cStor User Guide - Deploying a sample application

This user guide will guide you in deploying your sample application in a cStor setup.

Launch Sample Application

• Deploying a sample application

Deploying a sample application

To deploy a sample application using the above created CSPC and StorageClass, a PVC, that utilises the created StorageClass, needs to be deployed. Given below is an example YAML for a PVC which uses the SC created earlier.

kind: PersistentVolumeClaim

apiVersion: v1

metadata:

name: cstor-pvc

spec:

storageClassName: cstor-csi-disk

accessModes:

- ReadWriteOnce

resources:

requests:

storage: 5Gi

Apply the above PVC yaml to dynamically create volume and verify that the PVC has been successfully created and bound to a PersistentVolume (PV).

kubectl get pvc

Sample Output:

NAME STATUS VOLUME CAPACITY ACCESS MODES STORAGECLASS AGE

cstor-pvc Bound pvc-f1383b36-2d4d-4e9f-9082-6728d6c55bd1 5Gi RWO cstor-csi-disk 12s

Now, to deploy an application using the above created PVC specify the claimName parameter under volumes.

Given below is a sample busybox application YAML that uses the PVC created earlier.

apiVersion: v1

kind: Pod

metadata:

name: busybox

namespace: default

spec:

containers:

- command:

- sh

- -c

- 'date >> /mnt/openebs-csi/date.txt; hostname >> /mnt/openebs-csi/hostname.txt; sync; sleep 5; sync; tail -f /dev/null;'

image: busybox

imagePullPolicy: Always

name: busybox

volumeMounts:

- mountPath: /mnt/openebs-csi

name: demo-vol

volumes:

- name: demo-vol

persistentVolumeClaim:

claimName: cstor-pvc

Apply the above YAML. Verify that the pod is running and is able to write data to the volume.

kubectl get pods

Sample Output:

NAME READY STATUS RESTARTS AGE

busybox 1/1 Running 0 97s

The example busybox application will write the current date into the mounted path, i.e, /mnt/openebs-csi/date.txt when it starts. To verify, exec into the busybox container.

kubectl exec -it busybox -- cat /mnt/openebs-csi/date.txt

Sample Output:

Fri May 28 05:00:31 UTC 2021