AWS provider Terraform Modules — 25 Questions

Question 1

Which directory structure is considered standard for a Terraform module?

Accepted Answer

A directory containing main.tf, variables.tf, and outputs.tf.. A standard module should contain at least main.tf, variables.tf, and outputs.tf.

Answer

One single file named 'all.tf'.

Answer

A binary executable file that compiles the infrastructure.

Answer

A separate folder for every single resource.

Question 2

What is the primary benefit of using a module registry compared to a local file path for module distribution?

Accepted Answer

It enables version control and easier sharing across the organization.. Registries provide versioning, documentation generation, and centralized discovery for teams.

Answer

It allows you to run Terraform commands faster.

Answer

It removes the need for input variables.

Answer

It automatically converts your code to a higher-level language.

Question 3

When refactoring a large infrastructure configuration, you move a resource into a child module. How do you handle the existing state to prevent Terraform from destroying and recreating the resource?

Accepted Answer

Use the 'terraform state mv' command to move the resource address.. The 'terraform state mv' command is required to map the old address to the new module-relative address.

Answer

Run 'terraform refresh' to automatically detect the move.

Answer

Rename the resource in the configuration to match the old state.

Answer

Delete the state file and run 'terraform apply'.

Question 4

You have a nested module structure. How can you pass a variable from the root module through an intermediate module to a leaf module?

Accepted Answer

You must define the variable in the intermediate module and pass it to the leaf module.. Each intermediate module must define a variable and then pass it down using the 'source' or 'module' call block.

Answer

Define the variable only in the leaf module and refer to root by index.

Answer

You can use the 'global_vars' block in the root.

Answer

The intermediate module automatically inherits all root variables.

Question 5

You are designing a module that should conditionally create resources based on a boolean input. What feature should you use?

Accepted Answer

Use the 'count' meta-argument with a ternary expression.. The 'count' meta-argument is commonly used to toggle resource creation based on a boolean value.

Answer

Define multiple resources and use 'depends_on' to link them.

Answer

Use an 'if' block around the resource definition.

Answer

Use the 'module' meta-argument inside the resource.

Question 6

You need to output a complex object from a child module to be used by the root module. What is the best practice for defining the output?

Accepted Answer

Define an output block in the child module and reference it in the root module using the module prefix.. Using explicit output blocks in the child module makes the data available for access via 'module..'.

Answer

Assign the output to a global variable in the root module.

Answer

Use a data source to read the child module's internal state.

Answer

Write the output to a local file inside the module and read it in the root.

Question 7

Your team requires a custom module to be versioned strictly to prevent breaking changes during deployments. What is the recommended way to reference a module from a private Git repository?

Accepted Answer

Use the 'ref' parameter in the source URL string.. Using the 'version' argument in the source block allows pinning to specific tags or branches, ensuring stability.

Answer

Set the 'version' block inside the module definition.

Answer

Copy the module code locally every time a new version is released.

Answer

Use the 'module_version' argument in the module block.

Question 8

You are building a module that needs to be consumed by multiple teams. How should you structure your module to ensure that the root module can provide values for variable definitions without hardcoding them in the module itself?

Accepted Answer

Define variables in a variables.tf file within the module directory.. Using input variables allows the module to be generic and reusable by accepting values defined in the calling configuration.

Answer

Hardcode the values into the resource blocks directly.

Answer

Use terraform.tfvars files inside the module folder.

Answer

Define all values in a locals.tf file within the module.

Question 9

When should you use the 'for_each' meta-argument within a module?

Accepted Answer

To instantiate multiple copies of a module based on a map or set.. 'for_each' is used to create multiple instances of a module based on a map or set of strings.

Answer

To iterate over a list of variables inside a resource block.

Answer

To replace the 'count' meta-argument when you only need one instance.

Answer

To speed up the execution of the provider.

Question 10

Where do module outputs appear after a 'terraform apply'?

Accepted Answer

In the CLI output and the state file.. Outputs are displayed in the CLI output and stored in the state file.

Answer

In a file named 'outputs.json'.

Answer

They are automatically emailed to the Terraform administrator.

Answer

In the '.terraform/modules' directory.

Question 11

How can you protect a module's inputs from receiving incorrect types of data?

Accepted Answer

Use a 'validation' block with a condition inside the variable declaration.. Defining the 'type' constraint in the variable block ensures Terraform validates the input before applying changes.

Answer

Use the 'provider' block to enforce input types.

Answer

Write a custom bash script to check the inputs.

Answer

Terraform automatically validates all inputs as strings.

Question 12

You want to use a module that is hosted in a private GitHub repository. Which authentication method should Terraform use to access it?

Accepted Answer

Use the same credentials that 'git clone' would use for that repository.. Terraform uses the credentials configured in the local environment (e.g., ~/.git-credentials or SSH keys) to authenticate with private repositories.

Answer

The module must be public for Terraform to access it.

Answer

Terraform requires a special 'git_token' variable in the module block.

Answer

Embed your GitHub password in the source URL.

Question 13

What is the purpose of the 'terraform init' command when working with modules?

Accepted Answer

It downloads and installs the modules specified in the configuration.. 'terraform init' downloads and installs the modules specified in the configuration into the '.terraform/modules' directory.

Answer

It compiles the modules into machine code.

Answer

It pushes your local modules to the registry.

Answer

It updates the state file to match the modules.

Question 14

If a module has a required variable but you do not provide it in the calling configuration, what happens?

Accepted Answer

Terraform fails with an error during the planning phase.. Terraform will stop and prompt the user for the missing value during the plan or apply phase if it is not provided via command line or tfvars.

Answer

Terraform uses 'null' for the value.

Answer

Terraform uses the variable value from the previous state.

Answer

Terraform automatically sets the value to an empty string.

Question 15

You are using a module that depends on a specific provider version. Where should this constraint be defined?

Accepted Answer

In the 'required_providers' block within the module's 'terraform' block.. The 'required_providers' block within the 'terraform' block of the module is the correct location to pin versions.

Answer

In the 'provider' block of the calling root module.

Answer

In the root module only.

Answer

In a shell environment variable.

Question 16

Which argument in a module block allows you to provide a custom name to the module instance?

Accepted Answer

The label immediately following the 'module' keyword.. The module block itself uses the label to name the instance, but the 'source' argument defines the location.

Answer

'name'

Answer

'instance_name'

Answer

'alias'

Question 17

What is the impact of using 'sensitive = true' in a module output?

Accepted Answer

It prevents the value from being printed in the CLI output.. It marks the output as sensitive, preventing it from being printed to the console during 'terraform apply' or 'plan'.

Answer

It disables the ability to use that output in other modules.

Answer

It encrypts the data in the state file.

Answer

It automatically rotates the sensitive credentials.

Question 18

You need to share a module across your entire organization. Which registry type should you use?

Accepted Answer

A private module registry in Terraform Cloud or Enterprise.. Terraform Cloud or Terraform Enterprise private module registries are the standard for internal organization-wide sharing.

Answer

The public Terraform Registry.

Answer

A shared network drive.

Answer

An S3 bucket with public read access.

Question 19

Which THREE of the following are valid sources for a Terraform module?

Accepted Answer

The Terraform Registry.. Terraform supports modules from local paths, the Terraform Registry, and version control providers like Git.

Answer

A directly linked SQL database.

Answer

A raw HTTP file download link.

Question 20

What is the recommended approach for managing a module that has grown too large?

Accepted Answer

Break the module into smaller, focused sub-modules.. Refactoring into smaller, single-purpose sub-modules improves maintainability and readability.

Answer

Use 'terraform import' to split the resources.

Answer

Combine all files into a single 'main.tf'.

Answer

Rename the module to something more generic.