.. _playbooks_lookups:

*******
Lookups
*******

Lookup plugins retrieve data from outside sources such as files, databases, key/value stores, APIs, and other services. Like all templating, lookups execute and are evaluated on the Ansible control machine. Ansible makes the data returned by a lookup plugin available using the standard templating system. Before Ansible 2.5, lookups were mostly used indirectly in ``with_<lookup>`` constructs for looping. Starting with Ansible 2.5, lookups are used more explicitly as part of Jinja2 expressions fed into the ``loop`` keyword.

.. _lookups_and_variables:

Using lookups in variables
==========================

You can populate variables using lookups. Ansible evaluates the value each time it is executed in a task (or template).

.. code-block:: yaml+jinja

    vars:
      motd_value: "{{ lookup('file', '/etc/motd') }}"
    tasks:
      - debug:
          msg: "motd value is {{ motd_value }}"

For more details and a list of lookup plugins in ansible-core, see :ref:`plugins_lookup`. You may also find lookup plugins in collections. You can review a list of lookup plugins installed on your control machine with the command ``ansible-doc -l -t lookup``.

.. seealso::

   :ref:`working_with_playbooks`
       An introduction to playbooks
   :ref:`playbooks_conditionals`
       Conditional statements in playbooks
   :ref:`playbooks_variables`
       All about variables
   :ref:`playbooks_loops`
       Looping in playbooks
   `User Mailing List <https://groups.google.com/group/ansible-devel>`_
       Have a question?  Stop by the google group!
   :ref:`communication_irc`
       How to join Ansible chat channels
