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)

The FROM instruction

Every Dockerfile must have a FROM instruction, and it must be the first instruction in the file. (Actually, the ARG instruction can be used before a FROM instruction, but it is not a required instruction. We will talk more about that in the ARG instruction section.)

The FROM instruction sets the base for the image being created and instructs the Docker daemon that the base of the new image should be the existing Docker image specified as the parameter. The specified image can be described using the same syntax we saw in the Docker container run command from Chapter 2, Learning Docker Commands. Here, it's a FROM instruction that specifies using the official nginx image with a version of 1.15.2:

# Dockerfile
FROM nginx:1.15.2

Note that in this example, there is no repository specified that indicates that the specified image is the official nginx image....