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 WORKDIR instruction

We have seen the WORKDIR instruction used in some of the examples used to demonstrate other instructions. It is sort of like a combination of the Linux cd and mkdir commands. The WORKDIR instruction will change the current working directory in the image to the value provided in the instruction. If any segment of the path in the parameter of the WORKDIR instruction does not yet exist, it will be created as part of the execution of the instruction. The syntax for the WORKDIR instruction is as follows:

# WORKDIR instruction syntax
WORKDIR instruction syntax
WORKDIR /path/to/workdir

The WORKDIR instruction can use ENV or ARG parameter values for all or part of its parameter. A Dockerfile can have more than one WORKDIR instruction, and each subsequent WORKDIR instruction will be relative to the previous one (if a relative path is used). Here is an example that...