How Kubernetes manages state
As discussed previously, we know that Kubernetes makes an effort to enforce the desired state of the operator in a given cluster. Deployments give operators the ability to define an end state and the mechanisms to effect change at a controlled rate of stateless services, such as microservices. Since Kubernetes is a control and data plane that manages the metadata, current status, and specification of a set of objects, Deployments provide a deeper level of control for your applications. There are a few archetypal deployment patterns that are available: recreate, rolling update, blue/green via selector, canary via replicas, and A/B via HTTP headers.
