Imagine you and your team have built an app. Now the testing team wants to test it. Normally, they may need to install: Node.js npm packages dependencies environment setup configurations Even after all that, errors can still happen because their system may be different from yours. Docker solves this problem by packaging your app, runtime, dependencies, and configuration into one image. The tester only needs Docker installed. They can run your image directly and test the app. Follow these steps to create your own Docker image: Create the folder structure displayed in the image. Create a server.js file and add the following code inside the file. It is a demo code that displays the OS information when the user opens the URL in the browser. const http = require ( " http " ); const os = require ( " os " ); const server = http . createServer (( req , res ) => { res . writeHead ( 200 , { " Content-Type " : " text/html " }); res .…