Tohuwabohu excorcism

Installation https://askubuntu.com/questions/983351/how-to-install-terraform-in-ubuntu

Introduction: https://www.terraform.io/intro/getting-started/build.html

Skeleton project https://github.com/skipidar/terraform-skeleton

Apply terraform bash script

#!/bin/bash
set -eo pipefail

if [[ ! -d ".terraform" ]]
then
  terraform init
fi

terraform validate
terraform plan

#terraform apply

terraform {
  required_providers {
    aws = {
      source  = "hashicorp/aws"
      version = "~> 3.0"
    }
  }
}

provider "aws" {
  profile = "default"
  region  = format("%s", var.aws_region)
}

Create “variables.tf”

variable "aws_region" {
  description = "The AWS region to deploy the resources into"
  type = string
  default = "eu-central-1"
}

variable "aws_account_id" {
  description = "The AWS account identifier of the project"
  type = string
  default = "453267903880"
}

variable "prefix" {
  description = "The resource prefix"
  type = string
  default = "alf-dev-con1"
}


locals {
  iot_policy = "${var.prefix}-thing2"
}

locals defines inner variables. Only here one can combine other variables

Use the variable

provider "aws" {
  profile = "default"
  region  = var.region
}

data "template_file" "tf_iot_policy" {
  vars = {
    aws_region = "${var.aws_region}"
    aws_account_id = "${var.aws_account_id}"
  }
  template = <<EOF
{
  "Version": "2012-10-17",
  "Statement": [
    {
      "Effect": "Allow",
      "Action": [
        "iot:Connect",
        "iot:Publish",
        "iot:Receive",
        "iot:Subscribe"
      ],
      "Resource": "arn:aws:iot:$${aws_region}:$${aws_account_id}:*"
    }
  ]
}
EOF
}

Usage

resource "aws_iot_policy" "iot_policy" {
  name   = "${local.iot_policy}"
  policy = "${data.template_file.tf_iot_policy.rendered}"
}