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Configure Quotas for API Objects

This page shows how to configure quotas for API objects, including PersistentVolumeClaims and Services. A quota restricts the number of objects, of a particular type, that can be created in a namespace. You specify quotas in a ResourceQuota object.

Before you begin
Create a namespace
Create a ResourceQuota
Create a PersistentVolumeClaim
Attempt to create a second PersistentVolumeClaim
Notes
Clean up
What's next

Before you begin

You need to have a Kubernetes cluster, and the kubectl command-line tool must be configured to communicate with your cluster. If you do not already have a cluster, you can create one by using Minikube, or you can use one of these Kubernetes playgrounds:

To check the version, enter kubectl version.

Create a namespace

Create a namespace so that the resources you create in this exercise are isolated from the rest of your cluster.

kubectl create namespace quota-object-example

Create a ResourceQuota

Here is the configuration file for a ResourceQuota object:

`admin/resource/quota-objects.yaml`
`apiVersion: v1 kind: ResourceQuota metadata: name: object-quota-demo spec: hard: persistentvolumeclaims: "1" services.loadbalancers: "2" services.nodeports: "0"`

Create the ResourceQuota:

kubectl create -f https://k8s.io/examples/admin/resource/quota-objects.yaml --namespace=quota-object-example

View detailed information about the ResourceQuota:

kubectl get resourcequota object-quota-demo --namespace=quota-object-example --output=yaml

The output shows that in the quota-object-example namespace, there can be at most one PersistentVolumeClaim, at most two Services of type LoadBalancer, and no Services of type NodePort.

status:
  hard:
    persistentvolumeclaims: "1"
    services.loadbalancers: "2"
    services.nodeports: "0"
  used:
    persistentvolumeclaims: "0"
    services.loadbalancers: "0"
    services.nodeports: "0"

Create a PersistentVolumeClaim

Here is the configuration file for a PersistentVolumeClaim object:

`admin/resource/quota-objects-pvc.yaml`
`kind: PersistentVolumeClaim apiVersion: v1 metadata: name: pvc-quota-demo spec: storageClassName: manual accessModes: - ReadWriteOnce resources: requests: storage: 3Gi`

Create the PersistentVolumeClaim:

kubectl create -f https://k8s.io/examples/admin/resource/quota-objects-pvc.yaml --namespace=quota-object-example

Verify that the PersistentVolumeClaim was created:

kubectl get persistentvolumeclaims --namespace=quota-object-example

The output shows that the PersistentVolumeClaim exists and has status Pending:

NAME             STATUS
pvc-quota-demo   Pending

Attempt to create a second PersistentVolumeClaim

Here is the configuration file for a second PersistentVolumeClaim:

`admin/resource/quota-objects-pvc-2.yaml`
`kind: PersistentVolumeClaim apiVersion: v1 metadata: name: pvc-quota-demo-2 spec: storageClassName: manual accessModes: - ReadWriteOnce resources: requests: storage: 4Gi`

Attempt to create the second PersistentVolumeClaim:

kubectl create -f https://k8s.io/examples/admin/resource/quota-objects-pvc-2.yaml --namespace=quota-object-example

The output shows that the second PersistentVolumeClaim was not created, because it would have exceeded the quota for the namespace.

persistentvolumeclaims "pvc-quota-demo-2" is forbidden:
exceeded quota: object-quota-demo, requested: persistentvolumeclaims=1,
used: persistentvolumeclaims=1, limited: persistentvolumeclaims=1

Notes

These are the strings used to identify API resources that can be constrained by quotas:

String	API Object
"pods"	Pod
"services	Service
"replicationcontrollers"	ReplicationController
"resourcequotas"	ResourceQuota
"secrets"	Secret
"configmaps"	ConfigMap
"persistentvolumeclaims"	PersistentVolumeClaim
"services.nodeports"	Service of type NodePort
"services.loadbalancers"	Service of type LoadBalancer

Clean up

Delete your namespace:

kubectl delete namespace quota-object-example

What's next

For cluster administrators

For app developers

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