Book Image

Kubernetes for Developers

By : Joseph Heck
Book Image

Kubernetes for Developers

By: Joseph Heck

Overview of this book

Kubernetes is documented and typically approached from the perspective of someone running software that has already been built. Kubernetes may also be used to enhance the development process, enabling more consistent testing and analysis of code to help developers verify not only its correctness, but also its efficiency. This book introduces key Kubernetes concepts, coupled with examples of how to deploy and use them with a bit of Node.js and Python example code, so that you can quickly replicate and use that knowledge. You will begin by setting up Kubernetes to help you develop and package your code. We walk you through the setup and installation process before working with Kubernetes in the development environment. We then delve into concepts such as automating your build process, autonomic computing, debugging, and integration testing. This book covers all the concepts required for a developer to work with Kubernetes. By the end of this book, you will be in a position to use Kubernetes in development ecosystems.
Table of Contents (16 chapters)
Title Page
Packt Upsell
Contributors
Preface
Index

Tagging your container images


Using the :latest tag on Docker images is incredibly convenient, but it can easily lead to confusion as to what exactly is running. If you do use :latest, then it is a very good idea to also tell Kubernetes to always attempt to pull a new image when loading the container. We will see how to set this in Chapter 4, Declarative Infrastructure, when we talk about declaratively defining our applications.

An alternative is to make explicit tags, building with a tag, and also using docker tag to tag the image as latest for the convenience factor, but maintaining specific tags within the declarations that you check in to source control. For this example, the tag chosen is 0.2.0, using semantic versioning to represent a value to use with the container, and matched to a git tag as well.

The steps that were used while making this example were:

git tag 0.2.0
docker build -t quay.io/kubernetes-for-developers/nodejs:0.2.0 .
git push origin master --tags
docker push quay.io/kubernetes...