Google Analytics Mobile for Rails Metal

google_analytics.rb

# Allow the metal piece to run in isolation
require(File.dirname(__FILE__) + "/../../config/environment") unless defined?(Rails)

class GoogleAnalytics
  extend Rack::Utils

  G_COOKIE_NAME = '__utmmobile'
  GIF_DATA = "GIF89a\001\000\001\000\200\000\000\377\377\377\377\377\377!\371\004\001\n\000\001\000,\000\000\000\000\001\000\001\000\000\002\002L\001\000;"
  UTM_GIF_LOCATION = "http://www.google-analytics.com/__utm.gif";

  def self.call(env)
    if env["PATH_INFO"] =~ /^\/ga$/
      ga_mobile_response(env)
    else
      [404, {"Content-Type" => "text/html"}, ["Not Found"]]
    end
  end

  def self.logger
    Rails.logger
  end

  def self.ga_mobile_response(env)
    request = Rack::Request.new(env)

    document_referer = request.params['utmr'].blank? ? '-' : escape(request.params['utmr'])
    document_path = request.params['utmp'].blank? ? '' : escape(request.params['utmp'])

    account = request.params['utmac']
    user_agent = request.user_agent.to_s
    domain_name = env['SERVER_NAME']

    #remote_address = env['REMOTE_ADDR']
    remote_address = env['HTTP_X_FORWARDED_FOR']
    if remote_address.blank?
      remote_address = ''
    elsif remote_address =~ /^([^.]+\.[^.]+\.[^.]+\.).*/
      remote_address = "#{$1}0"
    else
      remote_address = ''
    end

    visitor_id = request.cookies[G_COOKIE_NAME]

    if visitor_id.blank?
      guid = env['HTTP_X_DCMGUID'] || env['HTTP_X_UP_SUBNO'] || env['HTTP_X_JPHONE_UID'] || env['HTTP_X_EM_UID']

      message = ''
      if guid.blank?
        message = "#{user_agent}#{Digest::SHA1.hexdigest(rand.to_s)}#{Time.now.to_i}"
      else
        message = "#{guid}#{account}"
      end

      md5string = Digest::MD5.hexdigest(message)

      visitor_id = "0x#{md5string[0,16]}"
    end

    queries = []
    queries << "utmwv=4.4sh"
    queries << "utmn=#{rand(1000000*1000000)}"
    queries << "utmhn=#{escape(domain_name)}"
    queries << "utmr=#{escape(document_referer)}"
    queries << "utmp=#{escape(document_path)}"
    queries << "utmac=#{account}"
    queries << "utmcc=__utma%3D999.999.999.999.999.1%3B"
    queries << "utmvid=#{visitor_id}"
    queries << "utmip=#{remote_address}"

    uri = URI.parse(UTM_GIF_LOCATION + '?' + queries.join('&'))

    unless ENV['RAILS_ENV'] == 'test'
      Net::HTTP.version_1_2
      Net::HTTP.start(uri.host, uri.port) do |http|
        http.get(uri.request_uri, {
          "user_agent" => request.user_agent.to_s,
          "Accepts-Language" => env['HTTP_ACCEPT_LANGUAGE'].to_s
        })
      end
      logger.debug "-----Send Request To Google Analytics-----"
      logger.debug uri.to_s
      logger.debug "------------------------------------------"
    end

    headers = {}
    headers["X-GA-MOBILE-URL"] = uri.to_s unless request.params['utmdebug'].blank?
    headers["Cache-Control"] = "private, no-cache, no-cache=Set-Cookie, proxy-revalidate"
    headers["Pragma"] = "no-cache"
    headers["Expires"] = "Wed, 17 Sep 1975 21:32:10 GMT"

    options = env['rack.session.options']
    cookies = {
      :value => visitor_id,
      :expires => 2.years.from_now,
      :path => "/",
      :domain => domain_name
    }

    response = Rack::Response.new(GIF_DATA, 200, headers)
    response.set_cookie(G_COOKIE_NAME, cookies.merge(options))
    response.finish
  end
end

Ruby on RailsでGoogle Analytics携帯対応: りめも～んRC を参考にさせていただきました。
jpmobile は必要ありません。