Allow the usage of AnnPodRetainAfterCompletion with populators

[alromeros]

What this PR does / why we need it:

When introducing populators we somehow assumed that having the PVC' in Lost phase would interfere with the behavior of AnnPodRetainAfterCompletion. After better testing, the pod state and logs are still fetchable after completion.

This PR allows the usage of this annotation.

Which issue(s) this PR fixes (optional, in fixes #<issue number>(, fixes #<issue_number>, ...) format, will close the issue(s) when PR gets merged):
Fixes #

Special notes for your reviewer: Let's see how tests behave.

Release note:

Allow the usage of AnnPodRetainAfterCompletion with populators

[alromeros]

/test pull-containerized-data-importer-e2e-hpp-latest

[alromeros]

Hey @mhenriks, what do you think of skipping the cleanup when using AnnPodRetainAfterCompletion? I think that for debugging purposes we can allow keeping all the clone objects (even the PVC prime in lost state).

Another possibility is to have the PVC Prime in terminating state until the user deletes the pod, but having the PVC stuck there seems awkward to me. Maybe we could also consider removing the PVC protection finalizer to delete the PVC prime.

[mhenriks]

Only do this for host clone

[mhenriks]

One thing to note here though. Pods will be in the source namespace. With cross namespace clone, the user may not have access to them. And I'm not sure we want to allow the user to do this in cross namespace case

[alromeros]

Yeah that's a good point. What about the check in the DV controller to see if we use populators or not?

containerized-data-importer/pkg/controller/datavolume/controller-base.go

Lines 1180 to 1184 in bd63352

	// currently populators don't support retain pod annotation so don't use populators in that case
	if retain := dv.Annotations[cc.AnnPodRetainAfterCompletion]; retain == "true" {
	log.Info("Not using CDI populators, currently we don't support populators with retainAfterCompletion annotation")
	return false, nil
	}

Are we ok with turning to populators even if we only use AnnPodRetainAfterCompletion with host assisted clone?

[alromeros]

I guess we are since it's basically the same behavior without populators.

[mhenriks]

Without populators, the target pod is in the target namespace. With populators both pods are in the source then rebind happens. The reason for having the target pod in the source is to better support k8s native cross namespace auth (when it goes live). In that case there will be no clone token. So can't do cross namespace host clone

[alromeros]

@mhenriks This could be also an opportunity to add the importer pod name annotation to the target PVC. I personally liked the idea and find it better than expecting users to build the pod name with the UID.

[alromeros]

/test pull-containerized-data-importer-e2e-istio

[mhenriks]

Let's future proof this for when cross namespace datasource goes live. In that case pvc.spec.dataCource.Namespace may be set

[alromeros]

/test pull-containerized-data-importer-fossa

[mhenriks]

/lgtm
/approve

[kubevirt-bot]

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[alromeros]

Backporting this as requested in Jira
/cherrypick release-v1.57

[kubevirt-bot]

@alromeros: #2873 failed to apply on top of branch "release-v1.57":

Applying: Allow the usage of AnnPodRetainAfterCompletion with populators
Using index info to reconstruct a base tree...
M	pkg/controller/datavolume/controller-base.go
M	pkg/controller/datavolume/import-controller_test.go
M	pkg/controller/populators/import-populator_test.go
M	pkg/controller/populators/populator-base.go
M	tests/cloner_test.go
M	tests/import_proxy_test.go
M	tests/import_test.go
Falling back to patching base and 3-way merge...
Auto-merging tests/import_test.go
CONFLICT (content): Merge conflict in tests/import_test.go
Auto-merging tests/import_proxy_test.go
Auto-merging tests/cloner_test.go
Auto-merging pkg/controller/populators/populator-base.go
Auto-merging pkg/controller/populators/import-populator_test.go
CONFLICT (content): Merge conflict in pkg/controller/populators/import-populator_test.go
Auto-merging pkg/controller/datavolume/import-controller_test.go
Auto-merging pkg/controller/datavolume/controller-base.go
CONFLICT (content): Merge conflict in pkg/controller/datavolume/controller-base.go
error: Failed to merge in the changes.
hint: Use 'git am --show-current-patch=diff' to see the failed patch
Patch failed at 0001 Allow the usage of AnnPodRetainAfterCompletion with populators
When you have resolved this problem, run "git am --continue".
If you prefer to skip this patch, run "git am --skip" instead.
To restore the original branch and stop patching, run "git am --abort".

In response to this:

Backporting this as requested in Jira
/cherrypick release-v1.57

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