Use Terraform to automagically create instances on different providers.

modules.tf

This contains the modules that will be used.

variables.tf

Where the variables are defined.

providers.tf

The providers that will be used.

terraform.tfvars

Where you actually define the variables. This file is ignored by .gitignore.

1. Read the documentation provided by Terraform from the link above.
2. If you clone the instance you'll need to do the following in order to get the modules sync'd.

terraform get

Within a module you declare a variables.tf file. The root variables that are defined in terraform.tfvars must be passed into the module. Look at an example below.

modules.tf

module "example" {
  source = "./example"
  subnet_id = "${var.example_subnet_id}"
}

/variables.tf

variable "example_subnet_id" {}

/terraform.tfvars

example_subnet_id = "subnet-1234"

/example/variables.tf

variable "subnet_id" {}

/example/main.tf

resource "aws_instance" "sample" {
  subnet_id = "${var.subnet_id}"
}