.. _VMware_module_development:

****************************************
Guidelines for VMware module development
****************************************

The Ansible VMware collection (on `Galaxy <https://galaxy.ansible.com/community/vmware>`_, source code `repository <https://github.com/ansible-collections/community.vmware>`_) is maintained by the VMware Working Group. For more information see the `team community page <https://github.com/ansible/community/wiki/VMware>`_.

.. contents::
   :local:

Testing with govcsim
====================

Most of the existing modules are covered by functional tests. The tests are located `here <https://github.com/ansible-collections/community.vmware/tree/main/tests/integration/targets>`_.

By default, the tests run against a vCenter API simulator called `govcsim <https://github.com/vmware/govmomi/tree/master/vcsim>`_. ``ansible-test`` will automatically pull a `govcsim container <https://quay.io/repository/ansible/vcenter-test-container>`_ and use it to set-up the test environment.

You can trigger the test of a module manually with the ``ansible-test`` command. For example, to trigger ``vcenter_folder`` tests:

.. code-block:: shell

    source hacking/env-setup
    ansible-test integration --python 3.7 vcenter_folder

``govcsim`` is handy because it is much faster than a regular test environment. However, ``govcsim`` does not
support all the ESXi or vCenter features.

.. note::

   Do not confuse ``govcsim`` with ``vcsim``. ``vcsim`` is an older and outdated version of vCenter simulator, whereas ``govcsim`` is new and written in Go language.

Testing with your own infrastructure
====================================

You can also target a regular VMware environment. This paragraph explains step by step how you can run the test-suite yourself.

Requirements
------------

- 2 ESXi hosts (6.5 or 6.7)
   - with 2 NIC, the second ones should be available for the test
- a VCSA host
- a NFS server
- Python dependencies:
    - `pyvmomi <https://github.com/vmware/pyvmomi/tree/master/pyVmomi>`_
    - `requests <https://2.python-requests.org/en/master/>`_

If you want to deploy your test environment in a hypervisor, both `VMware or Libvirt <https://github.com/goneri/vmware-on-libvirt>`_ work well.

NFS server configuration
^^^^^^^^^^^^^^^^^^^^^^^^

Your NFS server must expose the following directory structure:

.. code-block:: shell

    $ tree /srv/share/
    /srv/share/
    ├── isos
    │   ├── base.iso
    │   ├── centos.iso
    │   └── fedora.iso
    └── vms
    2 directories, 3 files

On a Linux system, you can expose the directory over NFS with the following export file:

.. code-block:: shell

    $ cat /etc/exports
    /srv/share  192.168.122.0/255.255.255.0(rw,anonuid=1000,anongid=1000)

.. note::

    With this configuration all the new files will be owned by the user with the UID and GID 1000/1000.
    Adjust the configuration to match your user's UID/GID.

The service can be enabled with:

.. code-block:: shell

   $ sudo systemctl enable --now nfs-server


Configure your installation
---------------------------

Prepare a configuration file that describes your set-up. The file
should be called :file:`test/integration/cloud-config-vcenter.ini` and based on
:file:`test/lib/ansible_test/config/cloud-config-vcenter.ini.template`. For instance, if you have deployed your lab with
`vmware-on-libvirt <https://github.com/goneri/vmware-on-libvirt>`_:

.. code-block:: ini

    [DEFAULT]
    vcenter_username: administrator@vsphere.local
    vcenter_password: !234AaAa56
    vcenter_hostname: vcenter.test
    vmware_validate_certs: false
    esxi1_hostname: esxi1.test
    esxi1_username: root
    esxi1_password: root
    esxi2_hostname: test2.test
    esxi2_username: root
    esxi2_password: root

Using an HTTP proxy
-------------------
Hosting test infrastructure behind an HTTP proxy is supported. You can specify the location of the proxy server with the two extra keys:

.. code-block:: ini

    vmware_proxy_host: esxi1-gw.ws.testing.ansible.com
    vmware_proxy_port: 11153

In addition, you may need to adjust the variables of the following `var files <https://github.com/ansible-collections/community.vmware/tree/main/tests/integration/targets/prepare_vmware_tests/vars>`_ to match the configuration of your lab. If you use vmware-on-libvirt to prepare your lab, you do not have anything to change.

Run the test-suite
------------------

Once your configuration is ready, you can trigger a run with the following command:

.. code-block:: shell

    source hacking/env-setup
    VMWARE_TEST_PLATFORM=static ansible-test integration --python 3.7 vmware_host_firewall_manager

``vmware_host_firewall_manager`` is the name of the module to test.

``vmware_guest`` is much larger than any other test role and is rather slow. You can enable or disable some of its test playbooks in `main.yml <https://github.com/ansible-collections/community.vmware/tree/main/tests/integration/targets/vmware_guest/defaults/main.yml>`_.


Unit-test
=========

The VMware modules have limited unit-test coverage. You can run the test suite with the
following commands:

.. code-block:: shell

    source hacking/env-setup
    ansible-test units --venv --python 3.7 '.*vmware.*'

Code style and best practice
============================

datacenter argument with ESXi
-----------------------------

The ``datacenter`` parameter should not use ``ha-datacenter`` by default. This is because the user may
not realize that Ansible silently targets the wrong data center.

esxi_hostname should not be mandatory
-------------------------------------

Depending upon the functionality provided by ESXi or vCenter, some modules can seamlessly work with both. In this case,
``esxi_hostname`` parameter should be optional.

.. code-block:: python

    if self.is_vcenter():
        esxi_hostname = module.params.get('esxi_hostname')
        if not esxi_hostname:
            self.module.fail_json("esxi_hostname parameter is mandatory")
        self.host = self.get_all_host_objs(cluster_name=cluster_name, esxi_host_name=esxi_hostname)[0]
    else:
        self.host = find_obj(self.content, [vim.HostSystem], None)
    if self.host is None:
        self.module.fail_json(msg="Failed to find host system.")

Example should use the fully qualified collection name (FQCN)
-------------------------------------------------------------

Use FQCN for examples within module documentation. For instance, you should use ``community.vmware.vmware_guest`` instead of just
``vmware_guest``.

This way, the examples do not depend on the ``collections`` directive of the
playbook.

Functional tests
----------------

Writing new tests
^^^^^^^^^^^^^^^^^

If you are writing a new collection of integration tests, there are a few VMware-specific things to note beyond
the standard Ansible :ref:`integration testing<testing_integration>` process.

The test-suite uses a set of common, pre-defined vars located `in prepare_vmware_tests <https://github.com/ansible-collections/community.vmware/tree/main/tests/integration/targets/test/integration/targets/prepare_vmware_tests/>`_ role.
The resources defined there are automatically created by importing that role at the start of your test:

.. code-block:: yaml

  - import_role:
      name: prepare_vmware_tests
    vars:
      setup_datacenter: true

This will give you a ready to use cluster, datacenter, datastores, folder, switch, dvswitch, ESXi hosts, and VMs.

No need to create too much resources
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

Most of the time, it's not necessary to use ``with_items`` to create multiple resources. By avoiding it,
you speed up the test execution and you simplify the clean up afterwards.

VM names should be predictable
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

If you need to create a new VM during your test, you can use ``test_vm1``, ``test_vm2`` or ``test_vm3``. This
way it will be automatically clean up for you.

Avoid the common boiler plate code in your test playbook
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

From Ansible 2.10, the test suite uses `modules_defaults`. This module
allow us to preinitialize the following default keys of the VMware modules:

- hostname
- username
- password
- validate_certs

For example, the following block:

.. code-block:: yaml

    - name: Add a VMware vSwitch
      community.vmware.vmware_vswitch:
        hostname: '{{ vcenter_hostname }}'
        username: '{{ vcenter_username }}'
        password: '{{ vcenter_password }}'
        validate_certs: 'no'
        esxi_hostname: 'esxi1'
        switch_name: "boby"
        state: present

should be simplified to just:

.. code-block:: yaml

    - name: Add a VMware vSwitch
      community.vmware.vmware_vswitch:
        esxi_hostname: 'esxi1'
        switch_name: "boby"
        state: present


Typographic convention
======================

Nomenclature
------------

We try to enforce the following rules in our documentation:

- VMware, not VMWare or vmware
- ESXi, not esxi or ESXI
- vCenter, not vcenter or VCenter

We also refer to vcsim's Go implementation with ``govcsim``. This to avoid any confusion with the outdated implementation.
