Terraform destroy for cleanup - Practice Problems & Coding Challenges

Challenge - 5 Problems

❓ service_behavior

intermediate

What happens when you run terraform destroy?

You have applied a Terraform configuration that created several cloud resources. Now you run terraform destroy. What is the expected result?

A Terraform deletes all resources it created according to the state file.

B Terraform only deletes resources that are manually tagged for deletion.

C Terraform archives the resources but does not delete them.

D Terraform creates a backup of resources and leaves them running.

💡 Hint

Think about what Terraform tracks and how it manages resources.

Terraform destroy uses the state file to identify and delete all resources it manages, cleaning up the infrastructure.

❓ Configuration

intermediate

Which command safely destroys resources with confirmation?

You want to destroy your Terraform-managed infrastructure but want to ensure you confirm before deletion. Which command should you use?

A terraform destroy -auto-approve

B terraform apply -destroy

C terraform delete

D terraform destroy

💡 Hint

Consider which command asks for confirmation by default.

The command 'terraform destroy' asks for confirmation before deleting resources unless '-auto-approve' is used.

❓ security

advanced

What is a best practice to avoid accidental resource deletion with terraform destroy?

You want to prevent accidental destruction of critical resources when running terraform destroy. Which approach is best?

A Run <code>terraform destroy</code> with <code>-auto-approve</code> to speed up deletion.

B Use resource lifecycle block with <code>prevent_destroy = true</code> on critical resources.

C Remove the state file before running <code>terraform destroy</code>.

D Manually delete resources in the cloud console before running <code>terraform destroy</code>.

💡 Hint

Think about how Terraform can protect resources from deletion.

Setting prevent_destroy = true in the lifecycle block stops Terraform from deleting those resources, preventing accidents.

❓ Architecture

advanced

How does Terraform handle dependencies during terraform destroy?

When destroying resources, how does Terraform manage the order of deletion to avoid errors?

A Terraform deletes resources in reverse order of creation based on dependency graph.

B Terraform deletes all resources simultaneously without order.

C Terraform deletes resources alphabetically by resource name.

D Terraform requires manual deletion order specified by the user.

💡 Hint

Think about how Terraform tracks resource relationships.

Terraform builds a dependency graph and deletes resources in reverse order to respect dependencies and avoid errors.

✅ Best Practice

expert

What is the recommended way to clean up Terraform-managed infrastructure in a CI/CD pipeline?

You want to automate infrastructure cleanup in a CI/CD pipeline after tests complete. Which approach follows best practices?

A Remove Terraform state files from the pipeline workspace to trigger cleanup.

B Manually run <code>terraform destroy</code> on local machine after pipeline finishes.

C Run <code>terraform destroy -auto-approve</code> with proper state backend configured and environment variables securely set.

D Delete cloud resources directly via cloud provider console after pipeline.

💡 Hint

Consider automation, security, and state management.

Automating terraform destroy with auto-approve and secure state backend ensures reliable, repeatable cleanup in pipelines.

Practice

1. What does the terraform destroy command do?

easy

A. It updates existing resources without deleting them.

B. It deletes all resources created by Terraform in the current workspace.

C. It creates new resources defined in the configuration.

D. It shows the current state of resources without making changes.

Solution

1. Step 1: Understand the purpose of terraform destroy

   This command is designed to remove all resources that Terraform manages in the current workspace. Unlike terraform apply which creates or updates resources, terraform destroy deletes them. It does not just show state or update resources.

2. Final Answer:

   It deletes all resources created by Terraform in the current workspace. -> Option B

3. Quick Check:

   terraform destroy = deletes resources [OK]

Hint: Destroy means delete all created resources [OK]

Common Mistakes:

• Confusing destroy with apply
• Thinking destroy only shows resources
• Assuming destroy updates resources

2. Which of the following is the correct syntax to run terraform destroy without asking for confirmation?

easy

A. terraform destroy -force

B. terraform destroy --yes

C. terraform destroy --confirm

D. terraform destroy -auto-approve

Solution

1. Step 1: Recall the flag to skip confirmation

   The correct flag to skip the confirmation prompt is -auto-approve. -force, --yes, and --confirm are not valid flags for terraform destroy.

2. Final Answer:

   terraform destroy -auto-approve -> Option D

3. Quick Check:

   Skip confirmation = -auto-approve [OK]

Hint: Use -auto-approve to skip confirmation [OK]

Common Mistakes:

• Using -force instead of -auto-approve
• Typing --yes which is invalid
• Assuming --confirm works

3. Given the following Terraform commands run in order:
terraform apply -auto-approve
terraform destroy
What will happen after the second command?

medium

A. All resources created by the first command will be deleted after confirmation.

B. Resources will be updated but not deleted.

C. Nothing will happen because destroy requires -auto-approve.

D. Terraform will show an error because destroy must be run before apply.

Solution

1. Step 1: Understand the effect of terraform apply -auto-approve

   This command creates or updates resources without asking for confirmation. This command will prompt for confirmation before deleting all resources created by Terraform.

2. Final Answer:

   All resources created by the first command will be deleted after confirmation. -> Option A

3. Quick Check:

   Destroy deletes resources after confirmation [OK]

Hint: Destroy deletes resources after confirmation unless skipped [OK]

Common Mistakes:

• Thinking destroy needs -auto-approve to work
• Believing destroy updates resources
• Assuming destroy must run before apply

4. You ran terraform destroy but it failed with an error about a locked state file. What should you do to fix this?

medium

A. Run terraform init again to reset the state.

B. Manually delete the state file from your local machine.

C. Use terraform force-unlock with the lock ID to unlock the state.

D. Delete all resources manually in the cloud provider console.

Solution

1. Step 1: Understand state locking in Terraform

   Terraform locks the state file during operations to prevent conflicts. If locked, commands like destroy fail. terraform force-unlock with the lock ID safely removes the lock so you can continue.

2. Final Answer:

   Use terraform force-unlock with the lock ID to unlock the state. -> Option C

3. Quick Check:

   Unlock state with force-unlock command [OK]

Hint: Use terraform force-unlock to fix locked state errors [OK]

Common Mistakes:

• Deleting state file manually causing data loss
• Running terraform init which doesn't unlock state
• Manually deleting cloud resources instead of fixing state

5. You want to automate cleanup of your test environment using Terraform. Which approach safely destroys all resources without manual confirmation and logs the output to a file?

hard

A. Run terraform destroy -auto-approve > destroy.log to skip confirmation and save output.

B. Run terraform apply -destroy -auto-approve to destroy and log output automatically.

C. Run terraform destroy --force --log=destroy.log to force destroy and log output.

D. Run terraform delete -auto-approve > destroy.log to delete resources and log output.

Solution

1. Step 1: Identify correct command to destroy without confirmation

   terraform destroy -auto-approve skips confirmation safely. Using shell redirection with > destroy.log saves the command output to a log file.

2. Final Answer:

   Run terraform destroy -auto-approve > destroy.log to skip confirmation and save output. -> Option A

3. Quick Check:

   Destroy + auto-approve + output redirection = Run terraform destroy -auto-approve > destroy.log to skip confirmation and save output. [OK]

Hint: Use -auto-approve and > file to automate and log destroy [OK]

Common Mistakes:

• Using invalid flags like --force or --log
• Confusing apply with destroy for cleanup
• Using terraform delete which is not a valid command