Certified Kubernetes Application Developer (CKAD) Study Guide, 2nd Edition

Chapter 3. Interacting with Kubernetes

As an application developer, you will want to interact with the Kubernetes cluster to manage objects that operate your application. Every call to the cluster is accepted and processed by the API server component. There are various ways to perform a call to the API server. For example, you can use a web-based dashboard, a command-line tool like kubectl, or a direct HTTPS request to the RESTful API endpoints.

The exam does not test the use of a visual user interface for interacting with the Kubernetes cluster. Your only client for solving exam questions is kubectl. This chapter will touch on the Kubernetes API primitives and objects, as well as the different ways to manage objects with kubectl.

API Primitives and Objects

Kubernetes primitives are the basic building blocks anchored in the Kubernetes architecture for creating and operating an application on the platform. Even as a beginner to Kubernetes, you might have heard of the terms Pod, Deployment, and Service, all of which are Kubernetes primitives. There are many more that serve a dedicated purpose in the Kubernetes architecture.

To draw an analogy, think back to the concepts of object-oriented programming. In object-oriented programming languages, a class defines the blueprint of a real-world functionality: its properties and behavior. A Kubernetes primitive is the equivalent of a class. The instance of a class in object-oriented programming is an object, managing its own state and ...