Introduction

🐳🤔 What is Docker?

Docker is like a magic box for your applications! 🪄 It lets you package your app and all its necessary parts, like libraries and configurations, into a neat little container. This container can then be moved around easily to different computers, servers, and even clouds! Docker ensures your app works the same regardless of where it goes, and you don't need to worry about installing anything on the host machine. It's like having your own personal genie 🧞 to handle all the messy installation and configuration stuff, so you can focus on making awesome apps! 🚀

🤔🤖💻 Why Should You Care about Docker?

Docker is like a magical box that helps you run your computer programs everywhere, whether it's on your own computer, or in the cloud 🌥️. It's like having a superpower that lets you take your apps wherever you go!

For example, imagine you made a cool video game 🎮, but your friend can't play it because they have a different computer system than you. With Docker🐳, you can package up the game and send it to your friend, and they can play it without any problems!

Let's take another example, imagine you own a bakery 🧁 and you want to share your delicious recipes with your friend who lives across the country🇮🇳. With Docker, you can package up all the ingredients, baking tools, and recipe instructions into one container, and easily send it to your friend without any hassle! They can then use the container to bake your amazing treats, without having to worry about finding all the right tools and ingredients themselves.

Or, let's say you want to run your bakery's website on a new computer, but you don't want to install all the complicated software and libraries you need. With Docker🐳, you can put everything you need into one container, and easily move it to a new computer without any hassle!

Docker is like having your own personal computer assistant 🤖 that can help you run your programs on any computer system with ease. So if you want to make your life easier and your programs more portable, then you should definitely know about Docker🐳!

🐳🧠 Understanding Docker: Key Concepts You Need to Know!

🌟 Docker Images: Think of it as a cake recipe 🎂. A cake recipe contains a list of ingredients and instructions to make a cake. Similarly, a Docker image contains a list of instructions to create a software application. Docker images are used to create Docker containers.

🐳 Docker Containers: A Docker container is like a bakery that uses the cake recipe to create multiple cakes 🧁. A container is a lightweight, standalone, and executable package that contains everything needed to run an application. Containers are created from Docker images and can be run, stopped, and deleted.

📦 Docker Registries: A Docker registry is like a cookbook 📚 where you can store and share your cake recipes with others. Similarly, Docker registries are used to store and share Docker images with others. Docker Hub is a popular public registry where developers can find and share Docker images.

📦🔗 Containerize Your Node.js App: Take Your App Anywhere!

🏗️Build a Node.JS Application:

First, let's create a directory📂 for our project and initialize a NodeJS package:

mkdir docker-blog
cd docker-blog
npm init -y

Next, let's install ExpressJS as a dependency🚀:

npm install express

Then, let's create an index.js file with the following code:

// Import the express dependency🚀
const express = require('express');

// Create🌎 a new Express application instance
const app = express();

//🛣️Defining a route handler for the root path
app.get('/', (req, res) => {
  res.send('Hello World!');
});

//🚪Start the server on port 3000
app.listen(3000, () => {
  console.log('Listening on port 3000');
});

This code creates an ExpressJS app that listens on port 3000 and responds with "Hello World!" when a GET request is made to the root endpoint.

🌎 Creating a DockerFile:

Create a file named Dockerfile in the root and add the following code:

# 🐳 Use an official Node.js runtime as a parent image
FROM node:14

# 📁 Set the working directory to /app inside the container
WORKDIR /app

# 🔍 Copy package.json and package-lock.json to the working directory from host machine
COPY package*.json ./

# 🏃 Install the app's dependencies inside the container
RUN npm install

# 📦 Copy the rest of the application code to the working directory
COPY . .

# 🚪 Expose port 3000 for incoming network traffic
EXPOSE 3000

# 👋 Define the command to run the app when the container starts
CMD ["npm", "start"]

👷‍♂️Building a Docker Image:

To build the Docker image, navigate to the directory where the Dockerfile is located and run the following command:

docker build -t node-docker .

🏃‍♀️Running that Particular Image:

Once the image is built, you can run a container from it using the following command:

docker run -p 3000:3000 node-docker

This will start a container from the node-docker image and map port 3000 inside the container to port 3000 on your local machine. 🎉

You should now be able to access your Node.js application by navigating to http://localhost:3000 in your web browser. 🚀👨‍💻

🎉Congratulations on making it this far!:

If you've made it this far in learning how to containerize a Node.js application with Docker, give yourself a well-deserved pat on the back! Congratulations on taking the initiative to learn new skills and techniques to improve your development and deployment workflows. With your newfound knowledge of Docker, you'll be able to streamline your application deployments and improve the consistency and reproducibility of your environments. Keep up the great work!