The Scenario
A junior developer wrote a `Dockerfile` for a simple Node.js Express API. The resulting image is 1.2GB because they used the `node:latest` base image, copied the `node_modules` folder from their local machine, and ran as the `root` user.
The Brief
Rewrite the Dockerfile. Use a smaller base image (e.g., Alpine), utilize multi-stage builds to exclude development dependencies (`devDependencies`), and ensure the container runs as a non-root user for security.
Deliverables
- The optimized `Dockerfile`
- An explanation of why multi-stage builds are critical for compiled languages (or for trimming `devDependencies` in Node)
Submission Guidance
A good Dockerfile should cache the `package.json` install step separately from the source code copy step to speed up rebuilds.
Submit Your Work
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