Kubernetes Interview Questions

Checkout Vskills Interview questions with answers in Kubernetes to prepare for your next job role. The questions are submitted by professionals to help you to prepare for the Interview.

Q.1 How is Kubernetes different from Docker Swarm?
Kubernetes focuses on open-source and modular orchestration, offering an efficient container orchestration solution for high-demand applications with complex configuration. Docker Swarm emphasizes ease of use, making it most suitable for simple applications that are quick to deploy and easy to manage.
Q.2 How is Kubernetes different from Docker?
A fundamental difference between Kubernetes and Docker is that Kubernetes is meant to run across a cluster while Docker runs on a single node. Kubernetes is more extensive than Docker Swarm and is meant to coordinate clusters of nodes at scale in production in an efficient manner.
Q.3 How is Kubernetes related to Docker?
Kubernetes is most commonly used with Docker managed containers, although it doesn't strictly depend on it. Kubernetes defines a Container Runtime Interface (CRI) that container platforms must implement in order to be compatible. These implementations are colloquially known as "shims". This makes Kubernetes platform agnostic so that instead of Docker you're free to use other platforms with corresponding shims, such as CRI-O or KataContainers.
Q.4 What is a container deployment?
Container deployment is the act of pushing (or deploying) containers to their target environment, such as a cloud or on-premises server. ... For more dynamic, large-scale systems, you might deploy hundreds or even thousands of containers a day. They are designed to be spun up and down quickly depending on the application.
Q.5 What is Container Orchestration?
Container orchestration is the automation of much of the operational effort required to run containerized workloads and services. This includes a wide range of things software teams need to manage a container's lifecycle, including provisioning, deployment, scaling (up and down), networking, load balancing and more.
Q.6 What is the need for Container Orchestration?
Container orchestration automates the scheduling, deployment, networking, scaling, health monitoring, and management of containers. Containers are complete applications; each one packaging the necessary application code, libraries, dependencies, and system tools to run on a variety of platforms and infrastructure.
Q.7 What are the features of Kubernetes?
The features of Kubernetes includes: Automated Scheduling, Self-Healing Capabilities, Automated rollouts & rollback, Horizontal Scaling & Load Balancing, Offers environment consistency for development, testing, and production and Infrastructure is loosely coupled to each component can act as a separate unit.
Q.8 How does Kubernetes simplify containerized Deployment?
Kubernetes is an open source container orchestration platform that allows large numbers of containers to work together in congruence and reduces operational burdens. It enables simplified heterogeneous deployment of application from On-Prem to Cloud to Edge.
Q.9 What do you know about clusters in Kubernetes?
A Kubernetes cluster is a set of nodes that run containerized applications. Containerizing applications packages an app with its dependences and some necessary services. Kubernetes clusters allow containers to run across multiple machines and environments: virtual, physical, cloud-based, and on-premises.
Q.10 What is Google Container Engine?
Google Container Engine (GKE) is a cluster management and container orchestration system developed to run and manage Docker containers. GKE schedules containers into a cluster and then manages them automatically based on defined stipulations and requirements.
Q.11 What are the ways to deploy containers?
There are two ways to do this: Directly, with the pull command. Indirectly, during the container deployment process.
Q.12 What is Kubernetes?
Kubernetes is an open-source container orchestration platform that enables the operation of an elastic web server framework for cloud applications. Kubernetes can support data center outsourcing to public cloud service providers or can be used for web hosting at scale.
Q.13 What is Kubernetes in AWS?
Kubernetes is open source software that allows you to deploy and manage containerized applications at scale. Kubernetes manages clusters of Amazon EC2 compute instances and runs containers on those instances with processes for deployment, maintenance, and scaling.
Q.14 What is EKS?
Amazon Elastic Container Service for Kubernetes (EKS) is a cloud-based container management service that natively integrates with Kubernetes to deploy applications. With Amazon EKS, an enterprise can use Kubernetes without having install, operate or manage the container orchestration software.
Q.15 What is kind cluster in Kubernetes?
kind is a tool for running local Kubernetes clusters using Docker container “nodes”. kind was primarily designed for testing Kubernetes itself, but may be used for local development or CI.
Q.16 What is a Kubernetes cluster a group of?
A Kubernetes cluster is a set of node machines for running containerized applications. The cluster is the heart of Kubernetes' key advantage: the ability to schedule and run containers across a group of machines, be they physical or virtual, on premises or in the cloud.
Q.17 What are pods and clusters in Kubernetes?
A cluster is central to the basic architecture of Kubernetes: If you're running Kubernetes, you're running at least one cluster. A pod is a unit of replication on a cluster; A cluster can contain many pods, related or unrelated [and] grouped under the tight logical borders called namespaces.”
Q.18 What is Kubernetes cluster in Azure?
Kubernetes clusters are groups of resources that include one or more pods. Pods are groups of containers. The primary way to deploy Kubernetes clusters in the Microsoft Azure cloud is the Azure Kubernetes Service (AKS). AKS is a managed service that you can use to configure and manage your clusters.
Q.19 Does Kubernetes deploy containers?
Kubernetes, also known as K8s, is an open-source system for automating deployment, scaling, and management of containerized applications. It groups containers that make up an application into logical units for easy management and discovery.
Q.20 What is difference between Kubernetes and Jenkins?
Jenkins is an automated software testing tool for your app. In comparison, Kubernetes is a system for automating deployment, scaling, and management. In short, the entire orchestration of containerized applications.
Q.21 What is the difference between terraform and Kubernetes?
Kubernetes is a container orchestration platform that allows developers to manage clusters of containers like Docker containers, while Terraform is an open-source infrastructure-as-code software tool that provides developers with a consistent CLI workflow to manage hundreds of cloud services.
Q.22 What is the difference between Ansible and Kubernetes?
The differences between these two products are profound. Ansible is an IT automation tool that deploys software, configures systems, and organizes more complex IT functions such as rolling updates or continuous deployments. On the other hand, Kubernetes is a system designed to orchestrate Docker containers.
Q.23 How is Kubernetes used in DevOps?
Kubernetes smoothens the container tasks. It eases activities like canary deployment, rolling updates, and horizontal auto-scaling. It plays a major role in streamlining the development, testing as well as deploying pipelines in the DevOps Managed Services.
Q.24 What is Kubeadm and Minikube?
Kubeadm is a tool to get Kubernetes up and running on already existing machine. Minikube is a tool which will allow you to start locally single node Kubernetes cluster. This is usually done in a VM - minikube supports VirtualBox KVM and others. It will start for you the virtual machine and take care of everything.
Q.25 Is minikube a cluster?
Minikube is a lightweight Kubernetes implementation that creates a VM on your local machine and deploys a simple cluster containing only one node. Minikube is available for Linux, macOS, and Windows systems.
Q.26 Which is better kind or minikube?
Kind is another Kubernetes SIGs project but is quite different compared to minikube. As the name suggests it moves the cluster into Docker containers. This leads to a significantly faster startup speed compared to spawning VM. Creating a cluster is very similar to minikube's approach.
Q.27 What does master node in a Kubernetes cluster do?
Master nodes host the control plane aspects of the cluster and are responsible for, among other things, the API endpoint which the users interact with and provide scheduling for pods across resources. Typically, these nodes are not used to schedule application workloads.
Q.28 What is Kops Kubeadm?
kubeadm installs clusters on existing infrastructure; whereas, kops builds the EC2 instances for you, and can also build VPC, IAM, Security groups and a number of other features as well. If you need HA masters or manifest-based cluster management, then kops may also be your first choice.
Q.29 What is rancher K3s?
K3s is an official CNCF sandbox project that delivers a lightweight yet powerful certified Kubernetes distribution designed for production workloads across resource-restrained, remote locations or on IoT devices.
Q.30 What is scheduling in Kubernetes?
In Kubernetes, scheduling refers to making sure that Pods are matched to Nodes so that Kubelet can run them.
Q.31 What is purpose of Kubelet?
kubelet is an agent that runs on each node in the cluster. It makes sure that containers are running in a Pod. The kubelet takes a set of PodSpecs that are provided through various mechanisms and ensures that the containers described in those PodSpecs are running and healthy.
Q.32 What is Kubernetes?
Kubernetes is an open-source container orchestration platform for automating the deployment, scaling, and management of containerized applications.
Q.33 What are the key features of Kubernetes?
Key features include automated scaling, load balancing, self-healing, service discovery, and rolling updates.
Q.34 What is a container in the context of Kubernetes?
A container is a lightweight, stand-alone executable package that includes everything needed to run a piece of software, including the code, runtime, libraries, and system tools.
Q.35 What are Pods in Kubernetes?
A Pod is the smallest deployable unit in Kubernetes, representing one or more containers that share the same network and storage context.
Q.36 What is a Node in Kubernetes?
A Node is a physical or virtual machine in a Kubernetes cluster where containers are scheduled to run.
Q.37 Explain the role of the Kubernetes Master Node.
The Master Node is responsible for managing the control plane components, including API server, etcd, scheduler, and controller manager.
Q.38 What is the Kubernetes Worker Node (Minion)?
A Worker Node, also known as a Minion, is responsible for running containers and executing tasks assigned by the Master Node.
Q.39 What is the role of the kubelet in Kubernetes?
The kubelet is an agent that runs on each Worker Node and is responsible for managing containers and ensuring they are in the desired state.
Q.40 What is a Kubernetes Cluster?
A Kubernetes Cluster is a set of nodes (Master and Worker Nodes) that work together to run containerized applications.
Q.41 How can you create a Kubernetes Cluster?
You can create a cluster using managed services like Google Kubernetes Engine (GKE), Amazon Elastic Kubernetes Service (EKS), or by setting up your own using tools like kubeadm.
Q.42 What is a Kubernetes Namespace?
A Namespace is a virtual cluster inside a Kubernetes Cluster, used to segregate resources and provide isolation for different teams or applications.
Q.43 What is a Deployment in Kubernetes?
A Deployment is a Kubernetes resource that defines a desired state for deploying and managing replicas of a containerized application.
Q.44 What is a Service in Kubernetes?
A Service defines a stable endpoint and policy for accessing a set of Pods, enabling load balancing and service discovery.
Q.45 Explain the difference between a StatefulSet and a Deployment.
A Deployment is suitable for stateless applications, while a StatefulSet is used for stateful applications that require unique identities and stable network names.
Q.46 What is a ConfigMap in Kubernetes?
A ConfigMap is a Kubernetes resource used to store configuration data separately from the application code, allowing for configuration changes without modifying the image.
Q.47 What is a Secret in Kubernetes?
A Secret is a Kubernetes resource for storing sensitive information, such as passwords or API keys, securely within the cluster.
Q.48 How does Kubernetes handle container scaling?
Kubernetes supports both horizontal and vertical scaling. Horizontal scaling is achieved by increasing or decreasing the number of Pods, while vertical scaling involves adjusting resource limits.
Q.49 What is an Ingress in Kubernetes?
An Ingress is a Kubernetes resource that manages external access to services within the cluster, typically used for HTTP routing and load balancing.
Q.50 What is the purpose of a Persistent Volume (PV) in Kubernetes?
A PV provides persistent storage in Kubernetes and decouples storage from Pods, allowing data to survive Pod restarts or rescheduling.
Q.51 How does Kubernetes handle application updates?
Kubernetes supports rolling updates, allowing new versions of applications to be deployed gradually while monitoring for issues.
Q.52 What is a Helm chart in Kubernetes?
Helm is a package manager for Kubernetes that uses charts to define, install, and upgrade even the most complex Kubernetes applications.
Q.53 What is a DaemonSet in Kubernetes?
A DaemonSet ensures that a specific Pod runs on every node in the cluster, useful for tasks like monitoring or log collection.
Q.54 How can you scale a StatefulSet in Kubernetes?
Scaling a StatefulSet can be done manually by updating the replica count or automatically using Horizontal Pod Autoscalers (HPAs).
Q.55 Explain the concept of Labels and Selectors in Kubernetes.
Labels are key-value pairs attached to objects, while Selectors are used to filter and group objects based on their labels.
Q.56 What is a Rolling Restart in Kubernetes?
A Rolling Restart is a controlled process where Pods are gradually terminated and replaced with new ones, ensuring minimal downtime during updates.
Q.57 How does Kubernetes handle self-healing?
Kubernetes monitors the health of Pods and automatically replaces failed Pods to maintain the desired state.
Q.58 What is the Kubernetes Dashboard?
The Kubernetes Dashboard is a web-based user interface for managing and monitoring Kubernetes clusters.
Q.59 What is a Resource Quota in Kubernetes?
A Resource Quota is a policy that limits the amount of compute resources, such as CPU and memory, that can be consumed by Pods and containers within a Namespace.
Q.60 How does Kubernetes handle rolling back deployments?
Kubernetes supports rolling back to a previous version of an application using the "rollback" command or by updating the Deployment resource.
Q.61 What is the purpose of the "kubectl" command?
The "kubectl" command-line tool is used to interact with Kubernetes clusters, allowing you to manage resources, view logs, and execute commands within Pods.
Q.62 How does Kubernetes handle Pod scheduling?
Kubernetes schedules Pods based on resource requirements, node affinity, and anti-affinity rules, among other factors, using the scheduler component.
Q.63 What is a "container image" in Kubernetes?
A container image is a lightweight, stand-alone executable package that includes everything needed to run a piece of software, including the code, runtime, libraries, and system tools.
Q.64 What is a "Taint" in Kubernetes?
A Taint is a node attribute that repels Pods unless a matching "toleration" is specified in the Pod's configuration.
Q.65 How does Kubernetes handle rolling updates with a zero-downtime strategy?
Kubernetes uses strategies like readiness probes to ensure that new Pods are ready before terminating old ones, achieving zero-downtime updates.
Q.66 What is the role of "kubectl apply" in Kubernetes?
kubectl apply is used to create or update resources in Kubernetes by applying configuration files, ensuring desired state.
Q.67 How does Kubernetes manage networking between Pods?
Kubernetes sets up a virtual network overlay that allows Pods to communicate with each other regardless of the physical network topology.
Q.68 What is a "headless service" in Kubernetes?
A headless service is a service without a cluster IP, used for stateful applications that require direct communication with individual Pods.
Q.69 How can you expose a service externally in Kubernetes?
Services can be exposed externally using NodePort, LoadBalancer, or Ingress resources, depending on the desired level of abstraction.
Q.70 What is a "Custom Resource Definition" (CRD) in Kubernetes?
A CRD allows users to define custom resources and their behavior, extending the Kubernetes API.
Q.71 How can you limit the CPU and memory usage of a Pod in Kubernetes?
Resource limits can be set in a Pod's configuration to restrict CPU and memory usage, preventing resource contention.
Q.72 What is "etcd" in Kubernetes?
etcd is a distributed key-value store used by Kubernetes to store cluster configuration and state information.
Q.73 What is a "ServiceAccount" in Kubernetes?
A ServiceAccount is used to control access to the Kubernetes API and define the permissions for Pods or users.
Q.74 How does Kubernetes handle rolling upgrades of the control plane components?
Kubernetes supports rolling upgrades of control plane components like the API server and controllers to minimize downtime during upgrades.
Q.75 What is the purpose of the "kubectl proxy" command?
kubectl proxy creates a proxy server between your local machine and the Kubernetes API server, allowing direct access to services and resources.
Q.76 How can you configure resource quotas for a Namespace in Kubernetes?
Resource quotas are defined using ResourceQuota objects within a Namespace to limit CPU, memory, storage, and other resources.
Q.77 What is "Horizontal Pod Autoscaling" (HPA) in Kubernetes?
HPA is a feature that automatically adjusts the number of replicas of a Pod based on resource utilization or custom metrics.
Q.78 What is "kube-proxy" in Kubernetes?
kube-proxy is a network proxy that maintains network rules on nodes, allowing communication to Pods and services.
Q.79 How can you upgrade the Kubernetes version of a cluster?
You can upgrade a Kubernetes cluster by following the official documentation, which typically involves updating the control plane and worker nodes.
Q.80 What is "NodePort" in Kubernetes?
NodePort is a service type that exposes a service on a static port across all nodes in the cluster, allowing external access.
Q.81 What is the role of the "kube-scheduler" in Kubernetes?
The kube-scheduler is responsible for selecting a suitable node for deploying Pods based on resource requirements, affinity, and constraints.
Q.82 How can you access logs from a Kubernetes Pod?
Logs from Pods can be accessed using "kubectl logs" or by integrating with centralized logging solutions like Elasticsearch and Fluentd.
Q.83 What is "Kubelet Authentication" in Kubernetes?
Kubelet authentication ensures that only authorized entities can communicate with Kubelets, securing the node-agent communication.
Q.84 What is "Kubelet Authorization" in Kubernetes?
Kubelet authorization defines who can access the Kubelet API and perform operations on Pods and nodes.
Q.85 What is "CNI" (Container Network Interface) in Kubernetes?
CNI is a specification and set of libraries for configuring network interfaces in Linux containers, allowing multiple network plugins to work with Kubernetes.
Q.86 How can you create a Pod in Kubernetes?
Pods can be created using YAML or JSON configuration files, which specify the Pod's metadata, containers, and other properties.
Q.87 What is the difference between a ReplicaSet and a Deployment?
A ReplicaSet ensures a specified number of replica Pods are running, while a Deployment provides declarative updates and rollback functionality for Pods.
Q.88 How does Kubernetes handle service discovery?
Kubernetes provides DNS-based service discovery, allowing Pods to communicate with services using DNS names.
Q.89 What is "kube-dns" in Kubernetes?
kube-dns is a Kubernetes addon that provides DNS-based service discovery within the cluster.
Q.90 What is the role of the "kube-controller-manager" in Kubernetes?
The kube-controller-manager includes several controller processes that manage various aspects of the cluster, such as ReplicationController and Service controllers.
Q.91 How does Kubernetes handle resource allocation and scheduling?
Kubernetes uses resource requests and limits to allocate resources to Pods and employs a scheduler to assign Pods to suitable nodes.
Q.92 What is the purpose of the "HorizontalPodAutoscaler" resource in Kubernetes?
The HorizontalPodAutoscaler allows automatic scaling of the number of Pods in a replication controller, deployment, or StatefulSet based on resource usage or custom metrics.
Q.93 What is the "kubectl exec" command used for?
kubectl exec is used to run commands in a running container within a Pod, facilitating debugging and troubleshooting.
Q.94 What is the "kubectl describe" command used for?
kubectl describe provides detailed information about Kubernetes resources, including their current state, events, and metadata.
Q.95 How does Kubernetes ensure high availability of applications?
Kubernetes achieves high availability through replica sets, load balancing, and automated recovery of failed Pods.
Q.96 What is the "rolling back" mechanism in Kubernetes Deployments?
Rolling back a Deployment involves specifying a previous revision or version to which the Deployment should be rolled back, allowing easy recovery from issues introduced in a new version.
Q.97 What is a "node selector" in Kubernetes?
A node selector is a field in a Pod's configuration that specifies constraints on the nodes where the Pod can be scheduled based on node labels.
Q.98 What is "PodAffinity" and "PodAntiAffinity" in Kubernetes?
PodAffinity defines rules for placing Pods close to each other, while PodAntiAffinity specifies rules for avoiding placing Pods close to each other.
Q.99 What is the "Kubeconfig" file in Kubernetes?
The Kubeconfig file stores cluster information, authentication details, and context settings for interacting with a Kubernetes cluster using "kubectl".
Q.100 What is "HorizontalPodAutoscaler" (HPA) in Kubernetes?
HPA automatically scales the number of Pods in a deployment or replica set based on observed CPU utilization or custom metrics.
Q.101 How does Kubernetes handle secret management?
Kubernetes provides the "Secret" resource to store and manage sensitive information such as API keys, passwords, and certificates securely.
Q.102 What is the "Garbage Collection" feature in Kubernetes?
Garbage Collection automatically deletes unused resources or objects in a Kubernetes cluster to free up resources and maintain cluster health.
Q.103 What is the role of "kubectl logs" in Kubernetes?
kubectl logs is used to retrieve and display logs from containers running in a Pod, aiding in debugging and troubleshooting.
Q.104 How can you expose an application using the LoadBalancer service type in Kubernetes?
To expose an application externally using the LoadBalancer service type, a cloud provider-specific load balancer is provisioned to distribute traffic to the service.
Q.105 What is the "ResourceQuota" resource in Kubernetes?
ResourceQuota allows administrators to set limits on resource usage (CPU, memory, storage) within a Namespace, preventing resource exhaustion.
Q.106 What is "kubectl rollout status" used for in Kubernetes?
kubectl rollout status is used to monitor the status of a rolling update, ensuring that Pods are successfully updated or rolled back.
Q.107 What is the purpose of the "PodDisruptionBudget" resource in Kubernetes?
PodDisruptionBudget specifies how many Pods of a certain application can be disrupted during maintenance activities, ensuring high availability.
Q.108 What is "Horizontal Pod Autoscaling" (HPA) based on custom metrics in Kubernetes?
HPA based on custom metrics allows you to autoscale your application based on application-specific metrics such as queue depth or response time.
Q.109 What is a "Service Mesh" in Kubernetes?
A Service Mesh is a dedicated infrastructure layer that handles communication and network traffic management between microservices in a Kubernetes cluster.
Q.110 How does Kubernetes support rolling updates with minimal disruption?
Kubernetes supports rolling updates by creating new Pods with the updated version while gradually terminating old Pods, ensuring minimal disruption to the application.
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