OpenTofu AWS Free-Tier Lab

Costmedium

Deployability iac ready

Status cloud lab

Validation make validate

OpenTofu Terraform AWS EC2 VPC aws terraform

Use the guide first.

The full learning guide is on this page. Open the repository files only when a step asks you to inspect code, fork the project, or download raw assets.

Read safety guide Project files on GitHub

Project Guide

Beginner-friendly infrastructure-as-code lab that creates a tiny AWS VPC, public subnet, security group, and optional free-tier EC2 instance with OpenTofu or Terraform.

What You Learn

• How OpenTofu/Terraform plans and applies infrastructure
• How providers, variables, outputs, and state work
• Why tags and destroy steps matter for cost control
• How to keep cloud labs small and reviewable

Architecture

flowchart TB
  Student["Student workstation"] --> Tofu["OpenTofu or Terraform"]
  Tofu --> AWS["AWS provider"]
  AWS --> VPC["VPC 10.52.0.0/16"]
  VPC --> Subnet["Public subnet"]
  Subnet --> SG["Security group"]
  SG --> EC2["Optional t3.micro nginx instance"]

Cost Warning

This lab can create AWS resources. Use free-tier eligible instance types, confirm your region, restrict SSH to your own IP, and destroy everything when done.

Prerequisites

• AWS account
• AWS CLI configured
• OpenTofu, or Terraform with TF=terraform

One-Command Local Validation

make validate

Validation is local: it checks formatting, initializes providers without a backend, and runs validate. It does not create AWS resources.

Review-Then-Apply Workflow

cp terraform.tfvars.example terraform.tfvars
make plan
make up
make logs
make down

Use Terraform instead of OpenTofu:

TF=terraform make validate
TF=terraform make plan
TF=terraform make up
TF=terraform make down

make up refuses to run until make plan has created tfplan, so students review the cloud changes first.

Troubleshooting

• tofu: command not found: install OpenTofu or prefix commands with TF=terraform.
• AWS credential errors: run aws sts get-caller-identity and confirm the expected account appears.
• SSH is open to the world: set allowed_ssh_cidr in terraform.tfvars to your public IP with /32.
• Duplicate names or stale state: run make logs to inspect outputs, then make down when you are done.

Cleanup

make down
rm -f tfplan

Always confirm the destroy plan before approving it.

Student Exercises

• Add an S3 backend for remote state.
• Add a second subnet in another Availability Zone.
• Add a budget alarm.
• Convert the EC2 instance into a reusable module.