Kubernetes has been noted quite widely in many circles related to the use of container technologies. This has been one of the reasons for large scale demand for Kubernetes interview questions. However, before looking for the best Kubernetes interview questions, you need to have a basic idea about Kubernetes itself.
In the most basic sense, Kubernetes can be described as a container orchestration tool. It is not dependent on vendors and is an open-source tool that provides a platform for automation of deployment, operations, and scaling of application containers across host clusters. The applications of Kubernetes have been associated with considerably lower costs for cloud computing expenses. Also, it has been a promising instrument in the simplification of architecture as well as operations.
Top Kubernetes Interview Questions and Answers
With this basic information on Kubernetes, let us start this discussion on the most popular Kubernetes interview questions and answers. These are the most frequently asked in a Kubernetes interview by the interviewer. So, if you are preparing for a Kubernetes interview, these questions will help you ace the interview. Let’s get ahead!
1. What is Kubernetes?
The first entry in this list of Kubernetes interview questions is probably one of the most basic ones. However, the majority of interviewers never skip this basic question.
Kubernetes (K8s) is an open source container orchestration platform which automates the process and eliminates the manual processes involved in containerized applications deployment and management. Kubernetes was originally developed by Google and released as open source, now managed by Cloud Native Computing Foundation.
Know More about Kubernetes : https://www.whizlabs.com/blog/introduction-to-kubernetes/
2. How can we control the resource usage of POD?
There are tools and services available to manage and optimize resource usage.
- Resource requests and limits
- Resource quota and limit ranges for Namespaces
We can control the amount of memory and CPU per POD by setting resource requests and limits in the pod configuration file.
3. How do you perform maintenance activities on the Kubernetes node?
The maintenance on the kubernetes node can be done by draining the kubernetes node.
kubectl drain -ignore-daemon set
The following commands will be used to perform the maintenance on a single node.
kubectl get nodes
kubectl drain <node name>
4. What is the Pod Disruption Budget (PDB)?
A Pod Disruption Budget (PDB) allows you to limit the disruption to the application when its pods need to be rescheduled. It will limit the number of pods of a replicated application that are down from the disruptions.
5. How do you monitor the Kubernetes cluster?
The kubernetes (k8s) clusters can be monitored using a combination of Heapster to collect metrics and InfluxDB to store it, and Grafana/Prometheus to present the collected data.
6. What is the relation between Docker and Kubernetes?
Answer: This is one of the most common questions asked in a Kubernetes interview. You can find this question commonly in all the lists of Kubernetes interview questions. The candidate should answer this question as Docker is a platform used for lifecycle management of containers with a Docker image, responsible for building runtime containers. However, Kubernetes is the solution for communication between the individual containers. Therefore, Kubernetes helps in manual linking and orchestration of containers running on multiple hosts created using Docker. Let us move towards the next entry in Kubernetes interview questions.
7. What is a node in Kubernetes?
In Kubernetes, the node is a worker machine. It can be a physical machine or a Virtual machine (VM). A node can have multiple pods.
8. What is the use of Kube-scheduler?
The Kube scheduler is a kubernetes controller on the control plane that is responsible for assigning the pods to nodes.
9. What are daemon sets in Kubernetes?
A Daemonset is used to ensure that all the eligible nodes run a copy of some or all of the desired pods. If a new node is added to the kubernetes cluster, a new pod will be added to the newly created node.
10. What is a cluster IP in Kubernetes?
The cluster IP is virtual IP assigned by the kubernetes to a service. Using the cluster IP, a service can be accessed from any node of the Kubernetes cluster.
11. What are the various services available in Kubernetes?
There are 4 types of Kubernetes services available:
12. What is kube-proxy in Kubernetes?
Kube-proxy is a network proxy that runs on each node of the cluster. It watches API servers for pods/services changes to maintain the network rules.
13. What is kubectl?
The Kubernetes command line tool, kubectl is an abbreviation for kubernetes control that allows to run commands against the clusters. Kubectl can be used to manage cluster resources, deploy applications and view logs.
14. What are the different types of pods available in Kubernetes?
There are two types of PODs are available:
- Single Container Pod
- Multi Container Pod
15. What is Prometheus?
Prometheus is an open source tool used for system monitoring and alerting. This monitoring tool can help you to monitor the kubernetes cluster.
16. What is the difference between a replica set and a replication controller?
The replica set and replication controller almost does the same. These are used to ensure that the desired number of replicas are running at a given time. The difference between replica set and the replication controller is the selector types. Replica set uses set based selectors and the replication controller uses equality-based selectors.
17. What is the difference between Equality Based selectors and Selector Based selectors?
Equality based selectors allow filtering by key and value. Set based selectors allow filtering keys according to a set of values.
18. How can we assign a static IP to the Kubernetes load balancer?
19. What is minikube?
Minikube is a tool used to run a kubernetes cluster locally. Minikube is available for Linux, Windows and MacOS. It creates a virtual machine on the local system and creates a cluster with a single node.
20. List some of the important Kubernetes commands.
It’s not possible to remember all the commands used to manage the kubernetes cluster. However, you may get a question from the interviewer to list some of the commands that are used frequently. Here is the list of commands that would be useful for the interview as well as for your day to day activities as a DevOps specialist.
- kubectl get pods
- kubectl get pods –all-namespaces
- kubectl get pod monkey -o wide
- kubectl get pod monkey -o yaml
- kubectl describe pod monkey
- kubectl scale deployment/POD_NAME –replicas=N
- kubectl rollout history deployment/DEPLOYMENT_NAME
- kubectl rollout undo deployment/DEPLOYMENT_NAME –to-revision=N
- kubectl get services
- kubectl expose deployment/dep_name –port=2001 –type=NodePort
- kubectl get pv
- kubectl get pvc
- kubectl get secrets
- kubectl create secret generic –help
- kubectl create secret generic mysql –from-literal=password=root
- kubectl get secrets mysql -o yaml
- kubectl create configmap foobar –from-file=config.js
- kubectl get configmap foobar -o yaml
- kubectl get pods –all-namespaces |grep dns
- kubectl get ingress
- kubectl expose deployment ghost –port=2368
- kubectl get daemonsets
- kubectl describe
- kubectl logs
- kubectl exec
- kubectl get nodes –show-labels
- kubectl get events
21. What are the secrets in Kubernetes?
Secrets is an object containing sensitive information such as keys or tokens. Secrets eliminates the need to store confidential information on our code. Secrets can be created independently of the pods that use them.
22. What is a federated cluster?
Kubernetes Federation (KubeFed) is aggregating multiple kubernetes clusters and treating them as a single cluster to manage. We can make the clusters from various cloud platforms and use federation to control them as one.
23. How do you run kubernetes locally?
There are multiple options available to run kubernetes locally.
- CodeReady Containers(CRC)
24. What is the difference between Kubernetes and Docker Swarm?
Answer: The third entry is also one of the top Kubernetes interview questions. The answer to this Kubernetes interview question would be a little detailed with a focus on different points. The difference points include installation and cluster configuration, GUI, auto-scaling, data volume, scalability, load balancing, logging and monitoring, and rolling updates and rollbacks. Here are the main points of difference between Kubernetes and Docker Swarm.
- Kubernetes has a complicated setup with the assurance of a robust cluster while Docker Swarm is easier to set up but without a robust cluster.
- The scalability of Docker Swarm is five times faster than Kubernetes. Kubernetes provides a dashboard as GUI while Docker Swarm does not have any GUI.
- Kubernetes is capable of auto-scaling while Docker Swarm cannot. However, Kubernetes needs manual intervention for load balancing of traffic as compared to the automatic load balancing in Docker Swarm.
- Kubernetes has integrated tools for logging and monitoring, unlike Docker Swarm, which needs third party tools for the same.
- Kubernetes is limited in term of data volumes as it can share storage with other containers in the same pod while Docker swarm could share storage volumes with other containers easily.
- The final point is the ability of Kubernetes to deploy rolling updates and automatic rollbacks. On the other hand, Docker Swarm could deploy rolling updates but does not have the ability for automatic rollbacks.
25. What is Container orchestration?
Answer: The answer to another one of the frequently asked Kubernetes interview questions shall be based on an example. If there are around 8 or 10 microservices for an application, and each of them is placed in separate containers, it would create obstacles for communication. Therefore, container orchestration becomes mandatory in such cases. Orchestration helps in enabling all services in individual containers to work in unison for accomplishing goals of a single server.
Note: If you’re aspiring to become a Kubernetes Certified Administrator? Start your preparation for the Kubernetes Certified Administrator exam.
26. What are the notable features of Kubernetes?
Answer: The coverage of best Kubernetes interview questions would also include “What are the notable features of Kubernetes”? You can point out the distinct features of automated scheduling, horizontal scaling, load balancing and self-healing capabilities as well as automated rollouts and rollbacks.
27. How can Kubernetes help in deployment with containers?
Answer: Another mention in Kubernetes interview questions is “How can Kubernetes help in deployment with containers”? The answer to this question would refer back to the basic objective of Kubernetes. As an orchestration tool, Kubernetes helps a cluster of containers in an application running on multiple hosts to communicate with each other. Kubernetes does not depend on the type of cloud and could be implemented on a public or private cloud. Furthermore, it is also functional in monitoring, scaling, and load balancing of containers, which makes it the best choice for simple containerized deployment.
Whatever be the technology, you may come across the myths associated with that. To uncover the myths and facts behind them, read out our previous article on Kubernetes Myths and Facts.
28. Can you explain clusters in Kubernetes?
Answer: Kubernetes helps in enforcing desired state management. This means that a particular configuration could be fed into cluster services, and then the cluster services have the privilege to execute the configuration in the infrastructure. Deployment files have the configurations that need to be fed to the cluster services. When the deployment file is fed to the API, the clusters are required to figure the scheduling of pods in the environment and ensuring their execution. Therefore, Kubernetes cluster includes the API, worker nodes, and the Kubelet process run by the nodes.
29. What is Google Container Engine?
Answer: This is one of the top Kubernetes interview questions. The answer would be, Google Container Engine can be described as an open-source management platform tailored for Docker containers and clusters. It is based on Kubernetes and provides support for the clusters that run in public cloud services of Google.
30. What do you know about a node in Kubernetes?
Answer: You would also get Kubernetes interview questions like this in your interview! The answer may go like, a node can be defined as the main worker machine in a Kubernetes cluster and is also known as minions. Nodes could be executed on a VM or a physical machine, and they provide the necessary services for running pods. The master in a Kubernetes system has the privileges for managing a node.
31. What are the components in Kubernetes Architecture?
Answer: Do the latest Kubernetes interview questions focus on Kubernetes architecture like “What are the components in Kubernetes Architecture”? Of course, yes! And the response suggests that there are two major components known as the master node and the worker node. Each of the components, in turn, have individual components in them.
Also Read: Top Jenkins Interview Questions
32. How does the master node work in Kubernetes?
Answer: The answer to the question would be that the master node controls the nodes having the containers. The containers are placed inside pods, and each pod may have different containers. The pods can be deployed through the command line interface or user interface. Following that, the pods are scheduled on the nodes, and then pods are allocated to the nodes based on resource requirements.
33. What is the Kubernetes controller manager?
Answer: Another latest Kubernetes interview question is on the Kubernetes controller manager. The controller manager works as a daemon that is used for embedding controllers and garbage collection as well as namespace creation. It helps in running multiple controller processes on the master node albeit compiled together for running as a single process.
34. What are different types of controller manager?
Answer: You can find Kubernetes architecture interview questions such as “What are different types of controller manager?” The notable controller managers that can run on the master node are node controller, service account and token controller, endpoints controller, and replication controller.
35. What is etcd?
Answer: etcd is a distributed key-value store that can be helpful for coordination between distributed work. It is responsible for the storage of configuration data of Kubernetes cluster and represents the state of the cluster at a specific time.
Want to know more about Kubernetes? Check out some interesting Kubernetes facts now!
36. What are the services in Kubernetes?
Answer: You can also get Kubernetes interview questions asking about the services in Kubernetes. You can point out to the services such as node port, cluster IP, external name creation, and load balancer.
37. What is a load balancer in Kubernetes?
Answer: It is also an important interview question commonly asked in a Kubernetes interview. You can state that load balancer is a method for exposing service, and two types of load balancers can be used in Kubernetes. The two-load balancer includes external load balancer and internal load balancer.
38. What is the role of cloud controller manager?
Answer: To answer this question, you can state that the cloud controller manager is an essential component for persistent storage, the abstraction of cloud-specific code from core Kubernetes code, and network routing.
39. Do you know anything about container resource monitoring?
Answer: Users need to have a clear impression of the performance of an application and resource utilization at different levels such as container, services, pod, and the cluster itself. Kubernetes provides these functionalities and so container resource monitoring is used.
40. What is a headless service?
Answer: A can also come across a different question in your Kubernetes interview such as “What is a headless service?”. Headless service can be described as any other normal service, albeit without any cluster IP.
41. What are the recommended security measures for Kubernetes?
Answer: It could be the next important question in your Kubernetes interview. The security measures include restriction of access to etcd, implementing regular security updates to the environment, implementation of continuous scanning for security vulnerabilities. Definition of strict resource policies, implementing network segmentation, the definition of resource quota, support for auditing, and using images from the authorized repository are also valid security measures.
42. Do you know anything about Kube-proxy?
Answer: The answer to this question would be that Kube-proxy is a network proxy that imitates the services with their configuration noted in Kubernetes API on each node.
43. What is Ingress network?
Answer: Ingress network can be described as a collection of rules that allows permission for connections into the Kubernetes cluster.
44. How is replica set different from replication controller?
Answer: You can say that the point of difference is in the use of selectors for replicating pods. Set-based selectors are applied in the replica set, and equity-based selectors are applied in replication controllers.
45. Do you know about federated clusters?
Answer: To demonstrate your knowledge about the federated cluster, you can state that federated clusters help in managing multiple Kubernetes clusters as a single cluster.
46. How can a company with distributed systems manage tasks consistently with Kubernetes?
Answer: Scenario-based Kubernetes interview questions such as “How can a company with distributed systems manage tasks consistently with Kubernetes?” can also appear in your Kubernetes interview. The response would be that Kubernetes can be used for customization of scheduling architecture and gain support for multiple container formats.
Preparing for a DevOps interview? Here we bring Top DevOps Interview Questions with detailed answers that will help you crack the interview!
47. How can a company improve efficiency and speed of technical operations with minimal costs?
Answer: This can be among another scenario-based Kubernetes interview questions in your interview. The response can imply suggestions to work on a CI/CD pipeline followed by working in the cloud and then scheduling of containers on a cluster. Kubernetes can help in the orchestration of the clusters, thereby reducing deployment time and better speed in different environments.
48. How can a company deal with a monolithic codebase issue?
Answer: The answer to this question would cover the transition of the monolithic codebase to a microservice design so that different microservices can be classified as containers. Then Kubernetes could be used for deploying and orchestrating the containers.
49. How can a company ensure optimal distribution of resources?
Answer: Kubernetes helps in the effective distribution of resources by allocating the resources that are used by a particular application.
50. Which of the following stores Kubernetes cluster data?
Answer: Multiple-choice Kubernetes questions can also be commonly observed in a Kubernetes interview, such as “Which of the following stores Kubernetes cluster data”? The options may be “Kube-API server”, “Kubelet,” “ETCD,” and “None of the above.” Here you can tick on “ETCD.”
51. Which ones are a core Kubernetes object?
Answer: Another multiple-choice Kubernetes interview question you can find in an interview is “Which ones are a core Kubernetes object”? And the options for this question can include “Pods,” “Services,” “Volumes,” and “All of the above.”
In this case, the correct choice would be “All of the above”.
Also Read: Kubernetes Myths & Facts that will help you to understand the spreaded Kubernetes myths and the facts behind them.
Based on an illustration of interview questions that you can find commonly related to Kubernetes, it can be concluded that the process is intense. Learning is the foremost trick that you can try for succeeding at an interview for Kubernetes professionals. To enhance your Kubernetes knowledge and get fully prepared for the interview, we recommend you to go through our Kubernetes training course.
However, you need to stay a step ahead by practicing the most common Kubernetes interview questions that you may be asked. A clear evaluation of the questions mentioned here can also help you gain confidence in responding to an interviewer. Furthermore, observing the Kubernetes interview questions and answers could also help you make the most of the interview time to show your skillset in Kubernetes.
Go ahead and grab the opportunity!
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