What is a Dockerfile?

A Dockerfile is a plain-text script that Docker reads to build a reproducible container image. It defines the base OS, installs dependencies, copies your application code, and specifies the startup command — eliminating the classic "works on my machine" problem.

How to Use This Generator

1. Select Stack — Choose Node.js, Python, or NGINX for static assets.
2. Configure Options — Set the runtime version, package manager, and port.
3. Copy to Root — Paste the output into a file named exactly Dockerfile at your project root.
4. Build & Run — Execute docker build -t myapp . then docker run -p 3000:3000 myapp.

FAQ

Why use Alpine images? Alpine-based images are 5-10× smaller than full Debian images, reducing build times and attack surface.

What is layer caching? By copying package.json before the rest of the source, Docker only re-runs npm ci when dependencies change — not on every code edit.