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Local Path Provisioner on AKS Edge Essentials

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Applications running in Azure Kubernetes Service (AKS) Edge Essentials might need to store and retrieve data. Persistent storage solutions enable you to store application data that's external from the pod running your application. Persistent storage also enables you to maintain application data, even if the application's pod fails.

The Local Path Provisioner tool provides a way for Kubernetes users to use the local storage in each node by enabling the ability to create persistent volume claims using local storage on the respective node.

This article describes how to set up Local Path Provisioner storage and deploy a sample container on your AKS Edge Essentials cluster. For more information, see the official Local Path Provisioner documentation.

Step 1: install prerequisites

In an elevated PowerShell window, run the following cmdlet:

kubectl apply -f https://raw.githubusercontent.com/Azure/AKS-Edge/main/samples/storage/local-path-provisioner/local-path-storage.yaml

Warning

Local-Path-Provisioner and Busybox images are not maintained by Microsoft and are pulled from the Rancher Labs repository. The Local-Path-Provisioner and BusyBox are only available as a Linux container image.

Once deployment is finished, make sure that the local-path storage class is available on your node by running the following cmdlet:

kubectl get StorageClass

If everything is correctly configured, you should see the following output:

NAME                   PROVISIONER             RECLAIMPOLICY   VOLUMEBINDINGMODE      ALLOWVOLUMEEXPANSION   AGE
local-path (default)   rancher.io/local-path   Delete          WaitForFirstConsumer   false                  21h

Step 2: create a Persistent Volume Claim (PVC)

The second step is to create a persistent volume claim (PVC). There are multiple configurations available, but this example creates a PVC with ReadWriteOnce access mode and requests 128MB of storage. In an elevated PowerShell window, run the following cmdlet:

kubectl apply -f https://raw.githubusercontent.com/Azure/AKS-Edge/main/samples/storage/local-path-provisioner/pvc.yaml

Step 3: deploy sample pod and verify resources

This step deploys a sample pod that binds to the PVC defined in the previous step. To deploy the sample pod, in an elevated PowerShell window, run the following cmdlet:

kubectl apply -f https://raw.githubusercontent.com/Azure/AKS-Edge/main/samples/storage/local-path-provisioner/pod.yaml

If everything is running and correctly attached, you should see output similar to the following. First, you should see that the PV has been created:

PS C:\WINDOWS\system32> kubectl get pv
NAME                                       CAPACITY   ACCESS MODES   RECLAIM POLICY   STATUS   CLAIM                    STORAGECLASS   REASON   AGE
pvc-0f217d0e-1d07-4d9e-91da-6b83534180b9   128Mi      RWO            Delete           Bound    default/local-path-pvc   local-path              16s

Next, you should see the PVC has been bound:

PS C:\WINDOWS\system32> kubectl get pvc
NAME             STATUS   VOLUME                                     CAPACITY   ACCESS MODES   STORAGECLASS   AGE
local-path-pvc   Bound    pvc-0f217d0e-1d07-4d9e-91da-6b83534180b9   128Mi      RWO            local-path     118s

Finally, you should see the sample pod running:

PS C:\WINDOWS\system32> kubectl get pod
NAME          READY   STATUS    RESTARTS   AGE
volume-test   1/1     Running   0          2m24s

Step 4: test persistent storage

A final test is to make sure that the storage is persistent, and that data will be maintained, even if the application's pod fails.

Start by writing something to the pod. In an elevated PowerShell window, run the following cmdlet:

kubectl exec volume-test -- sh -c "echo Hello AKS Edge! > /data/test"

Now delete the pod to simulate a pod failing, or even a deployment being removed:

kubectl delete -f https://raw.githubusercontent.com/Azure/AKS-Edge/main/samples/storage/local-path-provisioner/pod.yaml

Check that the pod was removed and then deploy the volume-test pod again:

kubectl apply -f https://raw.githubusercontent.com/Azure/AKS-Edge/main/samples/storage/local-path-provisioner/pod.yaml

Finally, read the content of the file that was previously written. If everything runs successfully, you should see the Hello AKS Edge! message.

kubectl exec volume-test -- sh -c "cat /data/test"
Hello AKS Edge!

Step 5: clean up deployment

Once you're finished with Local Path Provisioner, go to PowerShell and clean up your workspace by running:

kubectl delete -f https://raw.githubusercontent.com/Azure/AKS-Edge/main/samples/storage/local-path-provisioner/pod.yaml
kubectl delete -f https://raw.githubusercontent.com/Azure/AKS-Edge/main/samples/storage/local-path-provisioner/pvc.yaml

Next steps