Dynamic volume provisioning

Create a pod with a dynamically provisioned volume:

1. Create a PersistentVolumeClaim.
2. Create a pod.

First, install kubectl and configure it to work with the Managed Service for Kubernetes cluster you created.

Create a PersistentVolumeClaimCreate a PersistentVolumeClaim

1. Save the following PersistentVolumeClaim creation specification to a YAML file named pvc-dynamic.yaml.

   Note

   If the storageClassName parameter is not specified, the default storage class, yc-network-hdd, will be used. Learn how to change the default class in Update the default storage class.

   Learn more about the PersistentVolumeClaim creation specification in the Kubernetes guide.

   apiVersion: v1
   kind: PersistentVolumeClaim
   metadata:
     name: pvc-dynamic
   spec:
     accessModes:
       - ReadWriteOnce
     storageClassName: yc-network-hdd
     resources:
       requests:
         storage: 4Gi
   

2. Run this command:

   kubectl create -f pvc-dynamic.yaml
   

   Result:

   persistentvolumeclaim/pvc-dynamic created
   

3. View the information about the new PersistentVolumeClaim object:

   kubectl describe persistentvolumeclaim pvc-dynamic
   

   Result:

   Name:          pvc-dynamic
   Namespace:     default
   StorageClass:  yc-network-hdd
   ...
   Type    Reason                Age               From                         Message
   ----    ------                ----              ----                         -------
   Normal  WaitForFirstConsumer  9s (x3 over 15s)  persistentvolume-controller  waiting for first consumer to be created before binding
   

Create a pod with a dynamically provisioned volumeCreate a pod with a dynamically provisioned volume

1. Save the following pod creation specification to a YAML file named pod.yaml.

   Learn more about the pod creation specification in this Kubernetes guide.

   apiVersion: v1
   kind: Pod
   metadata:
     name: pod
   spec:
     containers:
     - name: app
       image: ubuntu
       command: ["/bin/sh"]
       args: ["-c", "while true; do echo $(date -u) >> /data/out.txt; sleep 5; done"]
       volumeMounts:
       - name: persistent-storage
         mountPath: /data
     volumes:
     - name: persistent-storage
       persistentVolumeClaim:
         claimName: pvc-dynamic
   

2. Run this command:

   kubectl create -f pod.yaml
   

   Result:

   pod/pod created
   

3. View the information about the new pod:

   kubectl describe pod pod
   

   Result:

   Name:         pod
   Namespace:    default
   Priority:     0
   ...
     Normal  Pulled                  11s   kubelet, cl1gqrct5oie********-ytas  Successfully pulled image "ubuntu"
     Normal  Created                 10s   kubelet, cl1gqrct5oie********-ytas  Created container
     Normal  Started                 10s   kubelet, cl1gqrct5oie********-ytas  Started container
   

   After creating the pod:

   • In the management console in Compute Cloud under Disks, a new disk will appear with the k8s-csi prefix in its name.

   • You can find the disk provisioning information in the PersistentVolumeClaim events:

     kubectl describe persistentvolumeclaim pvc-dynamic
     

     Result:

     Name:          pvc-dynamic
     Namespace:     default
     StorageClass:  yc-network-hdd
     ...
       Normal  ExternalProvisioning   4m10s (x3 over 4m10s)  persistentvolume-controller                                                              waiting for a volume to be created, either by external provisioner "disk-csi-driver.mks.ycloud.io" or manually created by system administrator
       Normal  Provisioning           4m10s                  disk-csi-driver.mks.ycloud.io_cat1h5l0v862oq74cp8j_d0f0b837-a875-11e9-b6cb-d00d********  External provisioner is provisioning volume for claim "default/pvc-dynamic"
       Normal  ProvisioningSucceeded  4m7s                   disk-csi-driver.mks.ycloud.io_cat1h5l0v862oq74cp8j_d0f0b837-a875-11e9-b6cb-d00d********  Successfully provisioned volume pvc-c4794058-ad68-11e9-b71a-d00d********
     

How to delete a volumeHow to delete a volume

To delete a dynamically provisioned volume, delete the PersistentVolumeClaim:

kubectl delete pvc <PersistentVolumeClaim_ID>

The disk will be deleted automatically from Yandex Compute Cloud.

See alsoSee also

• Volume
• Using encrypted disks for persistent volumes
• Static volume provisioning
• Managing storage classes