Dev Containers Tutorial#

The great thing about dev containers is that:

  • You will never again run into compatibility issues, regardless of whether you are on Windows, Mac, or Linux.

  • Your computer won’t be bloated by software, as containers are completely independent from your computer.

Prerequisites#

Before starting, you will need to complete the following tasks:

Additionally, this tutorial will assume that you are familiar with the following topics:

VS Code

A code editor with loads of functionality that makes programming as convenient and seamless as possible.

Creating a dev container in a project folder#

Given a project folder, first create a folder named .devcontainer/. Inside the folder, create the files devcontainer.json and Dockerfile. Your project directory should now look like this:

.devcontainer/
├── devcontainer.json
└── Dockerfile

Inside devcontainer.json, enter the following:

{
    "build": {
        "dockerfile": "Dockerfile"
    }
}

Installing software and packages#

Let’s say in our project we’d like to use Python, along with the numpy and matplotlib packages.

First we need to find a ‘base image’ as a starting point. Base images are found on the Docker Hub website.

By searching ‘python’ on Docker Hub, we can find the python image, which is essentially a clean PC installation with only Python installed.

On the same page, it will show a ‘Docker Pull Command’, which in this case is docker pull python. We are only interested in the last part, which we will place into our Dockerfile like so:

FROM python
RUN pip install numpy
RUN pip install matplotlib

  • The FROM keyword sets the base image, where python is from the previous Docker pull command.

  • The RUN keyword allows us to run arbitrary terminal commands. You can add as many RUN commands as you’d like.

Installing VS Code extensions#

In my example, I want to install the Python and Jupyter extensions. Gather the extension IDs and put them into a list:

["ms-python.python", "ms-toolsai.jupyter"]

Then inside the devcontainer.json file, place the list like so:

{
    "build": {
        "dockerfile": "Dockerfile"
    },
    "customizations": {
        "vscode": {
            "extensions": ["ms-python.python", "ms-toolsai.jupyter"]
        }
    }
}

Opening a project in a dev container#

Inside your project folder, open the command palette and select Dev Containers: Reopen in Container. Make sure to do this everytime you open the project.

Updating a dev container#

Whenever you make changes to your dev container, make sure to open the command palette and run Dev Containers: Rebuild Container to reflect those changes.