Posted on : 29 Apr, 2021, 08:05:27 AM

Top 50 Kubernetes Interview Questions And Answers

Top 50 Kubernetes Interview Questions And Answers

Created by : Somya Goswami


Kybernetes refers to a management technology application that has proven as the most important contributing precursor with the rise of application containers. IT makes practices more comfortable for enterprises in developing container-based applications by offering advanced features of the application that are common to systems like PaaS.

Kubernetes does not refer to a monolithic and acts like default optional solutions for pluggable. It is successful in developing platforms by building blocks while preserving user choice and flexibility. Kubernetes has become one of the positively impactful technologies for many industries, which opens main roles for Kubernetes professionals, but there is no doubt that this role comes with challenges, and the biggest one is the interview.

To make learners understand the in-depth detail before going for an interview, Wissenhive decided to cover the top 50 Kubernetes interview questions mostly asked during an interview by an interviewer.

 

1. What do you understand by the term Kubernetes?

Kubernetes refers to an open-source orchestration container system or tool designed to be used to automate tasks such as load balancing, logging, scaling, deployment, and monitoring of containerized applications. It can manage several containers and maintain the grouping of containers easily, providing logical units that are easy to manage and discover.

 

2. What does K8s Stand for?

K8s and Kube is another name for Kubernetes.

 

3. What are the key components of Kubernetes?

The three components that are used in Kubernetes are 

  • Addons
  • Node components
  • Master Components

 

4. What is the main difference between Docker Swarm and Kubernetes?

Features Docker Swarm Kubernetes
Installation and Cluster Simple installation with not robust cluster Complicated setup, but after installation, the cluster becomes robust.
GUI No GUI Kubernetes Dashboard
Scalability Highly scalable with 5x faster scales than Kubernetes Highly scalable and scales fast
Auto-scaling cannot do auto-scaling. can do auto-scaling
Balancing load Does not load traffic balance in a cluster between containers Needed manual intervention for traffic balancing
Rolling Updates and Rollbacks Deploy rolling updates, but not automatic rollback deploy rolling updates with automatic rollbacks
The volume of the DATA Share storage volumes with other containers Share storage volumes only with the containers available in the same pod.
Logging & Monitoring 3rd party application like ELK stack used for logging and monitoring In-built tools used for logging and monitoring

 

5. What are the two different types of Kubernetes pods?

The two different types of Kubernetes pods are single container pods and multi-container pods.

  • Single Container pods can be created with the command “run’’ in Kubernetes.
  • Multi Container pods can be created by using the command “create” in Kubernetes.

 

6. What do nodes mean in Kubernetes?

A node refers to a hardware’s smallest unit, which defines a single machine in the cluster that is very similar to a virtual machine from a physical machine or cloud provider in the data center. Every Kubernetes machine cluster can substitute other machines.

 

7. What are the main components of the node in Kubernetes?

There are mainly four components of Kubernetes, and those are

  • Address
  • Capacity
  • Condition
  • Information

 

8. What are some of the objects used for Kubernetes?

There are seven objects used in Kubernetes, and those are

  • Replication controllers and sets
  • Pods
  • Daemon sets
  • Jobs and cron jobs
  • Deployment
  • Distinctive identities
  • Stateful sets

 

9. What do you understand by orchestration when it comes to DevOps and Software?

Orchestration is a process that refers to integrating various services that allow synchronizing or processing information in a timely fashion. If an individual has five or six microservices to run an application and decides to place them in separate containers, it would inevitably create communication obstacles. It helps by enabling all individual container services to work for a single goal accomplishment in this situation seamlessly.

 

10. What is the name of the tools used for container orchestration?

There are three tools included in container Orchestration.

  • Apache Mesos
  • Docker Swarm
  • Kubernetes

 

11. How is the Kubernetes application similar to Docker?

There is no doubt that docker provides the best management of containers lifecycle and a building runtime of the containers by docker image, but Kubernetes is used to establish communication between docker. So Docker helps in building containers, and these containers communicate through Kubernetes, which runs on various hosts and can be orchestrated and linked manually by the usage of Kubernetes.

 

12. What are the main features included in Kubernetes?

The main features on Kubernetes are 

  • Automated rollouts and rollbacks
  • Storage orchestration
  • Service discovery and load balancing
  • Secret and configuration management
  • Automatic bin packing
  • Batch execution
  • Designed for extensibility
  • Self-healing

 

13. What is the use of the Kubernetes scheduler?

The Kubernetes scheduler refers to a controlling plan process that assigns Nodes’ pods. It helps in determining which nodes should be placed where in the scheduling queue for each pod according to available resources and constraints. Then it ranks every valid note and binds them into the suitable node.

 

14. What are Daemon sets?

A Daemonsets refers to a process that ensures all Kubernetes nodes are running a copy of a pod, allowing the individual to run a daemon on each node. When an individual adds a new node to the cluster, a pod automatically gets added for matching nodes. Just like that, if you remove any node from the cluster, the pod automatically goes into the trash. It helps in cleaning up the pods if they were created previously.

 

15. What does Heapster stand for in Kubernetes?

Kubernetes Heapster runs with the pod in the cluster, which is related to how the application of Kubernetes would run. The pod of Heapster helps in discovering every node from the cluster and solves queries by using detailed information from kuvelets’ nodes from the Kubernetes on-machine agent. Kubelets fetches the data from cAdvisor.

 

16. What are the tasks performed by Kubernetes?

Kubernetes is used for distributed systems because it is a Linux kernel that helps an individual abstract the underlying hardware for the servers or nodes and allows a compatible and consistent interface for an application that consumes the shared resource pool.

 

17. What do you understand by the controller manager in Kubernetes?

The Kubernetes controller manager is one of the daemons that is used for collecting garbage, controlling core loops, and creating namespace. The controller manager permits the running of more than one method on the master node.

 

18. What are the different types of Controller managers included in Kubernetes?

There are six different types of controller manager included in Kubernetes, and those are 

  • endpoints controller
  • token controller
  • namespace controller
  • node controller
  • replication controller
  • service accounts controller

 

19. What are some of the key tools used for container monitoring?

  • Heapster
  • InfluxDB
  • Grafana
  • cAdvisor
  • Prometheus

 

20. What is Kubernetes Namespace?

Kubernetes Namespace is used to divide resources of clusters between different users and help the environment where various users spread teams or projects and provide resource scope.

 

21. What are the initial namespaces from which Kubernetes starts?

It starts with three initial namespaces, and those refer to 

  • Default
  • Kube – system
  • Kube – public

 

22. What are the uses of Kubernetes?

  • Can run on-premises public clouds Google, bare metal, OpenStack,  AWS, Azure, etc.
  • It helps individuals in avoiding issues like vendor lock as it can use any vendor-specific services or APIs except where Kubernetes provides an abstraction, examples - storage and load balancer.
  • Enables applications that require to be updated or released without any downtime.
  • Kubernetes enables an individual to ensure those containerized apps run when and where they want and helps them in finding tools and resources where they want to work.

 

23. What does Kubernetes Architecture include?

  • Mater node
  • API server
  • Scheduler
  • Worker/Slave nodes
  • Etcd
  • Docker Container
  • Pods
  • Kubelet

 

24. What are some of the services available in Kubernetes?

There are four different types of services provided by Kubernetes, and those are

  • Cluster IP service
  • External Name Creation service
  • Load Balancer service
  • Node Port service

 

25. What is the GKE?

The full form of GKE is Google Container Engine which focuses on orchestration and management systems for container clusters and Docker containers that run within public cloud services of Google. It is totally based on the Kubernetes as it refers to an open-source container management system of Google.

 

26. Why is Google Kubernetes Engine useful?

  • Cretes docker containers clusters
  • Update and upgrades the container clusters
  • Resize application controllers
  • Debug container’s cluster
  • It is used for creating a replication of jobs, controllers, container pods, services, and load balance.

 

27. Explain the uses of Kubelet?

Kubelet is one of the service agents that maintains and controls the whole group of pods by checking the specification of the pod by using Kubernetes. It operates and runs on every node and allows establishing communication between the slave node and the master node.

 

28. What are some of the disadvantages of using Kubernetes?

  • Not helpful dashboard of Kubernetes as it should be
  • Can reduce productivity
  • Complex process
  • not effective security
  • more costly than its alternatives

 

29. What do you understand with the term Kube proxy?

Kube-proxy is an implementation for both a load balancer and network proxy, which is also used to support service abstraction with other operations of networking. Kube-proxy is totally responsible for directing container traffic that depends on the port number and the IP.

 

30. What do we need to load a balancer in Kubernetes?

A load balancer is very important and needed in Kubernetes because it gives a very standard way to distribute traffic in networks among various services, which usually works in the background of the system.

 

31. How can Kubernetes be locally run?

To run Kubernetes locally, use a tool named minikube, which helps in running a single-mode cluster on a virtual machine of the computer. Minikube offers the best way for individuals who are in their learning period of Kubernetes.

 

32. What do you understand by the term headless service?

A headless service refers to a service that provides IP service but does not load-balancing and will return their associated pods’ IPs. Headless service allows individuals or users to interact with the pods instead of the interacting proxy directly.

 

33. What is proxy service in Kubernetes?

The proxy service of Kubernetes is a service that operates on the node and assists in obtaining it available to an external host.

 

34. Define ETCD?

ETCD refers to a distributed key-value store written by Go programming language used to coordinate distributed work. ETCD stocks and manages the Kubernetes cluster's configuration data, metadata, and state data that represents the cluster state at any time.

 

35. What does Prometheus' meaning stand for Kubernetes?

The application named Prometheus in Kubernetes is used for alerting and monitoring. It can be called out of an individual's system, grabbing real-time metrics, compressing them, and storing them properly in the database.

 

36. What do you understand by secrets in Kubernetes?

Kubernetes secrets refer to sensitive information such as the user's login credentials. There are objects included in Kubernetes that stocks sensitive information such as usernames and passwords after performing encryption.

 

37. What are the main uses of the Daemon sets?

There are three uses of Daemon, which stands for

  • Daemon allows running the storage platform, such as flustered and ceph on each node.
  • It runs the collection of logs on each node like fluentd and filebeat.
  • Daemon performs monitoring of nodes on each node.

 

38. Explain about Stateful sets?

The stateful set refers to a real-time API workload object which can be used for managing the application of stateful. These sets are also used as scaling and deployment management of sets of pods. The other data and state information of the stateful pods usually store in the storage of the disk, which helps in establishing the stateful set.

 

39. What do you understand about the Replica set?

As the name states, this set is used for making and keeping the replica pods stable, allowing users to specify the available number to the identical pods. The replica set can be determined as the replacement of the replication controller.

 

40. Explain the uses of labels in Kubernetes?

Labels in Kubernetes refer to the keys collection, which contains some of the values which remain connected with the associated services, replication controllers, and pods. Generally, labels are added to some of the objectives during the time of creation and can be modified at the run time by the users.

 

41. What are some of the important commands of kubectl?

There are eight different types of kubectl commands that are used during the process are

  • kubectl attach
  • kubectl apply
  • kubectl config current-context
  • kubectl config set.
  • kubectl annotate
  • kubectl cluster-info
  • kubectl config
  • kubectl autoscale

 

42. What are the main uses of the Kube-API server?

Kube-API server is one of the most used API servers in Kubernetes, which is used for validating and configuring objects of API that includes controllers, services, etc. Kube-API server provides the front end to the shared region to the cluster by analyzing which components are interacting with each other.

 

43. What are the different methods to provide API-Security?

The techniques to give API-Security on Kubernetes are:

  • It uses the correct mode of auth with authentication mode = Node of API server.
  • Assure the uses of Kube-dashboard a restrictive Role-Based Access Control or RBAC policy
  • Create kubeless that guards its API-mode=Webhook via authorization.

 

44. Explain Sematext Docker Agent?

Sematext Docker agent refers to a log collection agent with metrics and events, which runs in every docker host as a small container. These agents help in gathering events, metrics, and logs for all cluster containers and nodes.

 

45. What is the Kubernetes Network Policy?

The network Policy of Kubernetes explains how the pods in the identical namespace should communicate together and the endpoint of the network.

 

46. What are the main goals of the replication controller?

The main goals of the replication controller are

  • It is responsible for managing and directing the lifecycle of the pod.
  • It verifies and monitors whether the number of the approved replicas is running or not.
  • It helps the user to verify the pod status.
  • It facilitates altering a pod as the user can move its position the way they find them interested.

 

47. What is the work of persistent volume?

The persistent volume is a piece of storage unit in a cluster that is controlled and provisioned by the administrator. Persistent volume refers to resources in the cluster, just like nodes in the resources of a cluster. It is a volume plugin that has an independent life cycle of a single pod that uses the persistent volume.

 

48. Differentiate between Docker Volumes and Kubernetes volumes?

Scope Docker Volumes Kubernetes Volumes
Volume limit limited to a pod in the container. Not limited to any container.
Volume support Docker volumes do not support every container deployed in a Docker pod. Kubernetes volumes support every container deployed in a Kubernetes pod.

 

49. What are the various types of Kubernetes Volume?

The different types of Kubernetes Volume are:

  • Flocker
  • HostPath
  • PersistentVolumeClaim
  • downwardAPI
  • NFS
  • ISCSI
  • EmptyDir
  • GCE persistent disk
  • rbd

 

50. What is PVC?

The PVC or Persistent Volume Claim helps in storing requested pods by Kubernetes. The main advantage of PVC is an individual does not need to understand the underlying provisioning. The claim should be designed in the identical namespace wherever the pod is created.

With this blog, we Wissenhive come to the end of the top 50 most frequently asked Kubernetes interview questions. We hope these interview questions will help interviewees in cracking their Kubernetes Interview.

However, if a candidate wishes to brush up on their skills and knowledge, in that case, they can learn Devops or Kubernetes skills from industry experts by enrolling themselves in our Kubernetes certification courses.
Let us know if you are left with any queries related to Kubernetes interview questions; mention them in the comment option, and our team will respond to you as soon as possible or call us on our official number to clear your doubts.

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