fix: graceful-eviction still works after an unexpected restart of karmada-controller-manager

[chaunceyjiang]

Signed-off-by: chaunceyjiang chaunceyjiang@gmail.com

What type of PR is this?
/kind bug

What this PR does / why we need it:

When there are tasks in the GracefulEvictionTasks queue, graceful-eviction-controller will not work after restarting karmada-controller-manager.

Which issue(s) this PR fixes:
Fixes #

Special notes for your reviewer:

Does this PR introduce a user-facing change?:

`karmada-controller-manager`: Fixed a corner case that when there are tasks in the GracefulEvictionTasks queue, graceful-eviction-controller will not work after restarting karmada-controller-manager.

[codecov-commenter]

Codecov Report

Merging #3475 (ec0b677) into master (0f84dd7) will decrease coverage by 0.18%.
The diff coverage is 0.00%.

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@@            Coverage Diff             @@
##           master    #3475      +/-   ##
==========================================
- Coverage   53.76%   53.59%   -0.18%     
==========================================
  Files         210      210              
  Lines       19123    19192      +69     
==========================================
+ Hits        10281    10285       +4     
- Misses       8290     8355      +65     
  Partials      552      552              

Flag	Coverage Δ
unittests	53.59% <0.00%> (-0.18%)	⬇️

Flags with carried forward coverage won't be shown. Click here to find out more.

Impacted Files	Coverage Δ
...acefuleviction/crb_graceful_eviction_controller.go	0.00% <0.00%> (ø)
pkg/controllers/gracefuleviction/evictiontask.go	95.65% <ø> (-0.30%)	⬇️
...racefuleviction/rb_graceful_eviction_controller.go	0.00% <0.00%> (ø)

... and 4 files with indirect coverage changes

[RainbowMango]

@chaunceyjiang Please add a release-note.

/assign @Poor12

[XiShanYongYe-Chang]

Thanks, I think this patch is reasonable.
LGTM

[XiShanYongYe-Chang]

BTY, I think we can add some comments to explain why we need to care about the create event.

[RainbowMango]

BTY, I think we can add some comments to explain why we need to care about the create event.

Good point!

[XiShanYongYe-Chang]

Hi @chaunceyjiang. I guess we may have missed a little bit of our analysis.
After the karmada-controller-manager restarts, the spec of the rb/crb changes, and the generation increases by 1.

It can be obtained from the analysis of:
#3455 (comment)

This triggers the karmada-scheduler to scheduler the rb/crb again and updates the status. graceful controller will watch the update event and continues to process the event.
So, there will be no bug here.

[chaunceyjiang]

After the karmada-controller-manager restarts, the spec of the rb/crb changes,

Why does the spec change?

[chaunceyjiang]

It can be obtained from the analysis of:
#3455 (comment)

Note: This is caused by another bug.

Normally, if the resources remain unchanged and the status of the member cluster remains unchanged, then rb will not change.

It can be obtained from the analysis of:
#3455 (comment)
After the status is aggregated into the resource template, the resourceVersion in rb.spec.resource is inconsistent with that in the actual resource template.

If this resource does not have a 'status' field, then it will not trigger a change in the resourceVersion of the resource

[XiShanYongYe-Chang]

thanks
/lgtm

[RainbowMango]

/approve

[karmada-bot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: RainbowMango

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[XiShanYongYe-Chang]

Hi @chaunceyjiang, maybe we need to cherry-pick this patch to the previous branch, can you help do it?