Introduction to ansible-test

February 22, 2021 by Anshul Behl

As automation becomes crucial for more and more business cases, there is an increased need to test the automation code itself. This is where ansible-test comes in: developers who want to test their Ansible Content Collections for sanity, unit and integration tests can use  ansible-test  to achieve testing workflows that integrate with source code repositories.

Both ansible-core and ansible-base come packaged with a cli tool called ansible-test, which can be used by collection developers to test their Collection and its content. The ansible-test knows how to perform a wide variety of testing-related tasks, from linting module documentation and code to running unit and integration tests.

We will cover different features of ansible-test in brief below.

How to run ansible-test?

With the general availability of Ansible Content Collections with Ansible-2.9, a user can run ansible-test inside a collection to test the collection itself. ansible-test needs to be run from the collection root or below in order for ansible-test to run tests on the Collection.

If you try to run ansible-test from outside the above directory norms, it will throw an error like below:

root@root ~/.ansible/collections ansible-test sanity
ERROR: The current working directory must be at or below:
                                                                                                                                                                                                                                            
- an Ansible collection: {...}/ansible_collections/{namespace}/{collection}/                                                                                                                                                                
                                                                                                                                                                                                                                            
Current working directory: /root/.ansible/collections  

from the above output you can see how a collection root appears to ansible-test, it has to be in the form of:

{...}/ansible_collections/{namespace}/{collection}/

When you install a collection from Ansible Galaxy or Automation Hub, the default installation location is: {...}/ansible_collections/{namespace}/{collection}/ , which already satisfies the above directory convention.

Even if you specify the installation path to the ansible-galaxy cli (using the -p option), it will also install a collection inside the ansible_collections directory by creating one in the given path, like below:

root@root ~/temp ll
total 0

root@root ~/temp ansible-galaxy collection install arista.eos -p .
Process install dependency map
Starting collection install process
Installing 'arista.eos:1.2.0' to '/root/temp/ansible_collections/arista/eos'
Installing 'ansible.netcommon:1.4.1' to '/root/temp/ansible_collections/ansible/netcommon'

root@root ~/temp ll
total 4.0K
drwxrwxr-x. 4 root root 4.0K Jan 18 19:21 ansible_collections

Make sure you keep the above directory norm when you develop your collections and test them with ansible-test too, in your local development environment.

How to test your collection using ansible-test?

ansible-test provides ways to run different types of tests on your Collections, broadly these tests are of types listed below:

  • Sanity Tests
  • Unit Tests
  • Integration Tests

We will go through each of these tests in detail.

Sanity Tests

Sanity tests are made up of scripts and tools used to perform static code analysis. The primary purpose of these tests is to enforce Ansible coding standards and requirements. ansible-test includes a variety of sanity tests to perform the code analysis, which can be found in the documentation.

How to run?

You can run the sanity test suite from the root directory of your collection; below are different scenarios on how you can run the sanity tests.

# Run all sanity tests
ansible-test sanity

# Run all sanity tests against against certain files
ansible-test sanity plugins/modules/files/eos_acls.py

# Run all tests with a specific version of python (3.7 in this case)
ansible-test sanity --python 3.7

# Run all tests inside docker (good if you don't have dependencies installed)
ansible-test sanity --docker default

# Run validate-modules against a specific file
ansible-test sanity --test validate-modules lib/ansible/modules/files/template.py

To list all the sanity tests available:

ansible-test sanity --list-tests

How to ignore sanity tests?

Since sanity tests change between Ansible releases, a separate ignore file is needed for each Ansible major release.

The filename is tests/sanity/ignore-X.Y.txt where X.Y is the ansible-core/ansible-base release being used to test the collection.

Maintaining a separate file for each Ansible release allows a collection to pass tests for multiple versions of Ansible.

For information on the format of the ignore files, please refer to the dev guide.

There are only a limited number of cases where ignores would be needed, so please refer to the collections documentation.

Unit Tests

Unit tests are small isolated tests that target a specific library or module. As a collection developer/maintainer, you want to make sure that your code is unit tested, and ansible-test provides a way to run and do reporting of unit tests inside your collection.

  1. The tests/units is where all things related to unit testing live
  2. ansible-test uses PyTest underneath the surface to do unit testing, hence it expects the tests to be located in files starting with `test_` or ending with `_test.py`

For more information on how to write unit tests, please refer to the guide.

To run all the unit tests inside a collection, run the below command from collection root:

# Run all tests inside docker (good if you don't have dependencies installed)
ansible-test units --docker -v

Against a single module file by doing:

# Only runs if the module directory path and unit test file path are similar
ansible-test units --docker -v apt

Or against a specific python version by doing:

ansible-test units --docker -v --python 2.7 apt

If you are running unit tests against things other than modules, such as module utilities, specify the whole file path:

ansible-test units --docker -v test/units/module_utils/basic/test_imports.py

For advanced usage, see the help:

ansible-test units --help

Code Coverage

Code coverage reports make it easy to identify untested code for which more tests should be written.

Add the --coverage option to any test command to collect code coverage data. If you aren’t using the --venv or --docker options that create an isolated python environment, then you may have to use the --requirements option to ensure that the correct version of the coverage module is installed:

ansible-test coverage erase
ansible-test units --coverage apt
ansible-test coverage html

Reports can be generated in several different formats:

  • ansible-test coverage report - Console report.
  • ansible-test coverage html - HTML report.
  • ansible-test coverage xml - XML report.

To clear data between test runs, use the ansible-test coverage erase command. For a full list of features, see the online help:

ansible-test coverage --help

Integration Tests

These are end to end tests to check code path functions as expected and to catch breaking changes in the product that you are trying to automate. In the context of ansible-test essentially:

  1. The tests/integration is where all things related to integration tests live.
  2. The tests/integration/targets directory contains all our test cases. Each test case is a barebones Ansible Role.

For more detailed information and a working example on how to write an integration test, please check out the blog Adding integration tests to Ansible Content Collections.

Conclusion & Next Steps

As shown above, ansible-test can provide a lot of value testing Ansible Content Collections thoroughly.

For further reading and information, visit the Ansible Testing Strategies documentation. If you are unfamiliar with Ansible Collections, check out our YouTube playlist for everything about Ansible Collections. The videos will get you up to speed quickly.

Also, don’t forget to check out our Automate infrastructure workflows e-book if you want to learn more about building a unified, automated pipeline for infrastructure operations.

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Topics:
Continuous Integration, Ansible, Collections, testing


 

Anshul Behl

Anshul is a Senior Software Engineer at Red Hat who is responsible for helping the ansible partners take the journey of creating an Ansible Integration for their product and certifying that integration with Ansible.


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