Pod Identity

Use Pod Identity to access Keyvault.

Supported only on Linux

Examples
  • SecretProviderClass
# This is a SecretProviderClass example using aad-pod-identity to access Key Vault
apiVersion: secrets-store.csi.x-k8s.io/v1alpha1
kind: SecretProviderClass
metadata:
  name: azure-kvname-podid
spec:
  provider: azure
  parameters:
    usePodIdentity: "true"          # set to true for pod identity access mode
    keyvaultName: "kvname"
    cloudName: ""                   # [OPTIONAL for Azure] if not provided, azure environment will default to AzurePublicCloud
    objects:  |
      array:
        - |
          objectName: secret1
          objectType: secret        # object types: secret, key or cert
          objectVersion: ""         # [OPTIONAL] object versions, default to latest if empty
        - |
          objectName: key1
          objectType: key
          objectVersion: ""
    tenantId: "tid"                    # the tenant ID of the KeyVault  
  • Pod yaml
# This is a sample pod definition for using SecretProviderClass and aad-pod-identity to access Key Vault
kind: Pod
apiVersion: v1
metadata:
  name: busybox-secrets-store-inline-podid
  labels:
    aadpodidbinding: "demo"         # Set the label value to match selector defined in AzureIdentityBinding
spec:
  containers:
    - name: busybox
      image: k8s.gcr.io/e2e-test-images/busybox:1.29
      command:
        - "/bin/sleep"
        - "10000"
      volumeMounts:
      - name: secrets-store01-inline
        mountPath: "/mnt/secrets-store"
        readOnly: true
  volumes:
    - name: secrets-store01-inline
      csi:
        driver: secrets-store.csi.k8s.io
        readOnly: true
        volumeAttributes:
          secretProviderClass: "azure-kvname-podid"

Configure AAD Pod Identity to access Keyvault

Prerequisites

💡 Make sure you have installed pod identity to your Kubernetes cluster

This project makes use of the aad-pod-identity project to handle the identity management of the pods. Reference the aad-pod-identity README if you need further instructions on any of these steps.

Not all steps need to be followed on the instructions for the aad-pod-identity project as we will also complete some of the steps on our installation here.

  1. Install the aad-pod-identity components to your cluster

    • 💡 Follow the Role assignment documentation to setup all the required roles for aad-pod-identity components.

    • Install the RBAC enabled aad-pod-identiy infrastructure components:

      kubectl apply -f https://raw.githubusercontent.com/Azure/aad-pod-identity/master/deploy/infra/deployment-rbac.yaml
      
  2. Create an Azure User-assigned Managed Identity

    Create an Azure User-assigned Managed Identity with the following command. Get clientId and id from the output.

    az identity create -g <resourcegroup> -n <idname>
    
  3. Assign permissions to new identity Ensure your Azure user identity has all the required permissions to read the keyvault instance and to access content within your key vault instance. If not, you can run the following using the Azure CLI:

    # set policy to access keys in your keyvault
    az keyvault set-policy -n $KEYVAULT_NAME --key-permissions get --spn <YOUR AZURE USER IDENTITY CLIENT ID>
    # set policy to access secrets in your keyvault
    az keyvault set-policy -n $KEYVAULT_NAME --secret-permissions get --spn <YOUR AZURE USER IDENTITY CLIENT ID>
    # set policy to access certs in your keyvault
    az keyvault set-policy -n $KEYVAULT_NAME --certificate-permissions get --spn <YOUR AZURE USER IDENTITY CLIENT ID>
    
  4. Add an AzureIdentity for the new identity to your cluster

    Edit and save this as aadpodidentity.yaml

    Set type: 0 for User-Assigned Managed Identity; type: 1 for Service Principal In this case, we are using managed service identity, type: 0. Create a new name for the AzureIdentity. Set resourceID to id of the Azure User Identity created from the previous step.

    apiVersion: "aadpodidentity.k8s.io/v1"
    kind: AzureIdentity
    metadata:
      name: <any-name>
    spec:
      type: 0
      resourceID: /subscriptions/<subid>/resourcegroups/<resourcegroup>/providers/Microsoft.ManagedIdentity/userAssignedIdentities/<idname>
      clientID: <clientid>
    
    kubectl create -f aadpodidentity.yaml
    
  5. Add AzureIdentityBinding for the AzureIdentity to your cluster

    Edit and save this as aadpodidentitybinding.yaml

    apiVersion: "aadpodidentity.k8s.io/v1"
    kind: AzureIdentityBinding
    metadata:
      name: <any-name>
    spec:
      azureIdentity: <name of the AzureIdentity created in previous step>
      selector: <label value to match in your pod>
    
    kubectl create -f aadpodidentitybinding.yaml
    
  6. Add the following to this deployment yaml:

    Include the aadpodidbinding label matching the selector value set in the previous step so that this pod will be assigned an identity

    metadata:
    labels:
      aadpodidbinding: <AzureIdentityBinding Selector created from previous step>
    
  7. Update this sample deployment to create a SecretProviderClass resource with usePodIdentity: "true" to provide Azure-specific parameters for the Secrets Store CSI driver.

    Make sure to set usepodidentity to true

    usepodidentity: "true"
    
  8. Deploy your app

    kubectl apply -f pod.yaml
    

NOTE When using the Pod Identity option mode, there can be some amount of delay in obtaining the objects from keyvault. During the pod creation time, in this particular mode aad-pod-identity will need to create the AzureAssignedIdentity for the pod based on the AzureIdentity and AzureIdentityBinding, retrieve token for keyvault. This process can take time to complete and it’s possible for the pod volume mount to fail during this time. When the volume mount fails, kubelet will keep retrying until it succeeds. So the volume mount will eventually succeed after the whole process for retrieving the token is complete.