🐳 Docker Mastery — From Zero to Deployment

A complete, hands-on guide to Docker. Every section is a standalone reference you can return to anytime.

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🗺️ Learning Path

#	Topic	What You'll Learn
1	Docker Fundamentals	Architecture, Engine, Lifecycle, Registry
2	Writing Dockerfiles	Instructions, best practices, layering
3	Multistage Builds & Distroless	Slim images, build optimization
4	Networking	Bridge, host, custom networks, DNS
5	Storage — Bind Mounts & Volumes	Persistence, data sharing
6	Real-World Deployment on EC2	Django app, EC2 setup, public access

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⚡ Most-Used Commands

# Run a container
docker run -d -p 8080:80 --name my-nginx nginx

# See running containers
docker ps

# See all containers (including stopped)
docker ps -a

# View logs
docker logs my-nginx

# Shell into a running container
docker exec -it my-nginx bash

# Build an image
docker build -t myapp:latest .

# Stop and remove a container
docker stop my-nginx
docker rm my-nginx

# List images
docker images

# Remove an image
docker rmi myapp:latest

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🧠 Key Mental Models

Images vs Containers — an image is a blueprint (like a class), a container is a running instance (like an object).

Layers — every Dockerfile instruction adds a layer. Layers are cached. Put things that change least (dependencies) before things that change most (your code).

The Daemon — dockerd runs in the background doing all the work. The docker CLI just sends it instructions.

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📄 Also in this repo

• docs/cheatsheet.md — all commands in one place