Securing Pod Identity in Azure Kubernetes Service

Question

Pulumi · Accepted Answer

Securing Pod Identity in Azure Kubernetes Service (AKS) involves using Azure Active Directory (Azure AD) to assign an identity to each pod running in the AKS cluster, enabling the pods to authenticate with other Azure services following the principle of least privilege.

This is accomplished by using the Azure AD Pod Identity solution, which utilizes the Managed Identity components within AKS to bind Azure identities to pods securely. This allows pods to use an identity distinct from their node's identity and restricts the permissions each pod has to the minimal required for its specific role.

To implement this in Pulumi using Python, you'd use the `azure-native.containerservice` module to create an AKS cluster with a Managed Identity and specify a Pod Identity Profile.

Let's look at the code to create a basic AKS cluster with this configuration:

```python
import pulumi
import pulumi_azure_native as azure_native

# Define the AKS cluster with Azure AD Pod Identity enabled
aks_cluster = azure_native.containerservice.ManagedCluster(
    "aksCluster",
    resource_group_name="myResourceGroup",
    identity=azure_native.containerservice.ManagedClusterIdentityArgs(
        type="SystemAssigned"
    ),
    # Additional AKS configurations here...
    pod_identity_profile=azure_native.containerservice.ManagedClusterPodIdentityProfileArgs(
        enabled=True,
        # Assuming you are using the default namespace and have already set up Azure Identities
        user_assigned_identity_exceptions=[
            azure_native.containerservice.UserAssignedIdentityPropertiesArgs(
                name="myIdentity",
                namespace="default",
                pod_labels={"aadpodidbinding": "myIdentitySelector"}
            )
        ],
    )
)

pulumi.export('aks_cluster_name', aks_cluster.name)
```

In the above program:

- We initialize a new AKS cluster by creating an instance of `ManagedCluster` from the `azure-native.containerservice` module.
- The `identity` parameter is configured with `type="SystemAssigned"`, which enables Managed Identity for the AKS cluster.
- The `pod_identity_profile` parameter is set with `enabled=True` which signifies that Azure AD Pod Identity feature is enabled for the cluster.
- `user_assigned_identity_exceptions` is a list where you can specify the Azure AD identities your pods may assume. In the example above, we are adding one identity called `myIdentity` which pods in the default namespace with the label `aadpodidbinding: myIdentitySelector` will be able to use. You would need to create and configure this Azure AD Identity separately, and the label would be used within your pod specifications to link the identity.

Remember to replace `"myResourceGroup"` with the name of the actual resource group where you want to deploy, and configure other AKS parameters as needed.

This program is a basic starting point and does not include other potentially necessary configurations such as network settings, agent pool configurations, and more. Also, you'll need to manage and assign the Azure AD identities yourself, outside of this script. For full functionality, complete networking and other configurations must be included according to your requirements.

To include full networking and identity configurations, refer to the Pulumi documentation for [`ManagedCluster`](https://www.pulumi.com/registry/packages/azure-native/api-docs/containerservice/managedcluster/) and the broader [`azure-native.containerservice`](https://www.pulumi.com/registry/packages/azure-native/api-docs/containerservice/) module for additional context and available options.

Once this Pulumi program is executed, it will provision an AKS cluster with Azure AD Pod Identity enabled, allowing you to run pods with specific identities that can securely interact with other Azure resources.