In this example, a legacy data volume exists and a cluster-admin or
storage-admin needs to make it available for consumption in a particular
project. Using StorageClasses decreases the likelihood of other users and
projects gaining access to this volume from a claim because the claim would have
to have an exact matching value for the StorageClass annotation. This example
also disables dynamic provisioning. This example assumes:
Some familiarity with OpenShift Container Platform, GCE, and Persistent Disks
OpenShift Container Platform is properly configured to use GCE.
As a cluster-admin or storage-admin, define and create the StorageClass for historical financial data.
kind: StorageClass
apiVersion: storage.k8s.io/v1beta1
metadata:
name: finance-history (1)
provisioner: no-provisioning (2)
parameters: (3)| 1 | Name of the StorageClass. |
| 2 | This is a required field, but since there is to be no dynamic provisioning, a value must be put here as long as it is not an actual provisioner plug-in type. |
| 3 | Parameters can simply be left blank, since these are only used for the dynamic provisioner. |
Save the definitions to a YAML file (finance-history-storageclass.yaml) and create the StorageClass.
# oc create -f finance-history-storageclass.yaml storageclass "finance-history" created # oc get storageclass NAME TYPE finance-history no-provisioning
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The StorageClass exists. A cluster-admin or storage-admin can create the
Persistent Volume (PV) for use with the StorageClass. Create a manually
provisioned disk using GCE
(not dynamically provisioned) and a Persistent Volume that connects to the new GCE disk (gce-pv.yaml).
apiVersion: v1
kind: PersistentVolume
metadata:
name: pv-finance-history
annotations:
volume.beta.kubernetes.io/storage-class: finance-history (1)
spec:
capacity:
storage: 35Gi
accessModes:
- ReadWriteMany
gcePersistentDisk:
readOnly: false
pdName: the-existing-PD-volume-name-that-contains-the-valuable-data (2)
fsType: ext4| 1 | The StorageClass annotation, that must match exactly. |
| 2 | The name of the GCE disk that already exists and contains the legacy data. |
As a cluster-admin or storage-admin, create and view the PV.
# oc create -f gce-pv.yaml persistentvolume "pv-finance-history" created # oc get pv NAME CAPACITY ACCESSMODES RECLAIMPOLICY STATUS CLAIM REASON AGE pv-finance-history 35Gi RWX Retain Available 2d
Notice you have a pv-finance-history Available and ready for consumption.
As a user, create a Persistent Volume Claim (PVC) as a YAML file and specify the correct StorageClass annotation:
apiVersion: v1
kind: PersistentVolumeClaim
metadata:
name: pvc-finance-history
annotations:
volume.beta.kubernetes.io/storage-class: finance-history (1)
spec:
accessModes:
- ReadWriteMany
resources:
requests:
storage: 20Gi| 1 | The StorageClass annotation, that must match exactly or the claim will go unbound until it is deleted or another StorageClass is created that matches the annotation. |
Create and view the PVC and PV to see if it is bound.
# oc create -f pvc-finance-history.yaml persistentvolumeclaim "pvc-finance-history" created # oc get pvc NAME STATUS VOLUME CAPACITY ACCESSMODES AGE pvc-finance-history Bound pv-finance-history 35Gi RWX 9m # oc get pv (cluster/storage-admin) NAME CAPACITY ACCESSMODES RECLAIMPOLICY STATUS CLAIM REASON AGE pv-finance-history 35Gi RWX Retain Bound default/pvc-finance-history 5m
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You can use StorageClasses in the same cluster for both legacy data (no dynamic provisioning) and with dynamic provisioning. |