Top 10 Kubernetes Interview Questions for Freshers

Kubernetes originated from the Greek word, which means ‘governor’ or ‘captain’. It is a term that is also used in DevOps and the world of software development. The term refers to a robust bundle of solutions, which equips operations engineers for scaling and servicing server setup without any effort. If you want to appear for the Kubernetes application development interview, go through our Kubernetes interview questions compiled by our experts. With these top interview questions, you will be able to bag the top job offer.

We are going to cover the top contextual questions here. It will help in answering different questions, such as ways to monitor that the pod is always running or configuration map and secret. 

So, let’s take a look at some intermediate and advanced Kubernetes interview questions. 

1. What is Kubernetes?

Kubernetes is an extensible, portable, open-source platform that is used to manage workloads and services, which facilitates automation, as well as declarative configuration. It is a big rapidly growing ecosystem. Kubernetes tools, services, and support are extensively available. 

It was originally designed by Google. Now, it is maintained and managed by the Cloud Native Computing Foundation. Kubernetes helps in automating the task of management, monitoring, using, scaling, and load-balancing applications. 

2. How to Perform Maintenance Activity on the K8 Node?

If a security patch is available, the Kubernetes administrator will have to engage in maintenance tasks for applying a security patch for the running container to prevent it from being vulnerable which is an unavoidable aspect of administration. Here are the two commands that can help in draining the K8 node safely-

• kubectl drain –ignore-daemon set
• kubectl cordon

The first command will move the node for maintaining modes or will make the node unavailable, and after this Kubernetes will drain. Finally, this will eliminate the pod from the node. In case the drain command is a success, you can perform maintenance.

3. What are the Features of Kubernetes?

Here are some of the top features of Kubernetes:

• Automated Rollouts and Rollbacks: Supports rollbacks, as well as rollouts 
• Automatic Scheduling: Advanced scheduler for launching containers on cluster nodes
• Load Balancing: Provides Pods with their IP address and for a set of Pods a single DNS name. Thereafter, it can easily load balances across them.
• Horizontal Scaling: Scaling applications up and down according to the requirement. 
• Self-Healing Capabilities: Reschedule, replace, and then restart containers, which have failed or died. 
• Storage Orchestration: Mount automatically the storage system you prefer. 
•  Secret and Configuration Management: It lets you store and manage sensitive details.
• Let’s create predictable infrastructure. 

4. What is Orchestration When it Comes to DevOps and Software?

Orchestration is the integration of different services which allows them to synchronize information or automate processes in a timely manner. For instance, you have 6-7 microservices for the application to run. In case you place them in a separate container, it will create obstacles for communication. Orchestration helps in such a situation as it enables all services in a specific container to work effortlessly for accomplishing a certain goal. 

5. What are the Primary Differences Between Kubernetes and Docker Swarm?

Docker’s open-source, native container orchestration platform is Docker Swarm. It is used for clustering and scheduling Docker containers. It is different from Kubernetes in the following ways-

• Docker Swarm cannot auto-scale, but it is 5 times faster than Kubernetes. 
• It is convenient to set up Docker Swarm, but it doesn’t have a strong cluster. Kubernetes on the other hand is more complex, but it assures a strong cluster. 
• Docker Swarm performs automatic load balancing of traffic among the containers in the cluster. But Kubernetes will need manual intervention to load such traffic. 
• In Docker Swarm, there is no GUI, while Kubernetes has a GUI that is in the form of a dashboard. 
• Third-party tools, such as ELK stack are required for Docker to log and monitor, but Kubernetes comes with integrated tools that are used for the same purpose.
• While Docker Swarm can deploy rolling updates, it cannot deploy automatic rollbacks. Kubernetes, on the other hand, can deploy both automatic rollbacks and rolling updates.
• Docker Swarm is capable of sharing storage volumes with the containers, while Kubernetes can just share volumes with containers having the same pod. 

6. What is a Node in Kubernetes?

A node is the smallest basic unit of computing hardware, representing one machine in a cluster. This machine can be a virtual machine from the cloud provider or a physical machine present in the data center. Every machine is capable of substituting any other machine present in the Kubernetes cluster. Kubernetes has a master that controls the nodes, which have containers.

7. What is Pod in Kubernetes?

This is one of the most common Kubernetes interview questions. For this, it is better to give a thorough answer instead of just replying with one line. Pods are high-level structures wrapping one or more containers. It is because containers aren’t run in Kubernetes directly. Containers present in the same pod come to share a local network and have the same resource, letting them communicate with various other containers that are present in the same pod-like they are on the same machine.

8. What are the Disadvantages of Kubernetes?

The top disadvantages of Kubernetes are given below-

• Kubernetes dashboard is very user-friendly.
• Security is the primary problem with Kubernetes. So, it is not quite secure.
• Kubernetes is much costlier in comparison to others.
• It is complicated to use and thus, might reduce your productivity. 

9. What are the Three Namespaces Available on New Clusters?

The three namespaces on new clusters are given below-

• Default: This is the default namespace for objects that don’t have any other namespace. It acts as the primary target for the new user-added resources till the time an alternative namespace is created. 
• Kube-Public: This can be read by all users across the world with or without authentication. With this, it is easier to expose any cluster information required to bootstrap components. The public aspect is just a convention and not a requirement. 
• Kube-System: This is the namespace for objects, which are created by Kubernetes. 

10. What are the Primary Components of Kubelet as the Node Service Components in Kubernetes?

The primary components that Kubelet do are given below-

• The Kubelet is the node communicating with master components for working on all aspects of the Kubernetes cluster. 
• It offers access to the controllers for checking and reporting the cluster’s status. 
• It combines the available memory, CPU, and disk of a node in a large Kubernetes cluster. 
• Kubelet collects metrics pods.

We hope that our list of Kubernetes interview questions will familiarize you with the kind of questions asked in interviews. Going through these questions will help you ace your next interview.