Top 20 Kubernetes Interview Questions with Answers

Hello guys, if you are preparing for DevOps Engineer interview or a Developer interview, knowledge of Kubernetes is very important given the rise of Cloud computing and cloud native development. If you are looking for frequently asked Kubernetes interview questions to quickly revise key Kubernetes concepts then you have come to the right place. Earlier, I have shared 20 Docker Interview Questions and in this article, I am going to share frequently asked Kubernetes Interview questions with Answers. But, before we get to the 20 most important Kubernetes interview questions, let me tell you more about Kubernetes. In the most simple terms, Kubernetes is actually a bundle of software solutions that allow developers and engineers to scale and service server setups.

This article will help you immensely in preparing for an interview or even any certification exam that you need to take after completing Kubernetes training. Before we start, you need to understand that Kubernetes is a buzzword that attracts many expert professionals who are looking to advance their career prospects. So you will need to work hard and be disciplined to stay ahead of the pack.

Many multinational companies like Yahoo, Huwaei, eBay, Pokemon, SAP, SoundCloud, and OpenAI use Kubernetes on a day-to-day basis. What this means is that if you prepare yourself in the right way and position yourself correctly, opportunities will b limitless.

This is also complemented by the fact that there is a dearth of experienced and skilled Kubernetes practitioners in the market. So what you need to do is prepare yourself to fill that gap between supply and demand.

20 Kubernetes Interview Questions with Answers

For easy access, I have divided this article into three sections. The first section consists of basic Kubernetes interview questions. In this section, you will learn about topics like Autoscaling, Load Balancing, and Data Volumes. 

The second section consists of  interview questions related to the architecture of Kubernetes. This section covers topics like Kube-proxy and master node.

The third section deals with some multiple-choice questions. Here, you will get some practical exposure as well as enhance your quick thinking.  I have also tried to cover to basic kubectl command you can use to interact with pods and services

I have no doubt that the interview questions in this article will help you to land your dream job. 

1. Basic Kubernetes Interview Questions

This section focus on essential Kubernetes concepts and interview questions based upon that. 

1. What is Kubernetes?

Kubernetes is basically a container-management tool that is open-source and can scale, descale, and deploy containers. It is similar to Docker and was introduced by Google. This means that it has an interactive community and works well with all the cloud providers. We can say that Kubernetes is not just a containerization platform, but a platform that provides multi-container management solutions.

2. How is Kubernetes similar to Docker?

A Docker image can be used to build runtime containers and it also provides lifecycle management of containers. Kubernetes come in when these individual containers need to communicate with each other. What this essentially means is that Docker can be used to build individual containers and Kubernetes can be used to allow these individual containers to communicate with each other. Another important thing to note here is that containers running on multiple hosts can be connected to each other and linked using Kubernetes. 

3. What is Container Orchestration?

Container Orchestration effectively means that all the services inside the individual containers are working together seamlessly to meet the needs of the server. There are many microservices inside each container, and it is impossible for these microservices to communicate with each other without Container Orchestration. Container Orchestration creates harmony among containers by seamlessly allowing individual containers to work together and met the goal of a single server. 

4. Why do you need Container Orchestration?

When you have 4 or 5 microservices that perform various tasks for a single application, you can put these microservices inside separate containers. But you need to make sure that these containers interact with each other. So Container Orchestration becomes useful in such cases.

Basically, Container Orchestration is essential for making sure that containers communicate effortlessly with each other. There are also many challenges that can crop up if you do not use Container Orchestration. So Container Orchestration can be used to overcome these challenges.

5. What are some features of Kubernetes?

Kubernetes offer some amazing features like Automated Scheduling, Self-Healing Capabilities, Automated Rollouts and Rollbacks, Horizontal Scaling, and Load Balancing.
The automated scheduler can be used for launching containers on cluster nodes.
Self-Healing Capabilities allow rescheduling, restarting, and replacing of dead containers.
Kubernetes also supports automated rollouts and rollbacks for containers.
Kubernetes can also scale up and scale down applications according to your requirements. 

6. What is the Containerized Deployment process in Kubernetes?

Kubernetes is basically cloud-agnostic. What this means is that it can run on basically any cloud provider. This effectively simplifies the process of Containerized Deployment since the is no need for anything big like multiple hosts for load balancing.

 
Kubernetes can also run on any cloud platform since it is cloud-agnostic. For example, if you have a number of containers running on multiple hosts, all of these containers may have to communicate with each other. For this, you need something big that can be used for load balancing, scaling, and monitoring the containers.

7. What is Google Container Engine?

Google Container Engine is a managing platform for Docker Containers and clusters. It is open-source and supports only those containers that run inside Google's own cloud services. 

Google Container Engine is also known as GKE. One important thing to note here is that the Google Container Engine supports only those containers that run on its own public cloud platforms. 

Bonus Questions

1. What is Heapster?

Heapster is basically a data aggregator that is present cluster-wide. It is provided by Kubelet running on each node. It can also be seen as a container management tool that Kubernetes supports natively. It runs just like any other pod on the cluster. What this means is that it discovers all the nodes in a cluster and queries usage information from the Kubernetes cluster present on every node. 

2. What is Kubectl?

Kubectl can be seen as a platform that can be used for passing commands to the cluster. It also provides the CLI command for running Kubernetes commands against the Kubernetes cluster. It also has various ways and means for creating and managing the Kubernetes component.   

3. What is Minikube?

Minikube can be seen as a tool that makes it easier to run Kubernetes locally. It runs a single-node Kubernetes cluster inside a virtual machine.

4. What is Kubelet?

Kubelet is basically an agent service that runs on each and every node and also allows communication between the slave and the master. It essentially works on the description of containers that are provided to it in the PodSpec. It also makes sure that the containers that are described in the PodSpec are healthy and running.  

5. What can you tell us about a node in Kubernetes?

A node in the Kubernetes cluster can be seen as the main worker machine. Nodes are also known as minions. Nodes can run on physical machines or virtual machines. It provides all the necessary services for running pods. Nodes in the Kubernetes system are managed by masters. 

2. Kubernetes Architecture Interview Questions

8. What can you tell us about Kube-proxy?

Kube-proxy is basically a network proxy that is made up of configured services in Kubernetes API. It runs on each and every node and can do packet forwarding across multiple services. 

Kube-proxy can also run on each and every node. It can do simple TCP/UDP packet forwarding all across the backend network service. A Docker-linkable compatible environment can also provide the various IPs and ports that can be opened using a proxy.

9. What can you tell us about the different components of Kubernetes Architecture?

Kubernetes architecture is made up of 2 main components - the master node and the worker node. The master node is made up of the Kube-controller-manager, Kube-apiserver, and the Kube-scheduler. The worker node has kubelet and Kube proxy.

10. How does the master node work in Kubernetes?

The nodes are made up of containers and the Kubernetes master controls these nodes. The individual containers are housed inside pods and each pod can have a number of these containers. The Kube-apiserver makes sure that there is communication between the pods and the master node.

The Kubernetes master controls all the nodes and the containers that are present inside the nodes. The individual containers are housed inside pods. Inside each pod, you can have a large number of containers depending on your requirements. These pods can be deployed using the user interface or the command-line interface. 

The pods are allocated to different nodes based on the resource requirements. The Kube-apiserver can be used for making sure that there is always communication between the Kubernetes node and the master component. 

11. What do you know about the Kubernetes controller manager?

The controller manager is basically a daemon that embeds controllers and works in namespace creation and garbage collection. It is also responsible for communicating with the API server and managing the end-points. 

The master node runs multiple control processes. But all these processes are compiled together to run as a single process. This process is known as the Kubernetes controller manager. The Kubernetes controller manager is responsible for communicating with the API server and making sure that the end-points are managed. 

There are different types of controller managers running on the master node.

The node controller manages the status of a node like creation, updating, or deletion. 

The replication controller maintains the number of pods for each and every replication object. 

The service account and token controller can be used for creating default accounts as well as API access tokens for creating new namespaces. 

The endpoints controller takes care of all the endpoint objects like services and pods.  

12. What is ETCD?

ETCD is a distributed key-value store that coordinates distributed work. It is written in the Go programming language. It stores the configuration data of the Kubernetes cluster. ETCD can also be used for storing the configuration data of the Kubernetes cluster that represents the state of a cluster at any point in time. 

13. How does the Load Balancer work in Kubernetes?

A load balancer is a common and standard way of exposing service. Kubernetes offer customers two types of load balancer - the internal load balancer and the external load balancer. The internal load balancer allocates pods with the necessary configuration while the external load balancer directs the traffic from the external load. 

14. What is Ingress Network?

Ingress Network is basically a collection of rules that is an entry point to any Kubernetes cluster. It is an API object that manages access to the services inside a cluster. It is the most powerful way of exposing service. 

Bonus Questions

1. What are the different types of services Kubernetes offer?

The Cluster IP can be used for exposing the service on a cluster-internal IP. It means that the service will only be reachable from within the cluster. This is the default service type. 

The Node Port can be used for exposing the service on each node's IP at a static port. A Cluster IP service to which a Node Port service will route is automatically created.

The Load Balancer exposes the service externally by making use of a cloud provider's load balancer. Services to which the external load balancer will route are automatically created. 

The External Name maps the service to all the contents of the external name. There is no proxying of any kind during this setup. 

3. Multiple-Choice Questions

15. Where is the Kubernetes Cluster data stored?

A. Kube-apiserver

B. Kubelet

C. ETCD (Correct)

D. None of the above

16. Which of the following is a Kubernetes Controller?

A. Replicaset

B. Deployment

C. Rolling Updates

D. Both A and B (Correct)

17. Which of the following are core Kubernetes objects?

A. Pods

B. Services

C. Volumes

D. All of the above (Correct)

18. On which node does the Kube-proxy run?

A. Master Node

B. Worker Node

C. Both A and B (Correct)

D. None of the above

19. Which of the following was introduced in Kubernetes version 1.8?

A. Taints and Tolerations (Correct)

B. Cluster Level Logging

C. Secrets

D. Federated Clusters

20. Which handler is invoked by Kubelet to check if a container's IP address is open or not?

A. HTTPGetAction

B. ExecAction

C. TCPSocketAction (Correct)

D. None of the ABove

Conclusion

This is it. These are some of the most frequently asked Kubernetes interview questions. These Kubernetes questions will easily help you land your dream software job. If you liked this list of the Top 20 Kubernetes Interview Questions with Answers, feel free to share it with your friends and family. You can also drop a comment if you have any doubts regarding Kubernetes and we will get back to you in an instant.