Book Image

Docker Quick Start Guide

By : Earl Waud
Book Image

Docker Quick Start Guide

By: Earl Waud

Overview of this book

Docker is an open source software platform that helps you with creating, deploying, and running your applications using containers. This book is your ideal introduction to Docker and containerization. You will learn how to set up a Docker development environment on a Linux, Mac, or Windows workstation, and learn your way around all the commands to run and manage your Docker images and containers. You will explore the Dockerfile and learn how to build your own enterprise-grade Docker images. Then you will learn about Docker networks, Docker swarm, and Docker volumes, and how to use these features with Docker stacks in order to define, deploy, and maintain highly-scalable, fault-tolerant multi-container applications. Finally, you will learn how to leverage Docker with Jenkins to automate the building of Docker images and the deployment of Docker containers. By the end of this book, you will be well prepared when it comes to using Docker for your next project.
Table of Contents (10 chapters)

Creating Docker Images

In this chapter, we will learn how to create enterprise-grade Docker images. We will start off by learning about the main building block of Docker images, specifically the Dockerfile. Then, we will explore all the instructions available to use in a Dockerfile. There are some instructions that on the surface seem very similar. We will uncover what the differences are between the COPY and ADD instructions, the ENV and ARG instructions, and most importantly between the CMD and ENTRYPOINT instructions. Next, we will find out what the build context is and why it is important. Finally, we will cover the actual image build command.

If well-maintained, the average shipping container has a lifespan of around 20 years, whereas the average lifespan of a Docker container is 2.5 days.