title: Run Ansible task only on one server - AWS
body: <p>I have my ansible task running in all my api_servers which i would restrict it to run only on one IP (one of the api_server)
  I have added run_once: true but it didnt helps.</p>
  <p>Kindly advise.
  EDIT :</p>
  <p>Will the below work?  I have 10 instances of app_servers running, I want the task to run only on one app_server</p>
  <pre><code>run_once: true
  when:
      - inventory_hostname == groups['app_servers'][0]
  </code></pre>
  <p>Where my inventory file is like</p>
  <pre><code>[app_servers]
  prod_app_[1:4]
  </code></pre>