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Create a Windows Server container on an Azure Kubernetes Service (AKS) cluster using Azure CLI

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Azure Kubernetes Service (AKS) is a managed Kubernetes service that lets you quickly deploy and manage clusters. In this article, you use Azure CLI to deploy an AKS cluster that runs Windows Server containers. You also deploy an ASP.NET sample application in a Windows Server container to the cluster.

Screenshot of browsing to ASP.NET sample application.

This article assumes a basic understanding of Kubernetes concepts. For more information, see Kubernetes core concepts for Azure Kubernetes Service (AKS).

If you don't have an Azure subscription, create an Azure free account before you begin.

Prerequisites

  • This article requires version 2.0.64 or later of the Azure CLI. If using Azure Cloud Shell, the latest version is already installed.

  • The identity you use to create your cluster must have the appropriate minimum permissions. For more information on access and identity for AKS, see Access and identity options for Azure Kubernetes Service (AKS).

  • If you have multiple Azure subscriptions, select the appropriate subscription ID in which the resources should be billed using the az account command.

  • Verify the Microsoft.OperationsManagement and Microsoft.OperationalInsights providers are registered on your subscription. Check the registration status using the following az provider show commands:

    az provider show -n Microsoft.OperationsManagement -o table
az provider show -n Microsoft.OperationalInsights -o table

    If they're not registered, register them using the following az provider register commands:

    az provider register --namespace Microsoft.OperationsManagement
az provider register --namespace Microsoft.OperationalInsights

    Note

    Run the commands with administrative privileges if you plan to run the commands in this quickstart locally instead of in Azure Cloud Shell.

Limitations

The following limitations apply when you create and manage AKS clusters that support multiple node pools:

  • You can't delete the first node pool.

The following limitations apply to Windows Server node pools:

  • The AKS cluster can have a maximum of 10 node pools.
  • The AKS cluster can have a maximum of 100 nodes in each node pool.
  • The Windows Server node pool name has a limit of six characters.

Create a resource group

An Azure resource group is a logical group in which Azure resources are deployed and managed. When you create a resource group, you're asked to specify a location. This location is where resource group metadata is stored and where your resources run in Azure if you don't specify another region during resource creation.

  • Create a resource group using the az group create command. The following example creates a resource group named myResourceGroup in the eastus location.

    az group create --name myResourceGroup --location eastus

    The following example output shows the resource group created successfully:

    {
  "id": "/subscriptions/<guid>/resourceGroups/myResourceGroup",
  "location": "eastus",
  "managedBy": null,
  "name": "myResourceGroup",
  "properties": {
    "provisioningState": "Succeeded"
  },
  "tags": null,
  "type": null
}

Create an AKS cluster

In this section, we create an AKS cluster with the following configuration:

  • The cluster is configured with two nodes to ensure it operates reliably.
  • The --windows-admin-password and --windows-admin-username parameters set the administrator credentials for any Windows Server nodes on the cluster and must meet Windows Server password requirements.
  • The node pool uses VirtualMachineScaleSets.

Note

To run an AKS cluster that supports node pools for Windows Server containers, your cluster needs to use a network policy that uses Azure CNI (advanced) network plugin.

  1. Create a username to use as administrator credentials for the Windows Server nodes on your cluster. The following commands prompt you for a username and set it to WINDOWS_USERNAME for use in a later command (remember the commands in this article are entered into a BASH shell).

    echo "Please enter the username to use as administrator credentials for Windows Server nodes on your cluster: " && read WINDOWS_USERNAME

  2. Create a password for the administrator username you created in the previous step.

    echo "Please enter the password to use as administrator credentials for Windows Server nodes on your cluster: " && read WINDOWS_PASSWORD

  3. Create your cluster using the az aks create command and specify the --windows-admin-username and --windows-admin-password parameters. The following example command creates a cluster using the value from WINDOWS_USERNAME you set in the previous command. Alternatively, you can provide a different username directly in the parameter instead of using WINDOWS_USERNAME.

    az aks create \
    --resource-group myResourceGroup \
    --name myAKSCluster \
    --node-count 2 \
    --enable-addons monitoring \
    --generate-ssh-keys \
    --windows-admin-username $WINDOWS_USERNAME \
    --windows-admin-password $WINDOWS_PASSWORD \
    --vm-set-type VirtualMachineScaleSets \
    --network-plugin azure

    Note

    • If you get a password validation error, verify the password you set meets the Windows Server password requirements. If your password meets the requirements, try creating your resource group in another region. Then try creating the cluster with the new resource group.
    • If you don't specify an administrator username and password when setting --vm-set-type VirtualMachineScaleSets and --network-plugin azure, the username is set to azureuser and the password is set to a random value.
    • The administrator username can't be changed, but you can change the administrator password your AKS cluster uses for Windows Server nodes using az aks update. For more information, see Windows Server node pools FAQ.

    After a few minutes, the command completes and returns JSON-formatted information about the cluster. Occasionally, the cluster can take longer than a few minutes to provision. Allow up to 10 minutes for provisioning.

Add a node pool

By default, an AKS cluster is created with a node pool that can run Linux containers. You have to add another node pool that can run Windows Server containers alongside the Linux node pool.

  • Add a Windows node pool using the az aks nodepool add command. The following command creates a new node pool named npwin and adds it to myAKSCluster. The command also uses the default subnet in the default virtual network created when running az aks create. An OS SKU isn't specified, so the node pool is set to the default operating system based on the Kubernetes version of the cluster.

    az aks nodepool add \
    --resource-group myResourceGroup \
    --cluster-name myAKSCluster \
    --os-type Windows \
    --name npwin \
    --node-count 1

Connect to the cluster

You use kubectl, the Kubernetes command-line client, to manage your Kubernetes clusters. If you use Azure Cloud Shell, kubectl is already installed. To you want to install kubectl locally, you can use the az aks install-cli command.

  1. Configure kubectl to connect to your Kubernetes cluster using the `az aks get-credentials command. This command downloads credentials and configures the Kubernetes CLI to use them.

    az aks get-credentials --resource-group myResourceGroup --name myAKSCluster

  2. Verify the connection to your cluster using the kubectl get command, which returns a list of the cluster nodes.

    kubectl get nodes -o wide

    The following example output shows all nodes in the cluster. Make sure the status of all nodes is Ready:

    NAME                                STATUS   ROLES   AGE   VERSION   INTERNAL-IP   EXTERNAL-IP   OS-IMAGE                         KERNEL-VERSION      CONTAINER-RUNTIME
aks-nodepool1-90538373-vmss000000   Ready    agent   54m   v1.25.6   10.224.0.33   <none>        Ubuntu 22.04.2 LTS               5.15.0-1035-azure   containerd://1.6.18+azure-1
aks-nodepool1-90538373-vmss000001   Ready    agent   55m   v1.25.6   10.224.0.4    <none>        Ubuntu 22.04.2 LTS               5.15.0-1035-azure   containerd://1.6.18+azure-1
aksnpwin000000                      Ready    agent   40m   v1.25.6   10.224.0.62   <none>        Windows Server 2022 Datacenter   10.0.20348.1668     containerd://1.6.14+azure

    Note

    The container runtime for each node pool is shown under CONTAINER-RUNTIME. Notice aksnpwin987654 begins with docker://, which means it uses Docker for the container runtime. Notice aksnpwcd123456 begins with containerd://, which means it uses containerd for the container runtime.

Deploy the application

A Kubernetes manifest file defines a desired state for the cluster, such as what container images to run. In this article, you use a manifest to create all objects needed to run the ASP.NET sample application in a Windows Server container. This manifest includes a Kubernetes deployment for the ASP.NET sample application and an external Kubernetes service to access the application from the internet.

The ASP.NET sample application is provided as part of the .NET Framework Samples and runs in a Windows Server container. AKS requires Windows Server containers to be based on images of Windows Server 2019 or greater. The Kubernetes manifest file must also define a node selector to tell your AKS cluster to run your ASP.NET sample application's pod on a node that can run Windows Server containers.

  1. Create a file named sample.yaml and copy in the following YAML definition.

    apiVersion: apps/v1
kind: Deployment
metadata:
  name: sample
  labels:
    app: sample
spec:
  replicas: 1
  template:
    metadata:
      name: sample
      labels:
        app: sample
    spec:
      nodeSelector:
        "kubernetes.io/os": windows
      containers:
      - name: sample
        image: mcr.microsoft.com/dotnet/framework/samples:aspnetapp
        resources:
          limits:
            cpu: 1
            memory: 800M
        ports:
          - containerPort: 80
  selector:
    matchLabels:
      app: sample
---
apiVersion: v1
kind: Service
metadata:
  name: sample
spec:
  type: LoadBalancer
  ports:
  - protocol: TCP
    port: 80
  selector:
    app: sample

    For a breakdown of YAML manifest files, see Deployments and YAML manifests.

  2. Deploy the application using the kubectl apply command and specify the name of your YAML manifest.

    kubectl apply -f sample.yaml

    The following example output shows the deployment and service created successfully:

    deployment.apps/sample created
service/sample created

Test the application

When the application runs, a Kubernetes service exposes the application front end to the internet. This process can take a few minutes to complete. Occasionally, the service can take longer than a few minutes to provision. Allow up to 10 minutes for provisioning.

  1. Monitor progress using the kubectl get service command with the --watch argument.

    kubectl get service sample --watch

    Initially, the output shows the EXTERNAL-IP for the sample service as pending:

    NAME               TYPE           CLUSTER-IP   EXTERNAL-IP   PORT(S)        AGE
sample             LoadBalancer   10.0.37.27   <pending>     80:30572/TCP   6s

    When the EXTERNAL-IP address changes from pending to an actual public IP address, use CTRL-C to stop the kubectl watch process. The following example output shows a valid public IP address assigned to the service:

    sample  LoadBalancer   10.0.37.27   52.179.23.131   80:30572/TCP   2m

  2. See the sample app in action by opening a web browser to the external IP address of your service.

    Screenshot of browsing to ASP.NET sample application.

    Note

    If you receive a connection timeout when trying to load the page, you should verify the sample app is ready using the kubectl get pods --watch command. Sometimes, the Windows container isn't started by the time your external IP address is available.

Delete resources

If you don't plan on going through the following tutorials, you should delete your cluster to avoid incurring Azure charges.

  • Delete your resource group, container service, and all related resources using the az group delete command.

    az group delete --name myResourceGroup --yes --no-wait

    Note

    The AKS cluster was created with system-assigned managed identity (default identity option used in this quickstart). The Azure platform manages this identity, so it doesn't require removal.

Next steps

In this article, you deployed a Kubernetes cluster and deployed an ASP.NET sample application in a Windows Server container to it.

To learn more about AKS, and walk through a complete code to deployment example, continue to the following Kubernetes cluster tutorial.

AKS tutorial