Terraform Registry modules - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to use a Terraform Registry module named "vpc".

Terraform

module "my_vpc" {
  source = [1]
}

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

A"aws_vpc"

B"registry/vpc"

C"vpc_module"

D"terraform-aws-modules/vpc/aws"

Attempts:

3 left

💡 Hint

Common Mistakes

Using incorrect source format like just the module name.

Forgetting to include the provider in the source.

The source attribute specifies the module location. For Terraform Registry modules, it uses the format "namespace/module/provider".

2fill in blank

medium

Complete the code to specify the version of the Terraform Registry module.

Terraform

module "my_vpc" {
  source  = "terraform-aws-modules/vpc/aws"
  version = [1]
}

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

A"3.14.0"

B3.14

C"latest"

D3

Attempts:

3 left

💡 Hint

Common Mistakes

Using a number without quotes for version.

Using invalid version strings like "latest".

The version attribute must be a string specifying the exact module version, like "3.14.0".

3fill in blank

hard

Fix the error in the module block to correctly pass the VPC CIDR block.

Terraform

module "my_vpc" {
  source     = "terraform-aws-modules/vpc/aws"
  version    = "3.14.0"
  [1] = "10.0.0.0/16"
}

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

Acidrblock

Bcidr

CcidrBlock

Dcidr_block

Attempts:

3 left

💡 Hint

Common Mistakes

Using camelCase or incorrect variable names.

Using partial or abbreviated variable names.

The correct variable name to pass is cidr, matching the module's expected input.

4fill in blank

hard

Fill both blanks to define a module with source and enable DNS support.

Terraform

module "my_vpc" {
  source          = [1]
  enable_dns_hostnames = [2]
}

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

A"terraform-aws-modules/vpc/aws"

Btrue

Cfalse

D"true"

Attempts:

3 left

💡 Hint

Common Mistakes

Quoting boolean values like "true".

Using incorrect source strings.

The source must be the module path string, and enable_dns_hostnames is a boolean true or false, not a string.

5fill in blank

hard

Fill all three blanks to define a module with source, version, and enable public subnets.

Terraform

module "my_vpc" {
  source        = [1]
  version       = [2]
  public_subnets = [3]
}

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

A"terraform-aws-modules/vpc/aws"

B"3.14.0"

C["10.0.1.0/24", "10.0.2.0/24"]

Dtrue

Attempts:

3 left

💡 Hint

Common Mistakes

Using unquoted version numbers.

Passing booleans instead of lists for subnets.

Incorrect source strings.

The source is the module path string, version is a string with the version number, and public_subnets is a list of subnet CIDR blocks.

Practice

1. What is the main purpose of using Terraform Registry modules in your infrastructure code?

easy

A. To reuse tested infrastructure code easily

B. To write all infrastructure code from scratch

C. To avoid using any external code

D. To manually configure cloud resources without code

Solution

1. Step 1: Understand Terraform Registry modules

   Terraform Registry modules are pre-built, reusable pieces of infrastructure code shared publicly or privately.

2. Step 2: Identify the main benefit

   Using these modules helps you avoid rewriting code and ensures you use tested, reliable configurations.

3. Final Answer:

   To reuse tested infrastructure code easily -> Option A

4. Quick Check:

   Terraform Registry modules = reuse code easily [OK]

Hint: Modules = reuse tested code, save time [OK]

Common Mistakes:

• Thinking modules require writing all code manually
• Believing modules prevent code reuse
• Confusing modules with manual resource setup

2. Which of the following is the correct syntax to include a Terraform Registry module in your configuration?

easy

A. module "example" { source = "terraform-aws-modules/vpc/aws" version = "3.0.0" }

B. resource "example" { source = "terraform-aws-modules/vpc/aws" version = "3.0.0" }

C. module "example" (source = "terraform-aws-modules/vpc/aws", version = "3.0.0")

D. include "example" { source = "terraform-aws-modules/vpc/aws" version = "3.0.0" }

Solution

1. Step 1: Recognize the correct block type

   Terraform modules are included using the module block, not resource or include.

2. Step 2: Check syntax for module block

   The correct syntax uses curly braces with key-value pairs for source and version.

3. Final Answer:

   module "example" { source = "terraform-aws-modules/vpc/aws" version = "3.0.0" } -> Option A

4. Quick Check:

   Use module block with source and version [OK]

Hint: Use module block with source and version keys [OK]

Common Mistakes:

• Using resource block instead of module
• Using parentheses instead of braces
• Using include keyword which is invalid

3. Given this Terraform module block:

module "network" {
  source  = "terraform-aws-modules/vpc/aws"
  version = "3.0.0"
  name    = "my-vpc"
  cidr    = "10.0.0.0/16"
}

What will happen when you run terraform init?

medium

A. Terraform downloads the latest version ignoring the specified version

B. Terraform throws an error because version is missing

C. Terraform downloads version 3.0.0 of the VPC module from the registry

D. Terraform ignores the module and continues without it

Solution

1. Step 1: Understand terraform init behavior with modules

   When terraform init runs, it downloads modules specified with source and version.

2. Step 2: Check version usage

   The version is specified as "3.0.0", so Terraform downloads exactly that version from the registry.

3. Final Answer:

   Terraform downloads version 3.0.0 of the VPC module from the registry -> Option C

4. Quick Check:

   terraform init downloads specified module version [OK]

Hint: terraform init downloads modules with specified version [OK]

Common Mistakes:

• Assuming version is optional and causes error
• Thinking terraform ignores version and downloads latest
• Believing terraform skips modules on init

4. You wrote this module block:

module "db" {
  source = "terraform-aws-modules/rds/aws"
  version = "1.0.0"
  engine = "mysql"
}

When running terraform init, you get an error: Module version 1.0.0 not found. What is the likely cause?

medium

A. The source URL is incorrect and does not point to a module

B. The specified version 1.0.0 does not exist in the Terraform Registry for this module

C. The engine parameter is invalid and causes version error

D. Terraform init requires internet disabled to find modules

Solution

1. Step 1: Analyze the error message

   The error says version 1.0.0 not found, meaning Terraform cannot find that version in the registry for the module.

2. Step 2: Check common causes

   Either the version is mistyped or does not exist. The source looks correct, and engine parameter does not affect version lookup.

3. Final Answer:

   The specified version 1.0.0 does not exist in the Terraform Registry for this module -> Option B

4. Quick Check:

   Version not found error = wrong or missing version [OK]

Hint: Check module version exists in registry before using [OK]

Common Mistakes:

• Blaming source URL when it is correct
• Thinking parameters cause version errors
• Assuming terraform init works offline for modules

5. You want to use a Terraform Registry module but customize it with your own settings. Which approach is best practice?

hard

A. Use the module without specifying version to always get latest

B. Copy the module code into your project and edit it directly

C. Ignore the module and write all resources manually

D. Use the module with source and version, then override variables in your configuration

Solution

1. Step 1: Understand module customization

   Terraform modules accept input variables to customize behavior without changing module code.

2. Step 2: Identify best practice

   Using source and version ensures stable code, and overriding variables lets you customize safely.

3. Final Answer:

   Use the module with source and version, then override variables in your configuration -> Option D

4. Quick Check:

   Customize modules via variables, keep source and version fixed [OK]

Hint: Override variables, don't copy module code [OK]

Common Mistakes:

• Copying module code causes maintenance issues
• Not specifying version risks unexpected changes
• Ignoring modules wastes time and effort