In Kubernetes, all of the resources have their REST endpoints in the Kubernetes API server. REST endpoints enable operations for specif c objects, such as pods, by using /api/v1/namespaces/default/pods. Custom resources are the extensions of the Kubernetes API that can be dynamically added or removed during runtime. They enable users of the cluster to operate on extended resources.

Custom resources are defined in Custom Resource Definition (CRD) objects. Using the built-in Kubernetes resources, namely CRDs, it is possible to add new Kubernetes API endpoints by using the Kubernetes API itself.

In the following section, a new custom resource will be created for the requirements that typically require human interaction inside Kubernetes.