Book Image

Mastering Kubernetes

By : Gigi Sayfan
Book Image

Mastering Kubernetes

By: Gigi Sayfan

Overview of this book

Kubernetes is an open source system to automate the deployment, scaling, and management of containerized applications. If you are running more than just a few containers or want automated management of your containers, you need Kubernetes. This book mainly focuses on the advanced management of Kubernetes clusters. It covers problems that arise when you start using container orchestration in production. We start by giving you an overview of the guiding principles in Kubernetes design and show you the best practises in the fields of security, high availability, and cluster federation. You will discover how to run complex stateful microservices on Kubernetes including advanced features as horizontal pod autoscaling, rolling updates, resource quotas, and persistent storage back ends. Using real-world use cases, we explain the options for network configuration and provides guidelines on how to set up, operate, and troubleshoot various Kubernetes networking plugins. Finally, we cover custom resource development and utilization in automation and maintenance workflows. By the end of this book, you’ll know everything you need to know to go from intermediate to advanced level.
Table of Contents (22 chapters)
Mastering Kubernetes
Credits
About the Author
About the Reviewer
www.PacktPub.com
Customer Feedback
Preface
Index

Chapter 8. Running Stateful Applications with Kubernetes

In this chapter, we will look into what it takes to run stateful applications on Kubernetes. Kubernetes is taking a lot of work off our hands by automatically starting and restarting pods across the cluster nodes as needed, based on complex requirements and configurations such as namespaces, limits, and quotas. But, when pods run storage-aware software, such as databases and queues, relocating a pod can cause the system to break. First, we'll understand the essence of stateful pods and why they are much more complicated to manage in Kubernetes. We will look at a few ways to manage the complexity such as shared environment variables and DNS records. In some situations, a redundant in-memory state, a DaemonSet, or persistent storage claims can do the trick. The main solution that Kubernetes promotes for state-aware pods is the StatefulSet (previously called PetSet) resource that allows managing an indexed collection of pods with stable...