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 AnsibleModule:
from ansible.module_utils.basic import AnsibleModule
The 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
active configuration.
To reduce the maintenance burden on your own 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. For example, openstack.py contains utilities for modules that work with OpenStack instances.
Generic utilities (shared code used by many different kinds of modules) live in the common subdirectory or in the root directory. Utilities
used by a particular set of modules generally live in a sub-directory that mirrors
the directory for those modules. For example:
- lib/ansible/module_utils/urls.pycontains shared code for parsing URLs
- lib/ansible/module_utils/storage/emc/contains shared code related to EMC
- lib/ansible/modules/storage/emc/contains modules related to EMC
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’ve described the most widely used utilities below. For more details on any specific module utility,
please see the source code for module_utils.
Note
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 undermodule_utilswith GPLv3+ needs to be approved by the core team.
- All other 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.
 
- A file in 
 
- 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
- ismount.py- Single helper function that fixes os.path.ismount
- json_utils.py- Utilities for filtering unrelated output around module JSON output, like leading and trailing lines
- known_hosts.py- utilities for working with known_hosts file
- network/common/config.py- Configuration utility functions for use by networking modules
- network/common/netconf.py- Definitions and helper functions for modules that use Netconf transport
- network/common/parsing.py- Definitions and helper functions for Network modules
- network/common/network.py- Functions for running commands on networking devices
- network/common/utils.py- Defines commands and comparison operators and other utilises for use in networking modules
- 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)
- shell.py- Functions to allow modules to create shells and work with shell commands
- 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
