Kubernetes Interview Questions and Answers
Question - 21 : - Define Cluster IP
Answer - 21 : -
The Cluster IP is a Kubernetes service that offers a service inside the cluster that other apps inside cluster can access.
Question - 22 : - List various services available in Kubernetes
Answer - 22 : -
Various services available in Kubernetes are 1) Cluster IP service, 2) Load Balancer service, 3) Node Port service, 4) External Name Creation service.
Question - 23 : - Mention the types of controller managers
Answer - 23 : -
Types of controller managers are: 1) endpoints controller, 2) service accounts controller, 3) node controller, 4) namespace controller, 5) replication controller, 6) token controller.
Question - 24 : - Why use namespaces? What is the problem with using the default namespace?
Answer - 24 : -
While using the default namespace alone, it becomes hard over time to get an overview of all the applications you can manage in your cluster. Namespaces make it easier to organize the applications into groups that make sense, like a namespace of all the monitoring applications and a namespace for all the security applications, etc.
Namespaces can also be useful for managing Blue/Green environments where each namespace can include a different version of an app and also share resources that are in other namespaces (namespaces like logging, monitoring, etc.).
Another use case for namespaces is one cluster with multiple teams. When multiple teams use the same cluster, they might end up stepping on each other's toes. For example, if they end up creating an app with the same name it means one of the teams overrides the app of the other team because there can't be two apps in Kubernetes with the same name (in the same namespace).
Question - 25 : - What is an Operator?
Answer - 25 : -
"Operators are software extensions to K8s which make use of custom resources to manage applications and their components. Operators follow Kubernetes principles, notably the control loop."
Question - 26 : - Why do we need Operators?
Answer - 26 : -
The process of managing applications in Kubernetes isn't as straightforward as managing stateless applications, where reaching the desired status and upgrades are both handled the same way for every replica. In stateful applications, upgrading each replica might require different handling due to the stateful nature of the app, each replica might be in a different status. As a result, we often need a human operator to manage stateful applications. Kubernetes Operator is supposed to assist with this.
Question - 27 : - What is GKE?
Answer - 27 : -
GKE is Google Kubernetes Engine that is used for managing and orchestrating systems for Docker containers. With the help of Google Public Cloud, we can also orchestrate the container cluster.
Question - 28 : - What is Ingress Default Backend?
Answer - 28 : -
It specifies what to do with an incoming request to the Kubernetes cluster that isn't mapped to any backend i.e what to do when no rules being defined for the incoming HTTP request If the default backend service is not defined, it's recommended to define it so that users still see some kind of message instead of an unclear error.
Question - 29 : - Why load balancer is needed?
Answer - 29 : -
A load balancer is needed because it gives a standard way to distribute network traffic among different services, which runs in the backend.
Question - 30 : - How to run Kubernetes locally?
Answer - 30 : -
Kubernetes can be run locally using the Minikube tool. It runs a single-node cluster in a VM (virtual machine) on the computer. Therefore, it offers the ideal way for users who have just started learning Kubernetes.