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--- title: Use kubectl to deploy Kubernetes stateful app via dynamically provisioned share on Azure Stack Edge Pro GPU device| Microsoft Docs description: Describes how to create and manage a Kubernetes stateful application deployment via a dynamically provisioned share using kubectl on a Microsoft Azure Stack Edge Pro GPU device. services: databox author: alkohli ms.service: azure-stack-edge ms.topic: how-to ms.date: 02/22/2021 ms.author: alkohli --- # Use kubectl to run a Kubernetes stateful application with StorageClass on your Azure Stack Edge Pro GPU device [!INCLUDE [applies-to-GPU-and-pro-r-and-mini-r-skus](../../includes/azure-stack-edge-applies-to-gpu-pro-r-mini-r-sku.md)] This article shows you how to deploy a single-instance stateful application in Kubernetes using a StorageClass to dynamically provision storage and a deployment. The deployment uses `kubectl` commands on an existing Kubernetes cluster and deploys the MySQL application. This procedure is intended for those who have reviewed the [Kubernetes storage on Azure Stack Edge Pro device](azure-stack-edge-gpu-kubernetes-storage.md) and are familiar with the concepts of [Kubernetes storage](https://kubernetes.io/docs/concepts/storage/). ## Prerequisites Before you can deploy the stateful application, complete the following prerequisites on your device and the client that you will use to access the device: ### For device - You have sign-in credentials to a 1-node Azure Stack Edge Pro device. - The device is activated. See [Activate the device](azure-stack-edge-gpu-deploy-activate.md). - The device has the compute role configured via Azure portal and has a Kubernetes cluster. See [Configure compute](azure-stack-edge-gpu-deploy-configure-compute.md). ### For client accessing the device - You have a Windows client system that will be used to access the Azure Stack Edge Pro device. - The client is running Windows PowerShell 5.0 or later. To download the latest version of Windows PowerShell, go to [Install Windows PowerShell](/powershell/scripting/install/installing-windows-powershell). - You can have any other client with a [Supported operating system](azure-stack-edge-gpu-system-requirements.md#supported-os-for-clients-connected-to-device) as well. This article describes the procedure when using a Windows client. - You have completed the procedure described in [Access the Kubernetes cluster on Azure Stack Edge Pro device](azure-stack-edge-gpu-create-kubernetes-cluster.md). You have: - Created a `userns1` namespace via the `New-HcsKubernetesNamespace` command. - Created a user `user1` via the `New-HcsKubernetesUser` command. - Granted the `user1` access to `userns1` via the `Grant-HcsKubernetesNamespaceAccess` command. - Installed `kubectl` on the client and saved the `kubeconfig` file with the user configuration to C:\\Users\\&lt;username&gt;\\.kube. - Make sure that the `kubectl` client version is skewed no more than one version from the Kubernetes master version running on your Azure Stack Edge Pro device. - Use `kubectl version` to check the version of kubectl running on the client. Make a note of the full version. - In the local UI of your Azure Stack Edge Pro device, go to **Overview** and note the Kubernetes software number. - Verify these two versions for compatibility from the mapping provided in the Supported Kubernetes version<!-- insert link-->. You are ready to deploy a stateful application on your Azure Stack Edge Pro device. ## Deploy MySQL You will now run a stateful application by creating a Kubernetes Deployment and connecting it to the built-in StorageClass using a PersistentVolumeClaim (PVC). All `kubectl` commands you use to create and manage stateful application deployments need to specify the namespace associated with the configuration. To specify the namespace in a kubectl command, use `kubectl <command> -n <your-namespace>`. 1. Get a list of the pods running on your Kubernetes cluster in your namespace. A pod is an application container, or process, running on your Kubernetes cluster. ```powershell kubectl get pods -n <your-namespace> ``` Here's an example of command usage: ```powershell C:\Users\user>kubectl get pods -n "userns1" No resources found in userns1 namespace. C:\Users\user> ``` The output should state that no resources (pods) are found because there are no applications running on your cluster. 1. You will use the following YAML files. The `mysql-deployment.yml` file describes a deployment that runs MySQL and references the PVC. The file defines a volume mount for `/var/lib/mysql`, and then creates a PVC that looks for a 20-GB volume. A dynamic PV is provisioned and the PVC is bound to this PV. Copy and save the following `mysql-deployment.yml` file to a folder on the Windows client that you are using to access the Azure Stack Edge Pro device. ```yml apiVersion: v1 kind: Service metadata: name: mysql spec: ports: - port: 3306 selector: app: mysql clusterIP: None --- apiVersion: apps/v1 # for versions before 1.9.0 use apps/v1beta2 kind: Deployment metadata: name: mysql spec: selector: matchLabels: app: mysql strategy: type: Recreate template: metadata: labels: app: mysql spec: containers: - image: mysql:5.6 name: mysql env: # Use secret in real usage - name: MYSQL_ROOT_PASSWORD value: password ports: - containerPort: 3306 name: mysql volumeMounts: - name: mysql-persistent-storage mountPath: /var/lib/mysql volumes: - name: mysql-persistent-storage persistentVolumeClaim: claimName: mysql-pv-claim-sc ``` 2. Copy and save as a `mysql-pvc.yml` file to the same folder where you saved the `mysql-deployment.yml`. To use the builtin StorageClass that Azure Stack Edge Pro device on an attached data disk, set the `storageClassName` field in the PVC object to `ase-node-local` and accessModes should be `ReadWriteOnce`. > [!NOTE] > Make sure that the YAML files have correct indentation. You can check with [YAML lint](http://www.yamllint.com/) to validate and then save. ```yml apiVersion: v1 kind: PersistentVolumeClaim metadata: name: mysql-pv-claim-sc spec: storageClassName: ase-node-local accessModes: - ReadWriteOnce resources: requests: storage: 20Gi ``` 3. Deploy the `mysql-pvc.yaml` file. `kubectl apply -f <URI path to the mysql-pv.yml file> -n <your-user-namespace>` Here's a sample output of the deployment. ```powershell C:\Users\user>kubectl apply -f "C:\stateful-application\mysql-pvc.yml" -n userns1 persistentvolumeclaim/mysql-pv-claim-sc created C:\Users\user> ``` Note the name of the PVC created - in this example, `mysql-pv-claim-sc`. You will use it in a later step. 4. Deploy the contents of the `mysql-deployment.yml` file. `kubectl apply -f <URI path to mysql-deployment.yml file> -n <your-user-namespace>` Here's a sample output of the deployment. ```powershell C:\Users\user>kubectl apply -f "C:\stateful-application\mysql-deployment.yml" -n userns1 service/mysql created deployment.apps/mysql created C:\Users\user> ``` 5. Display information about the deployment. `kubectl describe deployment <app-label> -n <your-user-namespace>` ```powershell C:\Users\user>kubectl describe deployment mysql -n userns1 Name: mysql Namespace: userns1 CreationTimestamp: Thu, 20 Aug 2020 11:14:25 -0700 Labels: <none> Annotations: deployment.kubernetes.io/revision: 1 kubectl.kubernetes.io/last-applied-configuration: {"apiVersion":"apps/v1","kind":"Deployment","metadata":{"annotations":{},"name":"mysql","namespace":"userns1"},"spec":{"selector":{"matchL... Selector: app=mysql Replicas: 1 desired | 1 updated | 1 total | 1 available | 0 unavailable StrategyType: Recreate MinReadySeconds: 0 Pod Template: Labels: app=mysql Containers: mysql: Image: mysql:5.6 Port: 3306/TCP Host Port: 0/TCP Environment: MYSQL_ROOT_PASSWORD: password Mounts: /var/lib/mysql from mysql-persistent-storage (rw) Volumes: mysql-persistent-storage: Type: PersistentVolumeClaim (a reference to a PersistentVolumeClaim in the same namespace) ClaimName: mysql-pv-claim-sc ReadOnly: false Conditions: Type Status Reason ---- ------ ------ Available True MinimumReplicasAvailable Progressing True NewReplicaSetAvailable OldReplicaSets: <none> NewReplicaSet: mysql-695c4d9dcd (1/1 replicas created) Events: Type Reason Age From Message ---- ------ ---- ---- ------- Normal ScalingReplicaSet 24s deployment-controller Scaled up replica set mysql-695c4d9dcd to 1 C:\Users\user> ``` 6. List the pods created by the deployment. `kubectl get pods -l <app=label> -n <your-user-namespace>` Here's a sample output. ```powershell C:\Users\user>kubectl get pods -l app=mysql -n userns1 NAME READY STATUS RESTARTS AGE mysql-695c4d9dcd-rvzff 1/1 Running 0 40s C:\Users\user> ``` 7. Inspect the PersistentVolumeClaim. `kubectl describe pvc <your-pvc-name>` Here's a sample output. ```powershell C:\Users\user>kubectl describe pvc mysql-pv-claim-sc -n userns1 Name: mysql-pv-claim-sc Namespace: userns1 StorageClass: ase-node-local Status: Bound Volume: pvc-dc48253c-82dc-42a4-a7c6-aaddc97c9b8a Labels: <none> Annotations: kubectl.kubernetes.io/last-applied-configuration: {"apiVersion":"v1","kind":"PersistentVolumeClaim","metadata":{"annotations":{},"name":"mysql-pv-claim-sc","namespace":"userns1"},"spec":{"... pv.kubernetes.io/bind-completed: yes pv.kubernetes.io/bound-by-controller: yes volume.beta.kubernetes.io/storage-provisioner: rancher.io/local-path volume.kubernetes.io/selected-node: k8s-3q7lhq2cl-3q7lhq2 Finalizers: [kubernetes.io/pvc-protection] Capacity: 20Gi Access Modes: RWO VolumeMode: Filesystem Mounted By: mysql-695c4d9dcd-rvzff Events: Type Reason Age From Message ---- ------ ---- ---- ------- Normal WaitForFirstConsumer 71s (x2 over 77s) persistentvolume-controller waiting for first consumer to be created before binding Normal ExternalProvisioning 62s persistentvolume-controller waiting for a volume to be created, either by external provisioner "rancher.io/local-path" or manually created by system administrator Normal Provisioning 62s rancher.io/local-path_local-path-provisioner-6b84988bf9-tx8mz_1896d824-f862-4cbf-912a-c8cc0ca05574 External provisioner is provisioning volume for claim "userns1/mysql-pv-claim-sc" Normal ProvisioningSucceeded 60s rancher.io/local-path_local-path-provisioner-6b84988bf9-tx8mz_1896d824-f862-4cbf-912a-c8cc0ca05574 Successfully provisioned volume pvc-dc48253c-82dc-42a4-a7c6-aaddc97c9b8a C:\Users\user> ``` ## Verify MySQL is running To verify that the application is running, type: `kubectl exec <your-pod-with-the-app> -i -t -n <your-namespace> -- mysql -p` When prompted, provide the password. The password is in your `mysql-deployment` file. Here's a sample output. ```powershell C:\Users\user>kubectl exec mysql-695c4d9dcd-rvzff -i -t -n userns1 -- mysql -p Enter password: Welcome to the MySQL monitor. Commands end with ; or \g. Your MySQL connection id is 3 Server version: 5.6.49 MySQL Community Server (GPL) Copyright (c) 2000, 2020, Oracle and/or its affiliates. All rights reserved. Oracle is a registered trademark of Oracle Corporation and/or its affiliates. Other names may be trademarks of their respective owners. Type 'help;' or '\h' for help. Type '\c' to clear the current input statement. mysql> ``` ## Delete a deployment To delete the deployment, delete the deployed objects by name. These objects include deployment, service, and PVC. ```powershell kubectl delete deployment <deployment-name>,svc <service-name> -n <your-namespace> kubectl delete pvc <your-pvc-name> -n <your-namespace> ``` Here's sample output of when you delete the deployment and the service. ```powershell C:\Users\user>kubectl delete deployment,svc mysql -n userns1 deployment.apps "mysql" deleted service "mysql" deleted C:\Users\user> ``` Here's sample output of when you delete the PVC. ```powershell C:\Users\user>kubectl delete pvc mysql-pv-claim-sc -n userns1 persistentvolumeclaim "mysql-pv-claim-sc" deleted C:\Users\user> ``` ## Next steps To understand how to configure networking via kubectl, see [Deploy a stateless application on an Azure Stack Edge Pro device](azure-stack-edge-gpu-deploy-stateless-application-iot-edge-module.md)