title: Does Rails 4.2 use secret_token?
body: <p>Are both secret_key_base and secret_token needed for production in Rails 4.2?  Setting neither causes the following exception message:</p>
  
  <blockquote>
    <p>Missing <code>secret_token</code> and <code>secret_key_base</code> for 'production'
    environment, set these values in <code>config/secrets.yml</code></p>
  </blockquote>
  
  <p>The 4.2 upgrade guide (<a href="http://railsapps.github.io/updating-rails.html" rel="noreferrer">http://railsapps.github.io/updating-rails.html</a>) says this:</p>
  
  <blockquote>
    <p>When you create a new Rails application using the rails new command, a
    unique secret key is generated and written to the
    config/initializers/secret_token.rb file.</p>
  </blockquote>
  
  <p>But no such file was created when I generated my app, and there is no reference to secret_token in config/secrets.yml</p>
  
  <p>I'm assuming that the error message is wrong, and that only secret_key_base is needed.  When I run my app in production on my dev machine, it starts with just secret_key_base, but in Engineyard, setting secret_key_base (via an environment variable) isn't working.  I still get the error.</p>