Create a simple test server for spike using Terraform - MIND - can have slashes in gist file names - so have used - instead.

main.tf

provider "aws" {
  region  = "${var.region}"
  version = "~> 1.9"
}

provider "template" {
  version = "~> 1.0"
}

resource "aws_default_vpc" "default" {
    tags {
        Name = "Default VPC"
    }
}

module "security_groups" {
  vpc-id = "${aws_default_vpc.default.id}"
	my_ip_address = "${var.current_ip}"
	secgrp_des = "${var.secgrp_des}"
  source = "modules/security_groups"
}

module "ubuntu-spike" {
  # source = "${var.var}"
  source = "modules/instance"
  vpc_subnet         	= "${aws_default_vpc}"
  poc-vpc-id         	= "${aws_default_vpc.default.id}"
# Pass variables down from the security group module to the instance
	vpc-sec-grp-id     	= "${module.security_groups.spike_security_group_id}"
	# Specify the version of Ubuntu to use
  distro             	= "bionic"
	version							= "18.04"
	eip_allocation			= "${var.eip_allocation}"
	public_key					= "${var.public_key}"
}

output "pub_ip_address" {
  value = "${module.ubuntu-spike.public_ip}"
}
output "security_group_id" {
  value = "${module.security_groups.spike_security_group_id}"
}
output "pub_dns" {
  value = "${module.ubuntu-spike.public_dns}"
}
output "vpc_id" {
  value = "${aws_default_vpc.default.id}"
}
output "subnet_id" {
	value = "${module.ubuntu-spike.instance_default_vpc_subnet}"
}

modules-instance-data.tf

data "aws_ami" "ubuntu" {
  most_recent = true

  filter {     name = "name"
	values = ["ubuntu/images/hvm-ssd/ubuntu-${var.distro}-18.04-amd64-server-*"]
	}

  filter {
    name   = "virtualization-type"
    values = ["hvm"]
  }

  owners = ["099720109477"] # Canonical
}

modules-instance-main.tf

# Create a new instance of the latest Ubuntu AMI
# t2.micro node

# Associate an existing IP address if required

resource "aws_eip_association" "staticip" {
  allocation_id = "${var.eip_allocation}"
  instance_id 	= "${aws_instance.spike.id}"
}

resource "aws_default_subnet" "default_az1" {
  availability_zone = "eu-west-2c"

    tags {
        Name = "Default subnet"
    }
}
resource "aws_instance" "spike" {
  ami           					= "${data.aws_ami.ubuntu.id}"
  user_data     					= "${data.template_file.userdata.rendered}"
  instance_type 					= "t2.micro"
  key_name      					= "${var.public_key}"
  vpc_security_group_ids 	= ["${var.vpc-sec-grp-id}"]
  subnet_id 							= "${aws_default_subnet.default_az1.id}"

  root_block_device {
    volume_size           = "10"
    delete_on_termination = "true"
  }

  tags {
		Name = "spike-instance"
  }
}

modules-instance-outputs.tf

output "public_ip" {
  value = "${aws_eip_association.staticip.public_ip}"
}

# Using splat here to allow for multiple servers if needed
output "public_dns" {
  value = "${aws_instance.spike.*.public_dns}"
}

output "instance_default_vpc_subnet" {
	value = "${aws_default_subnet.default_az1.id}"
}

modules-instance-variables.tf

variable "eip_allocation" {
	default = ""
}
variable "public_key" {
	type 		= "string"
}
variable "vpc_subnet" {
  type 		= "string"
	default = ""
}
variable "distro" {}

variable "poc-vpc-id" {
  type = "string"
}
variable "vpc-sec-grp-id" {
  type = "string"
}

variable "vpc-sec-id" {
  default = ""
}

# sets up a template to be used by the resources to be used by cloudinit
data "template_file" "userdata" {
  template = "${file("templates/userdata.tpl")}"

  vars {
    amiused = "${data.aws_ami.ubuntu.id}"
  }
}

modules-security_groups-main.tf

resource "aws_security_group" "spike" {
  vpc_id = "${var.vpc-id}"

  name = "spike-sg"
	tags {
	Name = "spike-sg"
	}
}
resource "aws_security_group_rule" "allow-tcp-22" {
		security_group_id = "${aws_security_group.spike.id}"
  	type				= "ingress"
    protocol    = "tcp"
    from_port   = 22
    to_port     = 22
    cidr_blocks = ["${var.my_ip_address}/32"]
		description = "${var.secgrp_des}"
  }
resource "aws_security_group_rule" "allow-all-outbound" {
		security_group_id = "${aws_security_group.spike.id}"
  	type				= "egress"
    protocol    = "-1"
    from_port   = 0
    to_port     = 0
    cidr_blocks = ["0.0.0.0/0"]
  }

modules-security_groups-outputs.tf

output "spike_security_group_id" {
  value = "${aws_security_group.spike.id}"
}

modules-security_groups-variables.tf

variable "vpc-id" {
  type = "string"
}
variable "my_ip_address" {
	description = "Enter you current IP address"
}
variable "secgrp_des" {}

private_vars.tf

#This is where you put the private variables specific to your environment.
variable "eip_allocation" {
	default = "eipalloc-<number>"
}
variable "public_key" {
	default = "<key-name>"
}
variable "current_ip" {
	default = "<your-current-local-ip-address>"
}

templates-userdata.tpl

#cloud-config
# Turned off package upgrade to speed up build process
package_upgrade: true
hostname: spiketest
manage_etc_hosts: true
packages:
 - facter
 - python-minimal
runcmd:
- echo "Ami used for this instance build - ${amiused}" > /home/ubuntu/current-ami-used.txt

vars.tf

variable "secgrp_des" {
  description = "Description for this security group"
  default     = "spiketest"
}
variable "region" {
  default = "eu-west-2"
}

variable "distro" {
  description = "Variable to specify which distro to spin up"
  default     = ""
}
variable "version" {
	description = "VAriable to set the distro version"
	default			= ""
}