Modules for reusability in GCP - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to declare a module source in Terraform.

GCP

module "network" {
  source = "[1]"
}

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

Anetwork-module

Bterraform-network

Cgcp-network

D./modules/network

Attempts:

3 left

💡 Hint

Common Mistakes

Using a module name instead of a path for source.

Omitting the source attribute.

The source attribute specifies the path to the module directory. Using a relative path like './modules/network' correctly points to the module folder.

2fill in blank

medium

Complete the code to pass a variable named 'region' to the module.

GCP

module "storage" {
  source = "./modules/storage"
  [1] = "us-central1"
}

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

Aregion

Blocation

Czone

Darea

Attempts:

3 left

💡 Hint

Common Mistakes

Using a different variable name than defined in the module.

Forgetting to pass required variables.

The variable name must match the input variable defined in the module. 'region' is the correct variable to pass the region value.

3fill in blank

hard

Fix the error in the module call by completing the missing attribute.

GCP

module "compute" {
  source = "./modules/compute"
  machine_type = [1]
}

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

Amachine-type

Bn1-standard-1

C"n1-standard-1"

Dstandard-1

Attempts:

3 left

💡 Hint

Common Mistakes

Omitting quotes around string values.

Using invalid variable names.

String values must be enclosed in quotes. Without quotes, Terraform treats it as a variable or keyword, causing an error.

4fill in blank

hard

Fill both blanks to define a module output that returns the module's network name.

GCP

output "network_name" {
  value = module.[1].[2]
}

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

Anetwork

Bname

Cid

Dnet

Attempts:

3 left

💡 Hint

Common Mistakes

Using incorrect module or output names.

Confusing output variable names with resource names.

The output accesses the module named 'network' and retrieves its output variable 'name'.

5fill in blank

hard

Fill all three blanks to create a module call with source, region variable, and project variable.

GCP

module "storage_bucket" {
  source = "[1]"
  region = "[2]"
  project = "[3]"
}

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

A./modules/storage_bucket

Bus-east1

Cmy-gcp-project

Dstorage_bucket_module

Attempts:

3 left

💡 Hint

Common Mistakes

Using incorrect source paths.

Passing variables without quotes.

Using wrong variable names.

The source is the local path to the module folder. The region and project variables are passed as strings matching expected inputs.

Practice

1. What is the main benefit of using modules in GCP infrastructure setup?

easy

A. They let you reuse code to create cloud resources easily.

B. They automatically fix errors in your cloud setup.

C. They increase the cost of cloud resources.

D. They replace the need for any configuration files.

Solution

1. Step 1: Understand what modules do

   Modules are reusable pieces of configuration that help you avoid repeating code.

2. Step 2: Identify the benefit in context

   Using modules makes your cloud setup easier and faster by reusing code.

3. Final Answer:

   They let you reuse code to create cloud resources easily. -> Option A

4. Quick Check:

   Modules = Reuse code [OK]

Hint: Modules help reuse code to save time and effort [OK]

Common Mistakes:

• Thinking modules fix errors automatically
• Believing modules increase costs
• Assuming modules remove all config files

2. Which of the following is the correct way to call a module in a Terraform configuration for GCP?

easy

A. module "storage" { source = "./modules/storage" }

B. call module storage from "./modules/storage"

C. use module storage located at ./modules/storage

D. import module storage from "./modules/storage"

Solution

1. Step 1: Recall Terraform module syntax

   Terraform uses the keyword module followed by a name and a block with source to specify the module path.

2. Step 2: Match the correct syntax

   module "storage" { source = "./modules/storage" } matches the correct syntax: module "name" { source = "path" }.

3. Final Answer:

   module "storage" { source = "./modules/storage" } -> Option A

4. Quick Check:

   Terraform module call = module "name" with source [OK]

Hint: Use 'module "name" { source = "path" }' to call modules [OK]

Common Mistakes:

• Using keywords like call or import which are invalid
• Missing quotes around module name
• Not using a block structure for module

3. Given this Terraform module call:

module "network" {
  source = "./modules/network"
  region = "us-central1"
}

What will happen if the module network does not accept a region variable?

medium

A. Terraform will deploy but with a default region.

B. Terraform will ignore the extra variable and deploy successfully.

C. Terraform will throw an error about an unknown variable.

D. Terraform will deploy but skip the network module.

Solution

1. Step 1: Understand variable passing in modules

   Terraform requires that variables passed to modules must be declared in the module's variables file.

2. Step 2: Identify behavior when unknown variable is passed

   If a variable is passed but not declared, Terraform throws an error about unknown input variable.

3. Final Answer:

   Terraform will throw an error about an unknown variable. -> Option C

4. Quick Check:

   Unknown module variable = error [OK]

Hint: Modules must declare variables before use [OK]

Common Mistakes:

• Assuming Terraform ignores unknown variables
• Thinking Terraform uses defaults without declaration
• Believing module is skipped silently

4. You have a module defined in ./modules/storage but when you run Terraform apply, it fails with:
Error: Module not found
What is the most likely cause?

medium

A. Terraform does not support modules in local folders.

B. The module code has syntax errors inside it.

C. You forgot to initialize the Terraform backend.

D. The source path in the module call is incorrect or misspelled.

Solution

1. Step 1: Understand the error meaning

   The error 'Module not found' means Terraform cannot locate the module source path.

2. Step 2: Check common causes

   The most common cause is a wrong or misspelled source path in the module call.

3. Final Answer:

   The source path in the module call is incorrect or misspelled. -> Option D

4. Quick Check:

   Module not found = wrong source path [OK]

Hint: Check module source path spelling if module not found error [OK]

Common Mistakes:

• Assuming syntax errors cause 'Module not found'
• Thinking Terraform disallows local modules
• Confusing backend init with module loading

5. You want to create multiple GCP VM instances with similar settings using a module. Which approach best uses modules for reusability and scalability?

hard

A. Use a module only once and duplicate its code for other VMs.

B. Create a module for one VM and call it multiple times with different instance names.

C. Create separate modules for each VM with hardcoded settings.

D. Write all VM configurations directly in the main file without modules.

Solution

1. Step 1: Understand module reusability

   Modules let you reuse the same configuration by calling them multiple times with different inputs.

2. Step 2: Identify scalable approach

   Calling one VM module multiple times with different names is scalable and clean.

3. Final Answer:

   Create a module for one VM and call it multiple times with different instance names. -> Option B

4. Quick Check:

   Reuse module calls for multiple resources [OK]

Hint: Call one module multiple times with different inputs [OK]

Common Mistakes:

• Duplicating module code instead of reusing
• Hardcoding settings in separate modules
• Avoiding modules and repeating code