What is Kubernetes?
This is one of the most basic Kubernetes interview questions yet one of the most important ones! Kubernetes is an open-source container orchestration tool or system that is used to automate tasks such as the management, monitoring, scaling, and deployment of containerized applications. It is used to easily manage Severl containers (since it can handle grouping of containers), which provides for logical units that can be discovered and managed.
How are Kubernetes and Docker related?
This is one of the most frequently asked Kubernetes interview questions, where the interviewer might as well ask you to share your experience working with any of them. Docker is an open-source platform used to handle software development. Its main benefit is that it packages the settings and dependencies that the software/application needs to run into a container, which allows for portability and several other advantages. Kubernetes allows for the manual linking and orchestration of several containers, running on multiple hosts that have been created using Docker.
What are the main differences between the Docker Swarm and Kubernetes?
Docker Swarm is Docker’s native, open-source container orchestration platform that is used to cluster and schedule Docker containers. Swarm differs from Kubernetes in the following ways:
- Docker Swarm is more convenient to set up but doesn’t have a robust cluster, while Kubernetes is more complicated to set up but the benefit of having the assurance of a robust cluster
- Docker Swarm can’t do auto-scaling (as can Kubernetes); however, Docker scaling is five times faster than Kubernetes
- Docker Swarm doesn’t have a GUI; Kubernetes has a GUI in the form of a dashboard
- Docker Swarm does automatic load balancing of traffic between containers in a cluster, while Kubernetes requires manual intervention for load balancing such traffic
- Docker requires third-party tools like ELK stack for logging and monitoring, while Kubernetes has integrated tools for the same
- Docker Swarm can share storage volumes with any container easily, while Kubernetes can only share storage volumes with containers in the same pod
- Docker can deploy rolling updates but can’t deploy automatic rollbacks; Kubernetes can deploy rolling updates as well as automatic rollbacks
What does the node status contain?
The main components of a node status are Address, Condition, Capacity, and Info.
What is the job of the kube-scheduler?
The kube-scheduler assigns nodes to newly created pods.
What is the Google Container Engine?
The Google Container Engine is an open-source management platform tailor-made for Docker containers and clusters to provide support for the clusters that run in Google public cloud services.
What is ‘Heapster’ in Kubernetes?
In this Kubernetes interview question, the interviewer would expect a thorough explanation. You can explain what it is and also it has been useful to you (if you have used it in your work so far!). A Heapster is a performance monitoring and metrics collection system for data collected by the Kublet. This aggregator is natively supported and runs like any other pod within a Kubernetes cluster, which allows it to discover and query usage data from all nodes within the cluster.
Name the initial namespaces from which Kubernetes starts?
- Default
- Kube – system
- Kube – public
What is etcd?
Kubernetes uses etcd as a distributed key-value store for all of its data, including metadata and configuration data, and allows nodes in Kubernetes clusters to read and write data. Although etcd was purposely built for CoreOS, it also works on a variety of operating systems (e.g., Linux, BSB, and OS X) because it is open-source. Etcd represents the state of a cluster at a specific moment in time and is a canonical hub for state management and cluster coordination of a Kubernetes cluster.
What is ClusterIP?
The ClusterIP is the default Kubernetes service that provides a service inside a cluster (with no external access) that other apps inside your cluster can access.
