DO007 – Ansible Basics: Automation Technical Overview — Lesson 2: Inventories, Ad Hoc Commands, Playbooks, Tasks, Modules, and Idempotence

Learning Objectives

• Explain the structures, services, data, settings, roles, and dependencies governing inventories and ad hoc commands.
• Implement and validate playbooks, modules, and idempotence using reviewable evidence.
• Evaluate the condition where a change succeeds in one environment but fails elsewhere because inventory, policy, version, or runtime assumptions differ and select a proportionate corrective response.

Detailed Topics

• inventories applied to the course scenario, expected platform behavior, dependencies, controls, and evidence.
• ad hoc commands applied to the course scenario, expected platform behavior, dependencies, controls, and evidence.
• playbooks applied to the course scenario, expected platform behavior, dependencies, controls, and evidence.
• modules applied to the course scenario, expected platform behavior, dependencies, controls, and evidence.
• idempotence applied to the course scenario, expected platform behavior, dependencies, controls, and evidence.

Instructor Demonstration

The instructor traces an IT leadership and engineering group evaluating Ansible for a standardized enterprise automation program. The walkthrough connects navigation, commands, configuration logic, system messages, and evidence captured in the Ansible adoption brief, prioritized use-case register, governance outline, and implementation roadmap. It also tests the exception where a change succeeds in one environment but fails elsewhere because inventory, policy, version, or runtime assumptions differ.

Hands-On Exercise

Complete a controlled Red Hat exercise covering Inventories, Ad Hoc Commands, Playbooks, Tasks, Modules, and Idempotence and preserve the verified result in the Ansible adoption brief, prioritized use-case register, governance outline, and implementation roadmap.

1. Confirm scope, prerequisites, versions, identities, dependencies, and acceptance criteria.
2. Execute the workflow while recording commands, settings, outputs, events, and system messages.
3. Test normal behavior, one boundary condition, and the stated exception.
4. Document corrections, evidence, ownership, retest criteria, rollback, and handover actions.

Scenario Analysis

• Identify which object, service, policy, setting, or sequence most strongly influences inventories.
• Compare two defensible responses and explain technical, security, operational, and support trade-offs.
• Determine how the Ansible adoption brief, prioritized use-case register, governance outline, and implementation roadmap should be approved, retained, retested, and updated.

Troubleshooting Guidance

Start where expected behavior first differs from the observed result. Check prerequisites, identity, configuration order, version compatibility, connectivity, status, resource limits, and evidence separately. Treat “a change succeeds in one environment but fails elsewhere because inventory, policy, version, or runtime assumptions differ” as a hypothesis until commands, logs, settings, and retest outcomes confirm the cause.

Validation Checklist

• Required platform components, identities, permissions, settings, and dependencies are present.
• The Ansible adoption brief, prioritized use-case register, governance outline, and implementation roadmap connects each conclusion to objective, reviewable evidence.
• Normal processing, a boundary condition, dependency behavior, and the stated exception were tested.
• Corrections, ownership, retest criteria, rollback, documentation, and operational handover are complete.

Lesson Outcome

Learners can apply Inventories, Ad Hoc Commands, Playbooks, Tasks, Modules, and Idempotence, explain the resulting platform behavior, and defend the outcome through the Ansible adoption brief, prioritized use-case register, governance outline, and implementation roadmap.