عرض عملي: كتابة Dockerfile متعدد المراحل لـ Shop

خطوة بخطوة

1. Write the two-stage Dockerfile with a .dockerignore.
2. Build with docker build -t shop:1.0 . and compare the size with a single-stage build.
3. Add a non-root user and confirm with docker exec shop whoami.
4. Run PostgreSQL with a volume on a shared network; run Shop against it.
5. Planned mistake: the app uses localhost for the database and fails to connect; fix with the container name db via an environment variable.
6. Remove and recreate the database container to show the data survives.