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Special thanks to Docker and Prakhar Srivastav for parts of this tutorial.

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Docker Engine is a tool that allows developers, sys-admins etc. to easily deploy their applications in a sandbox (called containers) to run on the host operating system i.e. Linux. The key benefit of Docker Engine is that it allows users to package an application with all of its dependencies into a standardized unit for software development. Unlike virtual machines, containers do not have the overhead of a full operating system and hence enable more efficient usage of the underlying system and resources.

The industry standard today is to use Virtual Machines (VMs) to run software applications. VMs run applications inside a guest Operating System, which runs on virtual hardware powered by the server’s host OS.

VMs are great at providing full operating system isolation for applications: there are very few ways a problem in the host operating system can affect the software running in the guest operating system, and vice-versa. But this isolation comes at great cost — the computational overhead spent virtualizing hardware for a guest OS to use is substantial.

Containers take a different approach: by leveraging the low-level mechanics of the host operating system, containers provide most of the isolation of virtual machines at a fraction of the computing power.

This tutorial aims to be the one-stop shop for getting your hands dirty with Docker. Apart from demystifying the Docker landscape, it'll give you hands-on experience with building and deploying your own webapps. You'll quickly build a multi-container wordpress service. Even if you have no prior experience with deployments, this tutorial should be all you need to get started.

This document contains a series of several sections, each of which explains a particular aspect of Docker. In each section, you will be typing commands (or writing code). All the code used in the tutorial is available in the Github repo.

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• Preface
  • Setting up your computer
• 1. Playing with Alpine
  • 1.1 Docker Run
  • 1.2 Terminology
• 2. Webapps with Docker
  • 2.1 Static Sites
  • 2.2 Docker Images
  • 2.3 Our First Image
  • 2.4 Dockerfile
• 3. Docker Compose
  • 3.1 Step 1: Setup
  • 3.2 Step 2: Create a Dockerfile
  • 3.3 Step 3: Define services in a Compose file
  • 3.4 Step 4: Build and run your app with Compose
  • 3.5 Step 5: Edit the compose file to add a bind mount
  • 3.6 Step 6: Re-build and run the app with Compose
  • 3.7 Step 7: Update the application
  • 3.8 Step 8: Experiment with some other commands
• 4. Docker Compose and Wordpress
  • 4.1 Define the project
  • 4.2 Build the project
  • 4.3 Bring up WordPress in a web browser

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Getting all the tooling setup on your computer can be a daunting task, but thankfully getting Docker up and running on your favorite OS has become very easy.

The getting started guide on Docker has detailed instructions for setting up Docker on Mac, Linux and Windows.

Once you are done installing Docker, test your Docker installation by running the following:

$ docker container run hello-world
Unable to find image 'hello-world:latest' locally
latest: Pulling from library/hello-world
03f4658f8b78: Pull complete
a3ed95caeb02: Pull complete
Digest: sha256:8be990ef2aeb16dbcb9271ddfe2610fa6658d13f6dfb8bc72074cc1ca36966a7
Status: Downloaded newer image for hello-world:latest

Hello from Docker.
This message shows that your installation appears to be working correctly.
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• What is Docker
• Docker Cheatsheet
• Docker Compose