10 Azure AKS Interview Questions and Answers

Azure Kubernetes Service (AKS) is a managed container orchestration service that simplifies deploying, managing, and scaling containerized applications using Kubernetes. As organizations increasingly adopt microservices architectures and containerization, proficiency in AKS has become a valuable skill. AKS integrates seamlessly with other Azure services, providing a robust platform for building and maintaining scalable applications.

This article offers a curated selection of interview questions designed to test your knowledge and expertise in Azure AKS. By reviewing these questions and their detailed answers, you will be better prepared to demonstrate your understanding of AKS concepts and best practices, positioning yourself as a strong candidate in technical interviews.

Azure AKS Interview Questions and Answers

1. Explain the purpose of node pools in AKS and how they can be used to manage different types of workloads.

Node pools in AKS are used to organize and manage nodes running containerized applications. Each pool can be configured with different VM sizes and scaling policies, optimizing resource allocation for specific workloads. For instance, you might use high-memory VMs for memory-intensive applications and GPU-enabled VMs for machine learning tasks. This separation ensures efficient hardware use and facilitates scaling and upgrading tasks.

2. What are some best practices for securing an AKS cluster?

Securing an AKS cluster involves several practices to maintain application and data integrity. Key practices include:

• Network Security: Use network policies to control pod traffic and Azure Network Security Groups (NSGs) to restrict cluster access.
• Authentication and Authorization: Integrate Azure Active Directory (AAD) for user authentication and use Kubernetes Role-Based Access Control (RBAC) for permissions management.
• Secrets Management: Store sensitive information in Kubernetes Secrets and use Azure Key Vault for added security.
• Pod Security: Implement Pod Security Policies and use security contexts for privilege and access control.
• Image Security: Use trusted container images and regularly scan them for vulnerabilities.
• Monitoring and Logging: Enable Azure Monitor and Azure Security Center for continuous monitoring.
• Regular Updates: Keep Kubernetes and associated components up to date with security patches.

3. What tools and services can you use to monitor and log activities in an AKS cluster?

To monitor and log activities in an AKS cluster, use tools like:

Azure Monitor: Collects, analyzes, and acts on telemetry from your environments, offering metrics, logs, and alerts.

Azure Log Analytics: Part of Azure Monitor, it allows querying and analyzing log data from your cluster.

Azure Application Insights: Provides application performance management, offering detailed telemetry data.

Prometheus and Grafana: Open-source tools for monitoring and alerting, integrated with AKS for detailed insights.

Fluentd: An open-source data collector for logs, sending them to destinations like Azure Log Analytics.

Kubernetes-native tools: Tools like kube-state-metrics and cAdvisor monitor cluster state and performance.

4. How do you implement Role-Based Access Control (RBAC) in AKS? Provide an example scenario.

RBAC in AKS manages access to the Kubernetes API server by defining roles and assigning them to users or groups. This ensures only authorized users perform specific actions, enhancing security.

Example Scenario:

1. Define the Role:

apiVersion: rbac.authorization.k8s.io/v1
kind: Role
metadata:
  namespace: default
  name: pod-reader
rules:
- apiGroups: [""]
  resources: ["pods"]
  verbs: ["get", "watch", "list"]

2. Create the RoleBinding:

apiVersion: rbac.authorization.k8s.io/v1
kind: RoleBinding
metadata:
  name: read-pods
  namespace: default
subjects:
- kind: User
  name: "example-user"
  apiGroup: rbac.authorization.k8s.io
roleRef:
  kind: Role
  name: pod-reader
  apiGroup: rbac.authorization.k8s.io

In this example, the Role pod-reader allows reading pods in the default namespace, and the RoleBinding read-pods assigns this role to example-user.

5. What are the best practices for disaster recovery in AKS? Discuss backup and restore strategies.

For disaster recovery in AKS, consider backup and restore strategies:

• Regular Backups: Back up Kubernetes resources, including etcd, using tools like Velero.
• Persistent Volume Snapshots: Use Azure Disk snapshots for point-in-time data copies.
• Multi-Region Deployment: Deploy clusters across multiple regions for high availability.
• Automated Disaster Recovery Drills: Conduct drills to test backup and restore processes.
• Use of Infrastructure as Code (IaC): Use tools like Terraform to manage infrastructure, enabling quick cluster recreation.
• Monitoring and Alerts: Implement monitoring and alerting to detect issues early.
• Secure Backup Storage: Ensure backup storage is secure and encrypted, using Azure Blob Storage with encryption.

6. How do you manage and optimize costs when running AKS clusters? Discuss some strategies and tools.

To manage and optimize costs in AKS:

1. Right-Sizing and Scaling:

• Use appropriate VM sizes and implement autoscaling to adjust node numbers based on demand.

2. Spot Instances:

• Utilize Azure Spot VMs for non-critical workloads to reduce costs.

3. Resource Quotas and Limits:

• Set quotas and limits to control resource consumption and prevent unexpected costs.

4. Monitoring and Alerts:

• Use Azure Monitor to track resource usage and set alerts for unusual spending patterns.

5. Reserved Instances:

• Purchase reserved instances for predictable workloads to benefit from discounts.

6. Cost Management Tools:

• Use Azure Cost Management and Billing to analyze and manage cloud spending.

7. Optimize Storage:

• Use appropriate storage classes and tiers for data, like Standard HDD for less accessed data.

8. Networking Costs:

• Optimize network traffic to reduce egress costs using VNet peering and private endpoints.

7. Explain different scaling strategies in AKS and their use cases.

In AKS, scaling strategies include manual scaling, horizontal pod autoscaling, and cluster autoscaling.

1. Manual Scaling

• Adjust the number of nodes or pods manually, useful for predictable workloads.

2. Horizontal Pod Autoscaling (HPA)

• Automatically adjusts pod numbers based on metrics like CPU utilization, ideal for variable workloads.

3. Cluster Autoscaling

• Automatically adjusts node numbers based on pending pod requirements, optimizing costs and handling dynamic workloads.

8. How would you integrate a service mesh like Istio with AKS?

To integrate Istio with AKS:

• Install Istio CLI: Download and install the Istio CLI.
• Install Istio on AKS: Use the Istio CLI to install Istio on your cluster.
• Label the Namespace: Label the namespace for automatic sidecar injection.
• Deploy Services: Deploy microservices to the labeled namespace for sidecar proxy injection.
• Configure Istio: Use Istio’s configuration resources for traffic, security, and observability management.

9. Discuss identity and access management in AKS. How do you secure access to your cluster?

Identity and access management in AKS involves:

• Azure Active Directory (AAD) Integration: Manage user access to the Kubernetes API server using AAD.
• Role-Based Access Control (RBAC): Define roles and assign them to users or groups to control resource access.
• Network Policies: Control communication between pods and services within the cluster.
• Managed Identities: Provide secure access to Azure resources without managing credentials.
• Pod Security Policies: Control pod security settings, such as restricting privileged containers.

10. How do you handle multi-region deployments in AKS for high availability and disaster recovery?

For multi-region deployments in AKS:

• Multiple AKS Clusters: Deploy clusters in different regions for redundancy and reduced failure risk.
• Azure Traffic Manager: Distribute traffic across clusters, supporting automatic failover.
• Data Replication: Ensure data is replicated across regions using Azure’s replication options.
• Backup and Restore: Regularly back up data and cluster configurations using Azure Backup and Azure Site Recovery.
• CI/CD Pipelines: Use pipelines to automate deployment across regions with tools like Azure DevOps.
• Monitoring and Alerts: Use Azure Monitor and Log Analytics to monitor cluster health and set alerts for issues.