Docker for Developers: The Practical Guide You Actually Need

Docker clicked for me the day I stopped thinking "containers" and started thinking "portable environments." Here's everything you need to go from zero to productive. What is Docker, actually? Docker packages your app + its dependencies into a container — like a lightweight VM, but faster and more portable. Without Docker: "It works on my machine!" With Docker: "It works in any machine!" Install Docker # macOS / Windows: Install Docker Desktop # https://www.docker.com/products/docker-desktop/ # Linux (Ubuntu) curl -fsSL https://get.docker.com -o get-docker.sh sh get-docker.sh Your First Container # Run nginx web server docker run -p 8080:80 nginx # Open http://localhost:8080 — it works! # Ctrl+C to stop # Run in background docker run -d -p 8080:80 --name my-nginx nginx # Check what's running docker ps # Stop it docker stop my-nginx The Dockerfile A Dockerfile is a recipe for your container image. # Node.js app example FROM node:20-alpine WORKDIR /app # Copy package files first (for laye