Test Kitchen Parent Child

Test Kitchen Parent-Child is a thin wrapper around Test Kitchen that adds support for inheritance in the .kitchen.yml configuration files for multi-role projects.

What is this for?

While Test Kitchen is a phenomenal tool for testing a suite of infrastructure code, it doesn't lend itself quite as well to testing many related suites that are contained in the same project.

I'm coming at this from the Ansible world where I've got a single project that houses all of my "roles" (machine profiles), and Test Kitchen is great for testing each individual role. The main pain point comes when these roles all use the same set of test configurations, and it would be great to share configs instead of duplicating them across dozens of roles.

Here's a sample directory structure of the type of project that this extension was written to help test:

ansible-project/
├── roles/
│   ├── ssh-role/
│   |   ├── .kitchen.yml
│   |   └── ...
│   ├── java-service-role/
│   |   ├── .kitchen.yml
│   |   └── ...
│   └── nginx-webserver-role/
│       ├── .kitchen.yml
│       └── ...
└── site.yml

This project aims at reducing the duplication between the .kitchen.yml files and improving the maintainability of more complex infrastructure projects.

Getting Started

Being only a simple extension to Test Kitchen, you should start with the guides there. See the Test Kitchen README to get started and to get your tests running without this extension.

Usage

This can be run in all the same ways as Test Kitchen, just using the command kitchen-pc instead of kitchen.

If you're using RubyGem to manage your gems:

# Install the gem by name
gem install test-kitchen-pc

# Run kitchen-pc the same way you run kitchen
kitchen-pc converge default-centos-6

Optionally, you can use Bundler to manage the gem by adding gem "test-kitchen-pc" to your Gemfile, then:

# Install the deps from the Gemspec
bundle install

# Run kitchen-pc the same way you run kitchen
bundle exec kitchen-pc converge default-centos-6

Configuration

To support inheritance, this extensions adds support for the top-level parent paremeter in any of the .kitchen.yml files that Test Kitchen is configured to read normally.

Let's say you have a project .kitchen.yml that defines a set of pretty generic settings for testing:

.kitchen.parent.yml

---
driver:
  name: docker

provisioner:
  name: ansible_playbook
  ansible_inventory: test/integration/inventory/hosts
  roles_path: ../

platforms:
  - name: centos-6
  - name: centos-7

suites:
  - name: default

The majority of this configuration will be the same across all of the infrastructure modules that you're testing. Using this extension, you can export all common configuration to a shared file, and then source the shared configuration using the parent parameter, then inline any customizations you may need to make.

For example, say we wanted to export the above as common configuration, but then have a role that needs to define some host aliases in the Docker driver:

roles/sample-role/.kitchen.yml

---
parent: ../../.kitchen.parent.yml

driver:
  name: docker
  run_options:
    add-host:
      - "sample-host:127.0.0.1"

This will result in the roles/sample-role/.kitchen.yml config being merged into the .kitchen.parent.yml file, with the former overriding and properties that are specified in both.

Development

If you'd like to contribute, feel free to open a PR. To run the tests prior to submitting the PR, just clone the project and run the integration tests:

# Install deps
bundle install

# Run integration tests
bundle exec kitchen-pc test