title: Ansible: 'item' is undefined
body: <p>I'm trying to use <code>with_items</code> with <code>delegate_to</code> to run a Docker container in several hosts. I have a group <code>test</code> in <code>/etc/ansible/hosts</code>:</p>
  
  <pre><code>[test]
  my_machine1
  my_machine2
  </code></pre>
  
  <p>And this task:</p>
  
  <pre><code> - name: Run app container
      docker:
        name: "{{artifact_id}}"
        insecure_registry: true
        image: "{{image}}:{{version}}"
        pull: always
        state: reloaded
        ports:
        - "{{port_mapping}}"
        delegate_to: '{{item}}'
        with_items:
        - "{{groups['test']}}"
  </code></pre>
  
  <p>But when I run it, I get this error:</p>
  
  <blockquote>
    <p>{"failed": true, "msg": "ERROR! 'item' is undefined"}</p>
  </blockquote>
  
  <p>What am I doing wrong?</p>
  
  <p>Thanks in advance</p>