Terraform modules

A terraform module is a collection of *.tf files within a specific directory.
A root module is defined at the root of your project.

Input Variables

Input variables expose optional configuration to the commandline interface.
They are defined in the root module, within variable blocks.

variable "image_id" {
  type = string
}

variable "availability_zone_names" {
  type    = list(string)
  default = ["us-west-1a"]
}

Modify variables on CLI

terraform apply -var="image_id=foobar"