✨ controllerutil: configure BlockOwnerDeletion when setting OwnerReference

[muwaqar]

Currently, SetOwnerReference() and SetControllerReference() in controllerutil do not allow configuring BlockOwnerDeletion field of the underlying OwnerReference. This is limiting for scenarios where one would like to use these helper methods but configure BlockOwnerDeletion field in a different way than the current defaults.

Fixes #2846

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• ✅login: muwaqar / (50abe5b)

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[troy0820]

/hold

In your issue you state

controllerutil SetControllerReference() implementation necessarily sets BlockOwnerDeletion = ptr.To(true). This means that the user needs to explicitly delete the referent resource before the owner can be cleaned up (see foreground deletion details).
users should be able to configure BlockOwnerDeletion while using these utility methods conveniently

but doesn't that go against what we want to use SetControllerReference for?

Allowing the BlockOwnerDeletion to be configurable changes the intention of why that is necessary and may conflate the workflow with the owner/controller references.

The requisite helper functions alleviate the need to change the configuration of SetControllerReference by using RemoveControllerReferfence

[muwaqar]

but doesn't that go against what we want to use SetControllerReference for?

@troy0820: based on my understanding of the original ControllerRef proposal, the controller reference is used to identify the owning controller only so that multiple controllers with sharing labels do not clash over the resource, but does not dictate any behavior for garbage collection of owned resources, and says:

When a controller is deleted, the objects it owns will either be orphaned or deleted according to the normal Garbage Collection behavior, based on OwnerReferences.

i interpret this to be users should be able to configure the cascade deletion behavior.

[alvaroaleman]

but doesn't that go against what we want to use SetControllerReference for?

Allowing the BlockOwnerDeletion to be configurable changes the intention of why that is necessary and may conflate the workflow with the owner/controller references.

The handler we have in Owns requires the ownerRef to have controller: true. Ending up with foreground deletion just because you use SetControllerRef is surprising IMHO, those two settings are orthogonal, if you do or do not want foreground deletion can not be derived from controller: true

/ok-to-test

[k8s-ci-robot]

@muwaqar: The following test failed, say /retest to rerun all failed tests or /retest-required to rerun all mandatory failed tests:

Test name	Commit	Details	Required	Rerun command
pull-controller-runtime-apidiff	50abe5b	link	false	/test pull-controller-runtime-apidiff

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[sbueringer]

Agree with what @muwaqar & @alvaroaleman wrote

[k8s-ci-robot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: alvaroaleman, muwaqar

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[k8s-ci-robot]

LGTM label has been added.

Git tree hash: b80abb6bc126e56415e0e2677b63ecdfdf422027

[alvaroaleman]

/hold cancel

[troy0820]

Thanks for the explanation @alvaroaleman and thanks for your contribution @muwaqar 🎉

[alvaroaleman]

/cherrypick release-0.18

[k8s-infra-cherrypick-robot]

@alvaroaleman: new pull request created: #2848

In response to this:

/cherrypick release-0.18

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