statics file server rack.

static_rack.rb

require 'rack/utils'
class StaticRack
    def call(env)
      path = env["SERVER_NAME"]
      file, headers = pick_file_and_headers_for_path(path, env)
      file_server  = ::Rack::File.new(file, headers)
      file_server.call(env)
    end

    private

    def get_best_encoding(request)
      Rack::Utils.select_best_encoding(%w(gzip identity), request.accept_encoding)
    end

    def headers
      @headers ||= {'Content-Type' => 'text/html' }
    end

    def pick_file_and_headers_for_path(path, env)
      request = Rack::Request.new(env)
      encoding = get_best_encoding(request)
      file_path = "#{Rails.root.to_s}/public/media_kits/" + path + '.html'
      if (File.exist?(file_path))
        if encoding == 'gzip'
          file_path = file_path + '.gz'
          headers['Content-Encoding'] = 'gzip'
        end
      else
        file_path = "#{Rails.root.to_s}/public/404.html"
      end
      [file_path, headers]
    end
end