Support for ImageTagMirrorSet via ImageContentSource in HostedCluster

[stianfro]

It is currently possible to create a HostedCluster and specify imageContentSources like this:

spec:
  imageContentSources:
    - mirrors:
        - 'mirror.example.com'
      source: docker.io

Which results in a ImageDigestMirrorSet inside the cluster:

apiVersion: config.openshift.io/v1
kind: ImageDigestMirrorSet
metadata:
  labels:
    hypershift.openshift.io/managed: 'true'
    machineconfiguration.openshift.io/role: worker
  name: cluster
spec:
  imageDigestMirrors:
    - mirrors:
        - 'mirror.example.com'
      source: docker.io

This again configures /etc/containers/registries.conf on the nodes in the cluster:

unqualified-search-registries = ["registry.access.redhat.com", "docker.io"]
short-name-mode = ""

[[registry]]
  prefix = ""
  location = "docker.io"

  [[registry.mirror]]
    location = "mirror.example.com"
    pull-from-mirror = "digest-only"

Howerer there does not seem to be a way to have a ImageTagMirrorSet be created through this flow.

There is also no way to create a mirror with pull-from-mirror = "all"
as the setting but I imagine this is an opinionated thing in OpenShift itself.

From my testing it doesn't even seem like creating a ImageTagMirrorSet manually inside a hosted cluster has any effect, the mirrors specified are never added to /etc/containers/registries.conf.

Are there any plans for adding support for this? If there are no immediate plans, could someone point me in the right direction on where to start if it is possible to contribute to this? 🙂