Docker Cheat Sheet

docker images
docker image ls

docker pull nginx
docker pull nginx:1.25

docker build -t myapp:1.0 .
docker build -f Dockerfile.dev -t myapp:dev .

docker rmi nginx
docker rmi $(docker images -q)  # All images

docker tag myapp:1.0 registry.com/myapp:1.0

docker push registry.com/myapp:1.0

docker run nginx
docker run -d nginx           # Detached
docker run -it ubuntu bash    # Interactive

docker run -d \
  --name web \
  -p 8080:80 \
  -v ./html:/usr/share/nginx/html \
  -e ENV_VAR=value \
  nginx

docker ps                     # Running
docker ps -a                  # All

docker stop container_name
docker start container_name
docker restart container_name

docker rm container_name
docker rm -f container_name   # Force
docker container prune        # All stopped

docker exec -it container_name bash
docker exec container_name ls /app

FROM node:18-alpine
WORKDIR /app
COPY package*.json ./
RUN npm install
COPY . .
EXPOSE 3000
CMD ["npm", "start"]

# Build stage
FROM node:18 AS builder
WORKDIR /app
COPY . .
RUN npm run build

# Production stage
FROM nginx:alpine
COPY --from=builder /app/dist /usr/share/nginx/html

ARG NODE_ENV=production
ENV NODE_ENV=${NODE_ENV}
ENV PORT=3000

# ENTRYPOINT: always runs
ENTRYPOINT ["node"]
# CMD: default args, can override
CMD ["app.js"]

HEALTHCHECK --interval=30s --timeout=3s \
  CMD curl -f http://localhost/ || exit 1

services:
  web:
    build: .
    ports:
      - "8080:80"
    volumes:
      - ./src:/app/src
    environment:
      - NODE_ENV=development

services:
  app:
    build: .
    ports:
      - "3000:3000"
    depends_on:
      - db
  db:
    image: postgres:15
    environment:
      POSTGRES_PASSWORD: secret
    volumes:
      - db_data:/var/lib/postgresql/data

volumes:
  db_data:

docker compose up             # Start
docker compose up -d          # Detached
docker compose up --build     # Rebuild
docker compose down           # Stop & remove
docker compose logs -f        # Follow logs

docker compose up -d --scale worker=3

docker volume create mydata

docker volume ls

docker run -v mydata:/app/data nginx
docker run -v ./local:/app/data nginx

docker network create mynet

docker run --network mynet nginx
docker network connect mynet container_name

docker volume inspect mydata
docker network inspect mynet

docker container prune

docker image prune

docker system prune
docker system prune -a  # Include unused images

docker system df