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

Understanding the Kubernetes networking model


The Kubernetes networking model is based on a flat address space. All pods in a cluster can directly see each other. Each pod has its own IP address. There is no need to configure any NAT. In addition, containers in the same pod share their pod's IP address and can communicate with each other through localhost. This model is pretty opinionated, but once set up, it simplifies life considerably both for developers and administrators. It makes it particularly easy to migrate traditional network applications to Kubernetes. A pod represents a traditional node and each container represents a traditional process.

Intra-pod communication (container to container)

A running pod is always scheduled on one (physical or virtual) node. That means that all the containers run on the same node and can talk to each other in various ways, such as the local filesystem, any IPC mechanism, or using localhost and well-known ports. There is no danger of port collision...