Author: Ifraaz

Container runtime essentials – build, run, manage, and orchestrate
All commands assume Docker Engine is installed and running.
Use sudo if not in docker group: sudo usermod -aG docker $USER → relogin.

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1. Setup & Info

Task	Command
Check version	docker --version
Docker info	docker info
Test installation	docker run hello-world
Enable/start Docker	sudo systemctl enable --now docker
Add user to docker group	sudo usermod -aG docker $USER
View Docker disk usage	docker system df

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2. Images

Action	Command
Search image	docker search nginx
Pull image	docker pull nginx:latest
List images	docker images or docker image ls
Remove image	docker rmi nginx
Remove dangling	docker image prune
Remove all unused	docker image prune -a
Build from Dockerfile	docker build -t myapp:1.0 .
Tag image	docker tag myapp:1.0 username/myapp:1.0
Push to registry	docker push username/myapp:1.0
Inspect image	docker image inspect nginx

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3. Containers

Action	Command
Run container	docker run nginx
Run detached	docker run -d --name web nginx
Run with port	docker run -d -p 8080:80 --name web nginx
Run interactive	docker run -it ubuntu bash
List running	docker ps
List all (incl. stopped)	docker ps -a
Stop container	docker stop web
Start stopped	docker start web
Restart	docker restart web
Remove container	docker rm web
Remove all stopped	docker container prune
Attach to running	docker attach web
Exec into container	docker exec -it web bash
View logs	docker logs web
Follow logs	docker logs -f web
Stats (CPU/RAM)	docker stats
Inspect container	docker inspect web

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4. Volumes & Bind Mounts

Type	Command
Volume (managed)	docker run -v myvol:/data ubuntu
Create volume	docker volume create myvol
List volumes	docker volume ls
Inspect volume	docker volume inspect myvol
Remove volume	docker volume rm myvol
Bind mount	docker run -v /host/path:/container/path ubuntu
Read-only	docker run -v /data:/app:ro nginx

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5. Networks

Action	Command
List networks	docker network ls
Create bridge	docker network create mynet
Run in network	docker run --network mynet --name db -d mysql
Connect container	docker network connect mynet web
Disconnect	docker network disconnect mynet web
Inspect	docker network inspect bridge

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6. Dockerfile Essentials

# syntax: docker/dockerfile:1
FROM ubuntu:22.04
LABEL maintainer="you@example.com"

# Update & install
RUN apt update && apt install -y curl vim

# Copy files
COPY app.py /app/
ADD https://example.com/file.tar.gz /tmp/

# Set workdir
WORKDIR /app

# Expose port
EXPOSE 8000

# Environment
ENV DEBUG=true

# Run command
CMD ["python3", "app.py"]

Build: docker build -t myapp .
Run: docker run -p 8000:8000 myapp

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7. Docker Compose (v2+)

Install: sudo apt install docker-compose-plugin or download binary

# docker-compose.yml
version: '3.8'
services:
  web:
    image: nginx:latest
    ports:
      - "8080:80"
    volumes:
      - ./html:/usr/share/nginx/html
    depends_on:
      - db
  db:
    image: mysql:8
    environment:
      MYSQL_ROOT_PASSWORD: secret
    volumes:
      - db-data:/var/lib/mysql
volumes:
  db-data:

Command	Action
docker compose up -d	Start in background
docker compose down	Stop & remove
docker compose logs -f	Follow logs
docker compose ps	List services
docker compose build	Build images
docker compose exec web bash	Shell into service

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8. Resource Management

Task	Command
Limit CPU	docker run --cpus="1.5" ubuntu
Limit memory	docker run -m 512m ubuntu
Restart policy	docker run --restart=unless-stopped nginx
Healthcheck	Add HEALTHCHECK CMD curl -f http://localhost/ || exit 1 in Dockerfile

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9. Cleanup & Prune

# Remove all stopped containers, unused networks, dangling images
docker system prune -a

# Remove all containers
docker rm -f $(docker ps -aq)

# Remove all images
docker rmi -f $(docker images -q)

# Remove all volumes
docker volume prune

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10. Docker Hub & Registry

Action	Command
Login	docker login
Logout	docker logout
Push	docker push username/app:tag
Run from private	docker run username/app:tag

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11. Debug & Inspect

Tool	Command
Container processes	docker top web
Resource usage	docker stats
Events stream	docker events
Image history	docker history nginx
Diff (changed files)	docker diff web
Export container	docker export web > web.tar
Import as image	cat web.tar | docker import - newimage

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12. One-Liners

# Run Ubuntu with bash
docker run -it --rm ubuntu bash

# Quick web server
docker run -d -p 80:80 --name web --restart always nginx

# Shell into running container
docker exec -it web sh

# Build and run in one line
docker build -t myapp . && docker run -p 5000:5000 myapp

# Cleanup everything
docker system prune -a --volumes

# Monitor logs + stats
docker stats & docker logs -f web

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13. Best Practices

• Use official images when possible
• Use specific tags (nginx:1.25), avoid :latest in prod
• Multi-stage builds for smaller images
• .dockerignore to speed up builds
• Non-root user in Dockerfile:

  RUN useradd -m appuser
  USER appuser

• Scan images: trivy image nginx

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14. Useful Tools

# Install
sudo apt install docker-compose-plugin trivy

# Scan for vulnerabilities
trivy image python:3.11

# Dive into image layers
dive nginx:latest

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15. Docker Desktop (GUI)

• Linux: Install via docs.docker.com
• Features: GUI, Kubernetes, Compose, Volume management

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16. Kubernetes Quick Start (kind)

# Install kind
curl -Lo ./kind https://kind.sigs.k8s.io/dl/v0.20.0/kind-linux-amd64
chmod +x kind && sudo mv kind /usr/local/bin/

# Create cluster
kind create cluster --name mycluster

# Use kubectl
kubectl get nodes

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Resources

• Official Docs: https://docs.docker.com
• Play with Docker: https://labs.play-with-docker.com
• Docker Hub: https://hub.docker.com

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