How to list applied Custom Resource Definitions in kubernetes with kubectl

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I recently applied this CRD file

https://raw.githubusercontent.com/jetstack/cert-manager/release-0.11/deploy/manifests/00-crds.yaml

With kubectl apply to install this: https://hub.helm.sh/charts/jetstack/cert-manager

I think I managed to apply it successfully:

xetra11@x11-work configuration]$ kubectl apply -f ./helm-charts/certificates/00-crds.yaml --validate=false
customresourcedefinition.apiextensions.k8s.io/challenges.acme.cert-manager.io created
customresourcedefinition.apiextensions.k8s.io/orders.acme.cert-manager.io created
customresourcedefinition.apiextensions.k8s.io/certificaterequests.cert-manager.io created
customresourcedefinition.apiextensions.k8s.io/certificates.cert-manager.io created
customresourcedefinition.apiextensions.k8s.io/clusterissuers.cert-manager.io created
customresourcedefinition.apiextensions.k8s.io/issuers.cert-manager.io created

But now I would like to "see" what I just applied here. I have no idea how to list those definitions or for example remove them if I think they will screw up my cluster somehow.

I was not able to find any information to that here: https://kubernetes.io/docs/concepts/extend-kubernetes/api-extension/custom-resources/#preparing-to-install-a-custom-resource

kubernetes-custom-resources kubernetes
5 Answers

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>.

user_97294130

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
user_85570350

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>

user_72076730

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

kubectl get crds

Describe the crd:

kubectl describe crd challenges.acme.cert-manager.io
user_40859940

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.

user_3986700
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