shorten a new URL
GET	/:code	Redirect to original URL
GET	/info/:code	Get details about a short URL
GET	/list	List all URLs
DELETE	/delete/:code	Delete a shortened URL

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📋 Notes

• Rate limiting: Max 5 requests/minute per IP.
• Expired links are automatically cleaned every 24 hours.
• Graceful shutdown is implemented (CTRL+C to terminate cleanly).
• Default short URL expiry is 7 days, customizable per link.

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🙌 Contributing

Pull requests are welcome!
Feel free to fork the project, open issues, and submit PRs!
Any suggestions to improve it further are appreciated.

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📢 Author

Built with ❤️ by Aum Sahayata.