main.tf

variable "access_key" {}
variable "secret_key" {}
variable "region" {}
variable ami {}
variable subnet_id {}
variable instance_type {
  default = "t2.micro"
  }
variable vpc_security_group_id {}
variable identity {}

provider "aws" {
  access_key = "${var.access_key}"
  secret_key = "${var.secret_key}"
  region     = "${var.region}"
}

module "server" {
  source = "./server"

  ami                   = "${var.ami}"
  subnet_id             = "${var.subnet_id}"
  vpc_security_group_id = "${var.vpc_security_group_id}"
  identity              = "${var.identity}"
  instance_type         = "${var.instance_type}"
}

output "public_ip" {
  value = "${module.server.public_ip}"
}

server_main.tf

variable ami {}
variable subnet_id {}
variable instance_type {}
variable vpc_security_group_id {}
variable identity {}

resource "aws_instance" "web" {
  ami                    = "${var.ami}"
  instance_type          = "${var.instance_type}"
  subnet_id              = "${var.subnet_id}"
  vpc_security_group_ids = ["${var.vpc_security_group_id}"]

  tags {
    Identity = "${var.identity}"
  }
}   
  
output "public_ip" {
  value = "${aws_instance.web.public_ip}"
}
  
output "public_dns" {
  value = "${aws_instance.web.public_dns}"
}