ansible/docs/docsite/rst/playbook_guide/playbooks_tests.rst

.. _playbooks_tests:

*****
Tests
*****

`Tests <https://jinja.palletsprojects.com/en/latest/templates/#tests>`_ in Jinja are a way of evaluating template expressions and returning True or False. Jinja ships with many of these. See `builtin tests`_ in the official Jinja template documentation.

The main difference between tests and filters are that Jinja tests are used for comparisons, whereas filters are used for data manipulation, and have different applications in jinja. Tests can also be used in list processing filters, like ``map()`` and ``select()`` to choose items in the list.

Like all templating, tests always execute on the Ansible controller, **not** on the target of a task, as they test local data.

In addition to those Jinja2 tests, Ansible supplies a few more and users can easily create their own.

.. contents::
   :local:

.. _test_syntax:

Test syntax
===========

`Test syntax <https://jinja.palletsprojects.com/en/latest/templates/#tests>`_ varies from `filter syntax <https://jinja.palletsprojects.com/en/latest/templates/#filters>`_ (``variable | filter``). Historically Ansible has registered tests as both jinja tests and jinja filters, allowing for them to be referenced using filter syntax.

As of Ansible 2.5, using a jinja test as a filter will generate a deprecation warning. As of Ansible 2.9+ using jinja test syntax is required.

The syntax for using a jinja test is as follows

.. code-block:: console

    variable is test_name

Such as

.. code-block:: console

    result is failed

.. _testing_strings:

Testing strings
===============

To match strings against a substring or a regular expression, use the ``match``, ``search`` or ``regex`` tests

.. code-block:: yaml

    vars:
      url: "https://example.com/users/foo/resources/bar"

    tasks:
        - debug:
            msg: "matched pattern 1"
          when: url is match("https://example.com/users/.*/resources")

        - debug:
            msg: "matched pattern 2"
          when: url is search("users/.*/resources/.*")

        - debug:
            msg: "matched pattern 3"
          when: url is search("users")

        - debug:
            msg: "matched pattern 4"
          when: url is regex("example\.com/\w+/foo")

``match`` succeeds if it finds the pattern at the beginning of the string, while ``search`` succeeds if it finds the pattern anywhere within string. By default, ``regex`` works like ``search``, but ``regex`` can be configured to perform other tests as well, by passing the ``match_type`` keyword argument. In particular, ``match_type`` determines the ``re`` method that gets used to perform the search. The full list can be found in the relevant Python documentation `here <https://docs.python.org/3/library/re.html#regular-expression-objects>`_.

All of the string tests also take optional ``ignorecase`` and ``multiline`` arguments. These correspond to ``re.I`` and ``re.M`` from Python's ``re`` library, respectively.

.. _testing_vault:

Vault
=====

.. versionadded:: 2.10

You can test whether a variable is an inline single vault encrypted value using the ``vault_encrypted`` test.

.. code-block:: yaml

    vars:
      variable: !vault |
        $ANSIBLE_VAULT;1.2;AES256;dev
        61323931353866666336306139373937316366366138656131323863373866376666353364373761
        3539633234313836346435323766306164626134376564330a373530313635343535343133316133
        36643666306434616266376434363239346433643238336464643566386135356334303736353136
        6565633133366366360a326566323363363936613664616364623437336130623133343530333739
        3039

    tasks:
      - debug:
          msg: '{{ (variable is vault_encrypted) | ternary("Vault encrypted", "Not vault encrypted") }}'

.. _testing_truthiness:

Testing truthiness
==================

.. versionadded:: 2.10

As of Ansible 2.10, you can now perform Python like truthy and falsy checks.

.. code-block:: yaml

    - debug:
        msg: "Truthy"
      when: value is truthy
      vars:
        value: "some string"

    - debug:
        msg: "Falsy"
      when: value is falsy
      vars:
        value: ""

Additionally, the ``truthy`` and ``falsy`` tests accept an optional parameter called ``convert_bool`` that will attempt
to convert boolean indicators to actual booleans.

.. code-block:: yaml

    - debug:
        msg: "Truthy"
      when: value is truthy(convert_bool=True)
      vars:
        value: "yes"

    - debug:
        msg: "Falsy"
      when: value is falsy(convert_bool=True)
      vars:
        value: "off"

.. _testing_versions:

Comparing versions
==================

.. versionadded:: 1.6

.. note:: In 2.5 ``version_compare`` was renamed to ``version``

To compare a version number, such as checking if the ``ansible_facts['distribution_version']``
version is greater than or equal to '12.04', you can use the ``version`` test.

The ``version`` test can also be used to evaluate the ``ansible_facts['distribution_version']``

.. code-block:: yaml+jinja

    {{ ansible_facts['distribution_version'] is version('12.04', '>=') }}

If ``ansible_facts['distribution_version']`` is greater than or equal to 12.04, this test returns True, otherwise False.

The ``version`` test accepts the following operators

.. code-block:: console

    <, lt, <=, le, >, gt, >=, ge, ==, =, eq, !=, <>, ne

This test also accepts a 3rd parameter, ``strict`` which defines if strict version parsing as defined by ``ansible.module_utils.compat.version.StrictVersion`` should be used.  The default is ``False`` (using ``ansible.module_utils.compat.version.LooseVersion``), ``True`` enables strict version parsing

.. code-block:: yaml+jinja

    {{ sample_version_var is version('1.0', operator='lt', strict=True) }}

As of Ansible 2.11 the ``version`` test accepts a ``version_type`` parameter which is mutually exclusive with ``strict``, and accepts the following values

.. code-block:: console

    loose, strict, semver, semantic, pep440

``loose``
  This type corresponds to the Python ``distutils.version.LooseVersion`` class. All version formats are valid for this type. The rules for comparison are simple and predictable, but may not always give expected results.

``strict``
  This type corresponds to the Python ``distutils.version.StrictVersion`` class. A version number consists of two or three dot-separated numeric components, with an optional "pre-release" tag on the end. The pre-release tag consists of a single letter 'a' or 'b' followed by a number.  If the numeric components of two version numbers are equal, then one with a pre-release tag will always be deemed earlier (lesser) than one without.

``semver``/``semantic``
  This type implements the `Semantic Version <https://semver.org>`_ scheme for version comparison.

``pep440``
  This type implements the Python `PEP-440 <https://peps.python.org/pep-0440/>`_ versioning rules for version comparison. Added in version 2.14.

Using ``version_type`` to compare a semantic version would be achieved like the following

.. code-block:: yaml+jinja

    {{ sample_semver_var is version('2.0.0-rc.1+build.123', 'lt', version_type='semver') }}

In Ansible 2.14, the ``pep440`` option for ``version_type`` was added, and the rules of this type are defined in `PEP-440 <https://peps.python.org/pep-0440/>`_. The following example showcases how this type can differentiate pre-releases as being less than a general release.

.. code-block:: yaml+jinja

   {{ '2.14.0rc1' is version('2.14.0', 'lt', version_type='pep440') }}

When using ``version`` in a playbook or role, don't use ``{{ }}`` as described in the `FAQ <https://docs.ansible.com/ansible/latest/reference_appendices/faq.html#when-should-i-use-also-how-to-interpolate-variables-or-dynamic-variable-names>`_

.. code-block:: yaml

    vars:
        my_version: 1.2.3

    tasks:
        - debug:
            msg: "my_version is higher than 1.0.0"
          when: my_version is version('1.0.0', '>')

.. _math_tests:

Set theory tests
================

.. versionadded:: 2.1

.. note:: In 2.5 ``issubset`` and ``issuperset`` were renamed to ``subset`` and ``superset``

To see if a list includes or is included by another list, you can use 'subset' and 'superset'

.. code-block:: yaml

    vars:
        a: [1,2,3,4,5]
        b: [2,3]
    tasks:
        - debug:
            msg: "A includes B"
          when: a is superset(b)

        - debug:
            msg: "B is included in A"
          when: b is subset(a)

.. _contains_test:

Testing if a list contains a value
==================================

.. versionadded:: 2.8

Ansible includes a ``contains`` test which operates similarly, but in reverse of the Jinja2 provided ``in`` test.
The ``contains`` test is designed to work with the ``select``, ``reject``, ``selectattr``, and ``rejectattr`` filters

.. code-block:: yaml

    vars:
      lacp_groups:
        - master: lacp0
          network: 10.65.100.0/24
          gateway: 10.65.100.1
          dns4:
            - 10.65.100.10
            - 10.65.100.11
          interfaces:
            - em1
            - em2

        - master: lacp1
          network: 10.65.120.0/24
          gateway: 10.65.120.1
          dns4:
            - 10.65.100.10
            - 10.65.100.11
          interfaces:
              - em3
              - em4

    tasks:
      - debug:
          msg: "{{ (lacp_groups|selectattr('interfaces', 'contains', 'em1')|first).master }}"

Testing if a list value is True
===============================

.. versionadded:: 2.4

You can use `any` and `all` to check if any or all elements in a list are true or not

.. code-block:: yaml

  vars:
    mylist:
        - 1
        - "{{ 3 == 3 }}"
        - True
    myotherlist:
        - False
        - True
  tasks:

    - debug:
        msg: "all are true!"
      when: mylist is all

    - debug:
        msg: "at least one is true"
      when: myotherlist is any

.. _path_tests:

Testing paths
=============

.. note:: In 2.5 the following tests were renamed to remove the ``is_`` prefix

The following tests can provide information about a path on the controller

.. code-block:: yaml

    - debug:
        msg: "path is a directory"
      when: mypath is directory

    - debug:
        msg: "path is a file"
      when: mypath is file

    - debug:
        msg: "path is a symlink"
      when: mypath is link

    - debug:
        msg: "path already exists"
      when: mypath is exists

    - debug:
        msg: "path is {{ (mypath is abs)|ternary('absolute','relative')}}"

    - debug:
        msg: "path is the same file as path2"
      when: mypath is same_file(path2)

    - debug:
        msg: "path is a mount"
      when: mypath is mount

    - debug:
        msg: "path is a directory"
      when: mypath is directory
      vars:
         mypath: /my/patth

    - debug:
        msg: "path is a file"
      when: "'/my/path' is file"


Testing size formats
====================

The ``human_readable`` and ``human_to_bytes`` functions let you test your
playbooks to make sure you are using the right size format in your tasks, and that
you provide Byte format to computers and human-readable format to people.

Human readable
--------------

Asserts whether the given string is human readable or not.

For example

.. code-block:: yaml+jinja

  - name: "Human Readable"
    assert:
      that:
        - '"1.00 Bytes" == 1|human_readable'
        - '"1.00 bits" == 1|human_readable(isbits=True)'
        - '"10.00 KB" == 10240|human_readable'
        - '"97.66 MB" == 102400000|human_readable'
        - '"0.10 GB" == 102400000|human_readable(unit="G")'
        - '"0.10 Gb" == 102400000|human_readable(isbits=True, unit="G")'

This would result in

.. code-block:: json

    { "changed": false, "msg": "All assertions passed" }

Human to bytes
--------------

Returns the given string in the Bytes format.

For example

.. code-block:: yaml+jinja

  - name: "Human to Bytes"
    assert:
      that:
        - "{{'0'|human_to_bytes}}        == 0"
        - "{{'0.1'|human_to_bytes}}      == 0"
        - "{{'0.9'|human_to_bytes}}      == 1"
        - "{{'1'|human_to_bytes}}        == 1"
        - "{{'10.00 KB'|human_to_bytes}} == 10240"
        - "{{   '11 MB'|human_to_bytes}} == 11534336"
        - "{{  '1.1 GB'|human_to_bytes}} == 1181116006"
        - "{{'10.00 Kb'|human_to_bytes(isbits=True)}} == 10240"

This would result in

.. code-block:: json

    { "changed": false, "msg": "All assertions passed" }


.. _test_task_results:

Testing task results
====================

The following tasks are illustrative of the tests meant to check the status of tasks

.. code-block:: yaml

    tasks:

      - shell: /usr/bin/foo
        register: result
        ignore_errors: True

      - debug:
          msg: "it failed"
        when: result is failed

      # in most cases you'll want a handler, but if you want to do something right now, this is nice
      - debug:
          msg: "it changed"
        when: result is changed

      - debug:
          msg: "it succeeded in Ansible >= 2.1"
        when: result is succeeded

      - debug:
          msg: "it succeeded"
        when: result is success

      - debug:
          msg: "it was skipped"
        when: result is skipped

.. note:: From 2.1, you can also use success, failure, change, and skip so that the grammar matches, for those who need to be strict about it.

.. _type_tests:

Type Tests
==========

When looking to determine types, it may be tempting to use the ``type_debug`` filter and compare that to the string name of that type, however, you should instead use type test comparisons, such as:

.. code-block:: yaml

    tasks:
      - name: "String interpretation"
        vars:
          a_string: "A string"
          a_dictionary: {"a": "dictionary"}
          a_list: ["a", "list"]
        assert:
          that:
          # Note that a string is classed as also being "iterable", "sequence" and "mapping"
          - a_string is string

          # Note that a dictionary is classed as not being a "string", but is "iterable", "sequence" and "mapping"
          - a_dictionary is not string and a_dictionary is mapping

          # Note that a list is classed as not being a "string" or "mapping" but is "iterable" and "sequence"
          - a_list is not string and a_list is not mapping and a_list is iterable

      - name: "Number interpretation"
        vars:
          a_float: 1.01
          a_float_as_string: "1.01"
          an_integer: 1
          an_integer_as_string: "1"
        assert:
          that:
          # Both a_float and an_integer are "number", but each has their own type as well
          - a_float is number and a_float is float
          - an_integer is number and an_integer is integer

          # Both a_float_as_string and an_integer_as_string are not numbers
          - a_float_as_string is not number and a_float_as_string is string
          - an_integer_as_string is not number and a_float_as_string is string

          # a_float or a_float_as_string when cast to a float and then to a string should match the same value cast only to a string
          - a_float | float | string == a_float | string
          - a_float_as_string | float | string == a_float_as_string | string

          # Likewise an_integer and an_integer_as_string when cast to an integer and then to a string should match the same value cast only to an integer
          - an_integer | int | string == an_integer | string
          - an_integer_as_string | int | string == an_integer_as_string | string

          # However, a_float or a_float_as_string cast as an integer and then a string does not match the same value cast to a string
          - a_float | int | string != a_float | string
          - a_float_as_string | int | string != a_float_as_string | string

          # Again, Likewise an_integer and an_integer_as_string cast as a float and then a string does not match the same value cast to a string
          - an_integer | float | string != an_integer | string
          - an_integer_as_string | float | string != an_integer_as_string | string

      - name: "Native Boolean interpretation"
        loop:
        - yes
        - true
        - True
        - TRUE
        - no
        - No
        - NO
        - false
        - False
        - FALSE
        assert:
          that:
          # Note that while other values may be cast to boolean values, these are the only ones which are natively considered boolean
          # Note also that `yes` is the only case sensitive variant of these values.
          - item is boolean

.. _builtin tests: https://jinja.palletsprojects.com/en/latest/templates/#builtin-tests

.. seealso::

   :ref:`playbooks_intro`
       An introduction to playbooks
   :ref:`playbooks_conditionals`
       Conditional statements in playbooks
   :ref:`playbooks_variables`
       All about variables
   :ref:`playbooks_loops`
       Looping in playbooks
   :ref:`playbooks_reuse_roles`
       Playbook organization by roles
   :ref:`tips_and_tricks`
       Tips and tricks for 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