kubectl get customresourcedefinitions

, or

kubectl get crd

.

You can then use

kubectl describe crd <crd_name>

to get a description of the CRD. And of course

kubectl get crd <crd_name> -o yaml

to get the complete definition of the CRD.

To remove you can use

kubectl delete crd <crd_name>

.

Custom Resources are like any other native Kubernetes resource.

All the basic kubeclt CRUD operations work fine for CRDs. So just use any of the below commands.

kubectl get crd <name of crd>
kubectl describe crd <name of crd>
kubectl get crd <name of crd> -o yaml 

First, you can list all your CRD's with

kubectl get crd

for example:

$ kubectl get crd
  NAME                                                        CREATED AT
  secretproviderclasses.secrets-store.csi.x-k8s.io            2022-07-06
  secretproviderclasspodstatuses.secrets-store.csi.x-k8s.io   2022-07-06

This is the list of available CRD's definitions, then you take the name of one and launch a

kubectl get <crd_name>

to get a list of applied resources from this CRD. For example:

$ kubectl get secretproviderclasses.secrets-store.csi.x-k8s.io
  NAME       AGE
  azure-kv   5d

Note: Use

-A

to target all namespaces or

-n <namespace>

You may arrive here confused about why you see your CRDs in

kubectl get api-resources

, e.g. this Istio Telemetry resource:

kubectl api-resources --api-group=telemetry.istio.io
NAME          SHORTNAMES   APIVERSION                    NAMESPACED   KIND
telemetries   telemetry    telemetry.istio.io/v1alpha1   true         Telemetry

but then attempting to

kubectl describe

them yields an error like

kubectl describe crd Telemetry.telemetry.istio.io
Error from server (NotFound): customresourcedefinitions.apiextensions.k8s.io "Telemetry.telemetry.istio.io" not found

or

kubectl describe crd telemetry.istio.io/v1alpha1
error: there is no need to specify a resource type as a separate argument when passing arguments in resource/name form (e.g. 'kubectl get resource/<resource_name>' instead of 'kubectl get resource resource/<resource_name>'

That's because you must use the plural form of the full name of the CRD. See

kubectl get crd

for the names, e.g.:

$ kubectl get crd |grep -i telemetry
telemetries.telemetry.istio.io                                     2022-03-21T08:49:29Z

So

kc describe crd telemetries.telemetry.istio.io

will work for this CRD.

List the crds (no namespace as crds are cluster scoped):

kubectl get crds

Describe the crd:

kubectl describe crd challenges.acme.cert-manager.io

Since CRDs are not namespaced (but in cluster scope), you'll probably want to list all the custom resources that were created in a specific namespace:

kubectl api-resources --verbs=list --namespaced -o name \
| xargs -n 1 kubectl get --show-kind --ignore-not-found -n <namespace>

You can read more about it here https://github.com/kubernetes/kubectl/issues/151