Docker Cheat Sheet

Table of Contents

• 1. Installation
• 1. Container Commands
• 1. Executing Commands in a Container
• 1. Image Commands
• 1. Container Registry Commands
• 1. System Commands
• 1. Docker Compose
• 1. Dockerfile Instructions
• 1. Docker Compose File Reference

Container Commands

	Example
Create and run a new container docker run	docker run nginx
Publish container port 80 to host port 8080 docker run -p 8080:80	docker run -p 8080:80 nginx
Run a container in the background docker run -d	docker run -d nginx
Mount a host directory to a container docker run -v :	docker run -v /home/user/app:/usr/share/nginx/html nginx
List currently running containers docker ps	docker ps
List all containers (running or stopped) docker ps --all	docker ps --all
Fetch the logs of a container docker logs	docker logs my_nginx
Fetch and follow the logs of a container docker logs -f	docker logs -f my_nginx
Stop a running container docker stop	docker stop my_nginx
Start a stopped container docker start	docker start my_nginx
Remove a container docker rm	docker rm my_nginx

Executing Commands in a Container

	Example
Execute a command in a running container docker exec	docker exec my_nginx ls /usr/share/nginx/html
Open a shell in a running container docker exec -it bash	docker exec -it my_nginx bash

Image Commands

	Example
Build a new image from the Dockerfile in the current directory and tag it docker build -t .	docker build -t myapp:1.0 .
List local images docker images	docker images
Remove an image docker rmi	docker rmi myapp:1.0

Container Registry Commands

	Example
Login to Docker Hub docker login	docker login
Login to another container registry docker login	docker login registry.example.com
Logout of Docker Hub docker logout	docker logout
Logout of another container registry docker logout	docker logout registry.example.com
Upload an image to a registry docker push	docker push myusername/myapp:1.0
Download an image from a registry docker pull	docker pull nginx:latest
Search Docker Hub for images docker search	docker search nginx

System Commands

	Example
Show Docker disk usage docker system df	docker system df
Remove unused data docker system prune	docker system prune
Remove all unused data docker system prune -a	docker system prune -a

Docker Compose

	Example
Create and start containers docker compose up	docker compose up
Create and start containers in background docker compose up -d	docker compose up -d
Rebuild images before starting containers docker compose up --build	docker compose up --build
Stop services docker compose stop	docker compose stop
Stop and remove containers and networks docker compose down	docker compose down
List running containers docker compose ps	docker compose ps
View the logs of all containers docker compose logs	docker compose logs
View the logs of a specific service docker compose logs	docker compose logs web
View and follow the logs docker compose logs -f	docker compose logs -f web
Pull the latest images docker compose pull	docker compose pull
Build or rebuild services docker compose build	docker compose build
Pull latest images before building docker compose build --pull	docker compose build --pull

Dockerfile Instructions

	Example
Set the base image FROM	FROM ubuntu:22.04
Set the base image and name the build stage FROM AS	FROM node:18 AS builder
Execute a command as part of the build process RUN	RUN apt-get update &6 apt-get install -y curl
Execute a command as part of the build process RUN ["exec", “parami", "param2"]	RUN ["npm", "“install"]
Execute a command when the container starts CMD ["exec", "parami", "param2"]	CMD ["node", “app.js"]
Configure the container to run as an executable ENTRYPOINT ["exec", "parami"]	ENTRYPOINT ["docker-entrypoint.sh"]
Set an environment variable ENV =	ENV NODE_ENV=production
Expose a port EXPOSE	EXPOSE 3000
Copy files from source to destination COPY	COPY . /app
Copy files from a build stage to destination COPY --from=	COPY --from=builder /app/dist /app
Set the working directory WORKDIR <WORKDIR /app
Create a mount point VOLUME	VOLUME /data
Set the user USER	USER node
Define a build argument ARG	ARG VERSION
Define a build argument with a default value ARG =	ARG VERSION=1.0
Set a metadata label LABEL =	LABEL maintainer="youdexample.com"
Set a healthcheck command HEALTHCHECK	HEALTHCHECK CMD curl -f http://localhost:3000/

Docker Compose File Reference

	Example
Set the name of the project name	name: myproject
A list of services defined in the file services	services: web: image: nginx
Set the image to use or build services..image	image: nginx: latest
Build context and options services..build	build: .
Build context (default is the current directory) services..build.context	context: ./app
Dockerfile to use (default is Dockerfile) services..build.dockerfile	dockerfile: Dockerfile.dev
Build stage to use services..build.target	target: builder
Build arguments services..build.args	args: VERSION: 1.0
Override the default command for the container services..command	command: npm start
Override the default entrypoint for the container services..entrypoint	entrypoint: /bin/sh
Mount volumes in the container services.. volumes	volumes: - ./data:/data
Publish container ports to the host services..ports	ports: - "8080:80"
Set environment variables in the container services..environment	environment: - NODE_ENV=production
Restart policy (no/always/on-failure/unless-stopped) services..restart	restart: always
Set the number of containers to run services..scale	scale: 3
List of networks to connect the container to services..networks	networks: - frontend
List of services to start before this service services..depends_on	depends_on: - db
Set metadata labels for the container services..labels	labels: - com.example.description=My app
A list of networks defined in the file networks	networks: - frontend
Set the network driver networks..driver	driver: bridge
Don't create the network, use an existing one networks..external	external: true
A list of volumes defined in the file volumes	volumes: db_data:
Set the name of the volume volumes..name	name: myvolume
Set the volume driver volumes..driver	driver: local
A list of configs defined in the file configs	configs: my_config: file: ./config.yml
A list of secrets defined in the file secrets	secrets: db_password: file: ./db_password.txt