Question

You are writing a Terraform configuration and want to declare an input that lets operators optionally override the instance size, but defaults to "t3.micro" when no value is supplied. You add the following to variables.tf:

variable "instance_type" {
  type    = string
  default = "t3.micro"
}

During 'terraform plan', no value is passed for this variable on the command line, in a .tfvars file, or via an environment variable. What happens?

Accepted Answer

Terraform uses "t3.micro" as the value because the default is applied when no explicit value is provided.

Answer

Terraform interactively prompts the operator to enter a value before continuing the plan.

Answer

Terraform fails with an error because a required variable was not assigned a value.

Answer

Terraform sets the variable to null and the plan proceeds with an empty instance_type.