It's getting more common to find yourself responsible for running the code you've written as well as developing the features. While many companies still have an operations group (generally retitled to SRE or DevOps) that help with expert knowledge, developers (like you) are often being asked to expand your knowledge and responsibility scope.
There's been a shift to treating infrastructure-like code for some time. Several years ago, I might have described the boundary as Puppet is used by operations folks and Chef is used by developers. All of that changed with the advent and growth first of clouds in general, and more recently with the growth of Docker. Containers provide a level of control and isolation, as well as development flexibility, that is very appealing. When using containers, you quickly move to where you want to use more than one container a time, for isolation of responsibility as well as horizontal scaling.
Kubernetes is a project open sourced from Google, now hosted by the cloud-native computing foundation. It exposes many of the lessons from Google's experience of running software in containers and makes it available to you. It encompasses not only running containers, but grouping them together into services, scaling them horizontally, as well as providing means to control how these containers interact together and how they get exposed to the outside world.
Kubernetes provides a declarative structure backed with an API and command-line tools. Kubernetes can be used on your laptop, or leveraged from one of the many cloud providers. The benefit of using Kubernetes is being able to use the same set of tools with the same expectations, regardless of running it locally, in a small lab at your company, or in any number of larger cloud providers. It's not exactly the write once, run anywhere promise of Java from days gone by; more we'll give you a consistent set of tools, regardless of running on your laptop, your company's datacenter, or a cloud provider such as AWS, Azure, or Google.
This book is your guide to leveraging Kubernetes and its capabilities for developing, validating, and running your code.
This book focuses on examples and samples that take you through how to use Kubernetes and integrate it into your development workflow. Through the examples, we focus on common tasks that you may want to use to take advantage of running your code with Kubernetes.
If you are a full-stack or backend software developer who's interested in, curious about, or being asked to be responsible for testing and running the code you're developing, you can leverage Kubernetes to make that process simpler and consistent. If you're looking for developer-focused examples in Node.js and Python for how to build, test, deploy, and run your code with Kubernetes, this book is perfect for you.
Chapter 1, Setting Up Kubernetes for Development, covers the installation of kubectl, minikube, and Docker, and running kubectl with minikube to validate your installation. This chapter also provides an introduction to the concepts in Kubernetes of Nodes, Pods, Containers, ReplicaSets, and Deployments.
Chapter 2, Packaging Your Code to Run in Kubernetes, explains how to package your code within containers in order to use Kubernetes with examples in Python and Node.js.
Chapter 3, Interacting with Your Code in Kubernetes, covers how to run containers in Kubernetes, how to access these containers, and introduces the Kubernetes concepts of Services, Labels, and Selectors.
Chapter 4, Declarative Infrastructure, covers expressing your application in a declarative structure, and how to extend that to utilize the Kubernetes concepts of ConfigMaps, Annotations, and Secrets.
Chapter 5, Pod and Container Lifecycles, looks at the life cycle of containers and Pods within Kubernetes, and how to expose hooks from your application to influence how Kubernetes runs your code, and how to terminate your code gracefully.
Chapter 6, Background Processing in Kubernetes, explains the batch processing concepts in Kubernetes of Job and CronJob, and introduces how Kubernetes handles persistence with Persistent Volumes, Persistent Volume Claims, and Stateful Sets.
Chapter 7, Monitoring and Metrics, covers monitoring in Kubernetes, and how to utilize Prometheus and Grafana to capture and display metrics and simple dashboards about Kubernetes in general, as well as your applications.
Chapter 8, Logging and Tracing, explains how to collect logs with Kubernetes using ElasticSearch, FluentD, and Kibana, and how you can set up and use distributed tracing with Jaeger.
Chapter 9, Integration Testing, covers testing strategies that take advantage of Kubernetes, and how to leverage Kubernetes in integration and end-to-end tests.
Chapter 10, Troubleshooting Common Problems and Next Steps, reviews a number of common pain points you may encounter when getting started with Kubernetes and explains how to resolve them, and provides an overview of a number of projects within the Kubernetes ecosystem that may be of interest to developers and the development process.
You need to have the following software and hardware requirements:
- Kubernetes 1.8
- Docker Community Edition
- kubectl 1.8 (part of Kubernetes)
- VirtualBox v5.2.6 or higher
- minikube v0.24.1
- MacBook or Linux machine with 4 GB of RAM or more
You can download the example code files for this book from your account at www.packtpub.com. If you purchased this book elsewhere, you can visit www.packtpub.com/support and register to have the files emailed directly to you.
You can download the code files by following these steps:
- Log in or register at www.packtpub.com.
- Select the
SUPPORTtab. - Click on
Code Downloads & Errata. - Enter the name of the book in the
Searchbox and follow the onscreen instructions.
Once the file is downloaded, please make sure that you unzip or extract the folder using the latest version of:
- WinRAR/7-Zip for Windows
- Zipeg/iZip/UnRarX for Mac
- 7-Zip/PeaZip for Linux
The code bundle for the book is also hosted on GitHub at following URLs:
In case there's an update to the code, it will be updated on the existing GitHub repository.
We also have other code bundles from our rich catalog of books and videos available at https://github.com/PacktPublishing/. Check them out!
There are a number of text conventions used throughout this book.
CodeInText: 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: "Mount the downloaded WebStorm-10*.dmg disk image file as another disk in your system."
A block of code is set as follows:
import signal
import sys
def sigterm_handler(_signo, _stack_frame):
sys.exit(0)
signal.signal(signal.SIGTERM, sigterm_handler)
When we wish to draw your attention to a particular part of a code block, the relevant lines or items are set in bold:
import signal
import sys
def sigterm_handler(_signo, _stack_frame):
sys.exit(0)
signal.signal(signal.SIGTERM, sigterm_handler)Any command-line input or output is written as follows:
kubectl apply -f simplejob.yamlBold: Indicates a new term, an important word, or words that you see onscreen. For example, words in menus or dialog boxes appear in the text like this. Here is an example: "Select System info from the Administration panel."
Feedback from our readers is always welcome.
General feedback: Email [email protected] and mention the book title in the subject of your message. If you have questions about any aspect of this book, please email us at [email protected].
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/submit-errata, selecting your book, clicking on the Errata Submission Form link, and entering the details.
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.
Please leave a review. Once you have read and used this book, why not leave a review on the site that you purchased it from? Potential readers can then see and use your unbiased opinion to make purchase decisions, we at Packt can understand what you think about our products, and our authors can see your feedback on their book. Thank you!
For more information about Packt, please visit packtpub.com.