Kubernetes has become the go-to container orchestration platform for managing applications at scale. If you’re preparing for a Kubernetes-related role, it’s essential to be ready for technical discussions. In this blog, we’ll cover the top 10 Kubernetes interview questions that you must know to ace your interview.
1. What is Kubernetes, and why is it used?
Kubernetes is an open-source container orchestration platform that automates the deployment, scaling, and management of containerized applications. It helps businesses manage complex applications efficiently by ensuring high availability, fault tolerance, and resource optimization.
2. What are the key components of Kubernetes architecture?
Kubernetes follows a master-worker architecture, consisting of:
- Master Node: API Server, Controller Manager, Scheduler, etcd (key-value store)
- Worker Node: Kubelet, Kube Proxy, and Container Runtime (e.g., Docker, containerd)
- Pods: The smallest deployable unit in Kubernetes that contains one or more containers.
3. What is a Pod in Kubernetes?
A Pod is the smallest and simplest unit in Kubernetes. It represents a single instance of a running process and can contain one or more containers that share network and storage resources. Pods are used to run and manage containerized applications efficiently.
4. How does Kubernetes handle service discovery and load balancing?
Kubernetes uses Services to expose applications running on a set of Pods. It provides load balancing through different types of Services:
- ClusterIP (default) – Exposes services internally within the cluster.
- NodePort – Makes the service accessible on a static port on each node.
- LoadBalancer – Integrates with external cloud provider load balancers.
- Ingress – Provides HTTP and HTTPS routing to services.
5. What is a Namespace in Kubernetes?
Namespaces help in logically partitioning cluster resources among different teams or projects. They are useful for multi-tenant environments where multiple users share a single Kubernetes cluster without interfering with each other’s resources.
6. What is a Deployment in Kubernetes?
A Deployment is a higher-level abstraction that manages Pods and ReplicaSets. It ensures that the desired number of Pod replicas are running at any time and facilitates rolling updates and rollbacks for seamless application updates.
7. How do you perform scaling in Kubernetes?
Scaling in Kubernetes can be done in two ways:
- Manual Scaling: Adjusting the number of Pod replicas using
kubectl scale deployment <deployment-name> --replicas=<count> - Autoscaling: Kubernetes provides Horizontal Pod Autoscaler (HPA) and Vertical Pod Autoscaler (VPA) for dynamically adjusting resources based on CPU and memory utilization.
8. What is a Persistent Volume (PV) and Persistent Volume Claim (PVC)?
Kubernetes provides a Persistent Volume (PV) abstraction to manage storage independently of the lifecycle of Pods. A Persistent Volume Claim (PVC) is a request for storage by users, binding to available PVs based on defined storage classes.
9. What is a ConfigMap and Secret in Kubernetes?
- ConfigMap: Stores non-sensitive configuration data like environment variables, command-line arguments, and configuration files.
- Secret: Stores sensitive information like passwords, API keys, and certificates securely using base64 encoding.
10. How does Kubernetes handle networking?
Kubernetes follows a flat networking model, allowing communication between all Pods across nodes without using NAT. It uses a Container Network Interface (CNI) plugin (e.g., Calico, Flannel, Cilium) to manage networking within the cluster.
Conclusion
Kubernetes is a powerful container orchestration platform, and being well-versed in these Kubernetes interview questions will give you a competitive edge in your next technical interview. Keep practicing with real-world scenarios and hands-on projects to solidify your Kubernetes expertise!
Looking for more interview prep tips? Stay tuned for more Kubernetes insights!