Devcontainers Repository

Note: All base images must be Codespace-compatible to ensure Docker and devcontainer features work as expected in Codespaces and local development environments.

This repository hosts multiple devcontainer builds, each organized in its own subdirectory. These builds are published to GitHub Container Registry (GHCR) and can be consumed by downstream projects.

Directory Structure

devcontainers/
  9569/
    Dockerfile
  tnl/
    Dockerfile
  nysd/
    Dockerfile
.github/
  workflows/
    build.yml

Devcontainer Images

Subdirectories

• 9569/: Python 3.7 environment for assessments and lessons.
• tnl/: Python 3.11 environment for teaching and learning resources.
• nysd/: Python 3.11 environment for Nanyang System Developer projects.

Image Tags

• :latest: Always points to the most recent build.
• :YYYYMMDD: Date-based tags for reproducibility.

CI/CD Workflow

The GitHub Actions workflow (build.yml) automates the following:

1. Detects changes in subdirectories.
2. Builds and pushes the corresponding container to GHCR.
3. Enforces a retention policy to keep :latest and builds less than 3 months before :latest.

Triggering Builds

• Automatic: On merging a PR to main.
• Manual: Via workflow dispatch.

Retention Policy

• Always keep :latest.
• Retain all builds less than 3 months before :latest.

Usage

Downstream projects can reference these devcontainers in their .devcontainer/devcontainer.json:

{
  "name": "9569-project",
  "image": "ghcr.io/nyjc-computing/devcontainer-9569:latest"
}

For reproducibility, pin to a specific date-based tag:

{
  "name": "9569-project",
  "image": "ghcr.io/nyjc-computing/devcontainer-9569:20250922"
}

Notes

• Each subdirectory has its own Dockerfile.
• Builds are restricted to one subdirectory per PR.