Getting Started with Docker: A Beginner-Friendly Guide

What is Docker?

Docker is a platform that packages your application and its dependencies into containers — lightweight, portable units that run the same everywhere.

Why Use Docker?

1. Solves “It works on my machine” issues


2. Speeds up deployment


3. Enables consistent environments for development and production

Core Concepts:

1. Image: A blueprint of your app and dependencies


2. Container: A running instance of an image


3. Dockerfile: A script that defines how to build an image

Example Dockerfile:

dockerfile

FROM node:18

WORKDIR /app

COPY . .

RUN npm install

CMD ["npm", "start"]

Basic Commands:

bash

docker build -t my-app .

docker run -p 3000:3000 my-app

Best Practices:

• Keep images small by using slim base images


• Use .dockerignore to exclude unnecessary files


• Tag images with version numbers (my-app:v1.0.0)

Conclusion:

Docker is a game-changer for modern development workflows. Once you grasp its basics, you’ll wonder how you ever lived without it.