Docker packages applications and their dependencies into portable containers. This reference covers the commands you use daily for building images, managing containers, handling data with volumes, and orchestrating multi-container apps with Docker Compose.
Images
Images are read-only templates used to create containers.
# Build an image
docker build -t myapp:latest . # Build from Dockerfile in current dir
docker build -t myapp:v1.0 -f Dockerfile.prod . # Use a specific Dockerfile
docker build --no-cache -t myapp . # Build without cache
docker build --target builder -t myapp . # Multi-stage: build specific target
docker build --build-arg NODE_ENV=production -t myapp . # Pass build arguments
# List images
docker images # List all local images
docker images -q # List image IDs only
docker images --filter "dangling=true" # List untagged images
# Pull and push
docker pull nginx:alpine # Pull from registry
docker push myrepo/myapp:latest # Push to registry
docker tag myapp:latest myrepo/myapp:v1.0 # Tag an image
# Remove images
docker rmi myapp:latest # Remove an image
docker rmi $(docker images -q -f dangling=true) # Remove dangling images
docker image prune # Remove unused images
docker image prune -a # Remove all unused images
# Inspect
docker image inspect myapp:latest # Detailed image info
docker history myapp:latest # Show image layersContainers
Containers are running instances of images.
# Run containers
docker run nginx # Run in foreground
docker run -d nginx # Run in background (detached)
docker run -d --name web nginx # Run with a name
docker run -d -p 8080:80 nginx # Map host:container ports
docker run -d -p 3000:3000 -p 3001:3001 app # Map multiple ports
docker run -d -e NODE_ENV=production app # Set environment variable
docker run -d --env-file .env app # Load env vars from file
docker run -d -v /host/path:/container/path app # Bind mount
docker run -d -v mydata:/data app # Named volume
docker run -d --restart unless-stopped app # Restart policy
docker run -it ubuntu bash # Interactive terminal
docker run --rm -it node:20 node # Auto-remove when stopped
docker run -d --network mynet app # Connect to a network
docker run -d --memory="512m" --cpus="1.5" app # Resource limits
# List containers
docker ps # Running containers
docker ps -a # All containers (including stopped)
docker ps -q # Container IDs only
docker ps --format "table {{.Names}}\t{{.Status}}\t{{.Ports}}" # Custom format
# Container lifecycle
docker start <container> # Start a stopped container
docker stop <container> # Graceful stop (SIGTERM)
docker restart <container> # Stop and start
docker kill <container> # Force stop (SIGKILL)
docker pause <container> # Freeze container
docker unpause <container> # Unfreeze container
docker rm <container> # Remove a stopped container
docker rm -f <container> # Force remove (even if running)
docker container prune # Remove all stopped containers
# Interact with running containers
docker exec -it <container> bash # Open a shell
docker exec -it <container> sh # Alpine/minimal images
docker exec <container> ls /app # Run a single command
docker logs <container> # View logs
docker logs -f <container> # Follow logs (live)
docker logs --tail 100 <container> # Last 100 lines
docker logs --since 1h <container> # Logs from last hour
docker top <container> # Running processes
docker stats # Live resource usage for all
docker stats <container> # Resource usage for one
# Copy files
docker cp file.txt <container>:/path/ # Host to container
docker cp <container>:/path/file.txt ./ # Container to host
# Inspect
docker inspect <container> # Full container details
docker inspect -f '{{.NetworkSettings.IPAddress}}' <container> # Specific field
docker port <container> # Show port mappingsVolumes
Volumes persist data beyond container lifecycle.
# Create and manage
docker volume create mydata # Create a named volume
docker volume ls # List volumes
docker volume inspect mydata # Volume details
docker volume rm mydata # Remove a volume
docker volume prune # Remove unused volumes
# Use volumes
docker run -d -v mydata:/app/data app # Named volume
docker run -d -v /host/path:/app/data app # Bind mount
docker run -d -v mydata:/app/data:ro app # Read-only mount
# Backup a volume
docker run --rm -v mydata:/data -v $(pwd):/backup \
alpine tar czf /backup/data-backup.tar.gz -C /data .
# Restore a volume
docker run --rm -v mydata:/data -v $(pwd):/backup \
alpine tar xzf /backup/data-backup.tar.gz -C /dataNetworks
Networks let containers communicate with each other.
# Create and manage
docker network create mynet # Create bridge network
docker network create --driver overlay mynet # Overlay network (Swarm)
docker network ls # List networks
docker network inspect mynet # Network details
docker network rm mynet # Remove a network
docker network prune # Remove unused networks
# Connect containers
docker network connect mynet <container> # Add container to network
docker network disconnect mynet <container> # Remove from network
# Run on a specific network
docker run -d --network mynet --name api app
docker run -d --network mynet --name db postgres
# 'api' container can reach 'db' at hostname 'db'Docker Compose
Compose defines multi-container applications in a docker-compose.yml file.
# Lifecycle
docker compose up # Start all services
docker compose up -d # Start in background
docker compose up --build # Rebuild images first
docker compose up -d --scale web=3 # Scale a service
docker compose down # Stop and remove containers
docker compose down -v # Also remove volumes
docker compose down --rmi all # Also remove images
# Management
docker compose ps # List running services
docker compose logs # View all logs
docker compose logs -f web # Follow logs for one service
docker compose exec web bash # Shell into a service
docker compose run --rm web npm test # Run a one-off command
# Build
docker compose build # Build all services
docker compose build --no-cache web # Rebuild without cache
docker compose pull # Pull latest images
# Config
docker compose config # Validate and view config
docker compose config --services # List service namesExample docker-compose.yml
services:
web:
build: .
ports:
- "3000:3000"
environment:
- NODE_ENV=production
- DATABASE_URL=postgres://db:5432/myapp
depends_on:
- db
- redis
volumes:
- ./src:/app/src
restart: unless-stopped
db:
image: postgres:16-alpine
volumes:
- pgdata:/var/lib/postgresql/data
environment:
POSTGRES_DB: myapp
POSTGRES_PASSWORD: secret
ports:
- "5432:5432"
redis:
image: redis:7-alpine
ports:
- "6379:6379"
volumes:
pgdata:System Cleanup
# View disk usage
docker system df # Disk usage summary
docker system df -v # Detailed breakdown
# Clean up everything
docker system prune # Remove stopped containers, unused networks, dangling images
docker system prune -a # Also remove unused images
docker system prune -a --volumes # Nuclear option: everything unused
# Selective cleanup
docker container prune # Remove stopped containers
docker image prune # Remove dangling images
docker volume prune # Remove unused volumes
docker network prune # Remove unused networksUseful Patterns
# Quick database for development
docker run -d --name postgres \
-e POSTGRES_PASSWORD=dev \
-p 5432:5432 \
-v pgdata:/var/lib/postgresql/data \
postgres:16-alpine
# Quick Redis
docker run -d --name redis -p 6379:6379 redis:7-alpine
# Run a one-off command in a fresh container
docker run --rm -it node:20 node -e "console.log(process.version)"
# Check what's using disk space
docker system df -v
# Follow all container logs
docker compose logs -f --tail=50Generate Dockerfiles with the Dockerfile Generator or Compose files with the Docker Compose Generator.