Ansible with Molecule Testing — Complete Automation Guide

Introduction

Test Ansible roles with Molecule using Docker, Podman, and Vagrant drivers. This guide covers installation, configuration, and production-ready playbook patterns.

Prerequisites

# Install required collection
ansible-galaxy collection install community.general
ansible --version

Quick Start

---
- name: Ansible with Molecule Testing
  hosts: all
  become: true
  vars:
    target_env: production

  tasks:
    - name: Ensure dependencies installed
      ansible.builtin.package:
        name: "{{ item }}"
        state: present
      loop:
        - python3
        - python3-pip

    - name: Configure service
      ansible.builtin.template:
        src: config.j2
        dest: /etc/service/config.yml
        mode: '0644'
      notify: Restart service

  handlers:
    - name: Restart service
      ansible.builtin.service:
        name: myservice
        state: restarted

Installation Playbook

- name: Install and configure
  ansible.builtin.package:
    name: "{{ item }}"
    state: present
  loop:
    - package1
    - package2

Configuration Management

- name: Deploy configuration
  ansible.builtin.template:
    src: "{{ item.src }}"
    dest: "{{ item.dest }}"
    owner: root
    mode: '0644'
  loop:
    - src: main.conf.j2
      dest: /etc/service/main.conf
    - src: auth.conf.j2
      dest: /etc/service/auth.conf
  notify: Restart service

Monitoring and Health Checks

- name: Verify service health
  ansible.builtin.uri:
    url: "http://{{ ansible_host }}:8080/health"
    status_code: 200
  register: health
  until: health.status == 200
  retries: 10
  delay: 5

Backup and Recovery

- name: Create backup
  ansible.builtin.command:
    cmd: "backup-tool --output /backups/{{ ansible_date_time.date }}.tar.gz"
  register: backup_result

- name: Fetch backup to controller
  ansible.builtin.fetch:
    src: "/backups/{{ ansible_date_time.date }}.tar.gz"
    dest: "./backups/{{ inventory_hostname }}/"
    flat: true

Troubleshooting

Issue	Cause	Fix
Connection refused	Service not running	Check service status and logs
Authentication failed	Wrong credentials	Verify vault-encrypted vars
Timeout	Resource unavailable	Increase timeout, check network
Idempotency issue	State mismatch	Add proper state checks

Best Practices

Use Vault for credentials — never hardcode passwords
Template configs — use Jinja2 for environment-specific values
Health checks — verify service after changes
Backup before changes — always create restore point
Test with Molecule — validate in isolated environment

Conclusion

Test Ansible roles with Molecule using Docker, Podman, and Vagrant drivers. Follow the patterns above for production-ready automation with proper error handling, health verification, and backup strategies.