When should you write Terraform configuration files for existing infrastructure that you want to start managing with Terraform?

• A. Before you run terraform import
• B. You can import infrastructure without corresponding Terraform code
• C. Terraform will generate the corresponding configuration files for you
• D. After you run terraform import

Answer: (A)

When bringing existing infrastructure under Terraform management, you should first write the Terraform configuration that defines the resources you intend to manage. The import operation needs a matching resource block in your configuration to map the real-world resource into Terraform’s state. Without that block already present, Terraform has nowhere to attach the imported data, and you’d end up with resources in state without corresponding code to drive them.

Terraform does not auto-generate configuration for you; it only populates the state for resources you’ve defined in code and then import. After you’ve defined the resource blocks, you run the import for each one to bring the actual infrastructure into state, then plan and apply to reconcile any differences.

So, the best order is to write the configuration first, then import the existing resources.