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[Docs] Document the resource module builder (#62222)
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377 changes: 377 additions & 0 deletions docs/docsite/rst/network/dev_guide/developing_resource_modules_network.rst
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.. _developing_resource_modules:

***********************************
Developing network resource modules
***********************************

.. contents::
:local:

The resource module builder is an Ansible Playbook that helps developers scaffold and maintain an Ansible network resource module.

The resource module builder has the following capabilities:

- Uses a defined model to scaffold a resource module directory layout and initial class files.
- Scaffolds either an Ansible role or a collection.
- Subsequent uses of the resource module builder will only replace the module arspec and file containing the module docstring.
- Allows you to store complex examples along side the model in the same directory.
- Maintains the model as the source of truth for the module and use resource module builder to update the source files as needed.
- Generates working sample modules for both ``<network_os>_<resource>`` and ``<network_os>_facts``.

Accessing the resource module builder
=====================================

To access the resource module builder:

1. clone the github repository:

.. code-block:: bash
git clone https://github.com/ansible-network/resource_module_builder.git
2. Install the requirements:

.. code-block:: bash
pip install -r requirements.txt
Creating a model
================

You must create a model for your new resource. The resource module builder uses this model to create:

* The scaffold for a new module
* The argspec for the new module
* The docstring for the new module

The model is then the single source of truth for both the argspec and docstring, keeping them in sync. Use the resource module builder to generate this scaffolding. For any subsequent updates to the module, update the model first and use the resource module builder to update the module argspec and docstring.

For example, the resource model builder includes the ``myos_interfaces.yml`` sample in the :file:`models` directory, as seen below:

.. code-block:: yaml
---
GENERATOR_VERSION: '1.0'
ANSIBLE_METADATA: |
{
'metadata_version': '1.1',
'status': ['preview'],
'supported_by': '<support_group>'
}
NETWORK_OS: myos
RESOURCE: interfaces
COPYRIGHT: Copyright 2019 Red Hat
LICENSE: gpl-3.0.txt
DOCUMENTATION: |
module: myos_interfaces
version_added: 2.9
short_description: 'Manages <xxxx> attributes of <network_os> <resource>'
description: 'Manages <xxxx> attributes of <network_os> <resource>.'
author: Ansible Network Engineer
notes:
- 'Tested against <network_os> <version>'
options:
config:
description: The provided configuration
type: list
elements: dict
suboptions:
name:
type: str
description: The name of the <resource>
some_string:
type: str
description:
- The some_string_01
choices:
- choice_a
- choice_b
- choice_c
default: choice_a
some_bool:
description:
- The some_bool.
type: bool
some_int:
description:
- The some_int.
type: int
version_added: '1.1'
some_dict:
type: dict
description:
- The some_dict.
suboptions:
property_01:
description:
- The property_01
type: str
state:
description:
- The state of the configuration after module completion.
type: str
choices:
- merged
- replaced
- overridden
- deleted
default: merged
EXAMPLES:
- deleted_example_01.txt
- merged_example_01.txt
- overridden_example_01.txt
- replaced_example_01.txt
Notice that you should include examples for each of the states that the resource supports. The resource module builder also includes these in the sample model.

See `Ansible network resource models <https://github.com/ansible-network/resource_module_models>`_ for more examples.

Using the resource module builder
=================================

To use the resource module builder to create a collection scaffold from your resource model:

.. code-block:: bash
ansible-playbook -e rm_dest=<destination for modules and module utils> \
-e structure=collection \
-e collection_org=<collection_org> \
-e collection_name=<collection_name> \
-e model=<model> \
site.yml
Where the parameters are as follows:

- ``rm_dest``: The directory where the resource module builder places the files and directories for the resource module and facts modules.
- ``structure``: The directory layout type (role or collection)

- ``role``: Generate a role directory layout.
- ``collection``: Generate a collection directory layout.

- ``collection_org``: The organization of the collection, required when `structure=collection`.
- ``collection_name``: The name of the collection, required when `structure=collection`.
- ``model``: The path to the model file.

To use the resource module builder to create a role scaffold:

.. code-block:: bash
ansible-playbook -e rm_dest=<destination for modules and module utils> \
-e structure=role \
-e model=<model> \
site.yml
Examples
========

Collection directory layout
---------------------------

This example shows the directory layout for the following:

- ``network_os``: myos
- ``resource``: interfaces

.. code-block:: bash
ansible-playbook -e rm_dest=~/github/rm_example \
-e structure=collection \
-e collection_org=cidrblock \
-e collection_name=my_collection \
-e model=models/myos/interfaces/myos_interfaces.yml \
site.yml
.. code-block:: text
├── docs
├── LICENSE.txt
├── playbooks
├── plugins
| ├── action
| ├── filter
| ├── inventory
| ├── modules
| | ├── __init__.py
| | ├── myos_facts.py
| | └── myos_interfaces.py
| └── module_utils
| ├── __init__.py
| └── network
| ├── __init__.py
| └── myos
| ├── argspec
| | ├── facts
| | | ├── facts.py
| | | └── __init__.py
| | ├── __init__.py
| | └── interfaces
| | ├── __init__.py
| | └── interfaces.py
| ├── config
| | ├── __init__.py
| | └── interfaces
| | ├── __init__.py
| | └── interfaces.py
| ├── facts
| | ├── facts.py
| | ├── __init__.py
| | └── interfaces
| | ├── __init__.py
| | └── interfaces.py
| ├── __init__.py
| └── utils
| ├── __init__.py
| └── utils.py
├── README.md
└── roles
Role directory layout
---------------------

This example displays the role directory layout for the following:

- ``network_os``: myos
- ``resource``: interfaces

.. code-block:: bash
ansible-playbook -e rm_dest=~/github/rm_example/roles/my_role \
-e structure=role \
-e model=models/myos/interfaces/myos_interfaces.yml \
site.yml
.. code-block:: text
roles
└── my_role
├── library
│ ├── __init__.py
│ ├── myos_facts.py
│ └── myos_interfaces.py
├── LICENSE.txt
├── module_utils
│ ├── __init__.py
│ └── network
│ ├── __init__.py
│ └── myos
│ ├── argspec
│ │ ├── facts
│ │ │ ├── facts.py
│ │ │ └── __init__.py
│ │ ├── __init__.py
│ │ └── interfaces
│ │ ├── __init__.py
│ │ └── interfaces.py
│ ├── config
│ │ ├── __init__.py
│ │ └── interfaces
│ │ ├── __init__.py
│ │ └── interfaces.py
│ ├── facts
│ │ ├── facts.py
│ │ ├── __init__.py
│ │ └── interfaces
│ │ ├── __init__.py
│ │ └── interfaces.py
│ ├── __init__.py
│ └── utils
│ ├── __init__.py
│ └── utils.py
└── README.md
Using the collection
--------------------

This example shows how to use the generated collection in a playbook:

.. code-block:: yaml
----
- hosts: myos101
gather_facts: False
tasks:
- cidrblock.my_collection.myos_interfaces:
register: result
- debug:
var: result
- cidrblock.my_collection.myos_facts:
- debug:
var: ansible_network_resources
Using the role
--------------

This example shows how to use the generated role in a playbook:

.. code-block:: yaml
- hosts: myos101
gather_facts: False
roles:
- my_role
- hosts: myos101
gather_facts: False
tasks:
- myos_interfaces:
register: result
- debug:
var: result
- myos_facts:
- debug:
var: ansible_network_resources
Resource module structure and workflow
======================================

The resource module structure includes the following components:

Module
* ``library/<ansible_network_os>_<resource>.py``.
* Imports the ``module_utils`` resource package and calls ``execute_module`` API

.. code-block:: python
def main():
result = <resource_package>(module).execute_module()
Module argspec
* ``module_utils/<ansible_network_os>/argspec/<resource>/``.
* Argspec for the resource.

Facts
* ``module_utils/<ansible_network_os>/facts/<resource>/``.
* Populate facts for the resource.
* Entry in ``module_utils/<ansible_network_os>/facts/facts.py`` for ``get_facts`` API to keep ``<ansible_network_os>_facts`` module and facts gathered for the resource module in sync for every subset.
* Entry of Resource subset in FACTS_RESOURCE_SUBSETS list in ``module_utils/<ansible_network_os>/facts/facts.py`` to make facts collection work.

Module package in module_utils
* ``module_utils/<ansible_network_os>/<config>/<resource>/``.
* Implement ``execute_module`` API that loads the configuration to device and generates the result with ``changed``, ``commands``, ``before`` and ``after`` keys.
* Call ``get_facts`` API that returns the ``<resource>`` configuration facts or return the difference if the device has onbox diff support.
* Compare facts gathered and given key-values if diff is not supported.
* Generate final configuration.

Utils
* ``module_utils/<ansible_network_os>/utils``.
* Utilities for the ``<ansible_network_os>`` platform.

Developer notes
===============

The tests rely on a role generated by the resource module builder. After changes to the resource module builder, the role should be regenerated and the tests modified and run as needed. To generate the role after changes:

.. code-block:: bash
rm -rf rmb_tests/roles/my_role
ansible-playbook -e rm_dest=./rmb_tests/roles/my_role \
-e structure=role \
-e model=models/myos/interfaces/myos_interfaces.yml \
site.yml
2 changes: 2 additions & 0 deletions docs/docsite/rst/network/dev_guide/index.rst
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Expand Up @@ -18,6 +18,7 @@ If you want to extend Ansible for Network Automation by creating a module or plu

Find the network developer task that best describes what you want to do:

* I want to :ref:`develop a network resource module <developing_resource_modules>`.
* I want to :ref:`develop a network connection plugin <developing_plugins_network>`.
* I want to :ref:`document my set of modules for a network platform <documenting_modules_network>`.

Expand All @@ -26,5 +27,6 @@ If you prefer to read the entire guide, here's a list of the pages in order.
.. toctree::
:maxdepth: 1

developing_resource_modules_network
developing_plugins_network
documenting_modules_network

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