Rack middleware to redirect HTTPS to HTTP

app.rb

require 'sinatra'
require 'only_http'

use OnlyHttp

get '/' do
  "We'll never see this over HTTPS!"
end

only_http.rb

require 'rack/request'
require 'uri'

class OnlyHttp
  def initialize(app)
    @app = app
  end
  
  def call(env)
    req = Rack::Request.new(env)
    if req.ssl?
      location = URI(req.url)
      location.scheme = 'http'
      
      [301, {"Location" => location.to_s, "Content-Type" => 'text/html', "Content-Length" => '0'}, []]
    else
      @app.call(env)
    end
  end
end