Essential Docker Commands: A Complete Reference Guide
Docker has revolutionized how developers build, ship, and run applications by providing lightweight containerization. Whether you're just starting with Docker or need a quick reference, mastering these essential commands will significantly improve your development workflow.
Image Management Commands
Pulling Images
The foundation of working with Docker starts with obtaining images from registries like Docker Hub.
docker pull [IMAGE_NAME]
Pull the latest version of an image:
docker pull nginx
Pull a specific version:
docker pull nginx:1.21
Listing Images
View all locally stored images:
docker images
For a more compact view:
docker images --format "table {{.Repository}}\t{{.Tag}}\t{{.Size}}"
Building Images
Create custom images from a Dockerfile:
docker build -t [IMAGE_NAME] .
Build with a specific tag:
docker build -t myapp:v1.0 .
Build from a different directory:
docker build -t myapp -f /path/to/Dockerfile /path/to/context
Removing Images
Remove a specific image:
docker rmi [IMAGE_ID]
Remove all unused images:
docker image prune
Force remove an image (even if containers are using it):
docker rmi -f [IMAGE_ID]
Container Lifecycle Commands
Running Containers
Start a new container from an image:
docker run [OPTIONS] [IMAGE] [COMMAND]
Common run options:
# Run in detached mode (background)
docker run -d nginx
# Run with port mapping
docker run -p 8080:80 nginx
# Run with environment variables
docker run -e NODE_ENV=production myapp
# Run with volume mounting
docker run -v /host/path:/container/path nginx
# Run interactively with a terminal
docker run -it ubuntu bash
Listing Containers
View running containers:
docker ps
View all containers (including stopped):
docker ps -a
View container IDs only:
docker ps -q
Starting and Stopping Containers
Start a stopped container:
docker start [CONTAINER_ID]
Stop a running container:
docker stop [CONTAINER_ID]
Restart a container:
docker restart [CONTAINER_ID]
Force kill a container:
docker kill [CONTAINER_ID]
Removing Containers
Remove a stopped container:
docker rm [CONTAINER_ID]
Remove a running container (force):
docker rm -f [CONTAINER_ID]
Remove all stopped containers:
docker container prune
Container Interaction Commands
Executing Commands in Containers
Run a command in a running container:
docker exec [CONTAINER_ID] [COMMAND]
Open an interactive shell:
docker exec -it [CONTAINER_ID] bash
Run a command as a specific user:
docker exec -u root [CONTAINER_ID] whoami
Viewing Container Output
View container logs:
docker logs [CONTAINER_ID]
Follow log output in real-time:
docker logs -f [CONTAINER_ID]
View last 100 lines of logs:
docker logs --tail 100 [CONTAINER_ID]
Inspecting Containers
Get detailed information about a container:
docker inspect [CONTAINER_ID]
View container resource usage:
docker stats [CONTAINER_ID]
View processes running in a container:
docker top [CONTAINER_ID]
File Operations
Copying Files
Copy files from container to host:
docker cp [CONTAINER_ID]:/path/in/container /host/path
Copy files from host to container:
docker cp /host/path [CONTAINER_ID]:/path/in/container
Network Commands
Listing Networks
View all Docker networks:
docker network ls
Creating Networks
Create a custom network:
docker network create [NETWORK_NAME]
Create a network with specific driver:
docker network create --driver bridge mynetwork
Connecting Containers to Networks
Connect a container to a network:
docker network connect [NETWORK_NAME] [CONTAINER_ID]
Run a container on a specific network:
docker run --network [NETWORK_NAME] nginx
Volume Management
Listing Volumes
View all Docker volumes:
docker volume ls
Creating Volumes
Create a named volume:
docker volume create [VOLUME_NAME]
Using Volumes
Mount a volume when running a container:
docker run -v [VOLUME_NAME]:/path/in/container nginx
Removing Volumes
Remove a specific volume:
docker volume rm [VOLUME_NAME]
Remove all unused volumes:
docker volume prune
System Maintenance Commands
System Information
View Docker system information:
docker info
Check Docker version:
docker version
Cleaning Up Resources
Remove all unused containers, networks, and images:
docker system prune
Remove everything including volumes:
docker system prune -a --volumes
View disk usage:
docker system df
Docker Compose Commands
When working with multi-container applications, Docker Compose provides additional commands:
Starting Services
Start all services defined in docker-compose.yml:
docker-compose up
Start in detached mode:
docker-compose up -d
Stopping Services
Stop all services:
docker-compose down
Stop and remove volumes:
docker-compose down -v
Viewing Service Status
List running services:
docker-compose ps
View service logs:
docker-compose logs [SERVICE_NAME]
Best Practices and Tips
Using Tags Effectively
Always specify image tags in production environments rather than relying on latest. This ensures consistency and prevents unexpected updates.
Container Naming
Use meaningful names for containers to make management easier:
docker run --name web-server nginx
Resource Management
Monitor resource usage regularly and clean up unused containers, images, and volumes to free up disk space.
Security Considerations
Avoid running containers as root when possible, and use specific image tags rather than generic ones to reduce security risks.
Conclusion
These Docker commands form the foundation of container management and will handle most day-to-day Docker operations. As you become more comfortable with these basics, you can explore advanced features like multi-stage builds, custom networks, and orchestration tools. Regular practice with these commands will make container management second nature and significantly improve your development workflow.
Remember that Docker commands often have many additional options and flags. Use docker [COMMAND] --help to explore all available options for any specific command.