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

Deploying a first application


We have created a few Docker Swarms on various platforms. Once created, a swarm behaves the same way on any platform. The way we deploy and update applications on a swarm is not platform-dependent. It has been one of Docker's main goals to avoid a vendor lock-in when using a swarm. Swarm-ready applications can be effortlessly migrated from, say, a swarm running on-premise to a cloud based swarm. It is even technically possible to run part of a swarm on-premise and another part in the cloud. It works, yet one has of course to consider possible side effects due to the higher latency between nodes in geographically distant areas.

Now that we have a highly available Docker Swarm up and running, it is time to run some workloads on it. I'm using a local swarm created with Docker Machine. We'll start by first creating a single service. For this we need to SSH into one of the manager nodes. I select node-1:

$ docker-machine ssh node-1

Creating a service

A service can be...