Docker Commands Cheatsheet for Developers

Docker is now a prerequisite for professional development. Whether you're running local databases, packaging apps for deployment, or working with microservices, these are the commands you'll reach for daily.

Images

# Pull an image
docker pull node:20-alpine
docker pull postgres:16

# List local images
docker images
docker image ls

# Build an image
docker build -t myapp:1.0 .                    # from Dockerfile in current dir
docker build -t myapp:1.0 -f docker/Dockerfile . # from specific file
docker build --no-cache -t myapp .             # ignore build cache

# Remove images
docker rmi myapp:1.0
docker image prune         # remove dangling (untagged) images
docker image prune -a      # remove ALL unused images

# Push to registry
docker tag myapp:1.0 username/myapp:1.0
docker push username/myapp:1.0

Containers

# Run a container
docker run node:20-alpine                         # run and exit
docker run -d nginx                               # detached (background)
docker run -it ubuntu bash                        # interactive terminal
docker run --rm alpine echo hello                 # remove when done
docker run -p 3000:3000 myapp                     # map host:container port
docker run -p 127.0.0.1:3000:3000 myapp           # bind to localhost only
docker run -e NODE_ENV=production myapp           # env variable
docker run --env-file .env myapp                  # env from file
docker run -v $(pwd):/app -w /app node:20 npm test # mount volume
docker run --name mycontainer myapp               # custom name

# List containers
docker ps                  # running
docker ps -a               # all (including stopped)
docker ps --format 'table {{.Names}}\t{{.Status}}\t{{.Ports}}'

# Start/stop/restart
docker start mycontainer
docker stop mycontainer    # graceful (SIGTERM, then SIGKILL after 10s)
docker kill mycontainer    # immediate (SIGKILL)
docker restart mycontainer

# Remove
docker rm mycontainer
docker rm -f mycontainer   # force remove running container
docker container prune     # remove all stopped containers

Debugging

# Execute commands inside a running container
docker exec -it mycontainer bash
docker exec -it mycontainer sh   # if no bash
docker exec mycontainer ls /app

# View logs
docker logs mycontainer
docker logs -f mycontainer         # follow (tail)
docker logs --tail 100 mycontainer # last 100 lines
docker logs --since 1h mycontainer # since 1 hour ago

# Inspect container
docker inspect mycontainer
docker inspect mycontainer | jq '.[0].NetworkSettings.IPAddress'

# Resource usage
docker stats                        # live stats for all containers
docker stats mycontainer
docker top mycontainer              # processes inside

# Copy files
docker cp mycontainer:/app/config.json ./config.json
docker cp ./local.txt mycontainer:/app/

Volumes

# Named volumes (persisted, managed by Docker)
docker volume create pgdata
docker run -v pgdata:/var/lib/postgresql/data postgres:16

# Bind mounts (host directory → container)
docker run -v /host/path:/container/path myapp
docker run -v $(pwd):/app myapp    # current directory

# Volume management
docker volume ls
docker volume inspect pgdata
docker volume rm pgdata
docker volume prune               # remove unused volumes

Docker Compose

# docker-compose.yml
version: '3.9'
services:
  app:
    build: .
    ports:
      - '3000:3000'
    environment:
      - DATABASE_URL=postgresql://postgres:password@db:5432/mydb
    depends_on:
      db:
        condition: service_healthy
    volumes:
      - .:/app
      - /app/node_modules  # prevent overwriting node_modules

  db:
    image: postgres:16
    environment:
      POSTGRES_PASSWORD: password
      POSTGRES_DB: mydb
    volumes:
      - pgdata:/var/lib/postgresql/data
    healthcheck:
      test: ['CMD-SHELL', 'pg_isready -U postgres']
      interval: 5s
      timeout: 5s
      retries: 5

volumes:
  pgdata:

docker compose up -d           # start all services in background
docker compose down            # stop and remove containers
docker compose down -v         # also remove volumes
docker compose logs -f app     # follow logs for 'app' service
docker compose exec app bash   # shell into 'app' service
docker compose ps              # status of all services
docker compose build --no-cache # rebuild images
docker compose pull            # pull latest images

Clean Up

# Nuclear option — remove everything
docker system prune -a --volumes

# More surgical
docker container prune  # stopped containers
docker image prune -a   # unused images
docker volume prune     # unused volumes
docker network prune    # unused networks

# Check disk usage
docker system df

Dockerfile Best Practices

# Use specific version tags, not 'latest'
FROM node:20.11-alpine

# Set working directory
WORKDIR /app

# Copy dependency files first (better layer caching)
COPY package.json package-lock.json ./
RUN npm ci --only=production

# Then copy source (changes frequently → later layer)
COPY . .

# Run as non-root user
RUN adduser -D appuser
USER appuser

EXPOSE 3000
CMD ["node", "server.js"]