http://blog.darkhax.com/2011/06/26/worst-url-shortener-ever

shrt.rb

require 'net/http'
require 'uri'

RIAK = ['localhost', 8098]

run lambda { |env|
  req = Rack::Request.new(env)
  if req.post? && req.path == '/'
    res = Net::HTTP.new(*RIAK).start do |http|
      http.post('/riak/shrt', req.params['url'], { 'Content-Type' => 'text/plain' })
    end
    loc = [req.base_url, 'r', res['location'].split('/').last].join('/')
    [res.code.to_i, { 'Content-Type' => 'text/plain', 'Location' => loc }, [res.message]]
  elsif req.get? && req.path.start_with?('/r/')
    key = req.path.split('/').last
    res = Net::HTTP.new(*RIAK).start do |http|
      http.get("/riak/shrt/#{key}")
    end
    [302, { 'Content-Type' => 'text/plain', 'Location' => res.body }, ['Redirecting...']]
  else
    [404, {'Content-Type' => 'text/plain'}, ['wat']]
  end
}