Book Image

Mastering Docker - Third Edition

By : Russ McKendrick, Scott Gallagher
Book Image

Mastering Docker - Third Edition

By: Russ McKendrick, Scott Gallagher

Overview of this book

Docker has been a game-changer when it comes to how modern applications are deployed and created. It has now grown into a key driver of innovation beyond system administration, with an impact on the world of web development. But how can you make sure you're keeping up with the innovations it's driving, or be sure you're using it to its full potential? Mastering Docker shows you how; this book not only demonstrates how to use Docker more effectively, but also helps you rethink and reimagine what's possible with it. You will cover concepts such as building, managing, and storing images, along with best practices to make you confident, before delving more into Docker security. You'll find everything related to extending and integrating Docker in new and innovative ways. Docker Compose, Docker Swarm, and Kubernetes will help you take control of your containers in an efficient manner. By the end of the book, you will have a broad, yet detailed, sense of what's possible with Docker, and how seamlessly it fits in with a range of other platforms and tools.
Table of Contents (17 chapters)

The Docker command-line client

Now that we have Docker installed, let's look at some Docker commands that you should be familiar with already. We will start with some common commands and then take a peek at the commands that are used for the Docker images. We will then take a dive into the commands that are used for the containers.

Docker has restructured their command-line client into more logical groupings of commands, as the number of features provided by the client grows quickly and commands start to cross over each other. Throughout this book, we will be using the new structure.

The first command we will be taking a look at is one of the most useful commands, not only in Docker, but in any command-line utility you use—the help command. It is run simply like this:

$ docker help

This command will give you a full list of all of the Docker commands at your disposal, along with a brief description of what each command does. For further help with a particular command, you can run the following:

$ docker <COMMAND> --help

Next, let's run the hello-world container. To do this, simply run the following command:

$ docker container run hello-world

It doesn't matter what host you are running Docker on, the same thing will happen on Linux, macOS, and Windows. Docker will download the hello-world container image and then execute it, and once it's executed, the container will be stopped.

Your Terminal session should look like the following:

Let's try something a little more adventurous—let's download and run a nginx container by running the following two commands:

$ docker image pull nginx
$ docker container run -d --name nginx-test -p 8080:80 nginx

The first of the two commands downloads the nginx container image, and the second command launches a container in the background, called nginx-test, using the nginx image we pulled. It also maps port 8080 on our host machine to port 80 on the container, making it accessible to our local browser at http://localhost:8080/.

As you can see from the following screenshots, the command and results are exactly the same on all three OS types. Here we have Linux:

This is the result on macOS:

And this is how it looks on Windows:

In the following three chapters, we will look at using the Docker command-line client in more detail. For now, let's stop and remove our nginx-test container by running the following:

$ docker container stop nginx-test
$ docker container rm nginx-test

As you can see, the experience of running a simple nginx container on all three of the hosts on which we have installed Docker is exactly the same. As am I sure you can imagine, trying to achieve this without something like Docker across all three platforms is a challenge, and also a very different experience on each platform. Traditionally, this has been one of the reasons for the difference in local development environments.