Question

Your team wants to prevent an incorrectly formatted value from being supplied for an input variable named `instance_type`. You need Terraform to reject any value that does not start with the letter 't' and produce a clear error message during the plan phase, without relying on the provider to fail later. Which addition to the variable block accomplishes this?

Accepted Answer

Add a `validation` block inside the `variable` block with a `condition` that evaluates the value and a `error_message` string

Answer

Add a `precondition` block referencing `var.instance_type` inside the resource that uses it

Answer

Add a `depends_on` argument to the variable block pointing to the resource

Answer

Set the variable's `type` to `string` so Terraform enforces the 't' prefix automatically