Kubernetes is an open-source container orchestration platform that automates the deployment, scaling, and management of containerized applications. Let’s analyze each statement:

A. Kubernetes is compatible with the container open container runtime.

Correct: Kubernetes supports the Open Container Initiative (OCI) runtime standards, which ensure compatibility with various container runtimes like containerd, cri-o, and others. This flexibility allows Kubernetes to work with different container engines beyond just Docker.

B. Kubernetes requires the Docker daemon to run Docker containers.

Incorrect: While Kubernetes historically used Docker as its default container runtime, it no longer depends on the Docker daemon. Instead, Kubernetes uses the Container Runtime Interface (CRI) to interact with container runtimes like containerd or cri-o. Docker’s runtime has been replaced by containerd in most modern Kubernetes deployments.

C. A container is the smallest unit of computing that you can manage with Kubernetes.

Correct: In Kubernetes, a container represents the smallest deployable unit of computing. Containers encapsulate application code, dependencies, and configurations. Kubernetesmanages containers through higher-level abstractions like Pods, which are groups of one or more containers.

D. A Kubernetes cluster must contain at least one control plane node.

Incorrect: While a Kubernetes cluster typically requires at least one control plane node to manage the cluster, this statement is incomplete. A functional Kubernetes cluster also requires at least one worker node to run application workloads. Both control plane and worker nodes are essential for a fully operational cluster.

Why These Answers?

Compatibility with OCI Runtimes: Kubernetes’ support for OCI-compliant runtimes ensures flexibility and avoids vendor lock-in.

Containers as Smallest Unit: Understanding that containers are the fundamental building blocks of Kubernetes is crucial for designing and managing applications in a Kubernetes environment.

JNCIA Cloud References:

The JNCIA-Cloud certification covers Kubernetes as part of its container orchestration curriculum. Understanding Kubernetes architecture, compatibility, and core concepts is essential for deploying and managing containerized applications in cloud environments.

For example, Juniper Contrail integrates with Kubernetes to provide advanced networking and security features for containerized workloads. Proficiency with Kubernetes ensures seamless operation of cloud-native applications.