Dockerized A Node.js Application

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JavaScript
Node.js
Express
Simple Express.js Server
Docker
Dockerized Express.js Server
Final Note

JavaScript

JavaScript is a multi-purpose, multi-paradigm, single-threaded programming language used on client and server-side.

Node.js

Node.js is a JavaScript runtime environment, It is responsible for running JavaScript on the server side.

You can download Node.js from here.

Node.js setup will install itself and npm (node package manager) which is use from installing dependencies.

Express.js

Express.js is the Node.js framework which is responsible for creating REST API's.

Simple Express.js Server

Now we need to create a simple Express.js:

For creating a server we need to create a new folder then inside that folder open your favorite IDE.

Now run this command (make sure you have node already installed).

    npm init // This will initialize npm within directory
    npm install express --save //This will install Express.js and save in package.json dependencies 
    mkdir index.js //Create a new file

Now add this code in index.js file:

    const express = require('express'); // Require express.js framework

    const app = express(); //Create a app container 

    app.get('/', function (req, res) { // Add a route (API)
    res.send('Hello World')
    }); 

    app.listen(3000); // Listen on a port

Now your express server is ready now run this:

    node index.js //This will run index.js file

Now open your browser in tab add this url http://localhost:3000.

Yahoo! Your first Express.js app is ready (Happy Hacking).

Docker

Docker is a tool designed to make it easier to create, deploy, and run applications by using containers.

This means that Docker makes our life easy by creating a container now we will create a container of our Node.js application but first download Docker from here.

Dockerized Express.js Server

Now we need to Dockerized our Node Application so add a Dockerfile in our project folder.

And add these commands inside Dockerfile.

   # This file is the main docker file configurations

   # Official Node JS runtime as a parent image 
   FROM node:9-alpine

   # Set the working directory to .
   WORKDIR .

  # Install app dependencies
  # A wildcard is used to ensure both package.json AND package- 
  lock.json are copied
  # where available (npm@5+)
 COPY package*.json ./

  # Install any needed packages
  RUN npm install

  # Bundle app source
  COPY . ./

  # Make port 3000 available to the world outside this container
  EXPOSE 3000

  # Run app.js when the container launches
  CMD ["npm", "start"]

Now run docker build --tag node:latest and then docker run --publish 8000:8080 --detach --name bb node:latest to build and run docker image locally

Yahoo! you first dockerized application is ready to server on http://localhost:3000.