Book Image

Learn Docker - Fundamentals of Docker 18.x

By : Dr. Gabriel N. Schenker
Book Image

Learn Docker - Fundamentals of Docker 18.x

By: Dr. Gabriel N. Schenker

Overview of this book

Docker containers have revolutionized the software supply chain in small and big enterprises. Never before has a new technology so rapidly penetrated the top 500 enterprises worldwide. Companies that embrace containers and containerize their traditional mission-critical applications have reported savings of at least 50% in total maintenance cost and a reduction of 90% (or more) of the time required to deploy new versions of those applications. Furthermore they are benefitting from increased security just by using containers as opposed to running applications outside containers. This book starts from scratch, introducing you to Docker fundamentals and setting up an environment to work with it. Then we delve into concepts such as Docker containers, Docker images, Docker Compose, and so on. We will also cover the concepts of deployment, orchestration, networking, and security. Furthermore, we explain Docker functionalities on public clouds such as AWS. By the end of this book, you will have hands-on experience working with Docker containers and orchestrators such as SwarmKit and Kubernetes.
Table of Contents (21 chapters)
Title Page
Packt Upsell
Contributors
Preface
Index

Stacks, services, and tasks


When using a Docker Swarm versus a single Docker host, there is a paradigm change. Instead of talking of individual containers that run processes, we are abstracting away to services that represent a set of replicas of each process, and like through become highly available. We also do not speak anymore of individual Docker hosts with well known names and IP addresses to which we deploy containers; we'll now be referring to clusters of hosts to which we deploy services. We don't care about an individual host or node anymore. We don't give it a meaningful name; each node rather becomes a number to us. We also don't care about individual containers and where they are deployed anymore—we just care about having a desired state defined through a service. We can try to depict that as shown in the following figure:

Containers are deployed to well known servers

Instead of deploying individual containers to well known servers like the preceding one, where we deploy container...