Prepare your Azure Arc-enabled Kubernetes cluster

An Azure Arc-enabled Kubernetes cluster is a prerequisite for deploying Azure IoT Operations. This article describes how to prepare a cluster before you deploy Azure IoT Operations. This article includes guidance for both Ubuntu and Windows.

The steps in this article prepare your cluster for a secure settings deployment, which is a longer but production-ready process. If you want to deploy Azure IoT Operations quickly and run a sample workload with only test settings, see the Quickstart: Run Azure IoT Operations in GitHub Codespaces with K3s instead. For more information about test settings and secure settings, see Deployment details > Choose your features.

Prerequisites

Microsoft supports Azure Kubernetes Service (AKS) Edge Essentials for deployments on Windows and K3s for deployments on Ubuntu. If you want to deploy Azure IoT Operations to a multi-node solution, use K3s on Ubuntu.

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.

  • An Azure resource group. Only one Azure IoT Operations instance is supported per resource group. To create a new resource group, use the az group create command. For the list of currently supported Azure regions, see Supported regions.

    az group create --location <REGION> --resource-group <RESOURCE_GROUP> --subscription <SUBSCRIPTION_ID>
    
  • Azure CLI version 2.64.0 or newer installed on your cluster 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 connectedk8s extension for Azure CLI:

    az extension add --upgrade --name connectedk8s
    
  • Hardware that meets the system 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.

Create and Arc-enable a cluster

This section provides steps to create clusters in validated environments on Linux and Windows.

To prepare a K3s Kubernetes cluster on Ubuntu:

  1. Create a single-node or multi-node K3s cluster. For examples, see the K3s quick-start guide or K3s related projects.

  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 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 --disable-auto-upgrade
    

    To prevent unplanned updates to Azure Arc and the system Arc extensions that Azure IoT Operations uses as dependencies, this command disables auto-upgrade. Instead, manually upgrade agents as needed.

    Important

    If your environment uses a proxy server or Azure Arc Gateway, modify the az connectedk8s connect command with your proxy information:

    1. Follow the instructions in either Connect using an outbound proxy server or Onboard Kubernetes clusters to Azure Arc with Azure Arc Gateway.
    2. Add 169.254.169.254 to the --proxy-skip-range parameter of the az connectedk8s connect command. Azure Device Registry uses this local endpoint to get access tokens for authorization.

    Azure IoT Operations doesn't support proxy servers that require a trusted certificate.

  5. 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.

  6. Create a k3s config file.

    sudo nano /etc/rancher/k3s/config.yaml
    
  7. 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
    
  8. Save the file and exit the nano editor.

  9. 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)
    
  10. 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
    
  11. Restart K3s.

    systemctl restart k3s
    

Advanced configuration

At this point, when you have an Azure Arc-enabled Kubernetes cluster but before you deploy Azure IoT Operations to it, you might want to configure your cluster for advanced scenarios.

Next steps

Now that you have an Azure Arc-enabled Kubernetes cluster, you can deploy Azure IoT Operations.