SinkBinding with subject described with MatchLabels on metav1.LabelSelector can report Ready without subject being deployed

[cardil]

Describe the bug
SinkBinding sometimes reports Ready even if its subject isn't ready (or even deployed). This bug is similar to #5442.

Expected behavior
SinkBinding shouldn't report Ready without matching subject being ready.

To Reproduce
#5511

Knative release version
TBD

[maschmid]

Why can't the SinkBinding be ready without a matching subject? IMHO the SinkBinding readiness signifies that it is Ready to properly modify a matching subject when it is created, but it is perfectly fine to create it afterwards.

(SinkBinding Readiness should signify the webhook is ready to properly modify a matching subject when it exists, so. e.g. if it ready before the webhook is modified to accept the matching resources, that would be a bug)

[maschmid]

e.g. consider the example with SinkBinding and CronJob in https://knative.dev/docs/eventing/sources/sinkbinding/ , The whole setup is ready when SinkBinding and CronJob are created. (but SinkBinding's subjects are the Jobs created by the CronJob later)

[cardil]

SinkBinding actually returns the Ready status as "subject not present" or similar, in some cases. So, now, it's mixed. Sometimes the absence of subject is propagated to Ready status, but in other cases it is not. See the repro #5511.

I think that in cases where it is possible to report Readiness of SinkBinding, we should propagate the subject status as well. There are some exceptions to this, as you have given an example of CronJob.

[github-actions]

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[cardil]

/remove-lifecycle stale

[github-actions]

This issue is stale because it has been open for 90 days with no
activity. It will automatically close after 30 more days of
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[cardil]

/remove-lifecycle stale

[github-actions]

This issue is stale because it has been open for 90 days with no
activity. It will automatically close after 30 more days of
inactivity. Reopen the issue with /reopen. Mark the issue as
fresh by adding the comment /remove-lifecycle stale.

[cardil]

/remove-lifecycle stale

[github-actions]

This issue is stale because it has been open for 90 days with no
activity. It will automatically close after 30 more days of
inactivity. Reopen the issue with /reopen. Mark the issue as
fresh by adding the comment /remove-lifecycle stale.