Hello internet! 👋 In this blog post I will cover how to get started with Visual Studio Code Dev Containers.

What are Dev Containers and why use them?

Dev Containers provide a containerised development environment within Visual Studio Code. With Dev Containers, you and your team can have a consistent development environment, regardless of the host OS. Moreover, it helps ease the onboarding process, getting new team members up and running quickly, and helps avoid common issues such as “it works on my machine” or “oh, you’ve got a different version of x”.

So without further ado, let’s get started! 🚀

Getting Started

To use Dev Containers, you will need the following:

My container runtime of choice is OrbStack. I’ve been using it for a while now and it has been great! 🎉 It’s fast and very lightweight. Podman is another great alternative, especially if you’re looking for a Docker alternative. Podman Desktop was released not long ago too, so definitely check it out if GUIs are more your thing 🙂

Creating a Dev Container

Dev Containers are configured using a devcontainer.json file which resides in a .devcontainer directory in your repository. This file defines the entire configuration for the containerised environment including the base image, extensions, settings and more.

For this blog post, I will create a Dev Container for developing Ansible content. We will need Ansible core, Python and the Ansible extension for Visual Studio Code.

Let’s start by creating the needed directories for the Ansible project:

mkdir -pv ansible-dev-containers-demo/.devcontainer

Next, we will create the devcontainer.json file:

touch ansible-dev-containers-demo/.devcontainer/devcontainer.json

Now, let’s add the following configuration to the devcontainer.json file:

{
    "name": "Ansible Dev Containers Demo",
    "build": {
        "dockerfile": "Dockerfile"
    },
    "customizations": {
        "vscode": {
            "settings": {
                "redhat.telemetry.enabled": false
            },
            "extensions": [
                "redhat.ansible"
            ]
        }
    }
}

Let’s break down the configuration. We will be building the base image using a simple Dockerfile. The Ansible extension will be installed in the Dev Container and Red Hat telemetry in the extension will be disabled.

Next, we’ll create the Dockerfile with the following content:

touch ansible-dev-containers-demo/.devcontainer/Dockerfile

FROM python:3.12-slim
# Install ansible-core
RUN pip install ansible-core

Now, let’s open the project in Visual Studio Code and we will see a toast notification that a Dev Container configuration file has been detected:

Dev Container toast notification

Click Reopen in Container to start building the Dev Container. Once built, open a terminal in Visual Studio Code, and you’ll see that we are running inside the Dev Container with Ansible and the extension installed:

root@b6c0de05320f:/workspaces/ansible-dev-containers-demo# ansible --version
ansible [core 2.17.2]
  config file = None
  configured module search path = ['/root/.ansible/plugins/modules', '/usr/share/ansible/plugins/modules']
  ansible python module location = /usr/local/lib/python3.12/site-packages/ansible
  ansible collection location = /root/.ansible/collections:/usr/share/ansible/collections
  executable location = /usr/local/bin/ansible
  python version = 3.12.4 (main, Jul  2 2024, 20:57:30) [GCC 12.2.0] (/usr/local/bin/python)
  jinja version = 3.1.4
  libyaml = True

Dev Container Ansible extension

You now have a containerised environment for Ansible development! 🎉

Rebuilding the Dev Container

If you need to rebuild the Dev Container, you can do so by opening the command palette (Ctrl|Command+Shift+P) and running the Dev Containers: Rebuild and Reopen in Container command.

Conclusion

Dev Containers are a great way for you and your team to have a consistent development environment. We only scratched the surface of what’s possible with Dev Containers in this post. In the future, I’ll cover running commands or scripts pre and post startup, 1Password SSH integration, environment variables, port forwarding and more! 🙂

If you’d like to learn more about Dev Containers, check out the official documentation.

Until next time! 👋