In backup sync flow put snapshotHandle as source in CSI VSContent

[anshulahuja98]

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Please add a summary of your change

Does your change fix a particular issue?

Fixes #(issue)
https://kubernetes.io/docs/concepts/storage/volume-snapshots/

Context:
We have few customers which have used same storage bucket across clusters, as a result of that their VSContents are syncing across clusters, After the sync the other cluster does not have permission on the snapshot of original cluster, it starts to rePUT the snapshot.
This leads to significant load on the CSI driver.

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• Accepted the DCO. Commits without the DCO will delay acceptance.
• Created a changelog file or added /kind changelog-not-required as a comment on this pull request.
• Updated the corresponding documentation in site/content/docs/main.

[codecov]

Codecov Report

Attention: Patch coverage is 0% with 2 lines in your changes missing coverage. Please review.

Project coverage is 58.77%. Comparing base (b0dc189) to head (d1d331f).
Report is 2 commits behind head on main.

Files	Patch %	Lines
pkg/controller/backup_sync_controller.go	0.00%	2 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #7924      +/-   ##
==========================================
- Coverage   58.79%   58.77%   -0.03%     
==========================================
  Files         345      345              
  Lines       28766    28768       +2     
==========================================
- Hits        16914    16908       -6     
- Misses      10423    10430       +7     
- Partials     1429     1430       +1     

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[shubham-pampattiwar]

Will the SnapshotHandle value be unique globally ? Or does it depend on:

• whether the storage across clusters is shared ?
• the csi driver of the storage provider ?

[kaovilai]

snapshotHandle in my experience is the unique identifier at the cloud provider level.

As long as it's the same cloud provider, same provisioner, then same snapshothandle = same unique content globally.

[kaovilai]

snapshotHandle for aws provisioner would be the same value as SnapshotId of an ec2 EBS snapshot
"SnapshotId": "snap-066877671789bd71b" which for the same account credentials should be unique globally regardless of cluster.

[anshulahuja98]

My understanding is also that same that it will mostly be unique across
Using a GUID in any naming ensures that.

In case of Azure it's a fully qualified URL with subscription, RG and snapshot name.

But again any GUID should ensure uniqueness.

[anshulahuja98]

@shubham-pampattiwar any other thoughts?

[shubham-pampattiwar]

If possible, Could you provide a link to the change/PR that is causing the rePUTs on the snapshot ?

[anshulahuja98]

tagged on slack

[shubham-pampattiwar]

added a few questions