Docker Cheat Sheet

Table of Contents

• 1 Most Common Steps
  • 1.1 Running a single service container
  • 1.2 Running a single interactive container
  • 1.3 Running multiple service containers (with docker compose)
  • 1.4 Running multiple interactive containers (manual approach)
  • 1.5 Key differences summary
  • 1.6 Editing the content of the image
  • 1.7 Containerizing an Application with Docker Build (Only Build)
  • 1.8 Containerizing an Application with Docker Compose (Build and Runs)
  • 1.9 Sharing a Docker Image
    • 1.9.1 Docker Hub for Public
    • 1.9.2 Private Registry
    • 1.9.3 Save as a File
    • 1.9.4 Share Dockerfile
• 2 Commands
  • 2.1 Working with Containers
  • 2.2 Getting Container Information
  • 2.3 Transferring Files
  • 2.4 Pulling Images from Registries
  • 2.5 Managing Images
  • 2.6 Inspecting Images
  • 2.7 Sharing Images via Registry
  • 2.8 Sharing Images via Files
  • 2.9 Running Containers - Service Mode
  • 2.10 Running Containers - Interactive Mode
  • 2.11 Working with Volumes
  • 2.12 Mounting Volumes
  • 2.13 Working with Networks
  • 2.14 Starting Multi-Container Applications
  • 2.15 Managing Running Services
  • 2.16 Working with Services
  • 2.17 Stopping Multi-Container Applications
  • 2.18 Rebuilding Services
  • 2.19 Other Compose Operations
  • 2.20 Scanning for Vulnerabilities
  • 2.21 Checking System Resources
  • 2.22 Cleaning Up Everything
  • 2.23 Bulk Container Operations
  • 2.24 Troubleshooting and Debugging

require(reticulate)

1 Most Common Steps

1.1 Running a single service container

docker run --name nginx1 -d -p 8080:80 nginx:latest
# Access at: http://localhost:8080

# Management commands
docker ps                    # Check running containers
docker logs nginx1           # View logs
docker logs -f nginx1        # Follow logs (live)
docker stop nginx1           # Stop the container
docker start nginx1          # Start it again
docker restart nginx1        # Restart the container
docker rm nginx1             # Remove (must stop first)
docker rm -f nginx1          # Force remove (even if running)

1.2 Running a single interactive container

# Start interactive container
docker run --name ubuntu1 -it ubuntu:latest bash

# Inside container
exit  # Exit and STOP the container

# Restart stopped container
docker start ubuntu1  # Starts but doesn't attach

# Re-enter the container (SAFE - recommended)
docker exec -it ubuntu1 bash
exit  # Exit but container keeps running ✅

# Alternative: attach to main process (RISKY)
docker attach ubuntu1
# Ctrl+P, Ctrl+Q  # Detach safely
# OR
exit  # This STOPS the container ❌

# Management
docker stop ubuntu1           # Stop
docker start ubuntu1          # Start again
docker restart ubuntu1        # Restart
docker rm ubuntu1             # Remove when done
docker rm -f ubuntu1          # Force remove

1.3 Running multiple service containers (with docker compose)

# Directory structure:
# project/
# ├── compose.yaml
# ├── Dockerfile (optional, for custom apps)
# └── app files

# Example compose.yaml for multi-service app:
# services:
#   web:
#     build: .
#     ports:
#       - "5001:8080"
#     networks:
#       - app-net
#   redis:
#     image: redis:alpine
#     networks:
#       - app-net
#     volumes:
#       - redis-data:/data
# networks:
#   app-net:
# volumes:
#   redis-data:

# Start all services
docker compose up -d              # Detached mode
docker compose up --build         # Rebuild images first
docker compose up -d --build      # Both

# View status
docker compose ps                 # List services
docker compose logs               # View all logs
docker compose logs -f            # Follow logs (live)
docker compose logs web           # Logs for specific service

# Stop services
docker compose stop               # Stop (containers remain)
docker compose down               # Stop and remove containers/networks
docker compose down -v            # Also remove volumes (deletes data!)

# Restart services
docker compose restart            # Restart all
docker compose restart web        # Restart specific service

# Execute commands in running services
docker compose exec web bash      # Enter web service container
docker compose exec redis redis-cli  # Run Redis CLI

# Scale services (run multiple instances)
docker compose up -d --scale web=3   # Run 3 instances of web

# View logs for specific service
docker compose logs -f web

1.4 Running multiple interactive containers (manual approach)

# Create custom network for containers to communicate
docker network create mynetwork

# Start first interactive container
docker run -it --name ubuntu1 --network mynetwork ubuntu:latest bash
# Ctrl+P, Ctrl+Q to detach without stopping

# Start second interactive container
docker run -it --name ubuntu2 --network mynetwork ubuntu:latest bash
# Ctrl+P, Ctrl+Q to detach without stopping

# Containers can now communicate with each other
docker exec -it ubuntu1 bash
ping ubuntu2  # Can ping by container name!
exit

# Re-enter any container
docker exec -it ubuntu1 bash
docker exec -it ubuntu2 bash

# Clean up
docker stop ubuntu1 ubuntu2
docker rm ubuntu1 ubuntu2
docker network rm mynetwork

# NOTE: For multiple containers, docker compose is much easier!
# Use the "multiple service containers" approach above instead.

1.5 Key differences summary

# Single container:
docker run              # Manual, one container at a time

# Multiple containers:
docker compose          # Automated, orchestrates multiple containers

# Interactive vs Service:
-it                     # Interactive (terminal access)
-d                      # Detached/daemon (runs in background)

# Entering containers:
docker exec -it         # SAFE - new process, won't stop container
docker attach           # RISKY - connects to main process, exit stops container

# Port mapping:
-p HOST:CONTAINER       # 8080:80 means localhost:8080 → container:80

1.6 Editing the content of the image

docker exec -it webserver sh # enter the running container
vi views/home.pug # edit a file (example)
i # press i to enter insert mode in vi
Esc # press Esc to exit insert mode
:wq # type :wq and press Enter to save and exit vi
exit # exit the container

1.7 Containerizing an Application with Docker Build (Only Build)

# Downloading
git clone ...
cd ...

# Building
docker build -t myprd:latest .
docker run --name myprd -d -p 8000:8000 myprd:latest

# Removing
docker stop myprd
docker rm myprd
docker rmi myprd:latest

1.8 Containerizing an Application with Docker Compose (Build and Runs)

# Downloading
git clone ...
cd ...

# Building
docker init
docker compose up -d # to start the application in detached mode
docker compose logs # to view logs

# Removing
docker compose down # to stop and remove the application containers
docker rmi myapp:latest

1.9 Sharing a Docker Image

1.9.1 Docker Hub for Public

# Maker
docker login
docker tag myapp:latest yourdockerhubusername/myapp:latest
docker push yourdockerhubusername/myapp:latest

# Downloader
docker pull yourdockerhubusername/myapp:latest
docker run --name myapp -d -p 8080:80 yourdockerhubusername/myapp:latest

1.9.2 Private Registry

# Maker
## Tag with ghcr.io
docker tag node-app-server:latest ghcr.io/YOUR_GITHUB_USERNAME/node-app-server:latest

## Login to GitHub
echo $GITHUB_TOKEN | docker login ghcr.io -u YOUR_GITHUB_USERNAME --password-stdin

## Push
docker push ghcr.io/YOUR_GITHUB_USERNAME/node-app-server:latest

1.9.3 Save as a File

# Maker
docker save -o myapp_latest.tar myapp:latest

# Downloader
docker load -i myapp_latest.tar
docker run --name myapp -d -p 8080:80 myapp:latest

1.9.4 Share Dockerfile

# Maker
# Share the Dockerfile and compose.yaml and any necessary files via email, GitHub, etc.

# Downloader
docker compose up --build

2 Commands

2.1 Working with Containers

docker ps                             # Check what's running
docker ps -a                          # See all (-a) containers including stopped
docker logs test                      # View container output
docker logs -f test                   # Follow (-f) logs in real-time
docker logs --tail 50 test            # View last (--tail) 50 lines only
docker logs -t test                   # Show timestamps (-t) in logs
docker exec -it test bash             # Enter container with interactive (-i) terminal (-t)
docker exec test ls -la /app          # Run command without entering
docker exec -u root -it test bash     # Enter as user (-u) root
docker attach test                    # Attach to main process (risky)
docker stop test                      # Stop a container
docker start test                     # Start a stopped container
docker restart test                   # Restart a container
docker rm test                        # Remove a stopped container
docker rm -f test                     # Force (-f) remove running container
docker rename old-name new-name       # Rename a container
docker pause test                     # Pause a container
docker unpause test                   # Unpause a container

2.2 Getting Container Information

docker inspect test                   # Full container details
docker inspect test | Select-String -Pattern 'Mounts' -Context 0,10  # Filter (PowerShell)
docker inspect test | grep -A 10 "Mounts"                             # Filter (Bash/Linux)
docker inspect --format='{{.NetworkSettings.IPAddress}}' test         # Get IP using format (--format)
docker inspect --format='{{.State.Status}}' test                      # Get status using format
docker inspect --format='{{.State.ExitCode}}' test                    # Get exit code using format
docker port test                      # Show port mappings
docker top test                       # View running processes
docker stats                          # Monitor resource usage (all)
docker stats test                     # Monitor specific container
docker diff test                      # See filesystem changes
docker export test > test.tar         # Export container filesystem

2.3 Transferring Files

docker cp test:/app/file.txt ./file.txt     # Copy (cp) from container to host
docker cp ./file.txt test:/app/file.txt     # Copy (cp) from host to container

2.4 Pulling Images from Registries

docker pull nginx:latest              # Pull from official Docker Hub
docker pull nigelpoulton/tu-demo:v2   # Pull from user registry (Docker Hub)
docker pull ghcr.io/regclient/regsync:latest  # Pull from GitHub Container Registry
docker pull myregistry.com/app:v1     # Pull from custom registry

2.5 Managing Images

docker images                         # List all local images
docker build -t myapp:v1 .            # Build with tag (-t) from current directory (.)
docker build -t myapp:v1 -f custom.Dockerfile .  # Use file (-f) custom Dockerfile
docker tag myapp:v1 username/myapp:v1 # Tag for registry
docker rmi nginx:latest               # Remove (rmi) an image
docker rmi $(docker images -q)        # Remove all images using quiet (-q) output
docker image prune                    # Remove dangling images
docker image prune -a                 # Remove all (-a) unused images
docker history nginx:latest           # View image layers

2.6 Inspecting Images

docker inspect nginx:latest           # Full image details
docker inspect nginx:latest | Select-String -Pattern 'Entrypoint' -Context 0,3  # Filter (PowerShell)
docker inspect nginx:latest | grep -A 3 "Entrypoint"                             # Filter (Bash/Linux)

2.7 Sharing Images via Registry

docker login                          # Login to Docker Hub
docker login ghcr.io                  # Login to custom registry
docker push username/myapp:v1         # Push to registry
docker logout                         # Logout from registry

2.8 Sharing Images via Files

docker save -o myapp.tar myapp:v1     # Save to output (-o) file
docker save myapp:v1 | gzip > myapp.tar.gz    # Save and compress with gzip
docker load -i myapp.tar              # Load from input (-i) file
docker load -i myapp.tar.gz           # Load from compressed input (-i) file
docker import myapp.tar myapp:imported  # Import from exported container

2.9 Running Containers - Service Mode

docker run --name test -d -p 8080:80 nginx:latest     # Detached (-d) with port (-p) mapping
docker run -e NODE_ENV=production -d myapp:latest     # With environment (-e) variable
docker run -v myvolume:/data -d nginx:latest          # With volume (-v) mount
docker run --network mynetwork -d nginx:latest        # On specific network (--network)
docker run --memory="512m" --cpus="1.5" -d nginx      # With resource limits (--memory, --cpus)
docker run --restart unless-stopped -d nginx          # With restart policy (--restart)

2.10 Running Containers - Interactive Mode

docker run --name test -it ubuntu:latest bash         # Interactive (-i) with terminal (-t)
docker run --rm -it ubuntu:latest bash                # Auto-remove (--rm) after exit
docker run -it -v $(pwd):/app ubuntu bash             # With volume (-v) current directory

2.11 Working with Volumes

docker volume ls                      # List all volumes
docker volume create myvolume         # Create a volume
docker volume inspect myvolume        # View volume details
docker run --rm -v myvolume:/data alpine ls -la /data  # Remove (--rm) after, volume (-v) mount
docker volume rm myvolume             # Remove a volume
docker volume prune                   # Remove all unused volumes

2.12 Mounting Volumes

docker run -v myvolume:/data -d nginx:latest          # Named volume (-v)
docker run -v /host/path:/container/path -d nginx     # Bind mount (-v) absolute path
docker run -v $(pwd):/app -d myapp                    # Bind mount (-v) current directory
docker run -v myvolume:/data:ro -d nginx              # Read-only (ro) mount

2.13 Working with Networks

docker network ls                     # List all networks
docker network create mynetwork       # Create a network
docker network create --driver bridge mynetwork  # With specific driver (--driver)
docker network inspect mynetwork      # View network details
docker network connect mynetwork test # Connect container to network
docker network disconnect mynetwork test  # Disconnect from network
docker network rm mynetwork           # Remove a network
docker network prune                  # Remove all unused networks

2.14 Starting Multi-Container Applications

docker compose up -d                  # Start all services detached (-d)
docker compose up -d --build          # Start and rebuild (--build) images
docker compose up                     # Start in foreground (see logs)
docker compose up -d --scale web=3    # Start with scale (--scale) multiple instances

2.15 Managing Running Services

docker compose ps                     # Check service status
docker compose logs                   # View all service logs
docker compose logs -f                # Follow (-f) logs in real-time
docker compose logs web               # Logs for specific service
docker compose logs -f --tail 50 web  # Follow (-f) last (--tail) 50 lines
docker compose stop                   # Stop services (keep containers)
docker compose start                  # Start stopped services
docker compose restart                # Restart all services
docker compose restart web            # Restart specific service

2.16 Working with Services

docker compose exec web bash          # Execute (exec) in service container
docker compose exec redis redis-cli   # Execute command in service
docker compose run web python manage.py migrate  # Run one-off command (new container)

2.17 Stopping Multi-Container Applications

docker compose down                   # Stop and remove containers/networks
docker compose down -v                # Also remove volumes (-v) - DELETES DATA!

2.18 Rebuilding Services

docker compose build                  # Rebuild all services
docker compose build web              # Rebuild specific service
docker compose up -d --build web      # Rebuild (--build) and restart detached (-d)

2.19 Other Compose Operations

docker compose config                 # View merged configuration
docker compose pull                   # Pull all service images
docker compose push                   # Push all service images

2.20 Scanning for Vulnerabilities

docker scout cves nginx:latest        # Scan image for CVEs (vulnerabilities)
docker scout quickview nginx:latest   # Quick security summary
docker scout compare --to nginx:1.25 nginx:latest  # Compare (--to) versions
docker scout cves --format sarif nginx:latest      # Output format (--format) SARIF

2.21 Checking System Resources

docker system df                      # Show disk usage
docker system df -v                   # Verbose (-v) disk usage
docker info                           # Docker system information
docker version                        # Docker version details

2.22 Cleaning Up Everything

docker system prune                   # Remove stopped containers, dangling images, unused networks
docker system prune -a                # Also remove all (-a) unused images
docker system prune -a --volumes      # Also remove volumes (--volumes) - DELETES DATA!
docker container prune                # Remove stopped containers only
docker image prune                    # Remove dangling images only
docker image prune -a                 # Remove all (-a) unused images
docker volume prune                   # Remove unused volumes only
docker network prune                  # Remove unused networks only

2.23 Bulk Container Operations

docker stop $(docker ps -q)           # Stop all using quiet (-q) output
docker rm $(docker ps -a -q)          # Remove all (-a) using quiet (-q) output
docker rmi $(docker images -q)        # Remove all images using quiet (-q) output

2.24 Troubleshooting and Debugging

docker events                         # Monitor Docker events (real-time)
docker wait test                      # Wait for container to stop
docker inspect --format='{{.HostConfig.Memory}}' test  # Check memory limit using format (--format)
docker exec test env                  # View environment variables