| name | devcontainer-helper |
| description | Use this skill when the user asks to create, configure, update, or explain a `devcontainer.json` file or development container environment. |
DevContainer Helper
This skill assists in creating and managing devcontainer.json files for consistent development environments.
Workflow
1. specific Requirements
Before generating the file, determine the user's needs:
- Base Environment: Do they want a pre-built image (e.g., Ubuntu, Python, Node), a custom
Dockerfile, or a docker-compose.yml setup?
- Languages & Tools: What languages (Node.js, Python, Go, Rust, etc.) and tools (Git, CLI utilities) are needed?
- Extensions: Are there specific VS Code extensions required?
- Ports: What ports need to be forwarded?
2. Generate Configuration
Use the template in assets/devcontainer-template.json as a starting point.
For Image-based (Simplest):
Use the image property. Add features for additional tools.
For Dockerfile:
Use build.dockerfile property pointing to their Dockerfile.
For Docker Compose:
Use dockerComposeFile and service properties.
3. Add Features
Encourage using "Features" over manual Dockerfile commands when possible for better maintainability.
Common features:
- Node.js:
ghcr.io/devcontainers/features/node:1
- Python:
ghcr.io/devcontainers/features/python:1
- Docker-in-Docker:
ghcr.io/devcontainers/features/docker-in-docker:2
- Git:
ghcr.io/devcontainers/features/git:1
4. Lifecycle Scripts
If the user needs to run commands (like npm install or pip install) after the container builds:
- Use
postCreateCommand for one-time setup.
- Use
postStartCommand for commands that run every time the container starts.
References
See references/cheatsheet.md for a list of common devcontainer.json properties and valid values.
