Registry

OpenShift Container Platform provides a built in container image registry which runs as a standard workload on the cluster. The registry is configured and managed by an infrastructure operator. It provides an out of the box solution for users to manage the images that run their workloads, and runs on top of the existing cluster infrastructure. This registry can be scaled up or down like any other cluster workload and does not require specific infrastructure provisioning. In addition, it is integrated into the cluster user authentication and authorization system which means that access to create and retrieve images is controlled by defining user permissions on the image resources.

The registry is typically used as a publication target for images built on the cluster as well as a source of images for workloads running on the cluster. When a new image is pushed to the registry, the cluster is notified of the new image and other components can react to and consume the updated image.

Image data is stored in two locations. The actual image data is stored in a configurable storage location such as cloud storage or a filesystem volume. The image metadata, which is exposed by the standard cluster APIs and is used to perform access control, is stored as standard API resources, specifically images and imagestreams.

The Image Registry Operator installs a single instance of the OpenShift Container Platform registry, and manages all registry configuration, including setting up registry storage.

After the control plane deploys, the Operator will create a default configs.imageregistry.operator.openshift.io resource instance based on configuration detected in the cluster.

If insufficient information is available to define a complete configs.imageregistry.operator.openshift.io resource, the incomplete resource will be defined and the Operator will update the resource status with information about what is missing.

The Image Registry Operator runs in the openshift-image-registry namespace, and manages the registry instance in that location as well. All configuration and workload resources for the registry reside in that namespace.

The configs.imageregistry.operator.openshift.io resource offers the following configuration parameters.

In OpenShift Container Platform, the Registry Operator controls the registry feature. The Operator is defined by the configs.imageregistry.operator.openshift.io Custom Resource Definition (CRD).

If you need to automatically enable the Image Registry default route, patch the Image Registry Operator CRD.

The image.config.openshift.io/cluster custom resource can contain a reference to a ConfigMap that contains additional certificate authorities to be trusted during image registry access.

The ConfigMap key is the host name of a registry with the port for which this CA is to be trusted, and the base64-encoded certificate is the value, for each additional registry CA to trust.

apiVersion: v1
kind: ConfigMap
metadata:
  name: my-registry-ca
data:
  registry.example.com: |
    -----BEGIN CERTIFICATE-----
    ...
    -----END CERTIFICATE-----
  registry-with-port.example.com..5000: | 1
    -----BEGIN CERTIFICATE-----
    ...
    -----END CERTIFICATE-----

You can configure additional CAs with the following procedure.

In addition to the configs.imageregistry.operator.openshift.io and ConfigMap resources, storage credential configuration is provided to the Operator by a separate secret resource located within the openshift-image-registry namespace.

The image-registry-private-configuration-user secret provides credentials needed for storage access and management. It overrides the default credentials used by the Operator, if default credentials were found.

OpenShift Container Platform provides a built in container image registry which runs as a standard workload on the cluster. The registry is configured and managed by an infrastructure operator. It provides an out of the box solution for users to manage the images that run their workloads, and runs on top of the existing cluster infrastructure. This registry can be scaled up or down like any other cluster workload and does not require specific infrastructure provisioning. In addition, it is integrated into the cluster user authentication and authorization system which means that access to create and retrieve images is controlled by defining user permissions on the image resources.

The registry is typically used as a publication target for images built on the cluster as well as a source of images for workloads running on the cluster. When a new image is pushed to the registry, the cluster is notified of the new image and other components can react to and consume the updated image.

Image data is stored in two locations. The actual image data is stored in a configurable storage location such as cloud storage or a filesystem volume. The image metadata, which is exposed by the standard cluster APIs and is used to perform access control, is stored as standard API resources, specifically images and imagestreams.

OpenShift Container Platform 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 Container Platform registry. In this situation OpenShift Container Platform 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.

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.

You can access your Red Hat Quay registry from OpenShift Container Platform like any remote container image registry.

All container images available through the Red Hat Container Catalog are hosted on an image registry, registry.redhat.io.

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

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

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

All imagestreams point to the new registry. Because the registry requires authentication for access, the Samples Operator creates the samples-registry-credentials secret.

You must place your credentials in two places:

You can access the registry from inside the cluster.

As a cluster administrator, you can list the image registry pods running in the openshift-image-registry project and check their status.

You can view the logs for the registry by using the oc logs command.

The OpenShift Container Registry provides an endpoint for Prometheus metrics. Prometheus is a stand-alone, open source systems monitoring and alerting toolkit.

The metrics are exposed at the /extensions/v2/metrics path of the registry endpoint.

Metrics query

Cluster role

Instead of logging in to the OpenShift Container Platform registry from within the cluster, you can gain external access to it by exposing it with a route. This allows you to log in to the registry from outside the cluster using the route address, and to tag and push images using the route host.

To expose the registry using DefaultRoute:

To expose the registry using custom routes: