Guidelines for VMware module development — Ansible Documentation

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# Guidelines for VMware module development

The VMware modules and these guidelines are maintained by the VMware Working Group. For further information see the team community page.

- Testing with govcsim

- Testing with your own infrastructure

  - Requirements

    - NFS server configuration

  - Configure your installation

  - If you use an HTTP proxy

  - Run the test-suite

- Unit-test

- Code style and best practice

  - datacenter argument with ESXi

  - esxi_hostname should not be mandatory

  - Functional tests

    - Writing new tests

    - No need to create too much resources

    - VM names should be predictable

- Typographic convention

  - Nomenclature

## Testing with govcsim

Most of the existing modules are covered by functional tests. The tests are located in the `test/integration/targets/`.

By default, the tests run against a vCenter API simulator called govcsim. `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:

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

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

Note

Do not confuse `govcsim` with `vcsim`. It’s old outdated version of vCenter simulator whereas govcsim is new and written in go lang

## 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:

    $ 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:

    $ 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:

    $ sudo systemctl enable --now nfs-server

### Configure your installation

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

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

### If you use an HTTP proxy

Support for hosting test infrastructure behind an HTTP proxy is currently in development. See the following pull requests for more information:

- ansible-test: vcenter behind an HTTP proxy <https://github.com/ansible/ansible/pull/58208>

- pyvmomi: proxy support <https://github.com/vmware/pyvmomi/pull/799>

- VMware: add support for HTTP proxy in connection API <https://github.com/ansible/ansible/pull/52936>

Once you have incorporated the code from those PRs, specify the location of the proxy server with the two extra keys:

    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 file to match the configuration of your lab: `test/integration/targets/prepare_vmware_tests/vars/real_lab.yml`. If you use vmware-on-libvirt <https://github.com/goneri/vmware-on-libvirt> to prepare you lab, you don’t have anything to change.

### Run the test-suite

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

    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 `test/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:

    source hacking/env-setup
    ansible-test units --tox --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.

    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.")

### 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 integration testing process.

The test-suite uses a set of common, pre-defined vars located in the `test/integration/targets/prepare_vmware_tests/` role. The resources defined there are automatically created by importing that role at the start of your test:

    - 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.

## 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.