Book Image

Getting Started with Kubernetes - Third Edition

By : Jonathan Baier, Jesse White
Book Image

Getting Started with Kubernetes - Third Edition

By: Jonathan Baier, Jesse White

Overview of this book

Kubernetes has continued to grow and achieve broad adoption across various industries, helping you to orchestrate and automate container deployments on a massive scale. Based on the recent release of Kubernetes 1.12, Getting Started with Kubernetes gives you a complete understanding of how to install a Kubernetes cluster. The book focuses on core Kubernetes constructs, such as pods, services, replica sets, replication controllers, and labels. You will understand cluster-level networking in Kubernetes, and learn to set up external access to applications running in the cluster. As you make your way through the book, you'll understand how to manage deployments and perform updates with minimal downtime. In addition to this, you will explore operational aspects of Kubernetes , such as monitoring and logging, later moving on to advanced concepts such as container security and cluster federation. You'll get to grips with integrating your build pipeline and deployments within a Kubernetes cluster, and be able to understand and interact with open source projects. In the concluding chapters, you'll orchestrate updates behind the scenes, avoid downtime on your cluster, and deal with underlying cloud provider instability within your cluster. By the end of this book, you'll have a complete understanding of the Kubernetes platform and will start deploying applications on it.
Table of Contents (23 chapters)
Title Page
Dedication
Packt Upsell
Contributors
Preface
Index

Cluster life cycle


There are a few more key items that we should cover so that you're armed with full knowledge about the items that can help you with creating highly available Kubernetes clusters. Let's discuss how you can use admission controllers, workloads, and custom resource definitions to extend your cluster.

Admission controllers

Admission controllers are Kubernetes code that allows you to intercept a call to the Kubernetes API server after it has been authenticated and authorized. There are standard admission controllers that are included with the core Kubernetes system, and people also write their own. There are two controllers that are more important than the rest:

  • TheMutatingAdmissionWebhook is responsible for calling Webhooks that mutate, in serial, a given request. This controller only runs during the mutating phase of cluster operating. You can use a controller like this in order to build business logic into your cluster to customize admission logic with operations such as CREATE...