05 · Configuration managementLab 30 / 59
Challengeansible
Ansible Roles, Variables & Idempotency — Challenge
Write a role that configures a server, then prove the second run changes nothing.
- Time
- 25 min
- Level
- Intermediate
- Objectives
- 4 objectives
- Cost
- Free
Where this fits in the platform
This lab adds
- Roles whose second run reports no changes at all
Which lets you
Before you start
You will need
- Ansible 2.15+
- A target host or container
You do not need these already — the lab environment below provides them.
You will be able to
- Structure a role so callers can override what they should
- Write tasks that report changed only when something changed
- Use handlers so a restart happens once, not per task
Cost — Free
— target a local container or VM.
The goal#
Achieve the same outcome as Ansible Roles, Variables & Idempotency, from an empty starting point, without the steps.
The playbook works. Running it twice restarts production, because every task reports changed whether or not anything changed.
Idempotency is the property that makes configuration management safe to run continuously, and it does not happen by accident.
Hands-on environment
Run this lab in a real terminal, free and in your browser. The environment is temporary and yours alone — break it as much as you like.
Start the challengeOpens in Killercoda, in a new tab — keep this page open for the steps.
This is the guided lab's environment — the same machine, with its walkthrough on the left. Work from the task above and leave those steps alone until you are done, or you are reading the answers.
Run it on your own machine
Run this lab on your own machine. One command starts the environment, with everything the lab needs already installed:
You will need:
- ansible
git clone https://github.com/EgyKode/EgyKode-lab.git
cd EgyKode-lab
./egykode start
./egykode shellYou need Docker and Git installed. Everything else runs inside the environment. The first start downloads it and takes a few minutes; later starts are seconds.
Not sure what you already have? Run: npm run doctor — it checks and changes nothing.
Anything you tick here is your own record. EgyKode cannot see inside that terminal, so the success criteria stay self-assessed even when the environment checks your work for you.
What must be true when you are done
Step 1 of 3
What must be true when you are done#
- A role installs and configures a service from variables, with no hardcoded values in tasks.
- The second run reports
changed=0— demonstrated, not assumed. - A configuration change triggers exactly one restart, via a handler.
- You can name two ways a task silently breaks idempotency.
Rules#
- Do not open the guided lab until you are finished, or until the same problem has held you up for 20 minutes.
- Documentation is allowed and encouraged.
- Verify every criterion with a command whose output you can read.
If you get stuck#
- What did you expect, exactly?
- What happened instead — the error text, not a paraphrase?
- Which layer is that error from?
- What is the smallest command that proves the layer below is fine?
You are done when
0 of 4
The concept behind it
Next up
Lab 30 of 59 on the project path