10.1. Persistent Volumes

A persistent volume is allocated storage for Kubernetes applications. You as the user don’t directly create persistent volumes, you request them with a persistent volume claim. The Kubernetes system processes your PersistentVolumeClaim and satisfies it by creating a PersistentVolume.

The Resource

Create the file deployment/pvc.yaml with the following contents:

apiVersion: v1
kind: PersistentVolumeClaim
metadata:
  name: mysite-data
spec:
  resources:
    requests:
      storage: 1Gi 
  accessModes:
  - ReadWriteOnce

Apply and Check the PVC

Apply the PersistentVolumeClaim resource:

$ kubectl apply -f pvc.yaml

Verify that the resource has been created:

Warning

On GKE the volume won’t be bound until a Pod asks for it. Just move on to the next lab and come back when your pod is applied.

$ kubectl get pvc
NAME   STATUS   VOLUME                                     CAPACITY   ACCESS MODES   STORAGECLASS   AGE
db     Bound    pvc-aa5c22d9-8251-4d44-b71f-e6a290b92aec   1Gi        RWO            standard       123m

Check the corresponding PersistentVolume resource:

$ kubectl get pv
NAME                                       CAPACITY   ACCESS MODES   RECLAIM POLICY   STATUS   CLAIM        STORAGECLASS   REASON   AGE
pvc-aa5c22d9-8251-4d44-b71f-e6a290b92aec   1Gi        RWO            Delete           Bound    default/db   standard                123m

The resource name is automatically generated. You can examine the resource with this command:

Note

Change the name of the pvc to match yours.

$ kubectl describe pv/pvc-aa5c22d9-8251-4d44-b71f-e6a290b92aec
Name:            pvc-aa5c22d9-8251-4d44-b71f-e6a290b92aec
Labels:          <none>
Annotations:     hostPathProvisionerIdentity: 04bedfd4-c332-4433-a681-b0fa67f97752
                 pv.kubernetes.io/provisioned-by: k8s.io/minikube-hostpath
Finalizers:      [kubernetes.io/pv-protection]
StorageClass:    standard
Status:          Bound
Claim:           default/db
Reclaim Policy:  Delete
Access Modes:    RWO
VolumeMode:      Filesystem
Capacity:        1Gi
Node Affinity:   <none>
Message:         
Source:
    Type:          HostPath (bare host directory volume)
    Path:          /tmp/hostpath-provisioner/default/db
    HostPathType:  
Events:            <none>

What provisioner was used?