create_before_destroy and prevent_destroy

Scenario: A broad cleanup plan includes the production data store, and an engineer notices only after approval.

create_before_destroy changes replacement ordering. prevent_destroy rejects plans that would destroy a protected instance while the lifecycle rule remains in configuration. It is a tripwire, not a backup and not protection from deleting the configuration plus state or using the provider console. Lifecycle decisions can propagate through dependencies and should be used selectively.

Analogy: A safety catch reduces accidental discharge; it does not make a weapon harmless or replace training.

A worked configuration

lifecycle {
  create_before_destroy = true
  prevent_destroy       = true
}

Use provider-native deletion protection, backups, least privilege, and policy controls alongside Terraform lifecycle rules. Document the exceptional process for removing protection so emergencies do not produce improvised state surgery.

Note: Treat the plan as a change contract: understand every create, update, replacement, and destroy before approving it.

Goal: Reinforce this lesson in the tf-lifecycle-safety Terraform lab. Open /labs/terraform and choose slug tf-lifecycle-safety; the lab runs real Terraform against the offline FakeCloud provider.