Cloud & DevOps — Terraform Practical Task

Student: Mykola Stepanov
Topic: Infrastructure as Code with Terraform
Cloud Provider: Amazon Web Services (AWS)
Region used: eu-central-1 / Europe (Frankfurt)

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Project Overview

This repository contains a Terraform practical task where I created basic AWS infrastructure using Infrastructure as Code.

The task required creating:

1. A Terraform project with AWS provider configuration.
2. A VPC using a module from the Terraform Registry.
3. Two EC2 instances using the Terraform count argument.
4. A Classic Load Balancer that distributes HTTP traffic between the two EC2 instances.

The project was created and tested locally from VS Code terminal on Windows.

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Practical Task Requirements

Task	Requirement	Implementation
Task 1	Install Terraform, create project folder, configure AWS provider, initialize and apply Terraform project	Terraform was installed locally and added to Windows PATH. Project folder was created with main.tf, terraform.tfvars, .gitignore, and Terraform commands were executed from VS Code terminal
Task 2	Create VPC using an appropriate Terraform Registry module	Used terraform-aws-modules/vpc/aws module to create VPC, public subnets, private subnets, route tables, and internet gateway
Task 3	Create two EC2 instances using count	Created two EC2 instances with count = 2 in private subnets
Task 4	Create a Classic Load Balancer in AWS	Created aws_elb Classic Load Balancer and attached both EC2 instances to it

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Architecture

The implemented AWS architecture includes:

• 1 VPC
• 2 public subnets
• 2 private subnets
• 2 EC2 instances
• 1 Classic Load Balancer
• Security groups for Load Balancer and EC2 instances
• Outputs for VPC ID, EC2 instance IDs, and Load Balancer DNS name

Basic traffic flow:

User / Browser
      |
      v
Classic Load Balancer
      |
      v
2 EC2 instances in private subnets

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Project Files

terraform-task/
├── main.tf
├── README.md
├── .gitignore
├── .terraform.lock.hcl
└── terraform-plan.txt       # optional text version of Terraform plan

Files that should not be pushed to GitHub:

terraform.tfvars
terraform.tfstate
terraform.tfstate.*
.terraform/
tfplan

terraform.tfvars contains AWS credentials, so it must stay local and should not be committed.

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Main Terraform Components

AWS Provider

The AWS provider was configured to work with AWS resources.

provider "aws" {
  region     = var.aws_region
  access_key = var.aws_access_key
  secret_key = var.aws_secret_key
}

Credentials were stored locally in terraform.tfvars.

---

Variables

Input variables were used to make the configuration more flexible.

variable "aws_region" {
  type = string
}

variable "aws_access_key" {
  type      = string
  sensitive = true
}

variable "aws_secret_key" {
  type      = string
  sensitive = true
}

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

---

VPC Module

A ready-made module from Terraform Registry was used to create the VPC.

module "vpc" {
  source  = "terraform-aws-modules/vpc/aws"
  version = "~> 5.0"

  name = "student-vpc"
  cidr = "10.0.0.0/16"

  public_subnets  = ["10.0.1.0/24", "10.0.2.0/24"]
  private_subnets = ["10.0.11.0/24", "10.0.12.0/24"]

  enable_nat_gateway = false
}

---

EC2 Instances

Two EC2 instances were created using count.

resource "aws_instance" "web" {
  count = 2

  ami                    = data.aws_ami.amazon_linux.id
  instance_type          = var.instance_type
  subnet_id              = module.vpc.private_subnets[count.index]
  vpc_security_group_ids = [aws_security_group.ec2_sg.id]

  user_data = <<-EOF
              #!/bin/bash
              echo "Hello from EC2 instance ${count.index + 1}" > /home/ec2-user/index.html
              cd /home/ec2-user
              nohup python3 -m http.server 80 &
              EOF

  tags = {
    Name = "student-ec2-${count.index + 1}"
  }
}

---

Classic Load Balancer

The Classic Load Balancer was created to distribute HTTP traffic across two EC2 instances.

resource "aws_elb" "student_lb" {
  name = "student-classic-lb"

  subnets         = module.vpc.public_subnets
  security_groups = [aws_security_group.lb_sg.id]
  instances       = aws_instance.web[*].id

  listener {
    lb_port           = 80
    lb_protocol       = "http"
    instance_port     = 80
    instance_protocol = "http"
  }

  health_check {
    target              = "HTTP:80/"
    interval            = 30
    timeout             = 3
    healthy_threshold   = 2
    unhealthy_threshold = 2
  }
}

---

Commands Used

Check Terraform installation

terraform version

Format Terraform files

terraform fmt

Initialize Terraform project

terraform init

Validate Terraform configuration

terraform validate

Create execution plan

terraform plan -out=tfplan

Save readable plan to text file

terraform show -no-color tfplan > terraform-plan.txt

Apply saved execution plan

terraform apply tfplan

Show Terraform outputs

terraform output

List resources from Terraform state

terraform state list

Destroy created infrastructure after verification

terraform destroy

---

Verification

The infrastructure was verified in several ways:

1. Terraform completed the apply operation successfully.
2. Terraform output displayed:
   • EC2 instance IDs
   • Load Balancer DNS name
   • VPC ID
3. AWS Console showed:
   • 2 running EC2 instances
   • 1 Classic Load Balancer
   • Load Balancer health checks with instances in service
4. Browser test confirmed that the Load Balancer returned a response from an EC2 instance.

Example browser result:

Hello from EC2 instance 1

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Cleanup

After verification, all created AWS resources were removed to avoid unnecessary costs.

terraform destroy

After destroy, the Terraform state was checked:

terraform state list

The state list was empty, which confirmed that Terraform no longer tracked any created resources.

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Security Notes

AWS credentials were not committed to the repository.

The following files were ignored:

.terraform/
terraform.tfvars
*.tfstate
*.tfstate.*
tfplan
crash.log
crash.*.log

This is important because:

• terraform.tfvars can contain AWS access keys.
• terraform.tfstate can contain sensitive infrastructure data.
• .terraform/ contains downloaded providers and modules.

---

Result

The practical task was completed successfully.

Implemented:

• AWS provider configuration
• VPC module from Terraform Registry
• Two EC2 instances using count
• Classic Load Balancer
• Security groups
• Terraform plan and apply workflow
• AWS Console verification
• Browser verification through Load Balancer DNS
• Cleanup using terraform destroy

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What I Learned

During this task I practiced:

• Installing and running Terraform locally.
• Working with Terraform files: main.tf, terraform.tfvars, .gitignore.
• Using input variables.
• Using Terraform Registry modules.
• Creating AWS infrastructure with Terraform.
• Checking Terraform execution plans.
• Applying Terraform changes.
• Reading Terraform outputs.
• Checking resources in AWS Console.
• Cleaning up resources with terraform destroy.

This task helped me better understand how Infrastructure as Code works in practice and how Terraform can create, manage, verify, and destroy cloud infrastructure.