AKS | Pod Sandboxing

Hi!

In a traditional Kubernetes cluster, pods share the same node and therefore have the same level of access to the host system. This can lead to potential security risks, particularly if a malicious actor gains access to a vulnerable pod. Pod sandboxing in AKS addresses this issue by creating a dedicated container for each pod, which is isolated from other pods and the host system.

AKS pod sandboxing achieves this isolation by running each pod in its own container, using the gVisor sandboxing technology. gVisor is an open-source sandboxing solution that provides a lightweight, container-based isolation mechanism for running untrusted workloads. This approach enables AKS to provide a secure runtime environment for each pod, without sacrificing performance or scalability.

AKS pod sandboxing also provides a number of other security features, including encryption at rest for pod volumes, network isolation through virtual networks, and integrated identity and access management through Azure Active Directory. These features help to protect sensitive data and prevent unauthorized access to Kubernetes resources.

To use AKS pod sandboxing, users can simply enable the feature when creating a new AKS cluster. Once enabled, all pods deployed to the cluster will be automatically sandboxed, providing an added layer of security and isolation.

In summary, pod sandboxing is an important technique for securing Kubernetes workloads, particularly in multi-tenant environments. AKS pod sandboxing provides a powerful and easy-to-use solution for isolating pods from one another and from the host system, using the lightweight gVisor sandboxing technology. By enabling AKS pod sandboxing, users can improve the security and reliability of their Kubernetes deployments, while maintaining performance and scalability.

How it works:

To achieve this functionality on AKS, Kata Containers running on Mariner AKS Container Host (MACH) stack delivers hardware-enforced isolation. Pod Sandboxing extends the benefits of hardware isolation such as a separate kernel for each Kata pod. Hardware isolation allocates resources for each pod and doesn’t share them with other Kata Containers or namespace containers running on the same host.

The solution architecture is based on the following components:

  • Mariner AKS Container Host
  • Microsoft Hyper-V Hypervisor
  • Azure-tuned Dom0 Linux Kernel
  • Open-source Cloud-Hypervisor Virtual Machine Monitor (VMM)
  • Integration with Kata Container framework

To use this feature with a pod, the only difference is to add runtimeClassName kata-mshv-vm-isolation to the pod spec.

Limitations:

Enable Pod Sandboxing to an existing AKS cluster:

az aks nodepool add --cluster-name myAKSCluster --resource-group myResourceGroup --name nodepool2 --os-sku mariner --workload-runtime KataMshvVmIsolation --node-vm-size Standard_D4s_v3

az aks update --name myAKSCluster --resource-group myResourceGroup

Documentation: https://learn.microsoft.com/en-gb/azure/aks/use-pod-sandboxing

Maxime.

Azure Policy Export

Hi!

Azure Policy definitions, initiatives, and assignments can each be exported as JSON with Azure CLI.

Here an example to export an Azure Policy. In the first we will list all the Azure Policies which contains the display name « virtual machine ». In the second step we will export the Azure Policy in JSON.

maxime@Azure:~$ az policy definition list --query "[?contains(displayName, 'virtual machine')]" -o table
Name                                  PolicyType    Mode     DisplayName                                                                                                                       Description
------------------------------------  ------------  -------  ----------------
0015ea4d-51ff-4ce3-8d8c-f3f8f0179a56  BuiltIn       All      Audit virtual machines without disaster recovery configured                                                                       Audit virtual machines which do not have disaster recovery configured. To learn more about disaster recovery, visit https://aka.ms/asr-doc.
04c4380f-3fae-46e8-96c9-30193528f602  BuiltIn       Indexed  [Preview]: Network traffic data collection agent should be installed on Linux virtual machines                                    Security Center uses the Microsoft Dependency agent to collect network traffic data from your Azure virtual machines to enable advanced network protection features such as traffic visualization on the network map, network hardening recommendations and specific network threats.


maxime@Azure:~$ az policy definition show -n 0015ea4d-51ff-4ce3-8d8c-f3f8f0179a56 -o jsonc
{
  "description": "Audit virtual machines which do not have disaster recovery configured. To learn more about disaster recovery, visit https://aka.ms/asr-doc.",
  "displayName": "Audit virtual machines without disaster recovery configured",
  "id": "/providers/Microsoft.Authorization/policyDefinitions/0015ea4d-51ff-4ce3-8d8c-f3f8f0179a56",
  "metadata": {
    "category": "Compute",
    "version": "1.0.0"
  },
  "mode": "All",
  "name": "0015ea4d-51ff-4ce3-8d8c-f3f8f0179a56",
  "parameters": {},
  "policyRule": {
    "if": {
      "field": "type",
      "in": [
        "Microsoft.Compute/virtualMachines",
        "Microsoft.ClassicCompute/virtualMachines"
      ]
    },
    "then": {
      "details": {
        "existenceCondition": {
          "field": "name",
          "like": "ASR-Protect-*"
        },
        "type": "Microsoft.Resources/links"
      },
      "effect": "auditIfNotExists"
    }
  },
  "policyType": "BuiltIn",
  "systemData": null,
  "type": "Microsoft.Authorization/policyDefinitions"
}

Maxime.

AKS | Pricing Tiers

Hi!

Azure Kubernetes Service (AKS) is now offering two pricing tiers for cluster management: the Free tier and the Standard tier.

Free tierStandard tier
When to use• You want to experiment with AKS at no extra cost
• You’re new to AKS and Kubernetes		• You’re running production or mission-critical workloads and need high availability and reliability
• You need a financially backed SLA
Supported cluster types• Development clusters or small scale testing environments
• Clusters with fewer than 10 nodes		• Enterprise-grade or production workloads
• Clusters with up to 5,000 nodes
Pricing• Free cluster management
• Pay-as-you-go for resources you consume		• Pay-as-you-go for resources you consume
Feature comparison• Recommended for clusters with fewer than 10 nodes, but can support up to 1,000 nodes
• Includes all current AKS features		• Uptime SLA is enabled by default
• Greater cluster reliability and resources
• Can support up to 5,000 nodes in a cluster
• Includes all current AKS features
# Create a new AKS cluster in the Free tier 
az aks create --resource-group myResourceGroup --name myAKSCluster --no-uptime-sla 

# Create a new AKS cluster in the Standard tier 
az aks create --resource-group myResourceGroup --name myAKSCluster --uptime-sla

# Update an existing cluster to the Free tier
az aks update --resource-group myResourceGroup --name myAKSCluster --no-uptime-sla

# Update an existing cluster to the Standard tier
az aks update --resource-group myResourceGroup --name myAKSCluster --uptime-sla

Documentation: https://learn.microsoft.com/en-us/azure/aks/free-standard-pricing-tiers

Maxime.