# Hands-on Infrastructure as Code: AWS Deployment with Terraform

I've been building a [DevOps automation project on my GitHub page](https://github.com/bernie-cm/devops-automation) to showcase how Terraform, Ansible and Docker can be used together to quickly deploy, and automate the configuration of assets using Infrastructure as Code (IaC).

### Set up local environment variables

For this project, I'm building on AWS. In order to use Terraform, I need to set up environment variables to store my **AWS Access Key ID**and then my **AWS Secret Access Key**. It's super important not to share these, or store them in a script that later gets pushed to GitHub.

```dockerfile
$ export AWS_ACCESS_KEY_ID=<your_aws_key>
$ export AWS_SECRET_ACCESS_KEY=<your_secret_key>
```

### Main configuration file

Once the local variables are set, two files will be required to create an EC2 instance on AWS through IaC. First, the [`main.tf`](http://main.tf) file.

```dockerfile
terraform {
  required_providers {
    aws = {
      source  = "hashicorp/aws"
      version = "~> 4.16"
    }
  }

  required_version = ">= 1.2.0"
}

provider "aws" {
  region = var.aws_region
}

resource "aws_instance" "app_server" {
  ami           = var.ami_id
  instance_type = var.instance_type

  tags = {
    Name = "DevOpsDemoInstance"
  }
}
```

Next, it's time to define a [`variables.tf`](http://variables.tf) file that will store the variables used by [`main.tf`](http://main.tf) during execution. For simple deployments, like this one, it would be enough to declare the variables in the [`main.tf`](http://main.tf) file. However, for more complex projects, or when better organisation is needed, or the configuration will be reused, it's best practice to use a [`variables.tf`](http://variables.tf) file. For that reason, that's the approach used here since this is a learning exercise.

### Variables file

```dockerfile
variable "aws_region" {
  description = "AWS region"
  type        = string
  default     = "ap-southeast-2"
}

variable "instance_type" {
  description = "EC2 instance type"
  type        = string
  default     = "t2.micro"
}

variable "ami_id" {
  description = "The AMI ID for the EC2 instance"
  type        = string
  default     = "ami-0b0a3a2350a9877be"
}
```

Finally, the next thing is to initialise the directory using `terraform init`, and then create the infrastructure using `terraform apply`and reviewing what will be built. Once satisfied, select `yes` and your AWS infrastructure will be provisioned. Once the proof-of-concept is finished, remember to use `terraform destroy` to tear down your infrastructure.