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

Demystifying declarative versus imperative

Docker Compose is a tool provided by Docker that is mainly used where you need to run and orchestrate containers running on a single Docker host. This includes, but is not limited to, development, continuous integration (CI), automated testing, manual QA, or demos.

Docker Compose uses files formatted in YAML as input. By default, Docker Compose expects these files to be called docker-compose.yml, but other names are possible. The content of a docker-compose.yml is said to be a declarative way of describing and running a containerized application potentially consisting of more than a single container.

So, what is the meaning of declarative?

First of all, declarative is the antonym of imperative. Well, that doesn't help much. Now that I have introduced...