The problem

The orders service is a small Node.js API. You write its Dockerfile from an empty file, one line per rep, so that the image runs as a normal user and starts with docker run orders.

The build context is the folder orders/. It holds package.json (one dependency, ms, and one dev dependency, is-number), package-lock.json, server.js (an HTTP server on port 3000) and worker.js (prints worker run and exits). The base image is node:22-bookworm-slim, a Debian image that has a node user with uid 1000. The app goes in /app.