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Enable Azure managed identity authentication for Kubernetes clusters with kubelogin

  • Straipsnis

The AKS-managed Microsoft Entra integration simplifies the Microsoft Entra integration process. Previously, you were required to create a client and server app, and the Microsoft Entra tenant had to assign Directory Readers role permissions. Now, the AKS resource provider manages the client and server apps for you.

Cluster administrators can configure Kubernetes role-based access control (Kubernetes RBAC) based on a user's identity or directory group membership. Microsoft Entra authentication is provided to AKS clusters with OpenID Connect. OpenID Connect is an identity layer built on top of the OAuth 2.0 protocol. For more information on OpenID Connect, see the OpenID Connect documentation.

Learn more about the Microsoft Entra integration flow in the Microsoft Entra documentation.

This article provides details on how to enable and use managed identities for Azure resources with your AKS cluster.

Limitations

The following are constraints integrating Azure managed identity authentication on AKS.

  • Integration can't be disabled once added.
  • Downgrades from an integrated cluster to the legacy Microsoft Entra ID clusters aren't supported.
  • Clusters without Kubernetes RBAC support are unable to add the integration.

Before you begin

The following requirements need to be met in order to properly install the AKS addon for managed identity.

  • You have Azure CLI version 2.29.0 or later installed and configured. Run az --version to find the version. If you need to install or upgrade, see Install Azure CLI.
  • You need kubectl with a minimum version of 1.18.1 or kubelogin. With the Azure CLI and the Azure PowerShell module, these two commands are included and automatically managed. Meaning, they're upgraded by default and running az aks install-cli isn't required or recommended. If you're using an automated pipeline, you need to manage upgrades for the correct or latest version. The difference between the minor versions of Kubernetes and kubectl shouldn't be more than one version. Otherwise, authentication issues occur on the wrong version.
  • If you're using helm, you need a minimum version of helm 3.3.
  • This configuration requires you have a Microsoft Entra group for your cluster. This group is registered as an admin group on the cluster to grant admin permissions. If you don't have an existing Microsoft Entra group, you can create one using the az ad group create command.

Note

Microsoft Entra integrated clusters using a Kubernetes version newer than version 1.24 automatically use the kubelogin format. Starting with Kubernetes version 1.24, the default format of the clusterUser credential for Microsoft Entra ID clusters is exec, which requires kubelogin binary in the execution PATH. There is no behavior change for non-Microsoft Entra clusters, or Microsoft Entra ID clusters running a version older than 1.24. Existing downloaded kubeconfig continues to work. An optional query parameter format is included when getting clusterUser credential to overwrite the default behavior change. You can explicitly specify format to azure if you need to maintain the old kubeconfig format .

Enable the integration on your AKS cluster

Create a new cluster

  1. Create an Azure resource group using the az group create command.

    az group create --name myResourceGroup --location centralus

  2. Create an AKS cluster and enable administration access for your Microsoft Entra group using the az aks create command.

    az aks create \
    --resource-group myResourceGroup \
    --name myManagedCluster \
    --enable-aad \
    --aad-admin-group-object-ids <id> [--aad-tenant-id <id>] \
    --generate-ssh-keys

    A successful creation of an AKS-managed Microsoft Entra ID cluster has the following section in the response body:

    "AADProfile": {
    "adminGroupObjectIds": [
    "5d24****-****-****-****-****afa27aed"
    ],
    "clientAppId": null,
    "managed": true,
    "serverAppId": null,
    "serverAppSecret": null,
    "tenantId": "72f9****-****-****-****-****d011db47"
}

Use an existing cluster

Enable AKS-managed Microsoft Entra integration on your existing Kubernetes RBAC enabled cluster using the az aks update command. Make sure to set your admin group to keep access on your cluster.

az aks update --resource-group MyResourceGroup --name myManagedCluster --enable-aad --aad-admin-group-object-ids <id-1>,<id-2> [--aad-tenant-id <id>]

A successful activation of an AKS-managed Microsoft Entra ID cluster has the following section in the response body:

"AADProfile": {
    "adminGroupObjectIds": [
        "5d24****-****-****-****-****afa27aed"
    ],
    "clientAppId": null,
    "managed": true,
    "serverAppId": null,
    "serverAppSecret": null,
    "tenantId": "72f9****-****-****-****-****d011db47"
    }

Migrate legacy cluster to integration

If your cluster uses legacy Microsoft Entra integration, you can upgrade to AKS-managed Microsoft Entra integration through the az aks update command.

Warning

Free tier clusters may experience API server downtime during the upgrade. We recommend upgrading during your nonbusiness hours. After the upgrade, the kubeconfig content changes. You need to run az aks get-credentials --resource-group <AKS resource group name> --name <AKS cluster name> to merge the new credentials into the kubeconfig file.

az aks update --resource-group myResourceGroup --name myManagedCluster --enable-aad --aad-admin-group-object-ids <id> [--aad-tenant-id <id>]

A successful migration of an AKS-managed Microsoft Entra ID cluster has the following section in the response body:

"AADProfile": {
    "adminGroupObjectIds": [
        "5d24****-****-****-****-****afa27aed"
    ],
    "clientAppId": null,
    "managed": true,
    "serverAppId": null,
    "serverAppSecret": null,
    "tenantId": "72f9****-****-****-****-****d011db47"
    }

Access your enabled cluster

  1. Get the user credentials to access your cluster using the az aks get-credentials command.

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

  2. Follow your instructions to sign in.

  3. Set kubelogin to use the Azure CLI.

    kubelogin convert-kubeconfig -l azurecli

  4. View the nodes in the cluster with the kubectl get nodes command.

    kubectl get nodes

Non-interactive sign-in with kubelogin

There are some non-interactive scenarios that don't support kubectl. In these cases, use kubelogin to connect to the cluster with a non-interactive service principal credential to perform continuous integration pipelines.

Note

Microsoft Entra integrated clusters using a Kubernetes version newer than version 1.24 automatically use the kubelogin format. Starting with Kubernetes version 1.24, the default format of the clusterUser credential for Microsoft Entra ID clusters is exec, which requires kubelogin binary in the execution PATH. There is no behavior change for non-Microsoft Entra clusters, or Microsoft Entra ID clusters running a version older than 1.24. Existing downloaded kubeconfig continues to work. An optional query parameter format is included when getting clusterUser credential to overwrite the default behavior change. You can explicitly specify format to azure if you need to maintain the old kubeconfig format .

  • When getting the clusterUser credential, you can use the format query parameter to overwrite the default behavior. You can set the value to azure to use the original kubeconfig format:

    az aks get-credentials --format azure

  • If your Microsoft Entra integrated cluster uses Kubernetes version 1.24 or lower, you need to manually convert the kubeconfig format.

    export KUBECONFIG=/path/to/kubeconfig
kubelogin convert-kubeconfig

Note

If you receive the message error: The Azure auth plugin has been removed., you need to run the command kubelogin convert-kubeconfig to convert the kubeconfig format manually.

For more information, you can refer to Azure Kubelogin Known Issues.

Troubleshoot access issues

Important

The step described in this section suggests an alternative authentication method compared to the normal Microsoft Entra group authentication. Use this option only in an emergency.

If you lack administrative access to a valid Microsoft Entra group, you can follow this workaround. Sign in with an account that is a member of the Azure Kubernetes Service Cluster Admin role and grant your group or tenant admin credentials to access your cluster.

Next steps