Uploaded image for project: 'Multiple Architecture Enablement'
  1. Multiple Architecture Enablement
  2. MULTIARCH-4552

Imagestreams should import manifestlist by default on a cluster with the multi payload

XMLWordPrintable

    • Icon: Epic Epic
    • Resolution: Unresolved
    • Icon: Critical Critical
    • None
    • None
    • None
    • Imagestreams should import manifestlist by default on a cluster with the multi payload
    • Product / Portfolio Work
    • OCPSTRAT-2082Imagestreams should import manifestlist by default on a cluster with the multi payload
    • 46% To Do, 0% In Progress, 54% Done
    • False
    • Hide

      None

      Show
      None
    • False
    • Not Selected
    • Hide

      28 Aug: Delaying to 4.21. The feature gate testing needs to go to a special disruptive bucket, because the change triggers a rollout of cluster-api. There's more work involved to make those changes, and we're unsure that this can land before the branching (Sept 15) as only critical bug fixes can get in.
      7 Aug: PR is still blocked on feature gate criteria.
      12 Jun: epic is waiting on https://github.com/openshift/api/pull/2266 - and this depends on a "verify-promotion" job which verifies that tests that are part of the featuregates have run successfully for a while (at least a few weeks)
      Next status expected in at least 3 weeks

      Show
      28 Aug: Delaying to 4.21. The feature gate testing needs to go to a special disruptive bucket, because the change triggers a rollout of cluster-api. There's more work involved to make those changes, and we're unsure that this can land before the branching (Sept 15) as only critical bug fixes can get in. 7 Aug: PR is still blocked on feature gate criteria. 12 Jun: epic is waiting on https://github.com/openshift/api/pull/2266 - and this depends on a "verify-promotion" job which verifies that tests that are part of the featuregates have run successfully for a while (at least a few weeks) Next status expected in at least 3 weeks
    • None

      The history of this epic starts with this PR which triggered a lengthy conversation around the workings of the image  API with respect to importing imagestreams  images as single vs manifestlisted. The imagestreams today by default have the `importMode` flag set to `Legacy` to avoid breaking behavior of existing clusters in the field. This makes sense for single arch clusters deployed with a single  arch payload, but when users migrate to use the multi payload, more often than not, their intent is to add nodes of other architecture types. When this happens - it gives rise to problems when using imagestreams with the default behavior of importing a single manifest image. The oc commands do have a new flag to toggle the importMode, but this breaks functionality of existing users who just want to create an imagestream and use it with existing commands.

      There was a discussion with David Eads and other staff engineers and it was decided that the approach to be taken is to default imagestreams' importMode to `preserveOriginal` if the cluster is installed with/ upgraded to a multi payload. So a few things need to happen to achieve this:

      • CVO would need to expose a field in the status section indicative of the type of payload in the cluster (single vs multi)
      • cluster-openshift-apiserver-operator would read this field and add it to the apiserver configmap. openshift-apiserver would use this value to determine the setting of importMode value.
      • Document clearly that the behavior of imagestreams in a cluster with multi payload is different from the traditional single payload

      Some open questions:

      • What happens to existing imagestreams on upgrades
      • How do we handle CVO managed imagestreams (IMO, CVO managed imagestreams should always set importMode to preserveOriginal as the images are associated with the payload)

       

              psundara@redhat.com Prashanth Sundararaman
              psundara@redhat.com Prashanth Sundararaman
              Brian Cogan
              None
              None
              Votes:
              0 Vote for this issue
              Watchers:
              8 Start watching this issue

                Created:
                Updated: