fix(nvca): apply primary-PV selector in model cache cleanup

[mesutoezdil]

TL;DR

The model cache cleanup selector was left empty because the result of
labels.Selector.Add was discarded. An empty selector matches every object, so
idle cleanup listed every PV in the cluster instead of only model-cache primary
PVs. This skewed the model cache backend count metric and made the cleanup loop
scan all PVs each tick. Reassign the Add result so the requirement applies, plus
a regression test.

Issues

Closes #440

Testing

go test ./pkg/storage/... with envtest passes. Added TestPrimaryPVSelector,
which fails before the fix (empty selector matches an empty label set) and passes
after. No QA needed.

Checklist

• I am familiar with the Contributing Guidelines.
• I have signed off my commits for Developer Certificate of Origin (DCO) compliance.
• New or existing tests cover these changes.
• The documentation is up to date with these changes.

Summary by CodeRabbit

• Bug Fixes

  • Corrected persistent volume label selector construction so model cache cleanup only targets volumes with the required primary-volume label.
  • Prevents unlabeled volumes from being matched incorrectly during cleanup.

• Tests

  • Added coverage validating selector behavior for empty/unlabeled volumes and for volumes carrying the expected primary-volume label value.

[coderabbitai]

📝 Walkthrough

Walkthrough

The primary PV selector now retains its label requirement, and a unit test verifies that it rejects unlabeled objects and matches PVs with the primary label.

Changes

Primary PV selector

Layer / File(s)	Summary
Selector construction and matching validation src/compute-plane-services/nvca/pkg/storage/modelcache_cleanup.go, src/compute-plane-services/nvca/pkg/storage/modelcache_cleanup_test.go	primaryPVSel is reassigned after adding the primary PV label requirement, with tests covering matching and non-matching label sets.

Estimated code review effort: 1 (Trivial) | ~5 minutes

Suggested reviewers: balajinvda

🚥 Pre-merge checks | ✅ 4 | ❌ 1

❌ Failed checks (1 warning)

Check name	Status	Explanation	Resolution
Docstring Coverage	⚠️ Warning	Docstring coverage is 0.00% which is insufficient. The required threshold is 80.00%.	Write docstrings for the functions missing them to satisfy the coverage threshold.

✅ Passed checks (4 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The title is valid Conventional Commits and accurately describes the bug fix in model cache cleanup.
Linked Issues check	✅ Passed	The selector fix and regression test satisfy the linked issue's requirements.
Out of Scope Changes check	✅ Passed	The PR only changes the cleanup fix and its test, with no unrelated scope visible.

✨ Finishing Touches

🧪 Generate unit tests (beta)

• Create PR with unit tests

Warning

There were issues while running some tools. Please review the errors and either fix the tool's configuration or disable the tool if it's a critical failure.

🔧 golangci-lint (2.12.2)

level=error msg="[linters_context] typechecking error: pattern ./...: directory prefix . does not contain main module or its selected dependencies"

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[coderabbitai]

🧹 Nitpick comments (1)

src/compute-plane-services/nvca/pkg/storage/modelcache_cleanup_test.go (1)

38-46: 📐 Maintainability & Code Quality | 🔵 Trivial | ⚡ Quick win

Use a table-driven test for the selector cases.

This test covers multiple scenarios inline. Convert them to table-driven cases so additional selector behaviors can be added consistently.

As per coding guidelines, tests covering multiple scenarios should use table-driven tests.

Proposed refactor

 func TestPrimaryPVSelector(t *testing.T) {
-	assert.False(t, primaryPVSel.Matches(labels.Set{}),
-		"empty label set must not match; selector should require the primary-PV label")
-	assert.True(t, primaryPVSel.Matches(labels.Set{primaryPVLabelKey: "true"}),
-		"a PV carrying the primary-PV label must match")
+	tests := []struct {
+		name     string
+		labelSet labels.Set
+		want     bool
+	}{
+		{
+			name: "empty labels do not match",
+			labelSet: labels.Set{},
+			want: false,
+		},
+		{
+			name:     "primary PV label matches",
+			labelSet: labels.Set{primaryPVLabelKey: "true"},
+			want:     true,
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			assert.Equal(t, tt.want, primaryPVSel.Matches(tt.labelSet))
+		})
+	}
 }

🤖 Prompt for AI Agents

Verify each finding against current code. Fix only still-valid issues, skip the
rest with a brief reason, keep changes minimal, and validate.

In `@src/compute-plane-services/nvca/pkg/storage/modelcache_cleanup_test.go`
around lines 38 - 46, Convert TestPrimaryPVSelector into a table-driven test
with named cases for the empty label set and a set containing primaryPVLabelKey.
Iterate over the cases with subtests, asserting each expected Matches result
while preserving the existing failure messages or equivalent scenario-specific
diagnostics.

Source: Coding guidelines

🤖 Prompt for all review comments with AI agents

Verify each finding against current code. Fix only still-valid issues, skip the
rest with a brief reason, keep changes minimal, and validate.

Nitpick comments:
In `@src/compute-plane-services/nvca/pkg/storage/modelcache_cleanup_test.go`:
- Around line 38-46: Convert TestPrimaryPVSelector into a table-driven test with
named cases for the empty label set and a set containing primaryPVLabelKey.
Iterate over the cases with subtests, asserting each expected Matches result
while preserving the existing failure messages or equivalent scenario-specific
diagnostics.

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📥 Commits

Reviewing files that changed from the base of the PR and between 2647a51 and 569d778.

📒 Files selected for processing (2)

• src/compute-plane-services/nvca/pkg/storage/modelcache_cleanup.go
• src/compute-plane-services/nvca/pkg/storage/modelcache_cleanup_test.go

🚧 Files skipped from review as they are similar to previous changes (1)

• src/compute-plane-services/nvca/pkg/storage/modelcache_cleanup.go

[balajinvda]

Changes look good.