title: Session across domains in Rails 4
body: <p>I have an issue with wanting to use session across domains (not subdomain).  Eg, I have .co.uk, .com.au, and .com all for the same address.  </p>
  
  <p>I know for subdomains I can use something like:</p>
  
  <pre><code>SomeApp::Application.config.session_store :cookie_store, key: '_some_app_session', domain =&gt; :all, :tld_length =&gt; 2
  </code></pre>
  
  <p>But I would like my solution to work between actually domains to have one set of sessions/cookies.</p>