Overview: terraform-makefile

This is my terraform workflow for every terraform project that I use personally/professionaly. If you've never heard of Terraform, may I suggest checking out my Ansible role to download, verify, and install Terraform for you!

Usage

• Keeps state in S3 and utilizes DynamoDB for locking.

Note - this could be out of date.

View a description of Makefile targets with help via the self-documenting makefile.

$ make
apply                          Have terraform do the things. This will cost money.
destroy-backend                Destroy S3 bucket and DynamoDB table
destroy                        Destroy the things
destroy-target                 Destroy a specific resource. Caution though, this destroys chained resources.
plan-destroy                   Creates a destruction plan.
plan                           Show what terraform thinks it will do
plan-target                    Shows what a plan looks like for applying a specific resource
prep                           Prepare a new workspace (environment) if needed, configure the tfstate backend, update any modules, and switch to the workspace

• Before each target, several private Makefile functions run to configure the remote state backend, validate,set-env, and init. You should never have to run these yourself.

Show a plan from the remote state

$ ENV=qa make plan
Removing existing ENV.tfvars from local directory

Pulling fresh qa.tfvars from s3://qa-useast1-terraform-state/bastion/
download: s3://qa-useast1-terraform-state/bastion/qa.tfvars to ./qa.tfvars
Initialized blank state with remote state enabled!
Remote state configured and pulled.
Local and remote state in sync
Refreshing Terraform state in-memory prior to plan...
The refreshed state will be used to calculate this plan, but
will not be persisted to local or remote state storage.

-/+ module.bastion.aws_instance.bastion
ami:                               "ami-61ce6c77" => "ami-35ab0823" (forces new resource)
associate_public_ip_address:       "true" => "<computed>"
availability_zone:                 "us-east-1a" => "<computed>"
ebs_block_device.#:                "0" => "<computed>"
ephemeral_block_device.#:          "0" => "<computed>"
iam_instance_profile:              "qa-bastion-instance-profile" => "qa-bastion-instance-profile"
instance_state:                    "running" => "<computed>"
instance_type:                     "t2.micro" => "t2.micro"
ipv6_addresses.#:                  "0" => "<computed>"
key_name:                          "qa_useast1_ec2key_bastion" => "qa_useast1_ec2key_bastion"
network_interface_id:              "eni-d00c2017" => "<computed>"
placement_group:                   "" => "<computed>"
private_dns:                       "ip-10-10-10-24.ec2.internal" => "<computed>"
private_ip:                        "10.10.10.24" => "<computed>"
public_dns:                        "ec2-52.52.52.52.compute-1.amazonaws.com" => "<computed>"
public_ip:                         "52.52.52.52" => "<computed>"
root_block_device.#:               "1" => "<computed>"
security_groups.#:                 "0" => "<computed>"
source_dest_check:                 "true" => "true"
subnet_id:                         "subnet-184a8440" => "subnet-184a8440"
tags.%:                            "6" => "6"
tags.ENV:                          "qa" => "qa"
tags.Name:                         "qa_useast1_bastion" => "qa_useast1_bastion"
tags.ROLES:                        "bastion" => "bastion"
tags.TERRAFORM:                    "true" => "true"
tags.TYPE:                         "bastion" => "bastion"
tenancy:                           "default" => "<computed>"
user_data:                         "1d902c0382fe19b53225a527fdc7bc95cfed875T" => "1d902c0382fe19b53225a527fdc7bc95cfed875T"
vpc_security_group_ids.#:          "1" => "1"
vpc_security_group_ids.1449472535: "sg-305ea24b" => "sg-305ea24b"

~ module.bastion.aws_route53_record.bastion-priv
records.#: "" => "<computed>"

~ module.bastion.aws_route53_record.bastion-pub
records.#: "" => "<computed>"

Plan: 1 to add, 2 to change, 1 to destroy.

Show root level output

ENV=qa make output
# Alternatively once you've run the make output, you can just run
terraform output

Output a module

MODULE=network ENV=qa make output

Output a nested module

MODULE=network.nat ENV=qa make output

Plan a specific module

ENV=prod make plan-target

Plan it all

ENV=prod make plan

Example Terraform project layout

Tree output of a Terraform module I create

$ tree -F -l
terraform-bastion
├── variables/
│   ├── prod-us-east-2.tfvars
│   └── qa-us-east-1.tfvars
├── main.tf
├── Makefile
├── .gitignore
├── .git/
├── modules/
│   └── bastion/
│       ├── bastion.tf
│       └── init.sh
├── README.md
└── LICENSE

        5 directories, 10 files

Example main.tf inside the tree

variable "region" {}

variable "env" {
  default = "qa"
}
variable "key_path" {}
variable "key_name" {}
variable "ec2_bastion_instance_type" {}
variable "ec2_bastion_user" {}
variable "accountid" {}
variable "profile" {}

terraform {
  required_version = ">= 0.11.10"
}

provider "aws" {
  region              = "${var.region}"
  profile             = "${var.env}"
  allowed_account_ids = ["${var.accountid}"]
}

data "terraform_remote_state" "vpc" {
  backend = "s3"

  // This must map to the workspace from the Makefile
  workspace = "${var.env}-${var.region}"

  // This must map to the bucket and key from the Makefile
  config {
    region         = "${var.region}"
    acl            = "private"
    profile        = "${var.profile}"
    bucket         = "${var.env}-${var.region}-yourCompany-terraform"
    key            = "${var.env}/vpc/terraform.tfstate"
    dynamodb_table = "${var.env}-${var.region}-yourCompany-terraform"
  }
}

module "bastion" {
  source           = "modules/bastion"
  env              = "${var.env}"
  region           = "${var.region}"
  instance_type    = "${var.ec2_bastion_instance_type}"
  bastion_key_name = "${var.key_name}"
  bastion_key_path = "${var.key_path}"
  vpc_id           = "${data.terraform_remote_state.vpc.vpc_id}"
  vpc_cidr         = "${data.terraform_remote_state.vpc.vpc_cidr}"
  subnet_ids       = "${data.terraform_remote_state.vpc.public_subnet_ids}"
  shell_username   = "${var.ec2_bastion_user}"
}

output "environment" {
  value = "${var.env}"
}

output "bastion_public_ip" {
  value = "${module.bastion.public_ip}"
}

output "bastion_private_ip" {
  value = "${module.bastion.private_ip}"
}

output "bastion_user" {
  value = "${var.ec2_bastion_user}"
}

Considerations

• Each time this makefile is used, the remote state will be pulled from the backend onto your machine. This can result in slightly longer iteration times.
• The makefile uses .ONESHELL which is a feature of gmake. OSX users may need to brew install gmake.
• To use ENV=qa make graph, you will need to install dot via your systems package manager.
• You should configure remote state encryption for S3 via KMS via encrypt and kms_key_id. This is a TODO and should be automated by the Makefile.

Author Info and License

(C) Philip Porada