gistfile1.rb

module Sinatra
  module Authorization

  def auth
    @auth ||= Rack::Auth::Basic::Request.new(request.env)
  end

  def unauthorized!(realm="flixcloud.com")
    response['WWW-Authenticate'] = %(Basic realm="#{realm}")
    throw :halt, [ 401, 'Authorization Required' ]
  end

  def bad_request!
    throw :halt, [ 400, 'Bad Request' ]
  end

  def authorized?
    request.env['REMOTE_USER']
  end

  def authorize(username, password)
    # Insert your logic here to determine if username/password is good
    false
  end

  def require_authorization
    return if authorized?
    unauthorized! unless auth.provided?
    bad_request! unless auth.basic?
    unauthorized! unless authorize(*auth.credentials)
    request.env['REMOTE_USER'] = auth.username
  end

  def admin?
    authorized?
  end

  end
end

gistfile2.rb

require 'sinatra/authorization'

class Whatever < Sinatra::Base
  helpers do
    include Sinatra::Authorization

    def authorize(username, password)
      User.authenticate(username, password)
    end
  end

  get '/something' do
    require_authorization
    # Do some other crap
  end

end