Book Image

Learn Docker - Fundamentals of Docker 18.x

By : Dr. Gabriel N. Schenker
Book Image

Learn Docker - Fundamentals of Docker 18.x

By: Dr. Gabriel N. Schenker

Overview of this book

Docker containers have revolutionized the software supply chain in small and big enterprises. Never before has a new technology so rapidly penetrated the top 500 enterprises worldwide. Companies that embrace containers and containerize their traditional mission-critical applications have reported savings of at least 50% in total maintenance cost and a reduction of 90% (or more) of the time required to deploy new versions of those applications. Furthermore they are benefitting from increased security just by using containers as opposed to running applications outside containers. This book starts from scratch, introducing you to Docker fundamentals and setting up an environment to work with it. Then we delve into concepts such as Docker containers, Docker images, Docker Compose, and so on. We will also cover the concepts of deployment, orchestration, networking, and security. Furthermore, we explain Docker functionalities on public clouds such as AWS. By the end of this book, you will have hands-on experience working with Docker containers and orchestrators such as SwarmKit and Kubernetes.
Table of Contents (21 chapters)
Title Page
Packt Upsell
Contributors
Preface
Index

The bridge network


The Docker bridge network is the first implementation of the container network model that we're going to look at in detail. This network implementation is based on the Linux bridge. When the Docker daemon runs for the first time, it creates a Linux bridge and calls it docker0. This is the default behavior, and can be changed by changing the configuration. Docker then creates a network with this Linux bridge and calls the network bridge. All the containers that we create on a Docker host and that we do not explicitly bind to another network leads to Docker automatically attaching to this bridge network.

To verify that we indeed have a network called bridge of type bridge defined on our host, we can list all networks on the host with the following command:

$ docker network ls

This should provide an output similar to the following:

Listing of all Docker networks available by default

In your case, the IDs will be different, but the rest of the output should look the same. We do...