OpenEBS

This tutorial covers the installation of OpenEBS as a Helm extension. OpenEBS can be installed as a helm chart by adding it as an extension to your configuration:

  1.   extensions:
  2.     helm:
  3.       repositories:
  4.       - name: openebs-internal
  5.         url: https://openebs.github.io/charts
  6.       charts:
  7.       - name: openebs
  8.         chartname: openebs-internal/openebs
  9.         version: "3.9.0"
  10.         namespace: openebs
  11.         order: 1
  12.         values: |
  13.           localprovisioner:
  14.             hostpathClass:
  15.               enabled: true
  16.               isDefaultClass: false

If you want OpenEBS to be your default storage class, set isDefaultClass to true.

Usage

Once installed, the cluster will have two storage classes available for you to use:

  1. k0s kubectl get storageclass
  1. NAME               PROVISIONER        RECLAIMPOLICY   VOLUMEBINDINGMODE      ALLOWVOLUMEEXPANSION   AGE
  2. openebs-device     openebs.io/local   Delete          WaitForFirstConsumer   false                  24s
  3. openebs-hostpath   openebs.io/local   Delete          WaitForFirstConsumer   false                  24s

The openebs-hostpath is the storage class that maps to /var/openebs/local.

The openebs-device is not configured and could be configured by manifest deployer accordingly to the OpenEBS documentation

Example

Use following manifests as an example of pod with mounted volume:

  1. apiVersion: v1
  2. kind: PersistentVolumeClaim
  3. metadata:
  4.   name: nginx-pvc
  5.   namespace: default
  6. spec:
  7.   accessModes:
  8.     - ReadWriteOnce
  9.   storageClassName: openebs-hostpath
  10.   resources:
  11.     requests:
  12.       storage: 5Gi
  13. ---
  14. apiVersion: apps/v1
  15. kind: Deployment
  16. metadata:
  17.   name: nginx
  18.   namespace: default
  19.   labels:
  20.     app: nginx
  21. spec:
  22.   selector:
  23.     matchLabels:
  24.       app: nginx
  25.   strategy:
  26.     type: Recreate
  27.   template:
  28.     metadata:
  29.       labels:
  30.         app: nginx
  31.     spec:
  32.       containers:
  33.       - image: nginx
  34.         name: nginx
  35.         volumeMounts:
  36.         - name: persistent-storage
  37.           mountPath: /var/lib/nginx
  38.       volumes:
  39.       - name: persistent-storage
  40.         persistentVolumeClaim:
  41.           claimName: nginx-pvc
  1. k0s kubectl apply -f nginx.yaml
  1. persistentvolumeclaim/nginx-pvc created
  2. deployment.apps/nginx created
  3. bash-5.1# k0s kc get pods
  4. NAME                    READY   STATUS    RESTARTS   AGE
  5. nginx-d95bcb7db-gzsdt   1/1     Running   0          30s
  1. k0s kubectl get pv
  1. NAME                                       CAPACITY   ACCESS MODES   RECLAIM POLICY   STATUS   CLAIM               STORAGECLASS       REASON   AGE
  2. pvc-9a7fae2d-eb03-42c3-aaa9-1a807d5df12f   5Gi        RWO            Delete           Bound    default/nginx-pvc   openebs-hostpath            30s