Shrinkit — Simple URL shortener 🔗

Shrinkit is a lightweight Ruby on Rails application that provides a minimal, secure URL shortening service. It stores long URLs and generates short, non-sequential short codes using Hashids (wrapped by EncodedService).

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Features ✅

• Create shortened URLs from long URLs via a small web UI
• Short codes generated using a secret salt with the hashids gem (configurable via env var)
• Validates URLs (protocol and host) with a custom UrlValidator
• Redirects short codes to the original long URL (with allow_other_host)
• Simple test suite using RSpec

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Quick Start 🔧

Requirements

• Ruby 3.4.6 (see .ruby-version)
• Bundler
• SQLite (default development DB)
• Node/npm is not required (this app uses importmaps)

Local setup

# Install gems
bundle install

# Create and migrate the database
bin/rails db:create db:migrate

# Run the test suite
bundle exec rspec

# Start the dev server
bin/rails server
# then visit http://localhost:3000

Docker (production-style image)

# Build (production Dockerfile)
docker build -t shrinkit .

# Run (ensure you provide RAILS_MASTER_KEY in production)
docker run -d -p 80:80 -e RAILS_MASTER_KEY=<your_master_key> --name shrinkit shrinkit

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Configuration ⚙️

Important environment variables

• MY_SECRET_KEY — Salt used by EncodedService (Hashids). Set this in production (do NOT use the dev fallback).
• ALPHABET — Optional custom alphabet for generated short codes.
• RAILS_MASTER_KEY — Required for running in production if credentials are encrypted.

EncodedService (short-code generation)

• Implemented in app/services/encoded_service.rb using the hashids gem.
• By default the service will use MY_SECRET_KEY and a sensible alphabet; change via env vars if needed.

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Usage 📋

• Visit the root (/) to submit a long URL.
• After creating a URL you'll be redirected to a show page that displays the short URL.
• Short URL format: http://<host>/<short_code> which internally maps to /urls/redirect/:short_code and performs a redirect to the original long_url.

API example (simple):

curl -X POST -d "url[long_url]=https://example.com" http://localhost:3000/urls

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Testing 🧪

Run RSpec:

bundle exec rspec

The repository includes specs for models, controllers, and services.

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Development notes & Internals 🔍

• Rails: ~> 8.1.1
• Database: sqlite3 for development/test
• Gems: hashids, base62 (helper utilities), brakeman and rubocop in dev/test
• Model: Url with long_url:string and short_code:string (see db/migrate/*_create_urls.rb)
• Validation: app/validators/url_validator.rb ensures a proper URL format and protocol