TF-004 Read, generate and modify configuration Practice Test 2 — 15 Questions

Question 1

An operator wants to pass output values from one Terraform configuration to another as input variables. Which approach is recommended?

Accepted Answer

Use a remote state data source to read the outputs from the first configuration's state.. Terraform's remote state data source (e.g., `terraform_remote_state`) allows one configuration to securely read output values from another configuration's state file stored in a shared backend (like S3, Azure Storage, or Consul). This avoids duplication, manual errors, and ensures that the second configuration always uses the latest outputs from the first, without requiring direct file access or environment variables.

Answer

Hardcode the output values in a variables file for the second configuration.

Answer

Store outputs in a shared file and use 'file()' function to read them.

Answer

Use environment variables to pass the output values.

Question 2

A Terraform configuration includes a resource block with a 'lifecycle' block that has 'create_before_destroy = true'. During an apply, the create step succeeds but the destroy step fails. What is the resulting state?

Accepted Answer

Both the old and new resources are in state.. When `create_before_destroy = true` is set, Terraform creates the new resource first, then destroys the old one. If the destroy step fails after the new resource is created, both resources exist in the state file because Terraform does not remove the old resource from state until the destroy operation completes successfully. The state retains both resource instances at the same address, which is why option D is correct.

Answer

Only the new resource remains in state, old resource is destroyed.

Answer

The state is empty for that resource address.

Answer

Only the old resource remains in state.

Question 3

A configuration uses variables defined in a 'variables.tf' file. The operator wants to override these variables for a specific run without modifying the file. Which method should they use?

Accepted Answer

Use the '-var' flag with 'terraform plan' or 'terraform apply'.. The `-var` flag on `terraform plan` or `terraform apply` allows operators to override variable values for a single run without modifying any files. This is the correct method because it provides a temporary override that does not persist across runs, unlike file-based or environment variable approaches.

Answer

Edit the state file directly.

Answer

Set environment variables with the same name as the variables.

Answer

Create a 'terraform.tfvars' file.

Question 4

Which TWO statements about Terraform provisioners are correct?

Accepted Answer

Provisioners should be used as a last resort when no other Terraform resource or data source fits.. Terraform provisioners are considered a last resort for tasks that cannot be accomplished with Terraform's declarative resource model. The official Terraform documentation explicitly states that provisioners should be used sparingly, as they introduce procedural logic and can cause state drift or failures that are hard to debug. This aligns with the principle of keeping configurations idempotent and relying on native resource attributes or data sources first.

Answer

Provisioners can only be used with the 'local-exec' and 'remote-exec' provisioners.

Answer

Provisioners are the primary way to configure resources after creation.

Answer

Provisioners run only once during initial creation by default.

Question 5

You are managing a Terraform configuration for a multi-tier application that includes AWS EC2 instances, an RDS database, and an Application Load Balancer. The configuration uses multiple modules and remote state stored in an S3 bucket with DynamoDB locking. Recently, a colleague made changes to the configuration and applied them successfully. However, you now need to make additional changes and, when you run 'terraform plan', you receive an error: "Error: Error acquiring the state lock". The error message indicates that the lock is held by a different user. You have confirmed that your colleague is not currently running Terraform. What is the most appropriate course of action to proceed with your changes?

Accepted Answer

Run 'terraform force-unlock ' to remove the stale lock.. Terraform uses DynamoDB for state locking to prevent concurrent modifications. When a lock becomes stale (e.g., due to a crash or network interruption), `terraform force-unlock ` is the proper command to manually release it. This preserves the integrity of the state file and avoids manual S3 or DynamoDB edits, which could corrupt the state or break the locking mechanism.

Answer

Edit the state file to remove the lock metadata.

Answer

Run 'terraform init -reconfigure' to reset the backend and release the lock.

Answer

Delete the lock file from the S3 bucket manually.

Question 6

A team is writing Terraform configurations for a multi-region deployment. They want to use a module from the public Terraform Registry that provisions AWS VPCs. The module has been updated recently, but the team wants to ensure that all deployments use the same version of the module to avoid unexpected changes. Which configuration approach should they take to lock the module version?

Accepted Answer

Use the 'version' argument in the module block to specify the exact version.. The 'version' argument in a module block is the standard Terraform mechanism for pinning a module from the Terraform Registry to a specific semantic version. This ensures that all deployments use the exact same module version, preventing unexpected changes from newer releases. The version constraint is evaluated against the registry's metadata and enforces the specified version during 'terraform init'.

Answer

Run 'terraform lock' on the module to record its version in the dependency lock file.

Answer

Reference the module source with a git URL and tag, such as 'git::https://github.com/...?ref=v1.0'.

Answer

Set the 'required_version' argument in the root module to match the module's version.

Question 7

Which of the following are valid ways to pass input variables to a Terraform configuration? (Select all that apply.)

Accepted Answer

Use the '-var' flag on the command line to set a single variable.. Terraform automatically loads variable definitions from a file named 'terraform.tfvars' (or 'terraform.tfvars.json') in the current directory when you run a plan or apply. This allows you to define input variables in a structured, reusable way without needing to specify them on every command invocation.

Question 8

Refer to the exhibit. A developer runs 'terraform plan' and receives the following error: 'Error: InvalidAMIID.NotFound: The image id '[ami-0c55b159cbfafe1f0]' does not exist'. What is the most likely cause?

Accepted Answer

The AMI is not available in the region specified in the provider configuration.. The error 'InvalidAMIID.NotFound' indicates that the specified AMI ID does not exist in the AWS region configured in the Terraform provider block. AMI IDs are region-specific; an AMI available in us-east-1 may not exist in eu-west-2. Terraform validates the AMI against the region's EC2 API, and if the ID is not found, it throws this exact error.

Answer

The 'tags' block is missing a required 'ami' tag.

Answer

The 'ami' argument is misspelled; it should be 'image_id'.

Answer

The AMI ID is malformed; it should start with 'ami-' but the rest is incorrect.

Question 9

You are a DevOps engineer at a company that manages infrastructure for multiple environments (dev, staging, prod) using Terraform. Each environment has its own state file stored in an S3 backend with DynamoDB locking. The team recently adopted a policy of running 'terraform plan' in CI/CD pipelines to review changes before applying. However, developers have reported that sometimes the plan output shows that Terraform wants to destroy and recreate resources that were not modified in their code changes. For example, a developer added a new tag to an S3 bucket in the staging environment, but the plan also showed that an unrelated EC2 instance would be replaced. Upon investigation, you notice that the state file for staging was last modified two days ago, but the developer's branch is based on a commit from one week ago. Which action is most likely to resolve the issue and ensure that plans only reflect changes from the current configuration changes?

Accepted Answer

Run 'terraform init -reconfigure' to ensure the local state is synchronized with the remote backend before planning.. `terraform init -reconfigure` forces Terraform to reinitialize the backend and re-download the latest state file from the remote S3 backend, discarding any stale local copy. The developer's local state was based on a week-old commit, while the actual remote state had been updated two days ago, causing Terraform to detect spurious differences (e.g., an unrelated EC2 instance) due to state drift. This command ensures the local state matches the remote state before planning, so the plan only reflects changes from the current configuration.

Answer

Set the 'skip_metadata_api_check' option in the provider to avoid changes.

Answer

Use 'terraform plan -target=aws_s3_bucket.bucket' to limit the plan to only the S3 bucket.

Answer

Run 'terraform plan -refresh=true' to refresh the state before planning.

Question 10

You are managing a multi-environment Terraform configuration using separate workspaces for 'dev', 'staging', and 'prod'. Each workspace uses the same root module but different variable values stored in terraform.tfvars files per workspace. Your team reports that after a recent change to the root module, running `terraform plan` in the 'dev' workspace shows that it will destroy and recreate a critical RDS database instance, even though no changes were made to the database configuration. The state file for 'dev' is stored in a remote S3 backend with DynamoDB locking. You suspect the issue is related to how Terraform generates and reads configuration. What is the most likely cause?

Accepted Answer

A new variable with a default value that forces recreation of the database was added to the root module, but the 'dev' workspace's tfvars file does not override it, so Terraform uses the default which differs from the current state.. When a new variable with a default value is added to the root module, and the 'dev' workspace's terraform.tfvars does not override it, Terraform uses the default value. If that default differs from the value currently tracked in the state (e.g., a database engine version or instance class), Terraform interprets this as a configuration change and plans to destroy and recreate the resource to match the new default. This is a common pitfall when variables are introduced without updating all workspace-specific variable files.

Answer

The S3 backend is misconfigured, causing the 'dev' workspace to use the 'prod' state file.

Answer

The root module was changed to use a different Terraform provider version that is incompatible with the existing state.

Answer

The DynamoDB lock is not being released after previous operations, causing state corruption.

Question 11

Which three of the following are valid methods for reading, generating, or modifying Terraform configuration? (Choose three.)

Accepted Answer

Using `terraform console` to interactively evaluate expressions and inspect resource attributes.. The `terraform fmt` command rewrites configuration files to a canonical format and style, which is a valid method for modifying configuration. The `templatefile` function reads a template file and renders it with supplied variables, enabling dynamic configuration generation. The `terraform console` command provides an interactive shell for evaluating expressions and inspecting resource attributes, which is a valid way to read and test configuration logic.

Answer

Using the `merge` function to combine multiple map values, but only when the source maps are defined in separate Terraform modules.

Answer

Using the `terraform plan -generate-config-out` flag to automatically create configuration from existing infrastructure.

Answer

Using the `terraform state push` command to directly edit the state file and then reflect those changes back into the configuration.

Question 12

Which four of the following are valid techniques for reading, generating, or modifying Terraform configuration? (Choose all that apply. There are four correct answers.)

Accepted Answer

Using a `data` source with a `for_each` and a `local` value to dynamically generate resource blocks based on a variable input.. The `templatefile` function is a valid technique for reading and generating configuration because it reads an external template file and renders it with variables from the current Terraform configuration, producing a string that can be used in resource arguments or other expressions. This is a core feature for dynamic configuration generation, such as injecting user data into cloud-init scripts or generating complex configuration files for provisioned resources.

Answer

Using `terraform console` to evaluate expressions and generate valid HCL configuration output.

Answer

Using `terraform state pull` to retrieve remote state and then using `terraform state mv` to rename a resource address in the local state file before pushing it back.

Question 13

Drag and drop the steps to handle sensitive data in Terraform outputs in the correct order.

Accepted Answer

First, define the output as sensitive. Next, run terraform apply. Then, use terraform output -json to retrieve the raw value. Finally, securely handle the raw value.. Sensitive outputs are redacted in CLI; -json reveals raw value for secure handling.

Answer

First, run terraform apply. Next, define the output as sensitive. Then, use terraform output -json to retrieve the raw value. Finally, securely handle the raw value.

Answer

First, define the output as sensitive. Next, use terraform output -json to retrieve the raw value. Then, run terraform apply. Finally, securely handle the raw value.

Answer

First, define the output as sensitive. Next, run terraform apply. Then, securely handle the raw value. Finally, use terraform output -json to retrieve the raw value.

Question 14

Match each Terraform variable type to its example value.

Accepted Answer

string: "hello". Terraform variable types: string uses quotes, number is numeric, bool is true/false, list is an array. Common mistakes include confusing numbers with strings and lists with bools.

Answer

string: 42

Answer

bool: ["a", "b"]

Question 15

Which Terraform command is used to check the syntax and internal consistency of configuration files?

Accepted Answer

terraform validate. The `terraform validate` command checks the syntax and internal consistency of Terraform configuration files, ensuring that the code is syntactically valid and that references between resources, data sources, and variables are correct. It does not access remote state or providers, making it a fast, offline validation step. This is the correct command for verifying configuration correctness before applying changes.

Answer

terraform fmt

Answer

terraform plan

Answer

terraform graph