Terraform vs CloudFormation vs Pulumi - When to Use Which

The Big Idea

What if you could build your entire cloud setup with just one command, perfectly every time?

The Scenario

Imagine setting up a whole city of buildings by hand, brick by brick, without any blueprint or tools.

Every time you want to add a new building or fix one, you have to start over or risk mistakes.

The Problem

Doing cloud setup manually means clicking through many screens or writing repetitive commands.

This is slow, easy to mess up, and hard to repeat exactly the same way.

It's like trying to build that city without a plan -- you waste time and might break things.

The Solution

Terraform, CloudFormation, and Pulumi let you write a clear plan for your cloud setup in code.

This plan can be saved, shared, and run again to build or update your cloud safely and quickly.

Before vs After

✗ Before

Click through AWS console to create each resource one by one

✓ After

terraform apply -auto-approve

What It Enables

You can build, change, and share your cloud setup like a recipe that anyone can follow perfectly every time.

Real Life Example

A company launches a new app and needs many servers, databases, and networks.

Using Terraform or Pulumi, they write one code file to create all resources at once, saving weeks of manual work.

Key Takeaways

Manual cloud setup is slow and error-prone.

Infrastructure as Code tools automate and simplify cloud management.

Terraform, CloudFormation, and Pulumi each offer ways to write and run cloud setup as code.

Practice

1. Which infrastructure as code tool is designed to work only with AWS and uses JSON or YAML for its templates?

easy

A. CloudFormation

B. Terraform

C. Pulumi

D. Ansible

Solution

1. Step 1: Identify AWS-only tool

   CloudFormation is the only tool among the options that works exclusively with AWS.

2. Step 2: Check template language

   CloudFormation uses JSON or YAML for its templates, unlike Terraform (HCL) or Pulumi (programming languages).

3. Final Answer:

   CloudFormation -> Option A

4. Quick Check:

   AWS-only + JSON/YAML = CloudFormation [OK]

Hint: AWS-only and JSON/YAML means CloudFormation [OK]

Common Mistakes:

• Confusing Terraform as AWS-only
• Thinking Pulumi uses JSON/YAML
• Selecting Ansible which is not IaC focused

2. Which of the following is the correct way to describe Pulumi's approach to infrastructure as code?

easy

A. Uses general-purpose programming languages like JavaScript or Python

B. Uses JSON or YAML templates tightly integrated with AWS

C. Uses shell scripts for provisioning

D. Uses a domain-specific language called HCL

Solution

1. Step 1: Identify Pulumi's language style

   Pulumi uses real programming languages such as JavaScript, Python, Go, or C# for defining infrastructure.

2. Step 2: Eliminate other options

   HCL is Terraform's language, JSON/YAML with AWS is CloudFormation, and shell scripts are not Pulumi's approach.

3. Final Answer:

   Uses general-purpose programming languages like JavaScript or Python -> Option A

4. Quick Check:

   Pulumi = real programming languages [OK]

Hint: Pulumi uses real programming languages, not templates [OK]

Common Mistakes:

• Confusing Pulumi with Terraform's HCL
• Thinking Pulumi uses JSON/YAML
• Assuming Pulumi uses shell scripts

3. Given the following statements, which tool supports multiple cloud providers and uses a simple declarative language called HCL?

1. Supports AWS, Azure, GCP
2. Uses JSON or YAML
3. Uses HCL
4. Uses programming languages like TypeScript

medium

A. Chef

B. Pulumi

C. CloudFormation

D. Terraform

Solution

1. Step 1: Match multi-cloud support

   Terraform supports multiple clouds like AWS, Azure, and GCP.

2. Step 2: Match language used

   Terraform uses HCL, a simple declarative language. JSON/YAML is CloudFormation, programming languages like TypeScript is Pulumi.

3. Final Answer:

   Terraform -> Option D

4. Quick Check:

   Multi-cloud + HCL = Terraform [OK]

Hint: Multi-cloud + HCL means Terraform [OK]

Common Mistakes:

• Choosing Pulumi for HCL language
• Selecting CloudFormation for multi-cloud
• Confusing Chef with IaC tools

4. You wrote a Pulumi program in Python but it fails to deploy because it uses AWS-specific resource names not supported by Azure. What is the main error here?

medium

A. Terraform should be used instead of Pulumi for AWS

B. Pulumi does not support Python as a language

C. Using AWS resource names in a multi-cloud Pulumi program without adjusting for Azure

D. CloudFormation templates are required for Azure deployments

Solution

1. Step 1: Identify the cause of failure

   The Pulumi program uses AWS resource names but tries to deploy on Azure, causing incompatibility.

2. Step 2: Understand Pulumi's multi-cloud nature

   Pulumi supports multiple clouds but resource names and APIs differ per cloud and must be adjusted accordingly.

3. Final Answer:

   Using AWS resource names in a multi-cloud Pulumi program without adjusting for Azure -> Option C

4. Quick Check:

   Cloud-specific resource names must match target cloud [OK]

Hint: Match resource names to target cloud in Pulumi [OK]

Common Mistakes:

• Thinking Pulumi can't use Python
• Believing Terraform is required for AWS
• Assuming CloudFormation works on Azure

5. You want to manage infrastructure across AWS and Azure using a single tool. You prefer writing code in TypeScript and want to reuse existing programming skills. Which tool should you choose and why?

hard

A. CloudFormation, because it is tightly integrated with AWS

B. Pulumi, because it supports multiple clouds and uses real programming languages like TypeScript

C. Terraform, because it supports multiple clouds and uses HCL

D. Ansible, because it uses YAML for automation

Solution

1. Step 1: Identify multi-cloud support with TypeScript

   Pulumi supports multiple clouds and allows writing infrastructure code in TypeScript, matching the requirement.

2. Step 2: Compare other tools

   Terraform supports multi-cloud but uses HCL, not TypeScript. CloudFormation is AWS-only. Ansible is for automation, not primarily IaC with TypeScript.

3. Final Answer:

   Pulumi, because it supports multiple clouds and uses real programming languages like TypeScript -> Option B

4. Quick Check:

   Multi-cloud + TypeScript = Pulumi [OK]

Hint: Multi-cloud + TypeScript means Pulumi [OK]

Common Mistakes:

• Choosing Terraform for TypeScript support
• Selecting CloudFormation for multi-cloud
• Confusing Ansible with IaC tools