Dockerizing a Node App

In this article I will be covering a basic understanding of how a Node.js application is structured assuming you have a working Docker installation. Please take the necessary steps to download Docker if you have not already.

Step 1: Initiate a new Node.Js App with NPM init

// package-lock.json
{
  "name": "your_app_name",
  "version": "2.0.0",
  "description": "Your First Dockerized App",
  "author": "Your Name",
  "main": "index.js",
  "scripts": {
    "start": "node index.js"
  },
  "dependencies": {
    "express": "^4.15.12"
  }
}

Step 2: Run npm -i (AKA: npm install)

Step 3: Create Index.js file

const express = require('express');
const app = express();

app.get('/', (req, res) => {
  res.send('What a wonderful World');
});

app.listen(3000, '0.0.0.0' () => {
  console.log('Server listening on Port 3000');
});

Step 4: Create your Dockerfile: touch Dockerfile

#YOUR NODE VERSION
FROM node:15

# CREATE APP DIRECTORY
WORKDIR /app

# INSTALL APP DEPENDENCIES
COPY package*.json ./

# INSTALL DEPENDENCIES
RUN npm install

# BUNDLE APP
COPY . .

# DEFINE PORT
EXPOSE 3000

# RUN DOCKER APP
CMD [ "node", "index.js" ]

Step 5: Touch docker-compose.yml

version: '3.7' 
services:   
 
    web:
        image: [Image-name]
        build: .
        command: node index.js
        ports: 
            - "3000:3000"
        volumes: 
            - ./[image-name]/app
            - /app/node_modules
        depends_on:
            - mongodb
    mongodb:
        image: "mongo"
        ports:
            - "27017:27017"

Step 6: Touch .dockerignore

node_modules/

Step 7: Build Your Docker Container

docker build -t [App-name] .

Step 8: Run Docker Container

docker run -it -p 3000:3000 [App-name]

FINISH!!!