fix: Volcano scheduler panic when scheduling Pods with delayed binding PVCs #4484
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…g PVCs Signed-off-by: ouyangshengjia <[email protected]>
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Summary of Changes
Hello @ouyangshengjia, I'm Gemini Code Assist1! I'm currently reviewing this pull request and will post my feedback shortly. In the meantime, here's a summary to help you and other reviewers quickly get up to speed!
This pull request provides a crucial bug fix for the Volcano scheduler, resolving a panic that previously occurred when scheduling Pods that use delayed binding PersistentVolumeClaims. The root cause was an attempt to perform storage capacity checks even when the CSI storage feature was explicitly disabled. The changes introduce a safeguard to prevent these unnecessary checks under such conditions, thereby ensuring the scheduler's stability and correct operation.
Highlights
- Bug Fix: Addresses a critical panic in the Volcano scheduler that occurred when scheduling Pods with delayed binding PersistentVolumeClaims (PVCs), specifically when the
--csi-storagefeature was disabled (which is its default setting). - Conditional Logic: Introduces a new conditional check at the beginning of the
hasEnoughCapacityfunction inpkg/scheduler/capabilities/volumebinding/binder.go. This check ensures that ifcapacityCheckEnabledisfalse, the function immediately returnstrue(indicating sufficient capacity) andnilfor capacity and error, bypassing the problematic capacity check logic. - Testing: Adds a new unit test,
TestBinderWithCapacityCheckDisabled, topkg/scheduler/capabilities/volumebinding/binder_test.go. This test verifies that thehasEnoughCapacityfunction behaves as expected when the capacity check feature is disabled, confirming the bug fix.
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Code Review
This pull request correctly fixes a panic in the Volcano scheduler that occurs when scheduling pods with delayed binding PVCs and CSI storage is disabled. The fix involves adding a check to bypass capacity validation when the feature is disabled, which prevents a nil pointer dereference. A new test case has been added to cover this scenario, and I've suggested an improvement to this test to make it more robust. Overall, the change is good and addresses the reported issue effectively.
| // This is an optional feature. If disabled, we assume that | ||
| // there is enough storage. | ||
| if !b.capacityCheckEnabled { | ||
| return true, nil, nil | ||
| } |
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This check prevents a nil pointer dereference when b.capacityCheckEnabled is false. This is a good defensive programming practice.
| func TestBinderWithCapacityCheckDisabled(t *testing.T) { | ||
| logger, ctx := ktesting.NewTestContext(t) | ||
| ctx, cancel := context.WithCancel(ctx) | ||
| defer cancel() | ||
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| binder := &volumeBinder{ | ||
| capacityCheckEnabled: false, | ||
| } | ||
| sufficient, _, err := binder.hasEnoughCapacity(logger, "", nil, nil, nil) | ||
| if err != nil { | ||
| t.Errorf("returned error: %v", err) | ||
| } | ||
| if !sufficient { | ||
| t.Error("expected sufficient, got insufficient") | ||
| } | ||
| } |
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While this test passes with the fix, it's a bit brittle because it passes nil for the claim parameter. This would cause a panic on claim.Spec if the capacityCheckEnabled check wasn't at the very beginning of the function.
To make the test more robust and accurately reflect the scenario that caused the original panic (accessing a nil csiDriverLister), it would be better to pass a valid claim with a storage request. This ensures we are testing the intended logic path.
This change will make the test more resilient to future code refactoring.
logger, ctx := ktesting.NewTestContext(t)
ctx, cancel := context.WithCancel(ctx)
defer cancel()
binder := &volumeBinder{
capacityCheckEnabled: false,
}
// A PVC with a storage request is needed to get past the first check in hasEnoughCapacity
// and properly test the scenario where csiDriverLister would be accessed.
pvc := makeTestPVC("test-pvc", "1Gi", "", pvcUnbound, "", "1", &waitClassWithProvisioner)
sufficient, _, err := binder.hasEnoughCapacity(logger, provisioner, pvc, &storagev1.StorageClass{}, nil)
if err != nil {
t.Errorf("returned error: %v", err)
}
if !sufficient {
t.Error("expected sufficient, got insufficient")
}
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/lgtm |
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/approve |
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[APPROVALNOTIFIER] This PR is APPROVED This pull-request has been approved by: Monokaix The full list of commands accepted by this bot can be found here. The pull request process is described here
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Approvers can indicate their approval by writing |
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Please also cherry-pick to release1.12 |
@Monokaix This bug was introduced by the feature "adapt k8s 1.33". It does not exist in release1.12. |
4 participants
What type of PR is this?
/kind bug
What this PR does / why we need it:
volcano-scheduler with the startup argument
--csi-storage=false(the argument defaults false), will panic when scheduling Pods with delayed binding PVCs.Which issue(s) this PR fixes:
Fixes #4480
Special notes for your reviewer:
@JesseStutler
Does this PR introduce a user-facing change?