Book Image

Kubernetes and Docker - An Enterprise Guide

By : Scott Surovich, Marc Boorshtein
Book Image

Kubernetes and Docker - An Enterprise Guide

By: Scott Surovich, Marc Boorshtein

Overview of this book

Containerization has changed the DevOps game completely, with Docker and Kubernetes playing important roles in altering the flow of app creation and deployment. This book will help you acquire the knowledge and tools required to integrate Kubernetes clusters in an enterprise environment. The book begins by introducing you to Docker and Kubernetes fundamentals, including a review of basic Kubernetes objects. You’ll then get to grips with containerization and understand its core functionalities, including how to create ephemeral multinode clusters using kind. As you make progress, you’ll learn about cluster architecture, Kubernetes cluster deployment, and cluster management, and get started with application deployment. Moving on, you’ll find out how to integrate your container to a cloud platform and integrate tools including MetalLB, externalDNS, OpenID connect (OIDC), pod security policies (PSPs), Open Policy Agent (OPA), Falco, and Velero. Finally, you will discover how to deploy an entire platform to the cloud using continuous integration and continuous delivery (CI/CD). By the end of this Kubernetes book, you will have learned how to create development clusters for testing applications and Kubernetes components, and be able to secure and audit a cluster by implementing various open-source solutions including OpenUnison, OPA, Falco, Kibana, and Velero.
Table of Contents (20 chapters)
Section 1: Docker and Container Fundamentals
Section 2: Creating Kubernetes Development Clusters, Understanding objects, and Exposing Services
Section 3: Running Kubernetes in the Enterprise

What is OPA and how does it work?

OPA is a lightweight authorization engine that fits well in Kubernetes. It didn't get its start in Kubernetes, but it's certainly found a home there. There's no requirement to build dynamic admission controllers in OPA, but it's very good at it and there are extensive resources and existing policies that can be used to start your policy library.

This section provides a high-level overview of OPA and its components with the rest of the chapter getting into the details of an OPA implementation in Kubernetes.

OPA architecture

OPA is comprised of three components – the HTTP listener, the policy engine, and the database:

Figure 11.1 – OPA architecture

The database used by OPA is in memory and ephemeral. It doesn't persist information used to make policy decisions. On the one hand, this makes OPA very scalable since it is essentially an authorization microservice. On the other hand...