non-www to www redirection for heroku

gistfile1.rb

class WwwRedirect
  def initialize(app)
    @app = app
  end

  def call(env)
    request = Rack::Request.new(env)

    if request.host =~ /^mysite.com/
      [301, {"Location" => request.url.sub("//", "//www.")}, self]
    else
      @app.call(env)
    end
  end

  def each(&block)
  end
end


config.autoload_paths += %W(#{config.root}/lib)
config.middleware.use "WwwRedirect"