Prepare your Azure Arc-enabled Kubernetes cluster

To prepare an Azure Arc-enabled Kubernetes cluster, you need:

• An Azure subscription. If you don't have an Azure subscription, create one for free before you begin.

• Azure CLI version 2.64.0 or newer installed on your development machine. Use az --version to check your version and az upgrade to update if necessary. For more information, see How to install the Azure CLI.

• The latest version of the following extensions for Azure CLI:

  az extension add --upgrade --name azure-iot-ops
  az extension add --upgrade --name connectedk8s
  

• Hardware that meets the system requirements:

  • Ensure that your machine has a minimum of 16-GB available RAM and 8 available vCPUs reserved for Azure IoT Operations.
  • Azure Arc-enabled Kubernetes system requirements.
  • K3s requirements.

• If you're going to deploy Azure IoT Operations to a multi-node cluster with fault tolerance enabled, review the hardware and storage requirements in Prepare Linux for Edge Volumes.

To prepare an Azure Arc-enabled Kubernetes cluster, you need:

• An Azure subscription. If you don't have an Azure subscription, create one for free before you begin.

• Hardware that meets the system requirements:

  • Ensure that your machine has a minimum of 16-GB available RAM, 8 available vCPUs, and 52-GB free disk space reserved for Azure IoT Operations.
  • Azure Arc-enabled Kubernetes system requirements.
  • AKS Edge Essentials requirements and support matrix.
  • AKS Edge Essentials networking guidance.

To prepare a K3s Kubernetes cluster on Ubuntu:

1. Install K3s following the instructions in the K3s quick-start guide.

2. Check to see that kubectl was installed as part of K3s. If not, follow the instructions to Install kubectl on Linux.

   kubectl version --client
   

3. Follow the instructions to Install Helm.

4. Create a K3s configuration yaml file in .kube/config:

   mkdir ~/.kube
   sudo KUBECONFIG=~/.kube/config:/etc/rancher/k3s/k3s.yaml kubectl config view --flatten > ~/.kube/merged
   mv ~/.kube/merged ~/.kube/config
   chmod  0600 ~/.kube/config
   export KUBECONFIG=~/.kube/config
   #switch to k3s context
   kubectl config use-context default
   sudo chmod 644 /etc/rancher/k3s/k3s.yaml
   

5. Run the following command to increase the user watch/instance limits.

   echo fs.inotify.max_user_instances=8192 | sudo tee -a /etc/sysctl.conf
   echo fs.inotify.max_user_watches=524288 | sudo tee -a /etc/sysctl.conf
   
   sudo sysctl -p
   

6. For better performance, increase the file descriptor limit:

   echo fs.file-max = 100000 | sudo tee -a /etc/sysctl.conf
   
   sudo sysctl -p
   

Configure multi-node clusters for Azure Container Storage

On multi-node clusters with at least three nodes, you have the option of enabling fault tolerance for storage with Azure Container Storage enabled by Azure Arc when you deploy Azure IoT Operations.

If you want to enable fault tolerance during deployment, configure your clusters by following the steps in Prepare Linux for Edge Volumes using a multi-node Ubuntu cluster.

Arc-enable your cluster

Connect your cluster to Azure Arc so that it can be managed remotely.

1. On the machine where you deployed the Kubernetes cluster, sign in with Azure CLI:

   az login
   

   If at any point you get an error that says Your device is required to be managed to access your resource, run az login again and make sure that you sign in interactively with a browser.

2. After you sign in, the Azure CLI displays all of your subscriptions and indicates your default subscription with an asterisk *. To continue with your default subscription, select Enter. Otherwise, type the number of the Azure subscription that you want to use.

3. Register the required resource providers in your subscription.

   Note

   This step only needs to be run once per subscription. To register resource providers, you need permission to do the /register/action operation, which is included in subscription Contributor and Owner roles. For more information, see Azure resource providers and types.

   az provider register -n "Microsoft.ExtendedLocation"
   az provider register -n "Microsoft.Kubernetes"
   az provider register -n "Microsoft.KubernetesConfiguration"
   az provider register -n "Microsoft.IoTOperations"
   az provider register -n "Microsoft.DeviceRegistry"
   az provider register -n "Microsoft.SecretSyncController"
   

4. Use the az group create command to create a resource group in your Azure subscription to store all the resources:

   For the list of currently supported Azure regions, see Supported regions.

   az group create --location <REGION> --resource-group <RESOURCE_GROUP> --subscription <SUBSCRIPTION_ID>
   

5. Use the az connectedk8s connect command to Arc-enable your Kubernetes cluster and manage it as part of your Azure resource group.

   az connectedk8s connect --name <CLUSTER_NAME> -l <REGION> --resource-group <RESOURCE_GROUP> --subscription <SUBSCRIPTION_ID> --enable-oidc-issuer --enable-workload-identity
   

6. Get the cluster's issuer URL.

   az connectedk8s show --resource-group <RESOURCE_GROUP> --name <CLUSTER_NAME> --query oidcIssuerProfile.issuerUrl --output tsv
   

   Save the output of this command to use in the next steps.

7. Create a k3s config file.

   sudo nano /etc/rancher/k3s/config.yaml
   

8. Add the following content to the config.yaml file, replacing the <SERVICE_ACCOUNT_ISSUER> placeholder with your cluster's issuer URL.

   kube-apiserver-arg:
    - service-account-issuer=<SERVICE_ACCOUNT_ISSUER>
    - service-account-max-token-expiration=24h
   

9. Save the file and exit the nano editor.

10. Get the objectId of the Microsoft Entra ID application that the Azure Arc service uses in your tenant and save it as an environment variable. Run the following command exactly as written, without changing the GUID value.

    export OBJECT_ID=$(az ad sp show --id bc313c14-388c-4e7d-a58e-70017303ee3b --query id -o tsv)
    

11. Use the az connectedk8s enable-features command to enable custom location support on your cluster. This command uses the objectId of the Microsoft Entra ID application that the Azure Arc service uses. Run this command on the machine where you deployed the Kubernetes cluster:

    az connectedk8s enable-features -n <CLUSTER_NAME> -g <RESOURCE_GROUP> --custom-locations-oid $OBJECT_ID --features cluster-connect custom-locations
    

12. Restart K3s.

    systemctl restart k3s
    

Azure Kubernetes Service Edge Essentials is an on-premises Kubernetes implementation of Azure Kubernetes Service (AKS) that automates running containerized applications at scale. AKS Edge Essentials includes a Microsoft-supported Kubernetes platform that includes a lightweight Kubernetes distribution with a small footprint and simple installation experience that supports PC-class or "light" edge hardware.

The AksEdgeQuickStartForAio.ps1 script automates the process of creating and connecting a cluster, and is the recommended path for deploying Azure IoT Operations on AKS Edge Essentials.

For instructions on running the script, see Configure an AKS Edge Essentials cluster for Azure IoT Operations.