Terraform apply for execution - Practice Problems & Coding Challenges

Challenge - 5 Problems

❓ service_behavior

intermediate

What happens when you run terraform apply without prior terraform plan?

You have a Terraform configuration ready. You run terraform apply directly without running terraform plan first. What will Terraform do?

A Terraform will apply changes immediately without showing any plan or confirmation.

B Terraform will show the execution plan and ask for confirmation before applying changes.

C Terraform will throw an error saying you must run <code>terraform plan</code> first.

D Terraform will only validate the configuration but not apply any changes.

💡 Hint

Think about Terraform's default behavior when applying changes.

By default, terraform apply runs a plan internally, shows it to you, and asks for confirmation before making changes.

❓ Configuration

intermediate

Which command applies Terraform changes automatically without interactive approval?

You want to apply Terraform changes in an automated script without manual confirmation. Which command should you use?

A terraform apply -auto-approve

B terraform apply -no-confirm

C terraform plan -auto-approve

D terraform deploy --force

💡 Hint

Look for the official Terraform flag that skips approval.

The -auto-approve flag skips the interactive approval step during terraform apply.

❓ Architecture

advanced

What is the effect of running terraform apply with a changed backend configuration?

You modify the backend configuration in your Terraform files (e.g., change S3 bucket for state). What happens when you run terraform apply after this change?

A Terraform will ignore the backend change and use the old backend.

B Terraform will delete the old state and start fresh with the new backend.

C Terraform will fail with an error about inconsistent backend configuration.

D Terraform will migrate the state to the new backend before applying changes.

💡 Hint

Think about how Terraform handles state backend changes.

Terraform automatically migrates the state to the new backend when backend config changes are detected during terraform init or terraform apply.

❓ security

advanced

Which risk is most relevant when running terraform apply with -auto-approve in a production environment?

You run terraform apply -auto-approve in production. What is the main security or operational risk?

A Unintended destructive changes may be applied without review.

B Terraform will expose sensitive variables in logs automatically.

C The state file will be encrypted with a weak algorithm.

D Terraform will disable all resource-level access controls.

💡 Hint

Consider what skipping approval means for changes.

Using -auto-approve skips manual review, so destructive or unintended changes can happen without warning.

🧠 Conceptual

expert

What is the state of resources after a failed terraform apply due to provider API timeout?

You run terraform apply and the provider API times out during resource creation. What is the expected state of the resources and Terraform state file?

A All resources are created and state file is fully updated despite timeout.

B No resources are created and Terraform state remains unchanged.

C Some resources may be created in the cloud but Terraform state is not updated for them.

D Terraform automatically rolls back all created resources and resets state.

💡 Hint

Think about partial failures and state synchronization.

Timeouts can cause resources to be created but Terraform state not updated, leading to drift and manual reconciliation needs.

Practice

1. What does the terraform apply command do in simple terms?

easy

A. It backs up your cloud resources to local storage.

B. It creates or changes cloud resources based on your configuration.

C. It only shows a list of resources without making changes.

D. It deletes all your cloud resources immediately.

Solution

1. Step 1: Understand the purpose of terraform apply

   The command is used to make your cloud setup real by creating or updating resources defined in your configuration files.

2. Step 2: Compare options with command behavior

   Only It creates or changes cloud resources based on your configuration. correctly describes this behavior. Options A, B, and C describe actions terraform apply does not perform.

3. Final Answer:

   It creates or changes cloud resources based on your configuration. -> Option B

4. Quick Check:

   terraform apply = create/change resources [OK]

Hint: Remember: apply means 'make changes happen' [OK]

Common Mistakes:

• Thinking terraform apply only shows plans without applying
• Confusing terraform apply with terraform destroy
• Assuming terraform apply backs up resources

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

easy

A. terraform apply -skip-confirm

B. terraform apply --no-approval

C. terraform apply -auto-approve

D. terraform apply --force

Solution

1. Step 1: Recall terraform apply options for skipping approval

   The official option to skip manual approval is -auto-approve.

2. Step 2: Verify other options

   Options B, C, and D are not valid terraform flags and will cause errors.

3. Final Answer:

   terraform apply -auto-approve -> Option C

4. Quick Check:

   -auto-approve skips approval [OK]

Hint: Use -auto-approve to skip approval prompt [OK]

Common Mistakes:

• Using incorrect flags like --no-approval
• Trying to use --force which is invalid
• Assuming terraform apply never asks for approval

3. Given this terraform apply output snippet:

Plan: 2 to add, 1 to change, 0 to destroy.

What will happen after you approve the apply?

medium

A. Two resources will be created, one resource will be updated, none deleted.

B. Two resources will be deleted, one created, none updated.

C. One resource will be created, two updated, none deleted.

D. No changes will happen because destroy count is zero.

Solution

1. Step 1: Interpret the plan summary

   The plan says 2 to add means 2 new resources will be created, 1 to change means 1 existing resource will be updated, and 0 to destroy means no resources will be deleted.

2. Step 2: Match the plan to the options

   Only Two resources will be created, one resource will be updated, none deleted. correctly describes this outcome. Options A, C, and D misunderstand the counts.

3. Final Answer:

   Two resources will be created, one resource will be updated, none deleted. -> Option A

4. Quick Check:

   Plan add=2, change=1, destroy=0 [OK]

Hint: Add = create, change = update, destroy = delete [OK]

Common Mistakes:

• Mixing up add and destroy counts
• Assuming zero destroy means no changes at all
• Confusing change with destroy

4. You run terraform apply but get an error: Error: No configuration files found. What is the likely cause?

medium

A. You ran terraform apply in a directory without terraform files.

B. You forgot to initialize terraform with terraform init.

C. You used the wrong terraform version.

D. You did not approve the plan before applying.

Solution

1. Step 1: Understand the error message

   The error says no configuration files found, meaning terraform cannot find any .tf files in the current folder.

2. Step 2: Evaluate options

   You ran terraform apply in a directory without terraform files. matches this cause. You forgot to initialize terraform with terraform init. would cause a different error about initialization. You used the wrong terraform version. is unlikely to cause this specific error. You did not approve the plan before applying. is unrelated because approval happens after plan generation.

3. Final Answer:

   You ran terraform apply in a directory without terraform files. -> Option A

4. Quick Check:

   No .tf files = error [OK]

Hint: Check current folder for .tf files before apply [OK]

Common Mistakes:

• Assuming terraform init missing causes this error
• Thinking approval is needed before apply runs
• Blaming terraform version without checking files

5. You want to automate terraform apply in a CI/CD pipeline but avoid manual approval. Which command and practice is best?

hard

A. Use terraform apply --force to skip all checks.

B. Run terraform apply directly without plan or approval.

C. Run terraform plan only, then manually approve changes later.

D. Use terraform apply -auto-approve after running terraform plan and saving the plan file.

Solution

1. Step 1: Understand CI/CD automation needs

   Automation requires no manual approval and safe application of changes. Saving a plan file ensures the exact changes are applied.

2. Step 2: Evaluate command options

   Use terraform apply -auto-approve after running terraform plan and saving the plan file. correctly uses terraform plan to create a plan file, then applies it with -auto-approve to skip manual confirmation. Run terraform apply directly without plan or approval. skips planning, which is risky. Run terraform plan only, then manually approve changes later. requires manual approval, not automated. Use terraform apply --force to skip all checks. uses an invalid flag.

3. Final Answer:

   Use terraform apply -auto-approve after running terraform plan and saving the plan file. -> Option D

4. Quick Check:

   Plan then apply with -auto-approve for automation [OK]

Hint: Plan first, then apply with -auto-approve in automation [OK]

Common Mistakes:

• Skipping plan step in automation
• Using invalid flags like --force
• Expecting manual approval in CI/CD