Day 8: Introduction to Infrastructure as Code (IaC)

Welcome to Week 2 of the Zero to Platform Engineer in 30 Days challenge! 🚀 This week, we’re diving into Infrastructure as Code (IaC) and CI/CD pipelines, two cornerstones of modern platform engineering. Today, we’ll focus on understanding what IaC is, why it matters, and how it helps manage infrastructure efficiently.

What Is Infrastructure as Code (IaC)?

Infrastructure as Code (IaC) is the practice of managing and provisioning infrastructure (e.g., servers, networks, databases) through machine-readable configuration files instead of manual processes.

Key Characteristics of IaC:

Declarative or Imperative: Define what the infrastructure should look like (declarative) or how to create it step by step (imperative).
Version Controlled: IaC files are stored in repositories like Git, making it easy to track changes.
Repeatable: Automate infrastructure provisioning consistently across environments.

Why IaC Matters

In traditional infrastructure management, scaling and maintaining environments can be time-consuming and error-prone. IaC solves this by:

Improving Consistency: Eliminate human error with automated provisioning.
Simplifying Scaling: Scale infrastructure on demand with code.
Enabling Agility: Spin up environments quickly for development, testing, and production.
Enhancing Collaboration: Teams can collaborate using version control systems like Git.

🎯 Real-World Use Case: Think about how a cloud provider like AWS enables you to create resources (e.g., EC2, S3) programmatically via tools like Terraform or AWS CloudFormation.

Popular IaC Tools

Here are some popular tools in the IaC space:

Terraform / Opentofu

Cloud-agnostic.
Widely used for provisioning infrastructure across multiple providers (AWS, Azure, GCP).

AWS CloudFormation

AWS-native IaC tool.
Best suited for managing resources within the AWS ecosystem.

Pulumi

Supports IaC in general-purpose programming languages (e.g., Python, TypeScript).

Ansible

Focused on configuration management but also supports provisioning.

In addition to tools like Terraform and CloudFormation, let’s talk about AWS CDK, a powerful framework for defining cloud infrastructure using familiar programming languages.

AWS CDK (Cloud Development Kit)

Define infrastructure using programming languages like TypeScript, Python, Java, and Go.
Generates CloudFormation templates under the hood.

Hands-On: Getting Started with IaC

Let’s explore Terraform and AWS CDK to see how these tools work in practice.

Terraform Example: Creating an S3 Bucket

Step 1: Install Terraform

Install terraform on your machine, following the official installation guide.
Verify the installation:

terraform version

Step 2: Create a Terraform Configuration File

Create a directory for your Terraform project:

mkdir terraform-iac-demo && cd terraform-iac-demo

Create a file named main.tf:

provider "aws" {
  region = "us-west-2"
}

resource "aws_s3_bucket" "zero-to-platform-engineer" {
  bucket = 'zero-to-platform-engineer'
  acl    = "private"
}

Step 3. Initialize Terraform:

terraform init

Step 4. Plan and Apply the Configuration:

terraform plan
terraform apply

🎯 Pro tip: Use the -auto-approve flag to skip the confirmation prompt.

Step 5: Clean Up

terraform destroy

AWS CDK Example: Creating an S3 Bucket

Step 1: Install AWS CDK

Install the AWS CDK on your machine, following the official installation guide.
Verify the installation:

cdk --version

Step 2: Create a CDK Project

Create a directory for your CDK project:

mkdir cdk-iac-demo && cd cdk-iac-demo

Initialize the CDK project:

cdk init app --language typescript

Step 3: Define Your Infrastructure

Open the lib/cdk-iac-demo-stack.ts file and add the following:

import * as cdk from 'aws-cdk-lib';
import { Construct } from 'constructs';
import * as s3 from 'aws-cdk-lib/aws-s3';

export class CdkIacDemoStack extends cdk.Stack {
  constructor(scope: Construct, id: string, props?: cdk.StackProps) {
    super(scope, id, props);

    new s3.Bucket(this, 'ZeroToPlatformEngineerBucket', {
      bucketName: 'zero-to-platform-engineer-bucket',
      versioned: true,
      removalPolicy: cdk.RemovalPolicy.DESTROY,
    });
  }
}

Step 4: Deploy the Infrastructure

Bootstrap your environment:

cdk bootstrap aws://<account-id>/<region>

Deploy the infrastructure:

cdk deploy

🎯 Pro tip: Use the —require-approval flag to skip the confirmation prompt.

🎯 When to Use AWS CDK:

You’re working primarily with AWS.
You prefer coding infrastructure in a general-purpose language.

🎯 When to Use Terraform:

You need a multi-cloud solution.
You prefer a declarative approach with a simpler setup.

Challenges for Today

Create an S3 bucket using both Terraform and AWS CDK.
Experiment with adding properties like versioning, encryption, or lifecycle rules.
Reflect: Which tool felt easier or more intuitive?

What’s Next?

Tomorrow, we’ll explore advanced Terraform configurations, including managing Kubernetes resources programmatically.

Get ready to level up your platform engineering skills! 🚀

👉 Check it out here: Zero to Platform Engineer Repository

Feel free to clone the repo, experiment with the code, and even contribute if you’d like! 🚀

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