Docker Registries

A Docker registry is a storage and distribution system for Docker images. Registries allow developers to store images in a central location and share them with other users or teams. Every image pushed to a registry can be pulled by others to run containers.

What is a Docker Registry?

A Docker registry hosts Docker images and manages their versions. It can be either **public** or **private**, depending on who can access the stored images. Docker registries simplify image distribution, deployment, and collaboration in software development.

Key Features of Docker Registries

• Centralized storage for Docker images
• Versioning and tagging of images
• Support for public and private repositories
• Secure image access with authentication
• Integration with CI/CD pipelines

Public vs Private Docker Registries

Common Docker Registry Commands

# Login to a registry
docker login

# Logout from a registry
docker logout

# Pull an image from registry
docker pull ubuntu:latest

# Push an image to registry
docker push myusername/myimage:tag

# List images on local machine
docker images

Setting Up a Private Registry

You can run your own private Docker registry using the official Docker Registry image:

# Start a private registry on port 5000
docker run -d -p 5000:5000 --name my-registry registry:2

# Push an image to private registry
docker tag ubuntu localhost:5000/my-ubuntu
docker push localhost:5000/my-ubuntu

# Pull image from private registry
docker pull localhost:5000/my-ubuntu

Best Practices for Docker Registries

• Use version tags to manage image versions effectively.
• Keep private registries secure with authentication.
• Regularly clean up unused images to save storage.
• Integrate registry usage with CI/CD pipelines.
• Monitor registry performance and access logs.

Conclusion

Docker registries provide a central hub to store, manage, and share Docker images. Whether public or private, they are critical for collaboration, deployment, and efficient DevOps workflows.