Certified Kubernetes Administrator (CKA) Exam Guide E-Book

Mélony Qin

• Herausgeber: Packt Publishing
• Kategorie: Fachliteratur
• Sprache: Englisch

Seitenzahl: 288

Veröffentlichungsjahr: 2022

Beschreibung

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.

Leseprobe

Certified Kubernetes Administrator (CKA) Exam Guide

Validate your knowledge of Kubernetes and implement it in a real-life production environment

Mélony Qin

BIRMINGHAM—MUMBAI

Certified Kubernetes Administrator (CKA) Exam Guide

Copyright © 2022 Packt Publishing

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Foreword

Over the last decade, Kubernetes has gone mainstream. Builders of cloud applications are expected to be familiar with cloud-native design tools and techniques. Becoming certified in Kubernetes demonstrates that you have the knowledge and skills necessary to meet the expectations of businesses, enterprises, and consumers.

Whether you are a cloud-native expert or a beginner, this book will familiarize you with the tools, technologies, and terminology in the cloud-native ecosystem. Mélony’s own experience getting involved in the cloud-native ecosystem and its rapidly changing array of open source projects and cloud-based products, enable her to write an approachable book that can serve as your guide to the modern way that today’s applications are built.

The expectations of business, customers, and users of today’s applications have never been greater. Kubernetes and cloud-native are the skills that will enable you to build applications that meet the standards necessary to compete in the world of modern application development.

Brendan Burns, co-founder of Kubernetes open source project.

I first met Mélony back in 2018. I’d been speaking at an event in London and when I finished, she approached the stage to ask a question. That was just a few days before she started working at Microsoft and I’ve had the pleasure of working with her since then. It’s rare to get to work with such a talented individual, someone who has a real passion for technology, learning, and helping others to learn.

I’ve been working in technology for over 30 years in roles across operations, engineering, and architecture. A lot of that time was spent working in large corporations. Containers and Kubernetes have had a massive effect on the way applications are developed, deployed, and managed. It would have solved so many problems if I’d had these tools available earlier on in my career. Back in 2014, a colleague of mine told me to keep a close eye on this “Docker” thing they’d heard about as they were convinced it was going to be a big deal. I have kept an eye on it and they were right. It has been a big deal!

As your maturity with containers grows, you’ll find yourself involved with Kubernetes. If you’re going to use Kubernetes, then you really need to understand how it works. It’s complicated and you can easily get things wrong, so you really, really need to know what you’re doing. Certification exams are always a great way to build your knowledge, test yourself, and prove that you know your stuff! I’ve sat all of the current Kubernetes certification exams and I can tell you from personal experience, these exams are hard. You can’t get away with guessing which multiple-choice answer is the right one. You can’t wing it. Oh no, you need to actually put the work in to learn Kubernetes before you sit this exam! And that’s a good thing, because it makes the Kubernetes certification more valuable knowing that you can’t pass it without putting in the effort.

If you’ve got this book in your hands or on your digital reading device of choice, then you’ve made a great start! Kubernetes certifications are hard, make no mistake, but you will pass if you put the work in. Mélony will guide you through the topics you need to learn and help set you up for success.

Good luck. You’ve got this!

Mark Whitby, Cloud-native architecture and engineering lead, principal global black belt (GBB) at Microsoft

Certifications are the best way to show the world your passion, your interests, and your skills, in the ever competitive and fierce landscape for talent sprung by the adoption of the cloud native paradigm. Mélony has done an amazing job to demystify the many mysteries of Kubernetes into simple, easy to understand concepts that will guide you in your studies, and hopefully lead you to a successful certification. She truly understands the learning journey and the many hurdles of cloud native, and she’s motivated to make your journey easier.

I met Mélony several years ago at one of the Microsoft OpenHacks events, and her passion for learning and sharing struck me. So, I’m both glad and proud to write the foreword to her new book, which undoubtedly will help many cloud native engineers in their own personal learning path.

Alessandro Vozza, Principal Software Engineer at Microsoft, CNCF Ambassador, Founder of Cloud Pirates

Note from the author

Containerization is an approach to managing applications; a container image contains all its deployment dependencies and configurations. Managing one, or even a couple of containers for dev/testing purposes, is relatively easy. The real challenge comes when you have to manage hundreds, or even thousands of containers, especially for enterprise-grade product environments, where you’ll be managing networking, deployments, configuration, etc. This is where the container orchestrator comes in.

Looking back, many open source container orchestrators have been popular in the market at one point in time. Although we’re still hearing about Docker Swarm, Mesosphere’s DC/OS, Kubernetes is by far the most popular container orchestration tool.

We have seen tremendous growth in Kubernetes and its ecosystem over the last 7 years. Yet, the complexity of managing the tool remains the major blocker for enterprises that prevents them from taking complete advantage of this fantastic technology. Learning Kubernetes and its ecosystem will help organizations overcome their challenges in deploying, managing, and operating Kubernetes clusters.

Acquiring a Certified Kubernetes Administrator (CKA) certification is the best way to help you train the essential skills on working with Kubernetes. In particular, you’ll learn how to manage and operate Kubernetes.

The Certified Kubernetes Administrator (CKA) certification is founded by Cloud Native Computing Foundation (CNCF), and it is designed to ensure that certification candidates have the skills and knowledge to help them establish their credibility and value in the job market, and to support business growth. It is widely recognized by various sizes of businesses across different industries.

This book is an exam guide and a knowledge book, and it covers all the important aspects required by the CKA certification. We’ll start with an introduction to Kubernetes architecture, turning to the core concept of Kubernetes. Then, we will dive deeply into the main Kubernetes primitives, installation and configuration, cluster management, workload scheduling, networking, and security. We’ll also cover various ways to troubleshoot Kubernetes.

Each chapter will cover core concepts as well as code samples. It is not a book to read conventionally – it is a practice guide that requires you to get out of your comfort zone and go break some eggs!

While I was writing this book, I was at the lowest point of my life, having relocated to a new continent, as well as undergoing surgery for the first time in my life during the first 2 months of relocation. This all took place alongside many other challenges. I can’t thank my family enough for the huge support I received from them, especially my beloved mother, Nancy Deng. I also want to thank my lovely local and remote friends, the Packt team, and other people who supported me during that period.

As a human being, those unprecedented life challenges also made me rethink the definition of living a meaningful life. Hence, I decided to turn those challenges into something positive and meaningful by pushing myself to the max to work on this book. This experience also encouraged me to create the CloudMelon Vis YouTube channel, alongside my website cloud-melon.com that I have been blogging on for years. Sharing is caring!

Rethinking my community evangelization in the past, I hope to make my life more meaningful by making a more positive impact on the community. This book aims to help people find their new career path with Kubernetes, in particular those who lost their jobs during the pandemic. Kubernetes is one of the most life-changing technologies that empowered my own career path, and I hope it will make a positive impact on your career, too.

Last but not least, I wish you the best of luck with your CKA exam and hope you will enjoy your journey in building your future with this book. Thanks!

Contributors

About the author

Mélony Qin, aka CloudMelon, is the founder of CloudMelonVision and a product manager at a top tech company, as well as being the author ofMicrosoft Azure Infrastructure, the Kubernetes Workshop, and Certified Kubernetes Administrator (CKA) Exam Guideby Packt Publishing, and the technical reviewer for Azure for Architects, Third Edition. Her community contribution mainly concerns OSS, DevOps, Kubernetes, serverless, big data analytics, and IoT on Microsoft Azure. She is also a member of the Association for Computing Machinery (ACM) and Project Management Institute (PMI). She can be reached via Twitter using@MelonyQ or @CloudMelonVis, through the Contact me page of her blog (www.cloud-melon.com), and via her YouTube channel: CloudMelon Vis https://www.youtube.com/c/CloudMelonVis.

About the reviewers

Erol Kavas has worked in the IT industry for more than 20 years, with 10 years dedicated to infrastructure, the cloud, and DevOps. He has helped many Canadian and US enterprises and governments to build their cloud foundations and embark upon their containerization and Kubernetes journeys. He is fully certified on AWS, Azure, Google Cloud Platform, and Kubernetes in all disciplines. He is a partner and chief consultant in a DevOps and cloud consulting firm that helps Canadian and US start-ups in their cloud and DevOps journeys. He is also a Microsoft Certified Trainer (MCT) regional lead for Canada and trains many new cloud professionals at CloudCamp.ca.

Dustin Specker has been in the tech industry for almost 10 years. He started as a frontend web developer focused on usability. In the last few years, Dustin has pivoted to developing cloud solutions. He has used Kubernetes for on-premises environments and public cloud for the last four years. He has earned the CKAD, CKA, and CKS certifications. He received a Bachelor of Science degree in nuclear engineering from the Missouri University of Science and Technology, where he discovered that he enjoyed programming much more than nuclear engineering.

Bruno S. Brasil is a cloud engineer who has used Linux since he was a kid. He started out working in on-premises environments before living out the migration to cloud solutions and joining the DevOps culture, choosing Google Cloud Platform as his specialization focus. Since then, he has worked on projects of this type as a consultant and engineer for several types of businesses, ranging from digital banks and marketplaces to start-ups. He has always focused on implementing best practices in the development of infrastructure as code, disseminating the DevOps culture, and implementing SRE strategies. He is enthusiastic about the open source community and believes that this is the most important path in terms of the growth of new professionals and new technologies.

Juri Sinar is a senior DevOps engineer working for a London fintech start-up. Kubernetes is the main platform that he has used to run and integrate infrastructure for the past five years. It helps Juri to connect and automate a large global network of open banking for his clients in a way that would not have been possible just 10 years ago.

Table of Contents

Preface

Part 1: Cluster Architecture, Installation, and Configuration

1

Kubernetes Overview

CKA exam overview

What to expect in your CKA exam

CKA exam tips and tricks

Cluster architecture and components

Kubernetes core concepts

Containerized workloads

Container images

Container registry

Container runtimes

Kubernetes basic workflow

Kubernetes plugin model

Kubernetes API primitives

Sharing a cluster with namespaces

Kubernetes in-market distribution and ecosystems

Upstream vanilla Kubernetes

Managed Kubernetes

Kubernetes ecosystems

Summary

2

Installing and Configuring Kubernetes Clusters

Technical requirements

Hands-on Kubernetes tooling

Core tools

Deployment tools

Other tools

Installing and configuring a Kubernetes cluster

Prerequisites for installing a Kubernetes cluster

Using minikube to set up a single node Kubernetes cluster

Using kubeadm to install a basic Kubernetes cluster

Setting up a highly available cluster with kubeadm

Summary

Mock CKA scenario-based practice test

Scenario 1:

Scenario 2:

Scenario 3 (optional):

FAQs

3

Maintaining Kubernetes Clusters

Demystifying Kubernetes cluster maintenance

Upgrading a Kubernetes cluster using kubeadm

Upgrading the master node

Upgrading the worker node

Working with etcd

Exploring the ETCD cluster pod

Listing etcd cluster members

Checking the etcd cluster status

Installing etcd

Backing up etcd

Restoring etcd

Summary

Mock CKA scenario-based practice test

Scenario 1

Scenario 2

Scenario 3

Scenario 4

FAQs

Part 2: Managing Kubernetes

4

Application Scheduling and Lifecycle Management

Technical requirements

The basics of Kubernetes workloads

Imperative management versus declarative management

Understanding pods

Deploying and managing applications

Deploying applications

Performing rolling updates and rollbacks

Rolling updates with kubectl

Rollback

Scaling applications

ReplicaSets

Workload scheduling

Understanding namespaces

Labels, node selectors, and annotations

Node affinity and anti-affinity

Taints and tolerations

Resource management

Configuring applications

Manifest management with kustomize

Common package management and templating with Helm

Summary

Mock CKA scenario-based practice test

Scenario 1

Scenario 2

Scenario 3

Scenario 4

Scenario 5

FAQs

5

Demystifying Kubernetes Storage

Technical requirements

Stateful versus stateless workloads

Kubernetes volumes

Ephemeral storage

Persistent storage

Cracking stateful applications in Kubernetes

Configuring an application with mounted storage

Configuring an application with persistent storage

Summary

Mock CKA scenario-based practice test

Scenario 1

Scenario 2

FAQs

6

Securing Kubernetes

Technical requirements

Securing Kubernetes in layers

Kubernetes authentication and authorization

Service accounts versus user accounts

Kubernetes service accounts

Organizing the cluster access using kubeconfig

Configuring access to multiple clusters

Kubernetes authorization

Kubernetes RBAC

Managing the security of Kubernetes applications

Summary

Mock CKA scenario-based practice test

Scenario 1

Scenario 2

Scenario 3

FAQs

7

Demystifying Kubernetes Networking

Technical requirements

Understanding the Kubernetes networking model

Container-to-container communication

Pod-to-pod communication

Pod-to-service and external-to-service communications

Node-to-node communication

Choosing an appropriate Container Network Interface plugin

CNI networking in Kubernetes

Decision metrics

Configuring Ingress controllers and Ingress resources

How Ingress and an Ingress controller works

Using multiple Ingress controllers

Work with Ingress resources

Ingress annotations and rewrite-target

Configuring and leveraging CoreDNS

Check whether the CoreDNS server is up and running

Pod IPs and DNS hostnames

Service IPs and DNS hostnames

Summary

Mock CKA scenario-based practice test

Scenario 1

Scenario 2

Scenario 3

Scenario 4

Scenario 5

Scenario 6

FAQs

Part 3: Troubleshooting

8

Monitoring and Logging Kubernetes Clusters and Applications

Technical requirements

Monitoring on a cluster node

Checking whether Metrics Server is installed

Installing Metrics Server in your current Kubernetes cluster

Checking out CPU/memory metrics

Monitoring applications on a Kubernetes cluster

Monitoring the resource usage of an application

Checking application details

Monitoring cluster events

Managing logs at the cluster node and Pod levels

Cluster-level logging

Checking out the node details

Checking the node status

Managing container stdout and stderr logs

Summary

Mock CKA scenario-based practice test

Scenario 1

FAQs

9

Troubleshooting Cluster Components and Applications

Technical requirements

General practices in Kubernetes troubleshooting

Troubleshooting cluster components

Inspecting the cluster

Inspecting the node

Troubleshooting applications

Getting a high-level view

Inspecting namespace events

Troubleshooting failing pods

Troubleshooting init containers

Summary

FAQs

10

Troubleshooting Security and Networking

Technical requirements

Troubleshooting RBAC failures

Initiating a minikube cluster

Managing a minikube cluster

Troubleshooting networking

Troubleshooting a Kubernetes DNS server

Troubleshooting a service in Kubernetes

Get a shell for troubleshooting

Summary

FAQs

Appendix - Mock CKA scenario-based practice test resolutions

Chapter 2 – Installing and Configuring Kubernetes Clusters

Scenario 1

Scenario 2

Scenario 3 (optional)

Chapter 3 – Maintaining Kubernetes Clusters

Scenario 1

Scenario 2

Scenario 3

Scenario 4

Chapter 4 – Application scheduling and lifecycle management

Scenario 1

Scenario 2

Scenario 3

Scenario 4

Scenario 5

Chapter 5 – Demystifying Kubernetes Storage

Scenario 1

Scenario 2

Chapter 6 – Securing Kubernetes

Scenario 1

Scenario 2

Scenario 3

Chapter 7 – Demystifying Kubernetes networking

Scenario 1

Scenario 2

Scenario 3

Scenario 4

Scenario 5

Scenario 6

Chapter 8 – Monitoring and logging Kubernetes Clusters and Applications

Scenario 1

Index

Other Books You May Enjoy

Preface

Kubernetes is by far the most popular container orchestration tool, yet the complexities of managing the tool have led to the rise of fully managed Kubernetes services over the past few years. The Certified Kubernetes Administrator (CKA) certification is designed to ensure that certification candidates have the skills and knowledge to help them establish their credibility and value in the job market, to support business growth.

This book will start with an introduction to the Kubernetes architecture and the core concept of Kubernetes, and then we will take a deep dive into main Kubernetes primitives with hands-on scenarios for installation and configuration, cluster management and workload scheduling, networking, and security. Furthermore, we’ll discuss how to troubleshoot Kubernetes in our daily practice.

By the end of this book, you will be well versed in working with Kubernetes installation and configuration, and comfortable with the cluster management, storage, network, security-related configurations, and troubleshooting skills on vanilla Kubernetes.

If you want to learn more about Kubernetes, check out this playlist Kubernetes in 30 days - https://www.youtube.com/watch?v=csPu6y6A7oY&list=PLyDI9q8xNovlhCqRhouXmSKQ-PP6_SsIQ

Who this book is for

This book is targeted toward application developers, DevOps engineers, data engineers, and cloud architects who want to pass the CKA exam to certify their Kubernetes Administrator skills in the market. A basic knowledge of Kubernetes is recommended.

What this book covers

Chapter 1, Kubernetes Overview, introduces the Kubernetes architecture and its core concepts. It dives into common Kubernetes tools and gets hands-on with them, showing the big picture of different distributions and ecosystems of Kubernetes.

Chapter 2, Installing and Configuring Kubernetes Clusters, introduces the different configurations of Kubernetes and gets your hands dirty by setting up a Kubernetes cluster with a single worker node and multiple worker nodes using proper tooling.

Chapter 3, Maintaining Kubernetes Clusters, introduces the different approaches while maintaining Kubernetes clusters, and gets hands-on performing upgrades for Kubernetes clusters, backing up and restoring ETCD. This chapter covers 25% of the CKA exam content.

Chapter 4, Application Scheduling and Lifecycle Management, describes using Kubernetes deployments to deploy pods, scaling pods, performing rolling updates and rollbacks, resource management, and using ConfigMaps to configure pods. This chapter covers 15% of the CKA exam content.

Chapter 5, Demystifying Kubernetes Storage, discusses the core concept of Kubernetes storage for stateful workloads and shows how to configure applications with mounted storage and dynamically persistent storage. This chapter covers 10% of the CKA exam content.

Chapter 6, Securing Kubernetes, covers how Kubernetes authentication and authorization pattern works, then dives into Kubernetes role-based access control (RBAC). From there, we’ll put managing the security of applications deployed on Kubernetes into perspective. This part is less than 5% of the CKA exam content.

Chapter 7, Demystifying Kubernetes Networking, describes using the Kubernetes networking model and core concepts, as well as how to configure Kubernetes networking on the cluster nodes and network policies, configuring Ingress controllers and Ingress resources, configuring and leveraging CoreDNS, as well as how to choose an appropriate container network interface plugin. This chapter covers 20% of the CKA exam content.

Chapter 8, Monitoring and Logging Kubernetes Clusters and Applications, describes how to monitor Kubernetes cluster components and applications, and how to get infrastructure-level, system-level, and application-level logs to serve as a source of log analytics or for further troubleshooting. Together with the next two chapters about troubleshooting cluster components and applications and troubleshooting Kubernetes security and networking, it covers 30% of the CKA exam content.

Chapter 9, Troubleshooting Cluster Components and Applications, describes the general troubleshooting approaches, and how to troubleshoot errors caused by cluster component failure and issues that occurred during the application deployments.

Chapter 10, Troubleshooting Security and Networking, follows on from Chapter 9 and provides the general troubleshooting approaches to troubleshoot errors caused by RBAC restrictions or networking settings. In Chapter 6, we touched on how to enable Kubernetes RBAC and work with Kubernetes DNS. Be sure to go back and review those important concepts before diving into this chapter.

To get the most out of this book

This book is a comprehensive hands-on study guide focusing on providing hands-on skills with scenarios, and at the same time providing core knowledge to help readers warm up. The software and hardware covered in the book are as follows:

Software/hardware covered in the book

Operating system requirements

Minikube

Windows, macOS, or Linux

kubectl, kubeadm

Windows or Linux

Docker Desktop

Windows 10 or 11

WSL 2

Windows 10 or 11

Download the color images

We also provide a PDF file that has color images of the screenshots and diagrams used in this book. You can download it here: https://packt.link/AKr3r.

Conventions used

There are a number of text conventions used throughout this book.

Code in text: Indicates code words in text, database table names, folder names, filenames, file extensions, pathnames, dummy URLs, user input, and Twitter handles. Here is an example: “You can start by setting up an alias for kubectl using the alias k=kubectl command, and then use the k get command.”

A block of code is set as follows:

apiVersion: v1kind: Podmetadata:   name: melon-serviceaccount-podspec:   serviceAccountName: melon-serviceaccount   containers:   - name: melonapp-svcaccount-container     image: busybox     command: ['sh', '-c','echo stay tuned!&& sleep 3600']

When we wish to draw your attention to a particular part of a code block, the relevant lines or items are set in bold:

spec:   serviceAccountName: melon-serviceaccount   containers:

Any command-line input or output is written as follows:

kubectl delete samelon-serviceaccount

Bold: Indicates a new term, an important word, or words that you see onscreen. For instance, words in menus or dialog boxes appear in bold. Here is an example: “This command will return the node that is now shown as uncordoned.”

Tips or important notes

Appear like this.

Get in touch

Feedback from our readers is always welcome.

General feedback: If you have questions about any aspect of this book, email us at [email protected] and mention the book title in the subject of your message.

Errata: Although we have taken every care to ensure the accuracy of our content, mistakes do happen. If you have found a mistake in this book, we would be grateful if you would report this to us. Please visit www.packtpub.com/support/errata and fill in the form.

Piracy: If you come across any illegal copies of our works in any form on the internet, we would be grateful if you would provide us with the location address or website name. Please contact us at [email protected] with a link to the material.

If you are interested in becoming an author: If there is a topic that you have expertise in and you are interested in either writing or contributing to a book, please visit authors.packtpub.com.

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Part 1: Cluster Architecture, Installation, and Configuration

This part looks at an overview of Kubernetes and explores its concepts and tooling. Furthermore, you will learn how to install and set up Kubernetes clusters. This part covers 25% of the CKA exam's content.

This part of the book comprises the following chapters:

Chapter 1, Kubernetes OverviewChapter 2, Installing and Configuring Kubernetes ClustersChapter 3, Maintaining Kubernetes Clusters

1

Kubernetes Overview

This chapter is an introduction to the Kubernetes architecture and Kubernetes core concepts. It dives into common Kubernetes tools and gets hands-on with them, showing the big picture of the different distributions and ecosystems in Kubernetes. In this chapter, we’re going to cover the following main topics:

CKA exam overviewCluster architecture and componentsKubernetes core concepts Kubernetes in-market distribution and ecosystems

CKA exam overview

Certified Kubernetes Administrator (CKA) certification is a hands-on exam with a set of common Kubernetes working scenarios. You need to achieve it within a limited time frame. We highly recommend you work through this book within your environment and make sure that you understand and practice all the steps until you train your intuition and can perform all the tasks quickly without thinking twice. Time management is the key to success in this exam.

At the time of writing this book, the CKA exam is based on Kubernetes 1.22. Please check out the official example page to make sure you’re up to date on any changes in the exam curriculum: https://www.cncf.io/certification/cka/. To learn more about the changes in Kubernetes, please check out the community release notes: https://github.com/kubernetes/kubernetes/releases.

The content of this book is well aligned with the CKA exam curriculum:

Part 1 – Chapters 1 to 3 cover Kubernetes Cluster Architecture, Installation, and Configurations, which makes up about 25% of the exam. Part 2 – Chapter 4 covers Workloads and Scheduling, which makes up about 15% of the exam, Chapter 5 covers Storage Services and Networking, which makes up about 10% of the exam, chapters 6 and 7 cover Services and Networking, which makes up about 20% of the exam.Part 3 – Chapters 8 to 10 cover Troubleshooting, which makes up about 30% of the exam.

The goal of the exam curriculum is to help you prepare for the CKA exam and help you get a thorough understanding of each area, which will help you become skilled Kubernetes administrators later on in your career. While going through this book, please feel free to jump to the area that you need to know the most about if you’re already familiar with some other topics.

Note that some Kubernetes security content before November 2020 has gradually moved to the Certified Kubernetes Security Specialist (CKS) exam. As a well-rounded Kubernetes administrator, it’s essential to have a deep understanding of Kubernetes security. In fact, it is somewhat difficult to separate Kubernetes security as a different topic; however, knowledge of topics such as security context and role-based access control (RBAC) is still required for you to perform certain tasks to be successful in the exam. Therefore, this book will still cover some key security concepts to lay the groundwork if you want to pursue the CKS certification later on. To get to know more about different Kubernetes certifications, check out the FAQs from the Linux Foundation website by navigating to https://docs.linuxfoundation.org/tc-docs/certification/faq-cka-ckad-cks.

What to expect in your CKA exam

Prior to your exam, you have to make sure the computer you’re going to use during the exam meets the system requirements defined by the exam provider. A webcam and microphone are mandatory to turn on during the exam. You’re only allowed to use a single instance of a Chromium-based browser for the exam. You can find a list of Chromium-based browsers here: https://en.wikipedia.org/wiki/Chromium_(web_browser).

Please make sure your hardware meets the minimum requirements by running the compatibility check tool, which you can find here: https://www.examslocal.com/ScheduleExam/Home/CompatibilityCheck. The detailed system requirements are defined here: https://docs.linuxfoundation.org/tc-docs/certification/faq-cka-ckad-cks#what-are-the-system-requirements-to-take-the-exam.

Important note

As this exam is an online remote-proctored exam, you can also check out what the exam is like here: https://psi.wistia.com/medias/5kidxdd0ry.

During your exam, you’re allowed to check the official Kubernetes documentation including articles and documents under https://kubernetes.io and https://github.com/kubernetes on the same browser instance as the exam screen. The CKA exam consists of a set of around 20 scenario-based tasks to be achieved with a Linux-based shell and a set of predefined Kubernetes clusters. Those scenario-based tasks are described as a problem to be resolved with additional information. Candidates are bound to come up with the solutions based on the provided information and perform the solution promptly. A CKA exam session is about 2 hours, and after that, the exam will be marked as delivered. You can take the exam with multiple monitors if you wish to, although check out the exam policy beforehand to make sure you have met all the requirements from the organizer: https://docs.linuxfoundation.org/tc-docs/certification/faq-cka-ckad-cks#how-is-the-exam-proctored.

We highly recommend you walk through the sample scenarios provided by killer.sh, an official exam simulator, and bookmark the official documents that will be useful for you. Go to the killer.sh training website at https://killer.sh/course/ to test out a simulated exam environment and test out the scenarios.

For more CKA exam instructions and tricks, please check out https://docs.linuxfoundation.org/tc-docs/certification/tips-cka-and-ckad.

You need a score of at least 66% to pass the exam, and the results will be emailed to you within 24 to 36 hours of finishing the exam. Accordingly, you will receive the certification in PDF form with a validity of 3 years, and a badge shortly after that. In case of any questions, you could email [email protected] for further help.

CKA exam tips and tricks

Two key factors to help you succeed in the CKA exam or any other Kubernetes certifications are as follows:

Excellent time management Practice, as we know that practice makes perfect

Before getting to the exam part, you have to be familiar with Kubernetes; don’t dwell only on the certification when you’re preparing for this exam. A deep understanding of the Kubernetes cluster architecture and ecosystem will help set a solid foundation on the way to learning any exam-related content.

Gaining some basic understanding of the Linux shell

Looking at the exam itself, a basic understanding of the Linux shell will assist you in achieving the goal quicker. The following commands will help you while you’re going through the exercises in this book:

sudo to avoid permission issues as much as possible, and sudo su to get root permissioncurl| grep in the command filtering result vi/vim/nano or other Linux text editor catcp/mv/mkdir/touchcp/scpA good understanding of the json path is a plus, and using jq for JSON parsing would be a good complement to locating the information that you want to get out of the command.

As we’re going through all the exam topics in this book, we’ll cover most of these commands in the exercises. Make sure you understand and can confidently perform all the exercises independently with no rush.

Setting up a kubectl alias to save time

A lot of commands will be used repeatedly while you’re working on various scenarios of the exam, so a friendly shortcut for kubectl is essential, as it will be used in nearly all of your commands:

alias k=kubectl

alias kg='kubectl get'

alias kgpo='kubectl get pod'

There’s a kubectl-aliases repository on GitHub that you can refer to (https://github.com/ahmetb/kubectl-aliases). This was created by a contributor who showed some really good examples of kubectl aliases.

If you don’t want to remember too much, you can try to understand the naming convention for shortcuts in Kubernetes. These would be things such as svc being short for services such that kubectl get services can become kubectl get svc, or kubectl get nodes can become k get no, for example. I have created a melonkube playbook repository, which covers all the shortcuts for Kubernetes objects (https://github.com/cloudmelon/melonkube/blob/master/00%20-%20Shortcuts.md).

You can refer to that to find what works best for you. However, please keep it simple as your mind may be get worked up during the actual exam for some reason. Practice and more practice will get you there sooner.

Setting kubectl autocomplete

You could set autocompletion in your shell; this will usually work in the Linux shell in your exam. You can achieve this with the following:

source <(kubectl completion bash) # setup autocomplete in bash into the current shell, bash-completion package should be installed first.

echo "source <(kubectl completion bash)" >> ~/.bashrc # add autocomplete permanently to your bash shell.

Working in conjunction with the shortcut, you can do the following:

alias k=kubectl

complete -F __start_kubectl k

Although sometimes it may take more time to look for the right commands from bash autocompletion, I would say focusing on building a good understanding of the technology with practice will help you skill up faster.

Bookmarking unfamiliar yet important documentation in your browser

Get yourself familiar with Kubernetes official documentation to know where to find the information you need. The goal of CKA is not about memorizing but hands-on skills; knowing how to find the right path and resolving the challenge is the key. You could bookmark the documentation in the following domains:

Kubernetes official documentation: https://kubernetes.io/docs/Kubernetes blog: https://kubernetes.io/blog/Kubernetes GitHub repository: https://github.com/kubernetes/

The first page that I usually recommend people to bookmark is the kubectl cheat sheet: https://kubernetes.io/docs/reference/kubectl/cheatsheet/. Another good bookmark is the official documentation search: https://kubernetes.io/search/?q=kubecon.

Be careful with the security context

The context is the most important indicator to let you know which Kubernetes cluster you’re currently working on. We’ll touch on the security context in more detail later in the book. I suggest you perform a context check before working on any new questions as you might get confused at times. Note that if you’re not operating on the target Kubernetes cluster of that question, you will not get scored.

You can use the following command to check out the context:

kubectl config current-context

If you want to go to a specific Kubernetes cluster, you can use the following command:

kubectl config use-context my-current-cluster-name

You can also check out a list of Kubernetes clusters you’ve worked on with the following command in the actual exam:

kubectl config get-contexts  

Managing your time wisely

Time management is the