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

DNS


DNS solves the issues seen with environment variables by allowing us to reference the services by their name. As services restart, scale out, or appear anew, the DNS entries will be updating and ensuring that the service name always points to the latest infrastructure. DNS is set up by default in most of the supported providers. You can add DNS support for your cluster via a cluster add on (https://kubernetes.io/docs/concepts/cluster-administration/addons/).

Note

If DNS is supported by your provider, but is not set up, you can configure the following variables in your default provider config when you create your Kubernetes cluster:ENABLE_CLUSTER_DNS="${KUBE_ENABLE_CLUSTER_DNS:-true}"DNS_SERVER_IP="10.0.0.10"DNS_DOMAIN="cluster.local"DNS_REPLICAS=1.

With DNS active, services can be accessed in one of two forms—either the service name itself, <service-name>, or a fully qualified name that includes the namespace, <service-name>.<namespace-name>.cluster.local. In our examples...