Docker

Learn Docker step by step — simple English, real diagrams, real Node.js and React examples. Start from "why does Docker exist" and build up to production-ready images.

Lessons

1. Why Docker Exists — The works-on-my-machine problem, VMs vs containers, the shared kernel, and how images travel through Docker Hub.
2. Dockerfile Instructions Explained — All 13 instructions from FROM to VOLUME, what Docker does internally at each line, and the classic interview pairs.
3. Docker Commands Cheat Sheet — The essential commands as one image's journey: build → images → run -p → ps → stop → rm/rmi → prune, plus the login → push flow and .dockerignore.
4. Install Docker on AWS EC2 — Launch an Ubuntu EC2 instance, install Docker with 8 commands, run the React app with -d -p, open the security group, and go live on a public IP.
5. Docker Network Types — bridge, host, none, overlay, and macvlan with clear IP diagrams, why custom bridges let containers talk by name, and all 5 docker network commands.
6. Docker Volumes — Watch MongoDB lose its data without a volume, then fix it: named vs anonymous volumes vs bind mounts, where the data really lives, and all 4 docker volume commands.
7. Docker Compose — Run a real 3-container app (client + API + MongoDB) from one docker-compose.yml: the file explained line by line, service names as addresses, and up / down / ps / logs.
8. Docker Swarm — Turn three EC2 machines into one cluster: what a cluster is, manager vs worker nodes, the security group ports, swarm init, the join token, and docker node ls.

New to Docker? Start with Why Docker Exists — everything else builds on it.