Configure storage for Azure Kubernetes Service (AKS)

Azure Kubernetes Service (AKS) simplifies the deployment, management, and scaling of containerized applications. However, setting up storage for AKS requires careful consideration to ensure that the application data is managed efficiently and securely. Proper configuration of storage in AKS includes determining the right type of storage, provisioning it, and integrating it with the pods that your applications run on.

Types of Storage Volumes in AKS

When configuring storage for AKS, you can choose from several types of storage volumes:

• Azure Disks: Block-level storage suitable for single pod access, ideal for databases and other stateful applications.
• Azure Files: Managed file storage that supports the SMB protocol and can be simultaneously accessed by multiple pods.
• Azure Blob: Object storage service for storing large amounts of unstructured data.

Choosing the Right Storage Option

The choice of storage type in AKS depends on your application’s requirements:

• If your application requires a high-performance, low-latency solution with consistent IOPS, Azure Disks would be the best choice.
• For applications that need shared access across multiple nodes or pods, Azure Files is preferable.
• If you need to store large volumes of unstructured data that is accessed less frequently, Azure Blob storage might be the right choice.

Provisioning Storage in AKS

To provision storage in AKS, you typically use Persistent Volumes (PV) and Persistent Volume Claims (PVC), which abstract the storage details away from the pod specification.

Here’s an example of provisioning an Azure Disk:

1. Create a PersistentVolume using an Azure Disk:

apiVersion: v1
kind: PersistentVolume
metadata:
name: azure-disk-pv
spec:
capacity:
storage: 100Gi
accessModes:
– ReadWriteOnce
azureDisk:
kind: Managed
diskName: your-disk-name
diskURI: /subscriptions/your-sub-id/resourceGroups/your-rg/providers/Microsoft.Compute/disks/your-disk-name
cachingMode: ReadOnly
fsType: ext4

2. Create the PersistentVolumeClaim:

apiVersion: v1
kind: PersistentVolumeClaim
metadata:
name: azure-disk-pvc
spec:
accessModes:
– ReadWriteOnce
resources:
requests:
storage: 100Gi
storageClassName: “”

3. Integrate the PVC with your POD:

apiVersion: v1
kind: Pod
metadata:
name: mypod
spec:
containers:
– name: mycontainer
image: nginx
volumeMounts:
– mountPath: “/mnt/azure”
name: volume
volumes:
– name: volume
persistentVolumeClaim:
claimName: azure-disk-pvc

When using Azure Files, a similar approach is taken, but you specify azureFile in the PersistentVolume instead:

azureFile:
secretName: azure-secret
shareName: yourfileshare
readOnly: false

Dynamic Provisioning

Rather than manually creating PVs and PVCs, you can leverage dynamic provisioning by using a StorageClass, which automates the deployment of storage resources.

apiVersion: storage.k8s.io/v1
kind: StorageClass
metadata:
name: azure-disk-sc
provisioner: kubernetes.io/azure-disk
parameters:
storageaccounttype: Standard_LRS
kind: Managed

By creating a PVC that references this StorageClass, AKS will automatically provision the necessary PV.

apiVersion: v1
kind: PersistentVolumeClaim
metadata:
name: azure-disk-pvc
spec:
accessModes:
– ReadWriteOnce
resources:
requests:
storage: 100Gi
storageClassName: azure-disk-sc

Security Considerations

When configuring storage for AKS, you must also address security concerns:

• Use Azure Key Vault to secure secrets required for accessing storage resources.
• Implement role-based access control (RBAC) to restrict who can access storage resources.
• Leverage network security groups and service endpoints to limit network access to your storage resources.

Monitoring Storage

It’s important to monitor the performance and health of your storage resources. Azure Monitor can be used to keep track of metrics like disk throughput, I/O, and availability.

Conclusion

Configuring storage for AKS involves deciding on the type of storage, provisioning it through PVs, PVCs, and possibly StorageClasses, and integrating it with pods. Security and monitoring must also be part of your strategy to ensure that your application’s storage needs are met securely and reliably.