Top Kubernetes Interview Questions and Answers

Here are top Kubernetes (K8s) interview questions,

1. What is Kubernetes (K8s)?

Kubernetes is an open-source container orchestration platform that automates the deployment, scaling, and management of containerized applications. 

 

2. What is a Pod in Kubernetes?

A Pod is the smallest deployable unit in Kubernetes, representing one or more containers that share the same network namespace and storage volumes.

 

3. How do you scale applications in Kubernetes?

Applications can be scaled in Kubernetes by adjusting the number of replicas in a Deployment or ReplicationController.

 

4. What is the role of a Deployment in Kubernetes?

A Deployment is used to manage the rollout and updates of a set of Pods, ensuring the desired number of replicas are running and providing declarative updates to the application.

 

5. What is a Service in Kubernetes?

A Service is an abstraction that defines a logical set of Pods and a policy by which to access them, providing a stable IP address and DNS name for the Pods.

 

6. How do you expose a Kubernetes Service to the outside world?

A Kubernetes Service can be exposed to the outside world using a LoadBalancer, NodePort, or an Ingress resource.

 

7. What are ConfigMaps and Secrets in Kubernetes?

ConfigMaps are used to store configuration data as key-value pairs, while Secrets are used to store sensitive information, like passwords or API tokens, in an encrypted manner.

 

8. How do you handle rolling updates in Kubernetes?

Kubernetes handles rolling updates automatically in a Deployment, where it gradually replaces old Pods with new ones to minimize downtime.

 

9. Explain the role of a Persistent Volume in Kubernetes.

A Persistent Volume is used to provide persistent storage for stateful applications in Kubernetes, allowing data to be retained across Pod restarts or rescheduling.

 

10. How does Kubernetes perform load balancing for Services?

Kubernetes performs load balancing for Services by distributing incoming traffic across all healthy Pods associated with the Service.

 

11. What is the purpose of a Node in Kubernetes?

A Node is a worker machine in Kubernetes responsible for running containers, managed by the control plane components.

 

12. How do you schedule Pods on specific Nodes in Kubernetes?

Pods can be scheduled on specific Nodes using NodeSelectors or Node Affinity.

 

13. Explain the difference between a StatefulSet and a Deployment in Kubernetes.

A Deployment is suitable for stateless applications, while a StatefulSet is designed for stateful applications that require stable, unique network identities and stable storage.

 

14. How can you monitor Kubernetes cluster health?

Kubernetes cluster health can be monitored using tools like Prometheus and Grafana or Kubernetes-native solutions like kube-state-metrics.

 

15. What is a DaemonSet in Kubernetes?

A DaemonSet ensures that a copy of a Pod is running on each Node in the cluster, typically used for monitoring agents, logging, etc.

 

16. How do you perform rolling back updates in Kubernetes?

Rolling back updates in Kubernetes can be done by reverting to the previous known-good version using `kubectl rollout undo` or by specifying the target revision during an update.

 

17. What are some popular Kubernetes network plugins for container networking?

Some popular Kubernetes network plugins include Flannel, Calico, Weave, and Cilium.

 

18. How do you secure communication between Kubernetes components?

Communication between Kubernetes components can be secured using Transport Layer Security (TLS) certificates and authentication tokens.

 

19. What are the different types of Kubernetes volumes?

Kubernetes supports various volume types, such as emptyDir, hostPath, PersistentVolume, ConfigMap, Secret, etc.

 

20. How do you troubleshoot a misbehaving Pod in Kubernetes?

To troubleshoot a misbehaving Pod, you can check the Pod's logs, describe the Pod, inspect resource limits, and check events related to the Pod.

 

Above are few top Kuberbetes interview questions. Remember to prepare and expand on these answers.

Good luck with your interview!  👍