Question

A cloud engineer manages infrastructure using separate IaC stacks: a networking stack that provisions a VPC and subnets, and an application stack that deploys compute instances into those subnets. The subnet IDs are generated dynamically at deployment time and change whenever the networking stack is recreated. The application stack must always reference the current subnet IDs without manual editing. What is the BEST way to pass the subnet IDs from the networking stack to the application stack?

Accepted Answer

Export the subnet IDs as stack outputs and import them into the application stack using cross-stack references

Answer

Hardcode the subnet IDs into the application stack template after the first deployment

Answer

Merge both stacks into a single monolithic template so no values need to be shared

Answer

Manually copy the subnet IDs into a spreadsheet and update the application template before each deployment