title: Rails session cookie not getting set
body: <p>I have a rails app that is a CMS that uses dynamic subdomains for each site.  For some reason when I deployed to production the session cookie is not getting set.  I'm thinking this is leading to the "Invalid Authenticity Token" errors that are being thrown everywhere.  </p>
  
  <p>I have my production.rb setup so that I can share sessions across subdomains.  What could be going wrong that the cookie isn't being set at all?</p>
  
  <pre><code>#production.rb
  config.action_controller.session[:domain] = '.domain.com'
  
  
  #environment.rb
  config.action_controller.session = {
     :session_key =&gt; '_app_session',
     :secret      =&gt; '.... nums and chars .....'
   }
  </code></pre>