go-url-shortener

A TinyURL-style URL shortening service built in Go with redirecting, analytics, and database storage.

Tech Stack

• Go 1.21+
• Gin (HTTP router)
• GORM (ORM)
• SQLite (pure Go driver - no CGO required)

Project Structure

go-url-shortener/
├── cmd/
│   └── server/
│       └── main.go          # Entry point
├── models/
│   └── url.go               # URL database model
├── handlers/
│   └── handlers.go          # HTTP handlers (POST /shorten, GET /:code)
├── database/
│   └── database.go          # DB connection & initialization
├── utils/
│   └── code.go              # Code generation utility
├── web/
│   └── index.html           # Web frontend UI
└── go.mod                   # Go module file

Setup & Installation

Prerequisites

1. Install Go from golang.org
2. Verify installation: go version

Steps

1. Install dependencies:

   go mod download

2. Run the server:

   go run ./cmd/server/main.go

   Or build and run:

   go build ./cmd/server
   ./server

3. Access the web interface:

   Open your browser and navigate to:

   http://localhost:8080
   

   You'll see a beautiful web interface where you can:

   • Enter a long URL
   • Click "Shorten URL" to create a short link
   • Copy the short URL with one click
   • Test redirects by visiting the short URL

4. Test the API (alternative to web UI):

   Create a short URL:

   # Using curl
   curl -X POST http://localhost:8080/shorten \
     -H "Content-Type: application/json" \
     -d '{"url": "https://example.com/very/long/url"}'
   
   # Using PowerShell
   Invoke-RestMethod -Uri http://localhost:8080/shorten -Method Post -ContentType "application/json" -Body '{"url":"https://example.com"}'

   Response:

   {
     "code": "Mu4DZ6",
     "short_url": "http://localhost:8080/Mu4DZ6"
   }

   Access the short URL:

   # Open in browser or use curl
   curl http://localhost:8080/Mu4DZ6
   # Browser will automatically redirect to the original URL

Implementation Status

✅ Completed

• Database setup with SQLite (pure Go driver)
• Code generation utility
• URL model with GORM
• Shorten handler (POST /shorten)
• Redirect handler (GET /:code) with visit tracking
• Main server setup and routing
• Web frontend UI (HTML/CSS/JavaScript)
• Testing and verification

Features

• ✅ Web Interface — Beautiful, modern UI for shortening URLs
• ✅ POST /shorten — create a short code for a long URL
• ✅ GET /:code — redirect to original URL and increment visits
• ✅ Persistent storage of mappings and visit counts
• ✅ Automatic collision handling for short codes
• ✅ Visit counter tracking
• ✅ Pure Go implementation (no CGO required)
• ✅ No npm/build tools required — simple HTML/CSS/JS frontend

API Endpoints

POST /shorten

Creates a short URL from a long URL.

Request:

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

Response:

{
  "code": "abc123",
  "short_url": "http://localhost:8080/abc123"
}

GET /:code

Redirects to the original URL and increments the visit counter.

Response: HTTP 302 Redirect to the original URL

GET /

Serves the web interface for easy URL shortening.

Response: HTML page with interactive UI

Future Enhancements

• Rate limiting
• Custom aliases
• Expiration dates
• Admin dashboard
• Analytics endpoint
• Dockerfile & compose for easy deployment

Learning Resources

• Go Tour
• Gin Framework Docs
• GORM Docs