Provisioner failure behavior in Terraform - Practice Problems & Coding Challenges

Challenge - 5 Problems

❓ service_behavior

intermediate

What happens when a local-exec provisioner fails during resource creation?

In Terraform, if a local-exec provisioner attached to a resource fails during the resource creation phase, what is the resulting behavior?

A Terraform marks the resource as created but reports the provisioner failure as a warning and continues.

B Terraform aborts the apply, marks the resource as tainted, and does not complete the resource creation.

C Terraform ignores the provisioner failure and completes the resource creation successfully.

D Terraform retries the provisioner indefinitely until it succeeds before marking the resource created.

💡 Hint

Think about how Terraform treats provisioner failures during resource creation.

Terraform treats provisioner failures during resource creation as errors, aborting the apply and marking the resource as tainted to indicate it needs recreation.

❓ service_behavior

intermediate

What is the default behavior of Terraform when a remote-exec provisioner fails during resource destruction?

If a remote-exec provisioner fails during the destruction of a resource, what does Terraform do by default?

A Terraform retries the provisioner once and then continues destroying the resource regardless of success.

B Terraform aborts the destroy operation and leaves the resource intact.

C Terraform ignores the failure and continues destroying the resource.

D Terraform marks the resource as tainted and stops the destroy operation.

💡 Hint

Consider how Terraform treats provisioner failures during destroy phase.

By default, Terraform ignores provisioner failures during resource destruction and continues with the destroy operation.

❓ Architecture

advanced

Which option correctly describes the effect of on_failure = 'continue' in a provisioner block?

In a Terraform provisioner block, setting on_failure = 'continue' changes the failure behavior. What is the exact effect of this setting?

A Terraform aborts the apply immediately on provisioner failure regardless of this setting.

B Terraform continues the apply even if the provisioner fails, but marks the resource as tainted.

C Terraform retries the provisioner until it succeeds before continuing the apply.

D Terraform continues the apply and does not mark the resource as tainted despite provisioner failure.

💡 Hint

Think about how on_failure controls marking resources as tainted.

Setting on_failure = 'continue' tells Terraform to continue the apply even if the provisioner fails and not mark the resource as tainted.

❓ security

advanced

What security risk arises if a provisioner script fails silently due to on_failure = 'continue'?

If a provisioner script that configures security settings fails but on_failure = 'continue' is set, what is the main security risk?

A The resource may be created without the intended security hardening, leaving it vulnerable.

B Terraform will alert the user immediately, preventing deployment.

C Terraform will roll back the resource, preventing insecure configurations.

D The provisioner failure will trigger an automatic security patch update.

💡 Hint

Consider what happens if security steps are skipped silently.

If the provisioner fails silently, the resource may lack critical security configurations, exposing it to vulnerabilities.

✅ Best Practice

expert

Which approach best ensures reliable provisioning with Terraform provisioners?

To minimize failures and ensure reliable execution of provisioner scripts in Terraform, which approach is best?

A Avoid provisioners entirely; use configuration management tools or cloud-init for provisioning instead.

B Use multiple provisioners with retries and <code>on_failure = 'continue'</code> to cover all failure cases.

C Use provisioners only for critical configuration and set <code>on_failure = 'continue'</code> to avoid apply failures.

D Run provisioners manually after Terraform apply to ensure success.

💡 Hint

Think about Terraform's recommended best practices for provisioning.

Terraform recommends avoiding provisioners when possible and using dedicated configuration management or cloud-init for reliable provisioning.