terraform.tf

# main.tf

# Variables
variable "profile" {
  description = "The AWS CLI profile to use (default: default)"
  default     = "default"
}

variable "region" {
  description = "The region to deploy resources"
  default     = "us-east-1"
}

variable "az" {
  description = "The AZ you want the instance deployed into (0, 1, 2, etc)"
  default     = "a"
}

locals {
  azs = {
    a = 0
    b = 1
    c = 2
    d = 3
    e = 4
    f = 5
    g = 6
  }
}

variable "os" {
  description = "The OS to deploy"
  default     = "ubuntu"
}

variable "size" {
  description = "The ec2 instance size"
  default     = "t2.micro"
}

variable "keyfile" {
  description = "The local public key file"
  default     = "~/.ssh/id_rsa.pub"
}

variable "allowed_cidr" {
  description = "The cidr address allowed to access the instance"
  default     = "0.0.0.0/0"
}

# Maps
variable "ami_names" {
  type = map(string)

  default = {
    ubuntu = "ubuntu/images/hvm-ssd/ubuntu-bionic-18.04-amd64-server*"
    aws    = "amzn-ami-hvm-*-x86_64-gp2"
    aws2   = "amzn2-ami-hvm-2.0.*-x86_64-gp2"
  }
}

variable "custom_ami" {
  description = "A custom AMI to use"
  default     = "YOU MUST SPECIFY IF YOU WANT TO USE THIS"
}

variable "os_users" {
  type = map(string)

  default = {
    ubuntu = "ubuntu"
    aws    = "ec2-user"
    aws2   = "ec2-user"
  }
}

variable "custom_user" {
  description = "The username to use with your custom AMI"
  default     = "YOU MUST SPECIFY IF YOU WANT TO USE THIS"
}

# Providers
provider "aws" {
  profile = var.profile
  region  = var.region
}

# Data lookups
data "aws_ami" "ami" {
  most_recent = true

  # self for own account, conical for ubuntu, or amazon for aws linux
  owners = ["self", "099720109477", "amazon"]

  filter {
    name = "name"
    # TF-UPGRADE-TODO: In Terraform v0.10 and earlier, it was sometimes necessary to
    # force an interpolation expression to be interpreted as a list by wrapping it
    # in an extra set of list brackets. That form was supported for compatibilty in
    # v0.11, but is no longer supported in Terraform v0.12.
    #
    # If the expression in the following list itself returns a list, remove the
    # brackets to avoid interpretation as a list of lists. If the expression
    # returns a single list item then leave it as-is and remove this TODO comment.
    values = [lookup(var.ami_names, var.os, var.custom_ami)]
  }
}

data "aws_vpc" "default" {
  default = "true"
}

# All AZs Available in the current region
data "aws_availability_zones" "available" {
}

# Resources
resource "aws_instance" "instance" {
  ami               = data.aws_ami.ami.id
  instance_type     = var.size
  availability_zone = data.aws_availability_zones.available.names[local.azs[var.az]]
  security_groups   = [aws_security_group.sec_grp.name]
  key_name          = aws_key_pair.key.key_name
  tags = {
    Name = "temp_tf_instance"
  }
}

resource "aws_key_pair" "key" {
  key_name   = "ssh-key"
  public_key = file(var.keyfile)
}

resource "aws_security_group" "sec_grp" {
  name_prefix = "ssh-only-sg_"
  description = "ssh_only"
  vpc_id      = data.aws_vpc.default.id

  ingress {
    from_port   = 22
    to_port     = 22
    protocol    = "tcp"
    cidr_blocks = [var.allowed_cidr]
  }
}

# outputs
output "instance_id" {
  value = aws_instance.instance.id
}

output "ssh_command" {
  value = "ssh -i ${var.keyfile} ${lookup(var.os_users, var.os, var.custom_user)}@${aws_instance.instance.public_ip}"
}