Book Image

Learn Docker - Fundamentals of Docker 19.x - Second Edition

By : Dr. Gabriel N. Schenker
Book Image

Learn Docker - Fundamentals of Docker 19.x - Second Edition

By: Dr. Gabriel N. Schenker

Overview of this book

Containers enable you to package an application with all the components it needs, such as libraries and other dependencies, and ship it as one package. Docker containers have revolutionized the software supply chain in both small and large enterprises. Starting with an introduction to Docker fundamentals and setting up an environment to work with it, you’ll delve into concepts such as Docker containers, Docker images, and Docker Compose. As you progress, the book will help you explore deployment, orchestration, networking, and security. Finally, you’ll get to grips with Docker functionalities on public clouds such as Amazon Web Services (AWS), Azure, and Google Cloud Platform (GCP), and learn about Docker Enterprise Edition features. Additionally, you’ll also discover the benefits of increased security with the use of containers. By the end of this Docker book, you’ll be able to build, ship, and run a containerized, highly distributed application on Docker Swarm or Kubernetes, running on-premises or in the cloud.
Table of Contents (25 chapters)
1
Section 1: Motivation and Getting Started
4
Section 2: Containerization, from Beginner to Black Belt
11
Section 3: Orchestration Fundamentals and Docker Swarm
18
Section 4: Docker, Kubernetes, and the Cloud

Chapter 14

Here are some sample answers to the questions presented in this chapter:

  1. Zero-downtime deployment means that a new version of a service in a distributed application is updated to a new version without the application needing to stop working. Usually, with Docker SwarmKit or Kubernetes (as we will see), this is done in a rolling fashion. A service consists of multiple instances and those are updated in batches so that the majority of the instances are up and running at all times.
  2. By default, Docker SwarmKit uses a rolling updated strategy to achieve zero-downtime deployments.
  3. Containers are self-contained units of deployment. If a new version of a service is deployed and does not work as expected, we (or the system) need to only roll back to the previous version. The previous version of the service is also deployed in the form of self-contained containers. Conceptually...