The must-know Kubernetes interview questions and answers in 2022

This is one of the most popular k8s interview questions. When security updates become available, the Kubernetes administrator must execute the maintenance work of applying the security patch to the running container to prevent it from becoming vulnerable, which is an unavoidable component of the administration. To safely drain the K8s node, use the following two commands:

• kubectl cordon
• kubectl drain –ignore-daemon set

Kubernetes' PodDisruptionBudget (pdb) is a handy layer of defense for dealing with this type of issue. If you already have a Kubernetes cluster running in production, try kubectl get pdb —all-namespaces.

A Kubernetes administrator can make a one-of-a-kind deployment. PodDisruptionBudget ensures that the application's minimum number of running pods is preserved, as specified by the property minAvailable in the spec file. This is useful while executing a drain, as the drain will stop until the PDB is respected, ensuring the application's High Availability (HA). In the following spec file, minAvailable is set to 2, implying that the minimum number of available pods is two (even after the election).

You will often come across these interview questions on Kubernetes. Init Containers are containers that operate before your containerized application's main container. They usually include setup scripts that prepare the environment for your containerized application. Init Containers also ensure that the larger server environment is prepared for your application to begin running.

• Before running the real POD, the init containers will set a stage for you.
• Wait a few minutes before using a command like sleep 60 to start the program Container.
• Create a volume from a git repository.

This is a common Kubernetes interview question. The interviewer may ask you to describe your professional experience with such questions. Docker is a no-cost, open-source software platform for development. Its key benefit is that it encapsulates the settings and dependencies that the software/application needs in a container, allowing for mobility and a variety of other benefits. Kubernetes enables the manual linking and orchestration of numerous containers running on multiple hosts developed with Docker.

Application monitoring with Kubernetes is not reliant on a single monitoring provider. To collect monitoring information on new clusters, you can utilize resource metrics or entire metrics pipelines.

The resource metrics pipeline only delivers a subset of metrics related to cluster components such as the Horizontal Pod Autoscaler controller and the kubectl top function. The lightweight, short-term, in-memory metrics-server collects these measurements, which are then provided via the metrics.k8s.io API.

A complete metrics pipeline gives you access to more detailed metrics. Using technologies such as the Horizontal Pod Autoscaler, Kubernetes may respond to these indicators by dynamically scaling or adjusting the cluster based on its present condition.

Minikube is a tool that allows you to run Kubernetes on your own machine. Minikube creates a single-node Kubernetes cluster on your personal computer (including Windows, macOS, and Linux PCs) so users can utilize Kubernetes for the daily design process with this.

Using the default namespace alone makes it difficult to keep track of all the applications you can manage in your cluster over time. Namespaces make it easy to group apps into logical groupings, such as a namespace for all monitoring programs and another for all security applications, and so on.

Namespaces are also useful for managing Blue/Green environments, as each namespace can include many versions of an app and share resources with other namespaces (namespaces like logging, monitoring, etc.).

In Kubernetes, managing applications isn't as simple as maintaining stateless applications, where reaching the required status and updates are done in the same way for each replica. Because of the stateful nature of stateful applications, upgrading each replica may necessitate distinct treatment. As a result, managing stateful applications frequently necessitates the use of a human operator. This is where Kubernetes Operator is supposed to help.

You will often come across these docker and Kubernetes interview questions. The primary differences between Kubernetes and Docker are listed below:

• The K8s have a difficult installation procedure, however once completed, the cluster is quite stable. The Docker swarm installation method, on the other hand, is fairly simple, but the cluster is not very robust.
• Although Kubernetes can handle auto-scaling, the Docker swarm is unable to handle pod auto-scaling based on incoming demand.
• Kubernetes is a full-fledged container orchestration system. Autoscaling is slower than Docker Swarm because it maintains cluster states more consistently.

The scheduler in K8 is in charge of spawning pods into nodes. Unstartable POD can be caused by a variety of circumstances. The most typical reason for POD not starting is a lack of resources; use commands like kubectl describe POD> -n Namespace> to find out why. Also, keep a watch on kubectl get events to observe all of the cluster's events.