A team builds the same stack — a load balancer, three EC2 instances and a database — by clicking through the console once for dev, once for test and once for production. The three environments have quietly drifted apart and a bug that only appears in production took a week to trace to a missing setting. They want the stack described once, reviewed in a pull request, and applied identically to each environment. Which service does that?

AWS Certified Cloud Practitioner (CLF-C02), objective 3. Cloud technology and services medium

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The options

Correct AWS CloudFormation

Correct. A template declares the resources and their settings, and applying the same template produces the same stack every time, so the description lives in version control where it can be reviewed and diffed.

Not correct AWS Config

Wrong, and it is the tempting near-miss. Config records how resources are configured over time and evaluates rules against them, so it would have TOLD you the environments had drifted. It never creates the environments in the first place.

Not correct AWS Systems Manager Session Manager

Wrong. Session Manager gives you a shell on an existing instance without opening SSH or a bastion. It operates servers that already exist; it does not provision load balancers or databases.

Not correct The AWS Management Console, with a written runbook for each step

Wrong. A runbook is a description of clicks that a human still has to perform correctly three times. That is exactly the process that produced the drift, and nothing about it is reviewable the way code is.

Why

Infrastructure as code means the environment is a file, not a memory of what someone clicked. CloudFormation takes a template and creates a stack from it; the AWS CDK lets you write that template in a programming language and synthesises CloudFormation underneath. Keep the pair straight: CloudFormation builds the resources, AWS Config watches them and reports when they stop matching what you wanted.

Where this comes from

Cited
AWS exam guide task statement 3.1

Practise this

Reading one question is not practice. The trainer will draw a set from objective 3 and space the ones you get wrong.

Practise AWS Certified Cloud Practitioner (CLF-C02)

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