10 Docker Registries

Docker registries are services that store and distribute container images, serving as the central mechanism by which images built in one location become available to be pulled and run anywhere else, from Docker Hub's public registry to private registries run by individual organizations.

Pulling From a Registry

Retrieving an image from a registry is the most basic, frequently performed registry interaction.

docker pull postgres:16

This pulls the postgres image, tagged 16, from Docker Hub, the default registry Docker uses unless told otherwise.

Pushing to a Registry

Publishing a locally built image to a registry makes it available for others (or other systems) to pull and use.

docker tag myapi:2.3.0 registry.example.com/myteam/myapi:2.3.0
docker push registry.example.com/myteam/myapi:2.3.0

Why Different Registries Exist

Docker Hub serves as a large, public registry widely used for official and community images, while private registries — self-hosted or provided by a cloud platform — give organizations control over their own images' storage, access, and distribution.

docker login registry.example.com

Authenticating with a private registry is typically necessary before pushing to it, or pulling from it if it requires authentication.

Why Registries Are Foundational to Container Workflows

Without a registry, sharing a built image between different machines, team members, or deployment environments would require some entirely manual transfer mechanism — registries provide the standard, reliable infrastructure that makes built images conveniently distributable wherever they're needed.

docker compose pull

Why Docker Registries Matter

Registries are the backbone of how container images actually get from where they're built to wherever they need to run, making a solid understanding of how to interact with them — pulling, pushing, authenticating — foundational to working effectively with containerized applications beyond a single local machine.