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Using the DevContainer for K8TRE Development

K8TRE now provides a Visual Studio Code DevContainer configuration to simplify setup of development environments. This guide explains how to use this feature.

What is a DevContainer?

A Development Container (DevContainer) defines a consistent, reproducible development environment with all tools and dependencies pre-configured. This eliminates "works on my machine" issues and speeds up onboarding for new contributors.

Prerequisites

To use the DevContainer, you'll need:

  1. Visual Studio Code installed on your computer
  2. Docker Desktop (or compatible container runtime)
  3. Visual Studio Code Remote - Containers extension

Using the DevContainer

  1. Clone the K8TRE repository: 

    git clone https://github.com/k8tre/k8tre.git
cd k8tre

  2. Open the folder in Visual Studio Code: 

    code .

  3. When prompted, click "Reopen in Container", or use the Command Palette (F1) and select "Remote-Containers: Reopen in Container".

  4. VS Code will build the DevContainer (this may take several minutes on the first run).

  5. Once the container is ready, you'll have access to:

  6. All required CLI tools (kubectl, kustomize, helm, argocd, etc.)
  7. Proper Python environment with dependencies
  8. Pre-configured Kubernetes extensions
  9. K3s for local development

Starting Development

Once inside the container:

  1. The container is already configured with:
  2. K3s running for local Kubernetes development
  3. Kubectl configured with the proper kubeconfig

  4. ArgoCD installed and ready to use

  5. Apply the K8TRE resources: 

    kubectl apply -f local/root-app-of-apps.yaml

  6. Access the ArgoCD UI:

  7. Set up port forwarding to access the ArgoCD UI: 
    kubectl port-forward svc/argocd-server -n argocd 8080:443
  8. Open https://localhost:8080 (or more likely https://localhost:8081 - check PORTS tab in VS Code) in your browser
  9. Get the initial admin password. This is displayed at startup or run the following command. 
    kubectl -n argocd get secret argocd-initial-admin-secret -o jsonpath="{.data.password}" | base64 -d; echo

  10. Log in with username: admin and the password retrieved above

  11. Follow the regular K8TRE development workflow

GitHub Codespaces

The same DevContainer configuration works with GitHub Codespaces. To use it:

  1. Go to the K8TRE GitHub repository
  2. Click the "Code" button
  3. Select the "Codespaces" tab
  4. Click "Create codespace on main"

This will create a cloud-based development environment with the same configuration.

Customizing the DevContainer

If you need to customize your development environment, you can modify:

  • .devcontainer/devcontainer.json - Main configuration file
  • .devcontainer/post-create.sh - Script that runs after container creation

See the DevContainer README for more details.