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Container Registry - Infrastructure Components | Architecture | OpenShift Dedicated 3
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Container Registry

Overview

OpenShift Dedicated can utilize any server implementing the container image registry API as a source of images, including the Docker Hub, private registries run by third parties, and the integrated OpenShift Dedicated registry.

Integrated OpenShift Container Registry

OpenShift Dedicated provides an integrated container image registry called OpenShift Container Registry (OCR) that adds the ability to automatically provision new image repositories on demand. This provides users with a built-in location for their application builds to push the resulting images.

Whenever a new image is pushed to OCR, the registry notifies OpenShift Dedicated about the new image, passing along all the information about it, such as the namespace, name, and image metadata. Different pieces of OpenShift Dedicated react to new images, creating new builds and deployments.

Third Party Registries

OpenShift Dedicated can create containers using images from third party registries, but it is unlikely that these registries offer the same image notification support as the integrated OpenShift Dedicated registry. In this situation OpenShift Dedicated will fetch tags from the remote registry upon imagestream creation. Refreshing the fetched tags is as simple as running oc import-image <stream>. When new images are detected, the previously-described build and deployment reactions occur.

Authentication

OpenShift Dedicated can communicate with registries to access private image repositories using credentials supplied by the user. This allows OpenShift Dedicated to push and pull images to and from private repositories. The Authentication topic has more information.

Red Hat Quay Registries

If you need an enterprise-quality container image registry, Red Hat Quay is available both as a hosted service and as software you can install in your own data center or cloud environment. Advanced registry features in Red Hat Quay include geo-replication, image scanning, and the ability to roll back images.

Visit the Quay.io site to set up your own hosted Quay registry account. After that, follow the Quay Tutorial to log in to the Quay registry and start managing your images. Alternatively, refer to Getting Started with Red Hat Quay for information about setting up your own Red Hat Quay registry.

You can access your Red Hat Quay registry from OpenShift Dedicated like any remote container image registry. To learn how to set up credentials to access Red Hat Quay as a secured registry, refer to Allowing Pods to Reference Images from Other Secured Registries.

Authentication Enabled Red Hat Registry

All container images available through the Red Hat Container Catalog are hosted on an image registry, registry.access.redhat.com. With OpenShift Dedicated 3.11 Red Hat Container Catalog moved from registry.access.redhat.com to registry.redhat.io.

The new registry, registry.redhat.io, requires authentication for access to images and hosted content on OpenShift Dedicated. Following the move to the new registry, the existing registry will be available for a period of time.

OpenShift Dedicated pulls images from registry.redhat.io, so you must configure your cluster to use it.

The new registry uses standard OAuth mechanisms for authentication, with the following methods:

  • Authentication token. Tokens, which are generated by administrators, are service accounts that give systems the ability to authenticate against the container image registry. Service accounts are not affected by changes in user accounts, so the token authentication method is reliable and resilient. This is the only supported authentication option for production clusters.

  • Web username and password. This is the standard set of credentials you use to log in to resources such as access.redhat.com. While it is possible to use this authentication method with OpenShift Dedicated, it is not supported for production deployments. Restrict this authentication method to stand-alone projects outside OpenShift Dedicated.

You can use docker login with your credentials, either username and password or authentication token, to access content on the new registry.

All image streams point to the new registry. Because the new registry requires authentication for access, there is a new secret in the OpenShift namespace called imagestreamsecret.

You must place your credentials in two places:

  • OpenShift namespace. Your credentials must exist in the OpenShift namespace so that the image streams in the OpenShift namespace can import.

  • Your host. Your credentials must exist on your host because Kubernetes uses the credentials from your host when it goes to pull images.

To access the new registry:

  • Verify image import secret, imagestreamsecret, is in your OpenShift namespace. That secret has credentials that allow you to access the new registry.

  • Verify all of your cluster nodes have a /var/lib/origin/.docker/config.json, copied from master, that allows you to access the Red Hat registry.