The Declarative Model and the Desired State
Explore the Kubernetes declarative model to understand how it manages the desired and observed state of applications. Learn about reconciliation, YAML manifests, and how controllers maintain consistency automatically. This lesson helps you grasp the core operational principles behind Kubernetes cluster management.
Declarative model
The declarative model and desired state are at the core of how Kubernetes operates. They operate on three basic principles:
Observed state
Desired state
Reconciliation
Observed state is what we have, desired state is what we want, and reconciliation is the process of keeping observed state in sync with desired state.
Note: We use the terms actual state, current state, and observed state to mean the same thing — the most up-to-date view of the cluster.
Working of the declarative model
In Kubernetes, the declarative model works like this: