Terragrunt for DRY configurations in Terraform - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to specify the Terragrunt configuration file format.

Terraform

terraform {
  source = "./modules/[1]"
}

Drag options to blanks, or click blank then click option'

Anetwork

Bcompute

Cstorage

Ddatabase

Attempts:

3 left

💡 Hint

Common Mistakes

Using unrelated module names that don't exist in the project.

The source attribute points to the module directory, here network is a common module name.

2fill in blank

medium

Complete the code to include a remote state backend configuration in Terragrunt.

Terraform

remote_state {
  backend = "[1]"
  config = {
    bucket = "my-terraform-state"
  }
}

Drag options to blanks, or click blank then click option'

Alocal

Bgcs

Cazurerm

Ds3

Attempts:

3 left

💡 Hint

Common Mistakes

Choosing a backend that does not match the cloud provider.

The s3 backend stores Terraform state files in an AWS S3 bucket.

3fill in blank

hard

Fix the error in the Terragrunt configuration to correctly include a dependency block.

Terraform

dependency "vpc" {
  config_path = "../[1]"
}

Drag options to blanks, or click blank then click option'

Acompute

Bnetwork

Cstorage

Ddatabase

Attempts:

3 left

💡 Hint

Common Mistakes

Using a wrong module name that does not exist in the path.

The dependency block references the network module directory to get outputs.

4fill in blank

hard

Fill both blanks to configure inputs and locals in Terragrunt.

Terraform

inputs = {
  environment = "[1]"
  region      = "[2]"
}

Drag options to blanks, or click blank then click option'

Aprod

Bdev

Cus-east-1

Deu-west-1

Attempts:

3 left

💡 Hint

Common Mistakes

Mixing production environment with a development region.

Setting environment to dev and region to us-east-1 is a common practice for development in AWS.

5fill in blank

hard

Fill all three blanks to define a Terragrunt configuration with remote state, inputs, and dependency.

Terraform

remote_state {
  backend = "[1]"
  config = {
    bucket = "terraform-state-bucket"
  }
}

inputs = {
  app_name = "[2]"
}

dependency "db" {
  config_path = "../[3]"
}

Drag options to blanks, or click blank then click option'

As3

Bmyapp

Cdatabase

Dlocal

Attempts:

3 left

💡 Hint

Common Mistakes

Using a local backend with an S3 bucket name.

Incorrect dependency path.

This configuration uses the s3 backend for remote state, sets the application name to myapp, and depends on the database module.

Practice

1. What is the main purpose of using Terragrunt with Terraform?

easy

A. To reuse Terraform configurations and avoid repeating code

B. To replace Terraform with a new tool

C. To write Terraform code in a different programming language

D. To deploy applications without infrastructure

Solution

1. Step 1: Understand Terragrunt's role

   Terragrunt is designed to help reuse and share Terraform code, making it easier to manage infrastructure without repeating code.

2. Step 2: Compare options

   Options B, C, and D describe incorrect uses or misunderstandings of Terragrunt's purpose.

3. Final Answer:

   To reuse Terraform configurations and avoid repeating code -> Option A

4. Quick Check:

   Terragrunt = DRY Terraform code reuse [OK]

Hint: Terragrunt helps avoid repeating Terraform code [OK]

Common Mistakes:

• Thinking Terragrunt replaces Terraform
• Believing Terragrunt changes Terraform language
• Confusing Terragrunt with application deployment tools

2. Which of the following is the correct way to include a Terraform module using Terragrunt?

easy

A. module "app" { source = "./app" }

B. include { path = find_in_parent_folders() }

C. terraform { backend = "s3" }

D. resource "aws_instance" "web" {}

Solution

1. Step 1: Identify Terragrunt syntax for including configs

   Terragrunt uses the include block with path = find_in_parent_folders() to reuse parent configs.

2. Step 2: Differentiate from Terraform syntax

   Options A, C, and D are Terraform syntax: A is a module block, C is backend config, D is a resource block, not Terragrunt includes.

3. Final Answer:

   include { path = find_in_parent_folders() } -> Option B

4. Quick Check:

   Terragrunt include uses find_in_parent_folders() [OK]

Hint: Terragrunt includes parent config with include + find_in_parent_folders() [OK]

Common Mistakes:

• Using Terraform module syntax instead of Terragrunt include
• Confusing backend config with include
• Writing resource blocks inside Terragrunt files

3. Given this Terragrunt configuration snippet:

include {
  path = find_in_parent_folders()
}

inputs = {
  region = "us-east-1"
  env    = "prod"
}

What will happen when you run terragrunt apply in this folder?

medium

A. Terragrunt will apply Terraform code without any variables

B. Terragrunt will fail because inputs cannot be used with include

C. Terragrunt will ignore the inputs block and only use parent config

D. Terragrunt will apply Terraform code using the parent config and inputs region=us-east-1, env=prod

Solution

1. Step 1: Understand include and inputs usage

   The include block imports parent config. The inputs block adds or overrides variables for this folder.

2. Step 2: Predict Terragrunt behavior on apply

   Terragrunt merges parent config with local inputs, so region and env variables are set as given.

3. Final Answer:

   Terragrunt will apply Terraform code using the parent config and inputs region=us-east-1, env=prod -> Option D

4. Quick Check:

   Include + inputs = merged config applied [OK]

Hint: Inputs override or add variables when using include [OK]

Common Mistakes:

• Thinking inputs are ignored with include
• Assuming inputs cause errors
• Believing variables are not passed to Terraform

4. You wrote this Terragrunt config:

include {
  path = find_in_parent_folders()
}

inputs = {
  region = "us-west-2"
  env = "dev"
}

terraform {
  source = "../modules/app"
}

When running terragrunt apply, you get an error: "Error: Unsupported block type". What is the likely cause?

medium

A. The terraform block cannot be nested inside the inputs block

B. The inputs block must come before include

C. The source path is incorrect

D. The region variable is invalid

Solution

1. Step 1: Check Terragrunt config block usage

   Terragrunt requires the terraform { source = ... } block at the root level. It cannot be nested inside other blocks like inputs.

2. Step 2: Identify error cause

   The error "Unsupported block type" usually means the block is misplaced or invalid in Terragrunt config.

3. Final Answer:

   The terraform block cannot be nested inside the inputs block -> Option A

4. Quick Check:

   Misplaced terraform block causes error [OK]

Hint: Terraform block must be correctly placed in Terragrunt config [OK]

Common Mistakes:

• Placing terraform block inside inputs or include
• Wrong order of blocks causing syntax errors
• Incorrect source path causing unrelated errors

5. You manage multiple environments (dev, staging, prod) with Terragrunt. You want to avoid repeating the backend configuration for each environment. Which approach best follows DRY principles?

hard

A. Define backend only in Terraform modules, not in Terragrunt

B. Copy the backend block into each environment's Terragrunt config

C. Create a root Terragrunt config with backend settings and use include in each environment folder

D. Use different backend types for each environment

Solution

1. Step 1: Understand DRY with Terragrunt

   Terragrunt allows sharing common config via a root config and include blocks in child folders.

2. Step 2: Evaluate options for backend reuse

   Create a root Terragrunt config with backend settings and use include in each environment folder uses root config for backend, avoiding repetition. Copy the backend block into each environment's Terragrunt config repeats code, violating DRY. Define backend only in Terraform modules, not in Terragrunt is incorrect because backend is configured in Terragrunt for remote state. Use different backend types for each environment adds complexity without reuse.

3. Final Answer:

   Create a root Terragrunt config with backend settings and use include in each environment folder -> Option C

4. Quick Check:

   Root config + include = DRY backend config [OK]

Hint: Put shared backend in root config, include it in environments [OK]

Common Mistakes:

• Copying backend config to each environment
• Configuring backend only in Terraform modules
• Using different backends unnecessarily