Posted on : 29 Apr, 2021, 08:05:27 AM
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.
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.
K8s and Kube is another name for Kubernetes.
The three components that are used in Kubernetes are
|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|
The two different types of Kubernetes pods are single container pods and multi-container pods.
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.
There are mainly four components of Kubernetes, and those are
There are seven objects used in Kubernetes, and those are
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.
There are three tools included in container Orchestration.
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.
The main features on Kubernetes are
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.
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.
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.
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.
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.
There are six different types of controller manager included in Kubernetes, and those are
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.
It starts with three initial namespaces, and those refer to
There are four different types of services provided by Kubernetes, and those are
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.
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.
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.
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.
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.
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.
The proxy service of Kubernetes is a service that operates on the node and assists in obtaining it available to an external host.
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.
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.
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.
There are three uses of Daemon, which stands for
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.
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.
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.
There are eight different types of kubectl commands that are used during the process are
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.
The techniques to give API-Security on Kubernetes are:
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.
The network Policy of Kubernetes explains how the pods in the identical namespace should communicate together and the endpoint of the network.
The main goals of the replication controller are
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.
|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.|
The different types of Kubernetes Volume are:
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.