Ansible Molecule: Test Roles & Collections in Containers (Guide) — Video Tutorial

Complete guide to testing Ansible roles with Molecule. Set up Docker-based testing, write verify playbooks, configure scenarios, and integrate with CI/CD.

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Tutorial summary

What you'll learn

Introduction
Molecule in Ansible Collection
Example Role Structure
Configuring Molecule with molecule.yml
Customizing the Converge Action in converge.yml
The converge.yml File
Links
Conclusion
Install Molecule
Initialize Role with Molecule

Introduction When developing Ansible roles within a collection, it is crucial to ensure that your code functions as expected and integrates seamlessly with the broader infrastructure. Molecule, a testing framework for Ansible roles, allows developers to automate the testing process, making it easier to catch issues early in the development cycle. In this article, we will explore how to test an Ansible role within a collection using Molecule, with a focus on the converge action. Molecule in Ansible Collection Adding Molecule to your Ansible collection is a straightforward process that enhances your development and testing workflow. Start by creating a new directory within your collection named "`extensions`." Navigate to this newly created directory using the command line and then initialize a new default Molecule scenario with the following: ```bash cd <path to your collection>/extensions/ molecule init scenario ``` This step sets the foundation for incorporating Molecule into your collection, allowing you to seamlessly integrate testing and development practices. The newly created scenario within the "extensions" directory becomes a pivotal component in orchestrating Molecule's testing lifecycle for your Ansible roles and playbooks. Example Role Structure To illustrate the testing process, consider the structure of a sample role located at `myrole/tasks/main.yml`: ```bash --- - name: Task running inside the role ansible.builtin.debug: msg: "This is a task from my_role" ``` This simple task, when executed, prints a debug message to provide a basic Playbooknstration of the role's functionality. Configuring Molecule with molecule.yml The configuration file `molecule.yml` outlines the testing environment and Ansible provisioner settings. Below is an example configuration: ```bash --- platforms: - name: instance provisioner: name: ansible config_options: defaults: collections_path: ${ANSIBLE_COLLECTIONS_PATH} ``` In this configuration, we define a single platform named `instance` and configure the Ansible provisioner. The `collections_path` option ensures that Ansible can locate the necessary collections during testing. Customizing the Converge Action in converge.yml The `converge.yml` file controls the steps executed during the Molecule converge action. Customize this file based on your role's requirements. Below is an example that includes a role from the collection: ```yaml --- - name: Include role from the collection hosts: localhost gather_facts: false tasks: - name: Testing role ansible.builtin.include_role: name: foo.bar.my_role tasks_from: main.yml ``` This snippet Playbooknstrates how to include the `my_role` role from the `foo.bar` collection and execute the tasks defined in its `main.yml` file. Adjust the role and collection names to match your specific project. By combining these elements, you create a cohesive testing environment for your Ansible roles within a col

About this tutorial

Author: Luca Berton
Difficulty: Beginner
Read time: 6 min
Category: installation

Topics covered

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