title: Is there some Ansible equivalent to "failed_when" for success
body: <p>Looking at the documentation about error handling <a href="http://docs.ansible.com/playbooks_error_handling.html" rel="nofollow noreferrer">Ansible error handling</a></p>
  
  <p>I only see a way to fail the provisioning fail_when, i am wondering if there is any way to do the oposite. </p>
  
  <p>something that looks like this:</p>
  
  <blockquote>
  <pre><code>- name: ping pong redis
    command: redis-cli ping
    register: command_result
    success_when: "'PONG' in command_result.stderr"
  </code></pre>
  </blockquote>
  
  <p>Thanks.</p>