1. Introduction
Running kubectl get all to retrieve a list of all resources in a namespace only does so much. While it returns a list of various resources in a namespace, it omits some resource types. Of course, this is undesirable when we really need an exhaustive list of all resources in the namespace.
In this tutorial, we’ll learn how to list all resources in a namespace in Kubernetes.
2. Using kubectl get all
As we mentioned earlier, we can get a list of some resources in a namespace when we run kubectl get all:
$ kubectl get all
NAME READY STATUS RESTARTS AGE
pod/app-deployment-5dc467b756-4zwcp 0/1 CreateContainerConfigError 0 5d19h
pod/app-deployment-5dc467b756-qplj6 0/1 CreateContainerConfigError 0 5d19h
NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE
service/kubernetes ClusterIP 10.96.0.1 <none> 443/TCP 5d22h
NAME READY UP-TO-DATE AVAILABLE AGE
deployment.apps/app-deployment 0/2 2 0 5d19h
NAME DESIRED CURRENT READY AGE
replicaset.apps/app-deployment-5dc467b756 2 2 0 5d19hHowever, some resource types, such as config map, would be missing from the returned list.
Wherever applicable, kubectl get all returns a list of pods, services, daemon sets, deployments, replica sets, jobs, cronjobs, and stateful sets. But it doesn’t display resources like config maps, secrets, persistent volumes, persistent volume claims, ingresses, service accounts, amongst others.
3. Using kubectl api-resources
When we want a more encompassing list of all resources in a namespace, we can combine the kubectl api-resources command with kubectl-get:
$ kubectl api-resources --verbs=list --namespaced -o name | xargs -n 1 kubectl get --ignore-not-found --show-kind -n <namespace>Let’s try the command on the default namespace of our cluster:
$ kubectl api-resources --verbs=list --namespaced -o name | xargs -n 1 kubectl get --ignore-not-found --show-kind
NAME DATA AGE
configmap/db-config 1 137m
...truncated..
NAME ENDPOINTS AGE
endpoints/kubernetes 192.168.49.2:8443 6d1h
LAST SEEN TYPE REASON OBJECT MESSAGE
76s Normal Pulling pod/app-deployment-5dc467b756-4zwcp Pulling image "adeyomola/app:latest"
...truncated...
NAME STATUS VOLUME CAPACITY ACCESS MODES STORAGECLASS AGE
persistentvolumeclaim/www-web-0 Bound pvc-43444fce-40e5-4b85-9336-95776ffe332e 1Gi RWO standard 139m
...truncated...
NAME READY STATUS RESTARTS AGE
pod/app-deployment-5dc467b756-4zwcp 0/1 CreateContainerConfigError 0 5d22h
...truncated...
NAME SECRETS AGE
serviceaccount/default 0 10d
NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE
service/kubernetes ClusterIP 10.96.0.1 <none> 443/TCP 6d1h
NAME READY UP-TO-DATE AVAILABLE AGE
deployment.apps/app-deployment 0/2 2 0 5d22h
NAME DESIRED CURRENT READY AGE
replicaset.apps/app-deployment-5dc467b756 2 2 0 5d22h
...truncated...
NAME CLASS HOSTS ADDRESS PORTS AGE
ingress.networking.k8s.io/minimal-ingress nginx-example * 80 44mFrom the output, we can see that ingresses, endpoints, service accounts, persistent volume claims, and config maps are amongst the returned resources. This is unlike the restrictive list from kubectl get all.
3.1. Understanding the kubectl api-resources Command
kubectl api-resources –verbs=list –namespaced -o name retrieves all namespaced API resource types that support the list API verb. Then it outputs their names. Those names are then redirected to xargs as standard input.
xargs -n 1 singly passes each of those names as initial arguments to kubectl get –ignore-not-found –show-kind -n <namespace>. Then, the kubectl get command returns a list of resources belonging to each resource type in the specified namespace.
The –ignore-not-found flag of kubectl get suppresses output if an instance of a requested resource type doesn’t exist in the namespace. In other words, the flag suppresses “No resources found in <namespace> namespace.” messages. Then, the –show-kind flag ensures that the output specifies the resource type of every resource.
The -n 1 arguments in the xargs command ensures that only one name from the kubectl api-resources output is used per iteration of the kubectl get command.
4. Using kubectl api-resources and for Loop
In place of xargs -n 1, we can pass the name of each resource type returned by kubectl api-resources –verbs=list –namespaced -o name to kubectl get –ignore-not-found –show-kind -n <namespace> using a for loop:
$ for i in $(kubectl api-resources --namespaced --verbs=list -o name | tr "\n" " ");
do
kubectl get $i --show-kind --ignore-not-found;
done
NAME DATA AGE
configmap/db-config 1 4h16m
...truncated...
NAME ENDPOINTS AGE
endpoints/kubernetes 192.168.49.2:8443 6d3h
...truncated..
NAME CLASS HOSTS ADDRESS PORTS AGE
ingress.networking.k8s.io/minimal-ingress nginx-example * 80 164mWe get pretty much the same output as when we used kubectl api-resources and kubectl get with xargs.
5. Retrieving a List of Multiple Resource Types
Sometimes, we’re not really interested in a list of all resources in a namespace. However, we want a list of all resources of specific resource types in a namespace. At such times, combining kubectl get and kubectl api-resources would be an overkill since the combination is somewhat non-specific.
Adding multiple, comma-separated arguments to kubectl get allows us to list all resources of specific resource types in a namespace:
$ kubectl get <resource type>,<resource type>,<resource type>,... -n <namespace>Let’s retrieve a list of config maps, persistent volumes, endpoints, ingress, and service accounts in the kube-system namespace:
$ kubectl get configmaps,pv,endpoints,ingress,serviceaccounts -n kube-system
NAME DATA AGE
configmap/coredns 1 10d
...truncated...
NAME CAPACITY ACCESS MODES RECLAIM POLICY STATUS CLAIM STORAGECLASS REASON AGE
persistentvolume/pvc-43444fce-40e5-4b85-9336-95776ffe332e 1Gi RWO Delete Bound default/www-web-0 standard 4h36m
persistentvolume/pvc-a6f90403-b427-4483-a6a4-7cf07d2d7852 1Gi RWO Delete Bound default/www-web-1 standard 4h36m
NAME ENDPOINTS AGE
endpoints/k8s.io-minikube-hostpath <none> 10d
endpoints/kube-dns 10.244.0.161:53,10.244.0.161:53,10.244.0.161:9153 6d4h
NAME SECRETS AGE
serviceaccount/attachdetach-controller 0 10d
serviceaccount/bootstrap-signer 0 10d
...truncated...6. Conclusion
In this article, we discussed how to list all resources in namespaces of a Kubernetes cluster. We also saw how to list resources of multiple (specific) resource types in a namespace.
Many times, running kubectl get all might be enough to show us a list of all resources we need to see in a namespace. Most of the resources it returns are the ones we’d commonly work with. However, whenever we need comprehensiveness, we’ll have to redirect names of API resource types from kubectl api-resources to kubectl get.