3.4. Mirror registry for Red Hat OpenShift
The mirror registry for OpenShift Container Platform is a small-scale Red Hat Quay deployment for disconnected cluster installation. You can use it to mirror OpenShift Container Platform release images before deploying a production-grade registry.
The mirror registry for Red Hat OpenShift is small-scale version of Red Hat Quay that you can use as a target for mirroring the required container images of OpenShift Container Platform for disconnected installations.
For disconnected deployments of OpenShift Container Platform, a container registry is required to execute the installation of the clusters. To run a production-grade registry service on such a cluster, you must create a separate registry deployment to install the first cluster. The mirror registry for Red Hat OpenShift addresses this need and is included in every OpenShift Container Platform subscription. It is available for download on the OpenShift console Downloads page.
The mirror registry for Red Hat OpenShift allows users to install a small-scale version of Red Hat Quay and its required components using the mirror-registry command line interface (CLI) tool. The mirror registry for Red Hat OpenShift is deployed automatically with pre-configured local storage and a local database. It also includes auto-generated user credentials and access permissions with a single set of inputs and no additional configuration choices to get started.
The mirror registry for Red Hat OpenShift provides a pre-determined network configuration and reports deployed component credentials and access URLs upon success. A limited set of optional configuration inputs like fully qualified domain name (FQDN) services, superuser name and password, and custom TLS certificates are also provided. This provides users with a container registry so that they can easily create an offline mirror of all OpenShift Container Platform release content when running OpenShift Container Platform in restricted network environments.
The mirror registry for Red Hat OpenShift is limited to hosting images that are required to install a disconnected OpenShift Container Platform cluster, such as release images or Operator images. It uses local storage. Content built by customers should not be hosted by the mirror registry for Red Hat OpenShift.
Unlike Red Hat Quay, the mirror registry for Red Hat OpenShift is not a highly-available registry. Only local file system storage is supported. Using the mirror registry for Red Hat OpenShift with more than one cluster is discouraged, because multiple clusters can create a single point of failure when updating your cluster fleet. It is advised to use the mirror registry for Red Hat OpenShift to install a cluster that can host a production-grade, highly available registry such as Red Hat Quay, which can serve OpenShift Container Platform content to other clusters.
More information is available at Creating a mirror registry with mirror registry for Red Hat OpenShift.