Description

OpenShift clusters have an internal registry. This registry is available within the cluster hostnetwork at `image-registry.openshift-image-registry.svc`. On Linux nodes, the cluster-dns-operator adds a /etc/hosts file entry
which allows the registry address to be resolved, and images to be pulled.

127.0.0.1   localhost localhost.localdomain localhost4 localhost4.localdomain4
::1         localhost localhost.localdomain localhost6 localhost6.localdomain6
172.30.154.17 image-registry.openshift-image-registry.svc image-registry.openshift-image-registry.svc.cluster.local # openshift-generated-node-resolver

Without an equivalent mechanism for updating the hosts file for Windows nodes, the internal registry is unusable, without a user manually intervening and adding an entry to the hosts file.

Engineering details

To test this, a Windows image can be copied to the internal registry by following the instructions in the OCP docs. Podman pull/push is described in the doc, but it will not work if you are doing this from a debug pod on a Linux node. Instead the image can be copied with skopeo.

skopeo copy docker://mcr.microsoft.com/powershell:lts-nanoserver-ltsc2022 docker://image-registry.openshift-image-registry.svc:5000/openshift/powershell:lts-nanoserver-ltsc2022 

The image can then be referenced in the pod spec:

      containers: 
        - name: windowswebserver
          image: image-registry.openshift-image-registry.svc:5000/openshift/powershell:lts-nanoserver-ltsc2022

Acceptance Criteria

• Windows workloads can use images pushed to the internal registry