Docker is an open-source project that automates the development, deployment and running of applications inside isolated containers. Containers allow developers to bundle up an application with all of the parts it needs, such as libraries and other dependencies, and ship it as one package.

Docker is both a daemon (a process running in the background) and a client command. It’s like a virtual machine but it’s different in important ways. First, there’s less duplication. With each extra VM you run, you duplicate the virtualization of CPU and memory and quickly run out resources when running locally. Docker is great at setting up a local development environment because it easily adds the running process without duplicating the virtualized resource. Second, it’s more modular. Docker makes it easy to run multiple versions or instances of the same program without configuration headaches and port collisions.

The goal of this course is to show you how to get a Node.js application into a Docker container. This course is intended for development, and not for a production deployment. The guide also assumes you have a working Docker installation and a basic understanding of how a Node.js application is structured. The course covers installation of Docker Desktop just in case you need help.

In the first section of this course we will create a simple web application in Node.js, then we will build a Docker image for that application, and lastly we will instantiate a container from that image.