Learn OpenTofu - Pre-Requisite Skills & Environment Setup

#Introduction

Welcome to the Learn OpenTofu series! Over 21 episodes we'll take a journey from zero to a production-ready infrastructure-as-code architecture. OpenTofu is the open-source fork of Terraform hosted by the Linux Foundation — and in this episode you'll prepare all the tools needed to follow along.

Before writing a resource or running tofu apply, a few foundations need to be solid: basic Linux CLI skills, an understanding of cloud computing concepts, structured data formats, installing the tofu binary, and a credential path to the cloud. Think of this episode as a roadmap: once you're done, your terminal is ready for the entire series.

#Main Discussion

#Core Skills: Linux CLI & Terminal Navigation

OpenTofu is operated almost entirely through the terminal. That's not a coincidence — real-world automation (CI/CD pipelines, remote servers, scripting) all live in the CLI. You don't need to be a sysadmin expert, but you should be comfortable with the basic commands below.

pwd                     # current directory location
ls -la                  # list files including hidden files
cd ~/lab-opentofu       # change directory
mkdir -p aws/modules    # create nested directories
cp main.tf backup/      # copy a file
grep "region" main.tf   # search text inside a file

Beyond navigation, understand file permissions. OpenTofu refuses to read state with overly permissive permissions, and the AWS CLI stores credentials in ~/.aws, which is sensitive. You'll keep running into the r, w, and x concepts. Finally, make sure you can use your distro's package manager: apt for Debian/Ubuntu, dnf for Fedora/RHEL, and brew for macOS.

#Basic Cloud Computing Concepts

OpenTofu doesn't work in a vacuum — it creates, modifies, and deletes cloud resources through APIs. Understand the role of the core components, because each one will become an OpenTofu resource in later episodes.

The component that will most shape your journey is IAM. OpenTofu talks to cloud APIs using IAM identity credentials. The principle of least privilege — granting the minimum access needed — will keep appearing throughout this series, because it's the first line of defense for infrastructure.

#Understanding JSON / YAML / HCL

OpenTofu uses HCL (HashiCorp Configuration Language), which is designed to be human-friendly and close to JSON. Understanding JSON and YAML speeds up learning HCL, since they're all based on key-value structures.

{
  "name": "web-server",
  "port": 80,
  "tags": ["dev", "backend"]
}

name: web-server
port: 80
tags:
  - dev
  - backend

resource "aws_instance" "web" {
  ami           = "ami-0c55b159cbfafe1f0"
  instance_type = "t3.micro"
 
  tags = {
    Name = "web-server"
  }
}

Notice the pattern: in JSON it's "key": value, in YAML it's key: value, in HCL it's key = value. The main difference with HCL: it adds the concept of a block — the resource "type" "name" { ... } structure that JSON and YAML don't have directly.

#Hardware & Tools to Prepare

OpenTofu's hardware requirements are very simple — a regular laptop is enough. Here's the list of tools you must prepare:

#Installing the OpenTofu CLI

OpenTofu is a single binary with no additional dependencies. Choose the method that fits your operating system:

curl -fsSL https://get.opentofu.org/install-opentofu.sh | sudo sh -s -- --install-method deb
sudo apt-get update && sudo apt-get install -y tofu

curl -fsSL https://get.opentofu.org/install-opentofu.sh | sudo sh -s -- --install-method rpm
sudo dnf update && sudo dnf install -y tofu

brew install opentofu

curl -fsSL https://get.opentofu.org/install-opentofu.sh | sudo sh -s -- --install-method standalone

Once installed, verify it:

tofu --version
OpenTofu v1.9.2
on linux_amd64

#Setting Up the VS Code Extension

You'll be writing .tf files constantly, so a good editor helps a lot. Install the OpenTofu extension (or HashiCorp Terraform as an alternative, since the syntax is identical) from the VS Code marketplace. Its main features: HCL syntax highlighting, autocomplete for resources and arguments, and automatic formatting that keeps things consistent before tofu validate checks it too.

#Setting Up Cloud Credentials

OpenTofu needs credentials to talk to cloud APIs. There are three paths you can take.

Path 1: AWS CLI. Install the AWS CLI, then configure it with aws configure:

aws configure
AWS Access Key ID [None]: AKIAXXXX
AWS Secret Access Key [None]: ****************
Default region name [None]: ap-southeast-1
Default output format [None]: json

This command stores your credentials in ~/.aws/credentials, and OpenTofu reads them automatically.

Path 2: GCP CLI. Install gcloud, then log in with application default credentials:

gcloud auth application-default login
gcloud config set project <PROJECT_ID>

Path 3: LocalStack (free and local). Don't have a cloud account? LocalStack provides a local emulator for hundreds of AWS APIs. You can run tofu apply that creates S3 buckets, EC2 instances, and more on your own laptop at no cost:

docker run -d --name localstack -p 4566:4566 localstack/localstack:latest
curl -s http://localhost:4566/_localstack/health

provider "aws" {
  region     = "us-east-1"
  access_key = "test"
  secret_key = "test"
 
  endpoints {
    s3  = "http://localhost:4566"
    ec2 = "http://localhost:4566"
  }
}

#Conclusion

Summary of episode 0:

• Master the basics of Linux CLI — navigation, files, permissions, and package managers.
• Understand the role of the basic cloud components (VM, VPC, IAM, storage) before provisioning them.
• HCL is key-value based like JSON/YAML, but it has the distinctive block concept.
• OpenTofu is a single binary — install, verify with tofu --version, and you're ready.
• Set up credentials via AWS CLI, gcloud, or LocalStack, and never spread secrets.

All the tools are now in your hands. In the next episode, episode 1, we'll discuss the history behind OpenTofu: HashiCorp's licensing change for Terraform in August 2023, the community manifesto, and the Linux Foundation ecosystem. See you there!