how to deploy nodejs app with docker

create docker file.md
create .dockerignore
use docker compose
push to a reggistry.

Key best practices
Don't run as root — use USER node (built into the official image).
Don't bake secrets into the image — pass them via env vars or a secrets manager, never COPY .env.
Use alpine or slim base images to keep size down.
Add a healthcheck so orchestrators know when your app is actually ready: