OPTIONAL - Terraform Basics teaser: Terraform is a fantastic tool used to provision immutable infrastructure. It is widely used for its declarative nature in Infrastructure as Code (IaC). notes:

OPTIONAL - Terraform Basics

Grab a Coffee/Tea
Sit back and relax
You can get your hands dirty in a few minutes

Please be patient as we build and connect all the components of this lab together

👋 Challenge 3 introduction.

OPTIONAL CHALLENGE

Estimated time to complete: 15 minutes

OPTIONAL - Terraform Basics

In this challenge you will learn * Basic use of Terraform to deploy cloud infrastructure in AWS cloud

Terraform Basics (OPTIONAL)

Terraform is a great tool that uses Infrastructure as Code (IaC) to define infrastructure; build, change, and destroy these infrastructure resources.

This challenge will introduce you to some basic Terraform concepts and to give you some experience in using Terraform to create and destroy cloud infrastructure resources.

[NOTE] You can perform the following steps at the TERMINAL, or in Visual Studio Code (VSCode). In VSCode you can open a terminal prompt. Choose either the TERMINAL tab, or the VSCODE tab from the top of the lab screen. We will walk through the steps using the TERMINAL but please feel free to do this in the VSCODE tab if you are more comfortable there!

☑️ Task 1 - Initialize a Terraform Project

Open the Terminal tab from the top of the lab.

Change to the /home/rhel/lab_exercises/1.Terraform_Basics folder

cd /home/rhel/lab_exercises/1.Terraform_Basics

Here you will find a main.tf file which has been created for you.

Take a quick look at this file

cat main.tf

It’s content will look like the following:

# Use AWS provider for Terraform
provider "aws" {
  region = "us-east-1"
}

resource "aws_instance" "basic_rhel" {
  ami           = "ami-0005e0cfe09cc9050"
  instance_type = "t2.micro"

  }

In this simple example, the main.tf file will declare a few things.

A provider for Terraform to work with. In this example the Terraform Provider in use is for AWS (Terraform Provider for AWS)
A resource to indicate the type of infrastructure resource, what AWS Machine Image (ami), and what instance type to use

Initialize the Terraform Project using the following command

terraform init

This will get Terraform to download and provision the backend with what it needs for the chosen AWS provider.

Once this is done, run the following command

ls -al

You will see the following has been created:

.terraform - This provides the backend requirements for Terraform
.terraform.lock.hcl - This is the dependency lock file

Now that you have initialized this Terraform Project, go ahead and build the resource(s)!

☑️ Task 2 - Plan and Apply the Terraform Project

From the project folder you have already initialized Terraform and you can now deploy, by running the terraform plan, then terraform apply commands

terraform plan -out myMagicalInstance

This creates a plan of your build based on the main.tf file you have. You can look at the output and see all the components being added (+) to the infrastructure plan.

Next let’s get Terraform to provision this plan

terraform apply myMagicalInstance

Terraform will now create the infrastructure you have defined in your manifest. You will notice that the number of resources created should reflect the number of resources specified.

Run the following AWS cli command to check for running instances and to get the instance ID. Simply copy and paste this command to the terminal prompt

aws ec2 describe-instances --filters "Name=instance-type,Values=t2.micro" --query "Reservations[*].Instances[*].[InstanceId]" --output table --region "us-east-1"

[NOTE] Note that you may see more than 1 instance, and that’s becasue of the infrastructure you created in earlier challenges in this lab.

Now, if you wanted to get detailed information about the AWS instance from Terraform you can look in the Terraform state file.

cat terraform.tfstate

Here you will see only the resources created (1 ec2 instance) by this Terraform project. This file provides you with a wealth of information regarding the infrastructure that was just provisioned.

OPTIONAL: Login to the AWS Console using the tab at the top of the lab to view the resource(s) created in AWS.

☑️ Task 3 - Make Changes to the Terraform Project

You have created and deployed your first AWS instance with a simple Terraform project. What if you want to make a change of some sort?

Edit the main.tf file and add more resources. Add a security group for example, and specify ports for ingess and egress..

vim main.tf

resource "aws_security_group" "terraform_group" {
  name = "myMagicalSecGroup"
  ingress {
	from_port = 22
	to_port = 22
	protocol = "tcp"
	cidr_blocks = ["0.0.0.0/0"]
}

  ingress {
	from_port = 80
	to_port = 80
	protocol = "tcp"
	cidr_blocks = ["0.0.0.0/0"]
}

  egress {
	from_port = 0
	to_port = 0
	protocol = "-1"
	cidr_blocks = ["0.0.0.0/0"]
}
}

Once you have made the these ADDITIONS, you will need to run terraform plan to update the plan. This will output the needed changes.

terraform plan --out myMagicalInstance

You will notice in the summary that the changes have been indicated with - and + for what has been added taken away. Please go ahead and apply the change.

Example output: Plan: 1 to add, 0 to change, 0 to destroy.

terraform apply myMagicalInstance

Terraform will make changes and add the additional resources specified by your main.tf file changes/additions.

OPTIONAL: Login to the AWS Console using the tab at the top of the lab to view the modifications that took place. The addition of the security group and the ingress / egress ports.

☑️ Task 4 - Deprovisioning resources of a Terraform Project

Terraform makes it really simple to clean up / remove / deprovision the project resources. Since you no longer need these resources, please destroy the infrastructure resources created by the Terraform project. Terraform will use the build files which act as a source of truth to de-provision all infrastructure and resources.

terraform destroy

You will be prompted if you want to continue, please enter yes.

Momentarily you will see confirmation of the resources destruction (1 ec2 instance, and 1 security group). basics2

OPTIONAL: Login to the AWS Console and validate that the AWS resource(s) have been deleted.

This concludes the Terraform Basics challenge