How to Containerize a Node.js App Using a Custom Dockerfile

A hands-on project demonstrates how to containerize a Node.js web application using Docker, walking through the creation and use of a custom Dockerfile. The application consists of a simple HTTP server built with Node.js that listens on port 3000 and returns a plain-text response. A Dockerfile defines the build instructions, while package.json and package-lock.json ensure reproducible dependency management. The image is built using the docker build command and run as a container via docker run, illustrating the full container lifecycle. The project highlights how Dockerfile instructions directly shape the resulting image and the behavior of the running container.