Question

A CloudOps engineer is deploying a fleet of EC2 web servers using an AWS CloudFormation template. The requirement is that after each instance launches, it must install packages, write configuration files, and start services in a defined order, and the CloudFormation stack must not report CREATE_COMPLETE until the instances have finished their configuration and signaled success. Which approach best meets these requirements?

Accepted Answer

Use AWS::CloudFormation::Init metadata with cfn-init in UserData, and pair a CreationPolicy on the instance with cfn-signal to report bootstrap completion.

Answer

Place all installation commands in the instance UserData script and rely on the default stack timeout to determine when configuration completes.

Answer

Use a DependsOn attribute between the EC2 instances and a wait resource so CloudFormation pauses until packages are installed.

Answer

Configure an SSM State Manager association to bootstrap the instances after the stack reaches CREATE_COMPLETE.