What are the best practices for using finalizers in Kubernetes?

What are the best practices for using finalizers in Kubernetes?

Finalizers are a powerful feature in Kubernetes that allow you to control the deletion of resources. Best practices include ensuring that finalizers are idempotent, handling cleanup logic properly, and avoiding blocking deletions.

Can you explain what idempotent means in this context?

Idempotent means that performing the same operation multiple times will have the same effect as performing it once. In the context of finalizers, this ensures that if a deletion is retried, it won't cause unintended side effects.

What happens if a finalizer fails to complete its task?

If a finalizer fails, the resource will remain in a 'terminating' state until the finalizer is removed or successfully completes its task. This can lead to resources being stuck, so it's crucial to handle failures gracefully.

Are there any common pitfalls to avoid when using finalizers?

Yes, common pitfalls include not handling timeouts, creating circular dependencies between finalizers, and failing to clean up resources properly, which can lead to resource leaks.