Question

You are authoring a reusable module named 'web-server' that provisions EC2 instances. The module needs the calling configuration to supply an instance size, but you do not want to hard-code any default so that consumers are forced to make an explicit choice. Inside the module, how should you declare this input so that Terraform requires the caller to pass a value?

Accepted Answer

Define a `variable "instance_size" {}` block in the module with no `default` argument, then reference it as `var.instance_size`.

Answer

Define an `output "instance_size" {}` block in the module and reference it as `var.instance_size`.

Answer

Define a `variable "instance_size" { default = "" }` block so callers can override the empty default.

Answer

Add `instance_size` to the `required_providers` block so Terraform prompts the caller during init.