CRD and CR¶
CRD¶
CRD
is the abbreviation of Custom Resource Definition
, which is a built-in native resource type of Kubernetes
. It is the definition of a custom resource (CR), which describes what a custom resource is.
CRD can register a new resource with the Kubernetes
cluster to extend the capabilities of the Kubernetes
cluster. With CRD
, you can customize the abstraction of the underlying infrastructure, customize resource types according to business needs, and use the existing resources and capabilities of Kubernetes
to define higher-level abstractions through the pattern of Lego blocks.
CR¶
CR
is the abbreviation of Custom Resource
, it is actually an instance of CRD
, and it is a resource description conforming to the field format definition in CRD
.
CRDs + Controllers¶
We all know that Kubernetes
has a very powerful expansion capability, but only CRD
is useless, and it needs the support of a controller (Custom Controller
) to reflect the value of CRD
, Custom Controller
You can listen to the CRUD
event of CR
to implement custom business logic.
In Kubernetes
, it can be said that CRDs + Controllers = Everything
.
Please also refer to the official Kubernetes documentation: