managing-configuration

Configuration Management

Purpose

This skill provides guidance for automating server and application configuration using Ansible and related tools. It covers playbook creation, role structure, inventory management (static and dynamic), secret management, testing patterns, and idempotency best practices to ensure safe, repeatable configuration deployments.

When to Use This Skill

Invoke this skill when:

• Creating Ansible playbooks to configure servers or deploy applications
• Structuring reusable Ansible roles with proper directory layout
• Managing inventories (static files or dynamic cloud-based)
• Securing secrets with ansible-vault or HashiCorp Vault integration
• Testing roles with Molecule before production deployment
• Ensuring idempotent playbooks that safely run multiple times
• Migrating from Chef or Puppet to Ansible
• Implementing GitOps workflows for configuration as code
• Debugging playbook failures or handler issues

Quick Start

Basic Playbook Example

---
# site.yml
- name: Configure web servers
  hosts: webservers
  become: yes

  tasks:
    - name: Ensure nginx is installed
      apt:
        name: nginx
        state: present
      notify: Restart nginx

    - name: Start nginx service
      service:
        name: nginx
        state: started
        enabled: yes

  handlers:
    - name: Restart nginx
      service:
        name: nginx
        state: restarted

Run with:

ansible-playbook -i inventory/production site.yml

Core Concepts

1. Idempotency

Run playbooks multiple times without unintended side effects. Use state-based modules (present, started, latest) instead of imperative commands.

Idempotent (good):

- name: Ensure package installed
  apt:
    name: nginx
    state: present

Not idempotent (avoid):

- name: Install package
  command: apt-get install -y nginx

See references/idempotency-guide.md for detailed patterns.

2. Inventory Management