Book Image

Certified Kubernetes Administrator (CKA) Exam Guide

By : Mélony Qin
4 (1)
Book Image

Certified Kubernetes Administrator (CKA) Exam Guide

4 (1)
By: Mélony Qin

Overview of this book

Kubernetes is the most popular container orchestration tool in the industry. The Kubernetes Administrator certification will help you establish your credibility and enable you to efficiently support the business growth of individual organizations with the help of this open source platform. The book begins by introducing you to Kubernetes architecture and the core concepts of Kubernetes. You'll then get to grips with the main Kubernetes API primitives, before diving into cluster installation, configuration, and management. Moving ahead, you’ll explore different approaches while maintaining the Kubernetes cluster, perform upgrades for the Kubernetes cluster, as well as backup and restore etcd. As you advance, you'll deploy and manage workloads on Kubernetes and work with storage for Kubernetes stateful workloads with the help of practical scenarios. You'll also delve into managing the security of Kubernetes applications and understand how different components in Kubernetes communicate with each other and with other applications. The concluding chapters will show you how to troubleshoot cluster- and application-level logging and monitoring, cluster components, and applications in Kubernetes. By the end of this Kubernetes book, you'll be fully prepared to pass the CKA exam and gain practical knowledge that can be applied in your day-to-day work.
Table of Contents (17 chapters)
1
Part 1: Cluster Architecture, Installation, and Configuration
5
Part 2: Managing Kubernetes
10
Part 3: Troubleshooting

Workload scheduling

Understanding the workload scheduling and how it works with the Kubernetes scheduler will be useful in your daily life as a Kubernetes Administrator. Kubernetes allows you to define node affinity rules, taints, and tolerations with the good use of labels, selectors, and annotations leading your way. Let’s first start with the notion of namespaces.

Understanding namespaces

Thinking about the separation of the workloads, namespaces come in handy. A namespace is a logical separation of all the namespaced objects deployed in a single Kubernetes cluster. Deployments, Services, and Secrets are all namespaced. Otherwise, some Kubernetes objects are cluster-wide, such as Nodes, StorageClass, and PersistentVolume. The name of a resource has to be unique within a namespace.

You can get all namespaces using the following command:

kubectl get namespaces

Alternatively, you can use this command:

kubectl get ns

You will see that the output gets...