Book Image

The Docker Workshop

By : Vincent Sesto, Onur Yılmaz, Sathsara Sarathchandra, Aric Renzo, Engy Fouda
5 (3)
Book Image

The Docker Workshop

5 (3)
By: Vincent Sesto, Onur Yılmaz, Sathsara Sarathchandra, Aric Renzo, Engy Fouda

Overview of this book

No doubt Docker Containers are the future of highly-scalable software systems and have cost and runtime efficient supporting infrastructure. But learning it might look complex as it comes with many technicalities. This is where The Docker Workshop will help you. Through this workshop, you’ll quickly learn how to work with containers and Docker with the help of practical activities.? The workshop starts with Docker containers, enabling you to understand how it works. You’ll run third party Docker images and also create your own images using Dockerfiles and multi-stage Dockerfiles. Next, you’ll create environments for Docker images, and expedite your deployment and testing process with Continuous Integration. Moving ahead, you’ll tap into interesting topics and learn how to implement production-ready environments using Docker Swarm. You’ll also apply best practices to secure Docker images and to ensure that production environments are running at maximum capacity. Towards the end, you’ll gather skills to successfully move Docker from development to testing, and then into production. While doing so, you’ll learn how to troubleshoot issues, clear up resource bottlenecks and optimize the performance of services. By the end of this workshop, you’ll be able to utilize Docker containers in real-world use cases.
Table of Contents (17 chapters)
Preface

Docker Layers and Caching

A registry is a way to store and distribute your Docker images. When you pull a Docker image from a registry, you might have noticed that the image is pulled in pieces and not as a single image. The same thing happens when you build an image on your system.

This is because Docker images consist of layers. When you create a new image using a Dockerfile, it will create more layers on top of the existing image you've built from. Each command you specify in the Dockerfile will create a new layer, with each containing all of the filesystem changes that occur before the command was performed and then after. When you run the image as a container from a Dockerfile, you're creating readable and writable layers on top of an existing group of read-only layers. This writable layer is known as the container layer.

As you'll see in the following exercises, when you build a container from a Dockerfile, the output presented shows each command run in...