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+.. _lookup_plugins:
+
+Lookup plugins
+==============
+
+.. contents::
+ :local:
+ :depth: 2
+
+Lookup plugins are an Ansible-specific extension to the Jinja2 templating language. You can use lookup plugins to access data from outside sources (files, databases, key/value stores, APIs, and other services) within your playbooks. Like all :ref:`templating <playbooks_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. You can use lookup plugins to load variables or templates with information from external sources. You can :ref:`create custom lookup plugins <developing_lookup_plugins>`.
+
+.. note::
+ - Lookups are executed with a working directory relative to the role or play,
+ as opposed to local tasks, which are executed relative the executed script.
+ - Pass ``wantlist=True`` to lookups to use in Jinja2 template "for" loops.
+ - By default, lookup return values are marked as unsafe for security reasons. If you trust the outside source your lookup accesses, pass ``allow_unsafe=True`` to allow Jinja2 templates to evaluate lookup values.
+
+.. warning::
+ - Some lookups pass arguments to a shell. When using variables from a remote/untrusted source, use the `|quote` filter to ensure safe usage.
+
+
+.. _enabling_lookup:
+
+Enabling lookup plugins
+-----------------------
+
+Ansible enables all lookup plugins it can find. You can activate a custom lookup by either dropping it into a ``lookup_plugins`` directory adjacent to your play, inside the ``plugins/lookup/`` directory of a collection you have installed, inside a standalone role, or in one of the lookup directory sources configured in :ref:`ansible.cfg <ansible_configuration_settings>`.
+
+
+.. _using_lookup:
+
+Using lookup plugins
+--------------------
+
+You can use lookup plugins anywhere you can use templating in Ansible: in a play, in variables file, or in a Jinja2 template for the :ref:`template <template_module>` module. For more information on using lookup plugins, see :ref:`playbooks_lookups`.
+
+.. code-block:: YAML+Jinja
+
+ vars:
+ file_contents: "{{ lookup('file', 'path/to/file.txt') }}"
+
+Lookups are an integral part of loops. Wherever you see ``with_``, the part after the underscore is the name of a lookup. For this reason, lookups are expected to output lists; for example, ``with_items`` uses the :ref:`items <items_lookup>` lookup:
+
+.. code-block:: YAML+Jinja
+
+ tasks:
+ - name: count to 3
+ debug: msg={{ item }}
+ with_items: [1, 2, 3]
+
+You can combine lookups with :ref:`filters <playbooks_filters>`, :ref:`tests <playbooks_tests>` and even each other to do some complex data generation and manipulation. For example:
+
+.. code-block:: YAML+Jinja
+
+ tasks:
+ - name: valid but useless and over complicated chained lookups and filters
+ debug: msg="find the answer here:\n{{ lookup('url', 'https://google.com/search/?q=' + item|urlencode)|join(' ') }}"
+ with_nested:
+ - "{{ lookup('consul_kv', 'bcs/' + lookup('file', '/the/question') + ', host=localhost, port=2000')|shuffle }}"
+ - "{{ lookup('sequence', 'end=42 start=2 step=2')|map('log', 4)|list) }}"
+ - ['a', 'c', 'd', 'c']
+
+.. versionadded:: 2.6
+
+You can control how errors behave in all lookup plugins by setting ``errors`` to ``ignore``, ``warn``, or ``strict``. The default setting is ``strict``, which causes the task to fail if the lookup returns an error. For example:
+
+To ignore lookup errors:
+
+.. code-block:: YAML+Jinja
+
+ - name: if this file does not exist, I do not care .. file plugin itself warns anyway ...
+ debug: msg="{{ lookup('file', '/nosuchfile', errors='ignore') }}"
+
+.. code-block:: ansible-output
+
+ [WARNING]: Unable to find '/nosuchfile' in expected paths (use -vvvvv to see paths)
+
+ ok: [localhost] => {
+ "msg": ""
+ }
+
+
+To get a warning instead of a failure:
+
+.. code-block:: YAML+Jinja
+
+ - name: if this file does not exist, let me know, but continue
+ debug: msg="{{ lookup('file', '/nosuchfile', errors='warn') }}"
+
+.. code-block:: ansible-output
+
+ [WARNING]: Unable to find '/nosuchfile' in expected paths (use -vvvvv to see paths)
+
+ [WARNING]: An unhandled exception occurred while running the lookup plugin 'file'. Error was a <class 'ansible.errors.AnsibleError'>, original message: could not locate file in lookup: /nosuchfile
+
+ ok: [localhost] => {
+ "msg": ""
+ }
+
+
+To get a fatal error (the default):
+
+.. code-block:: YAML+Jinja
+
+ - name: if this file does not exist, FAIL (this is the default)
+ debug: msg="{{ lookup('file', '/nosuchfile', errors='strict') }}"
+
+.. code-block:: ansible-output
+
+ [WARNING]: Unable to find '/nosuchfile' in expected paths (use -vvvvv to see paths)
+
+ fatal: [localhost]: FAILED! => {"msg": "An unhandled exception occurred while running the lookup plugin 'file'. Error was a <class 'ansible.errors.AnsibleError'>, original message: could not locate file in lookup: /nosuchfile"}
+
+
+.. _query:
+
+Forcing lookups to return lists: ``query`` and ``wantlist=True``
+----------------------------------------------------------------
+
+.. versionadded:: 2.5
+
+In Ansible 2.5, a new Jinja2 function called ``query`` was added for invoking lookup plugins. The difference between ``lookup`` and ``query`` is largely that ``query`` will always return a list.
+The default behavior of ``lookup`` is to return a string of comma separated values. ``lookup`` can be explicitly configured to return a list using ``wantlist=True``.
+
+This feature provides an easier and more consistent interface for interacting with the new ``loop`` keyword, while maintaining backwards compatibility with other uses of ``lookup``.
+
+The following examples are equivalent:
+
+.. code-block:: jinja
+
+ lookup('dict', dict_variable, wantlist=True)
+
+ query('dict', dict_variable)
+
+As demonstrated above, the behavior of ``wantlist=True`` is implicit when using ``query``.
+
+Additionally, ``q`` was introduced as a shortform of ``query``:
+
+.. code-block:: jinja
+
+ q('dict', dict_variable)
+
+
+.. _lookup_plugins_list:
+
+Plugin list
+-----------
+
+You can use ``ansible-doc -t lookup -l`` to see the list of available plugins. Use ``ansible-doc -t lookup <plugin name>`` to see specific documents and examples.
+
+
+.. seealso::
+
+ :ref:`about_playbooks`
+ An introduction to playbooks
+ :ref:`inventory_plugins`
+ Ansible inventory plugins
+ :ref:`callback_plugins`
+ Ansible callback plugins
+ :ref:`filter_plugins`
+ Jinja2 filter plugins
+ :ref:`test_plugins`
+ Jinja2 test plugins
+ `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