Top Kubernetes Interview Questions | JavaInUse

Kubernetes Interview Questions.

In this post we will look at Kubernetes questions. Examples are provided with explanation.

Kubernetes Interview Questions
Q: What is Kubernetes?
Kubernetes is Google's open source system for managing Linux containers across private, public and hybrid cloud environments.
It is a portable, extensible open-source platform for managing containerized workloads and services, that facilitates both declarative configuration and automation.
It has a large, rapidly growing ecosystem. Kubernetes services, support, and tools are widely available. It contains tools for orchestration, service discovery and load balancing that can be used with Docker and Rocket containers. As needs change, a developer can move container workloads in Kubernetes to another cloud provider without changing the code.
It helps automates the deployment, scaling, maintenance, scheduling and operation of multiple application containers across clusters of nodes.
Understanding need for Kubernetes

Q: What are the advantages of Kubernetes?
The advantages of using Kubernetes are as follows-
  • Automated Scheduling- Kubernetes provides advanced scheduler to launch container on cluster nodes. Kubernetes role is to automate the distribution (scheduling) of application containers across a cluster in an efficient way.
  • Auto Healing Capabilities - Kubernetes auto-healing mechanisms, such as auto-restarting, re-scheduling, and replicating containers
  • Automated Rollback - Sometimes you may want to rollback a Deployment; for example, when the Deployment is not stable, such as crash looping. By default, all of the Deployments rollout history is kept in the system so that you can rollback anytime you want.
  • Horizontal Scaling - Autoscaling is one of the key features in Kubernetes cluster. It is a feature in which the cluster is capable of increasing the number of nodes as the demand for service response increases and decrease the number of nodes as the requirement decreases.

Q: What is Docker?
Consider a scenario - You have just joined a new organization as a developer. You will now have to setup the project with the assistance of a fellow developer. He suggests you follow certain steps for setting up the required environment and then start the project deployable like a WAR. You do the same, but keep getting some or other issues regarding environment configuration. May be even your fellow developer has forgot some configuration property he might have set. Well you are stuck in such a situation. This is known as Dependency Hell. Other similar scenario of this dependency hell are - The application is running on my dev machine but not in production. Dont know what issue is. There is also other scenarios like Matrix of Hell. But this is mostly related to DEVOPS people. Docker to the rescue.
Docker is a tool designed to make it easier to create, deploy, and run applications by using containers.
Docker Tutorials

Q: Whats is difference between Kubernetes and Docker Swarm?
Docker already has its own orchestration manager named Docker Swarm. Docker Swarm is much easier to use and does not require to learn any new tool or technology since its part of Docker. Kubernetes helps manage more complex container deployments while Docker Swarm offers a simple approach to get started with. Kubernetes helps support higher demands production environments and is used by many large organizations.

Q: How to deploy Spring Boot WAR to Docker?
Deploying Spring Based WAR Application to Docker

Q: How to deploy Spring Boot JAR to Docker?
Deploying Spring Based JAR Application to Docker

Q: How to deploy multiple microservices to Docker?
Deploying Multiple Spring Boot Microservices using Docker Networking

Q: What are the scenarios in which a Java Developer will use Docker?
Following scenarios a java developer can use docker-
  • Sharing development workspace, with preconfigured development environment.
  • Continuous integration is one of the most popular use cases for Docker. Teams looking build and deploy their applications quickly use Docker, combined with ecosystem tools like Jenkins, to drive apps from dev, testing staging and into production without having to change any code.
  • Running UAT's using Docker

Q: What are namespaces in Kubernetes?
Kubernetes supports multiple virtual clusters backed by the same physical cluster. These virtual clusters are called namespaces. Kubernetes allows use of multiple namespaces.

Q: What is a node in Kubernetes?
A node is a worker machine in Kubernetes, previously known as a minion. A node may be a VM or physical machine, depending on the cluster. Each node has the services necessary to run pods and is managed by the master components. The services on a node include the container runtime, kubelet and kube-proxy.

Q: What is a pod in Kubernetes?
A Kubernetes pod is a group of containers that are deployed together on the same host. If you frequently deploy single containers, you can generally replace the word "pod" with "container" and accurately understand the concept.
Kubernetes POD

See Also

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