Question

A CloudOps engineer manages infrastructure using multiple CloudFormation stacks. A networking stack creates a VPC and subnets, and several application stacks need to reference the subnet IDs from the networking stack. The engineer wants a solution where application stacks can consume these values by name, and CloudFormation prevents the networking stack from being deleted or its exported values from being changed while they are still in use. Which approach meets these requirements?

Accepted Answer

Use the Outputs section of the networking stack with the Export field, and reference the values in application stacks using the Fn::ImportValue intrinsic function.

Answer

Store the subnet IDs in the Mappings section of each application stack and update them manually whenever the networking stack changes.

Answer

Pass the subnet IDs as CloudFormation parameters to each application stack manually at deployment time.

Answer

Use nested stacks so the networking resources are created as part of each application stack's template.