Using and developing module utilities¶
Ansible provides a number of module utilities, or snippets of shared code, that
provide helper functions you can use when developing your own modules. The
basic.py module utility provides the main entry point for accessing the
Ansible library, and all Python Ansible modules must import something from
ansible.module_utils. A common option is to import
from ansible.module_utils.basic import AnsibleModule
ansible.module_utils namespace is not a plain Python package: it is
constructed dynamically for each task invocation, by extracting imports and
resolving those matching the namespace against a search path derived from the
To reduce the maintenance burden in a collection or in local modules, you can extract
duplicated code into one or more module utilities and import them into your modules. For example, if you have your own custom modules that import a
my_shared_code library, you can place that into a
./module_utils/my_shared_code.py file like this:
from ansible.module_utils.my_shared_code import MySharedCodeClient
When you run
ansible-playbook, Ansible will merge any files in your local
module_utils directories into the
ansible.module_utils namespace in the order defined by the Ansible search path.
Naming and finding module utilities¶
You can generally tell what a module utility does from its name and/or its location. Generic utilities (shared code used by many different kinds of modules) live in the main ansible/ansible codebase, in the
common subdirectory or in the root directory of
lib/ansible/module_utils. Utilities used by a particular set of modules generally live in the same collection as those modules. For example:
lib/ansible/module_utils/urls.pycontains shared code for parsing URLs
openstack.cloud.plugins.module_utils.openstack.pycontains utilities for modules that work with OpenStack instances
ansible.netcommon.plugins.module_utils.network.common.config.pycontains utility functions for use by networking modules
Following this pattern with your own module utilities makes everything easy to find and use.
Standard module utilities¶
Ansible ships with an extensive library of
module_utils files. You can find the module utility source code in the
lib/ansible/module_utils directory under your main Ansible path. We describe the most widely used utilities below. For more details on any specific module utility, please see the source code for module_utils.
LICENSING REQUIREMENTS Ansible enforces the following licensing requirements:
- Utilities (files in
lib/ansible/module_utils/) may have one of two licenses:
A file in
module_utilsused only for a specific vendor’s hardware, provider, or service may be licensed under GPLv3+. Adding a new file under
module_utilswith GPLv3+ needs to be approved by the core team.
module_utilsmust be licensed under BSD, so GPL-licensed third-party and Galaxy modules can use them.
If there’s doubt about the appropriate license for a file in
module_utils, the Ansible Core Team will decide during an Ansible Core Community Meeting.
- Utilities (files in
All other files shipped with Ansible, including all modules, must be licensed under the GPL license (GPLv3 or later).
api.py- Supports generic API modules
basic.py- General definitions and helper utilities for Ansible modules
common/dict_transformations.py- Helper functions for dictionary transformations
common/file.py- Helper functions for working with files
common/text/- Helper functions for converting and formatting text
common/parameters.py- Helper functions for dealing with module parameters
common/sys_info.py- Functions for getting distribution and platform information
common/validation.py- Helper functions for validating module parameters against a module argument spec
facts/- Directory of utilities for modules that return facts. See PR 23012 for more information
json_utils.py- Utilities for filtering unrelated output around module JSON output, like leading and trailing lines
powershell/- Directory of definitions and helper functions for Windows PowerShell modules
pycompat24.py- Exception workaround for Python 2.4
service.py- Utilities to enable modules to work with Linux services (placeholder, not in use)
six/__init__.py- Bundled copy of the Six Python library to aid in writing code compatible with both Python 2 and Python 3
splitter.py- String splitting and manipulation utilities for working with Jinja2 templates
urls.py- Utilities for working with http and https requests
Several commonly-used utilities migrated to collections in Ansible 2.10, including:
ansible.posix.plugins.module_utils.mount.py- Single helper function that fixes os.path.ismount
community.general.plugins.module_utils.known_hosts.py- utilities for working with known_hosts file
For a list of migrated content with destination collections, see https://github.com/ansible/ansible/blob/devel/lib/ansible/config/ansible_builtin_runtime.yml.