Dockerize a simple NodeJS app

Create a working directory:

mkdir simpleweb
cd simpleweb

Create a package.json file:

$ cat package.json 
{
  "dependencies": {
    "express": "*"
  },
  "scripts": {
    "start": "node index.js"
  }
}

Create a NodeJS app:

$ cat index.js 
const express = require('express');
const app = express();
app.get('/', (req, res) => {
  res.send('Hello, world!');
  });
  app.listen(8080, () => {
  console.log('Listening on port 8080');
  });

Create a Dockerfile:

$ cat Dockerfile 
FROM node:alpine
WORKDIR /usr/app
COPY ./package.json .
RUN npm install
COPY ./index.js .
CMD ["npm", "start"]

Build and tag the image:

docker build -t simpleweb .

Run the dockerized app:

docker run -p 8080:8080 simpleweb

Open the browser and navigate to http://127.0.0.1:8080