lastapplied

Lastapplied is a term used to describe the most recently applied configuration for a resource in declarative configuration workflows, most notably within Kubernetes when using kubectl apply. It refers to the manifest that a user previously submitted through an apply operation and serves as a baseline for subsequent updates.

In Kubernetes, the last applied configuration is stored on the resource as an annotation named kubectl.kubernetes.io/last-applied-configuration. This annotation contains a JSON representation of the object’s spec as it was when the last successful apply occurred. The information is used by kubectl apply to perform a three-way merge: it compares the live object, the last applied configuration, and the new desired configuration to determine what changes to apply.

The last-applied annotation is primarily a client-side mechanism. It helps kubectl understand user intent during subsequent applies and supports drift detection and incremental updates. However, it is not the authoritative source of truth for the resource’s current state, which is reflected in the live spec and status. If a user edits a resource directly or bypasses apply, the last-applied annotation may become out of sync with reality and can lead to surprising patches unless re-applied.

With the introduction of server-side apply, Kubernetes began relying more on managedFields to track field ownership. In that context, the last-applied annotation remains a compatibility artifact and may be less central to state reconciliation, though it can still influence traditional client-side apply workflows. See also kubectl apply, server-side apply, and three-way merge.