title: Where can I get a list of Ansible pre-defined variables?
body: <p>I see that Ansible provide some pre-defined variables that we can use in playbooks and template files. For example, the host IP address is <code>ansible_eth0.ipv4.address</code>. Googleing and searching the docs I couldn't find a list of all available variables.<br />
  Would someone list them for me?</p>