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

Multi-host networking

In Chapter 10Single-Host Networking, we discussed how containers communicate on a single Docker host. Now, we have a Swarm that consists of a cluster of nodes or Docker hosts. Containers that are located on different nodes need to be able to communicate with each other. Many techniques can help us to achieve this goal. Docker has chosen to implement an overlay network driver for Docker Swarm. This overlay network allows containers attached to the same overlay network to discover each other and freely communicate with each other. The following is a schema for how an overlay network works:

Overlay network

We have two nodes or Docker hosts with the IP addresses 172.10.0.15 and 172.10.0.16. The values we have chosen for the IP addresses are not important; what is important is that both hosts have a distinct...