Book Image

The Kubernetes Book

By : Nigel Poulton, Pushkar Joglekar
Book Image

The Kubernetes Book

By: Nigel Poulton, Pushkar Joglekar

Overview of this book

Kubernetes is the leading orchestrator of cloud-native apps. With knowledge of how to work with Kubernetes, you can easily deploy and manage applications on the cloud or in your on-premises data center. The book begins by introducing you to Kubernetes and showing you how to install it. You’ll learn how to use Kubernetes Services and bring stable and reliable networking to apps that are deployed on Kubernetes. You'll delve deep into the powerful storage subsystem of Kubernetes and learn how to leverage the variety of external storage backends in your applications. As the book progresses, it shows you how to use features such as DaemonSets, Helm, and RBAC to enhance your Kubernetes applications. You'll explore the six categories of identifying vulnerabilities and look at a few ways to prevent and mitigate them. You'll also look at ways to secure the software delivery pipeline by discussing some image-related best practices. The book ends by sharing with you some resources that’ll help take your Kubernetes knowledge to the next level. By the end of the book, you’ll have the confidence and skills to leverage all the features of Kubernetes to develop scalable applications.
Table of Contents (23 chapters)
Free Chapter
1
Chapter 1
3
Chapter 2
5
Chapter 3
7
Chapter 4
9
Chapter 5
11
Chapter 6
13
Chapter 7
15
Chapter 8
17
Chapter 9
19
Chapter 10
21
Chapter 11

Performing a Rolling Update

In this section, we'll see how to perform a rolling update on the application we've just deployed. We'll assume the new version of the application has already been created and containerized as a Docker image with the edge tag. All that is left to do is use Kubernetes to push the update to production. For this example, we're ignoring real-world continuous integration (CI)/continuous deployment (CD) workflows and version control tools.

The first thing we need to do is update the image tag used in the Deployment's manifest file. The initial version of the app used an image tagged as nigelpoulton/k8sbook:latest. We'll update the .spec.template.spec.containers section of the Deployment manifest to reference the new nigelpoulton/k8sbook:edge image. This will ensure that next time the manifest is POSTed to the API server, all Pods in the Deployment will be updated to run the new edge image.

The following is the updated deploy...