fix(nvca): remove leftover intra-namespace egress NetworkPolicy from nvcf-backend at startup

[rohithb-hub]

TL;DR

Adds a one-time startup cleanup that deletes the allow-egress-intra-namespace NetworkPolicy from the shared nvcf-backend namespace if it still exists. This is a follow-up to the base branch's fix, which stops the policy from being created in nvcf-backend going forward but does not remove copies that already exist on clusters that reconciled before that fix shipped.

Additional Details (optional for docs, build, test, refactor, ci, chore, style, and revert PRs)

The base branch scopes ensureNetworkPolicies so nvcf-backend no longer gets the same-namespace ingress rule or the allow-egress-intra-namespace egress policy, since a same-namespace allow in that shared, multi-tenant namespace lets one customer's pod reach another customer's pod. That change only affects future reconciles: it stops new copies of the egress policy from being created, but the regular prune loop (pruneCustomNetworkPolicies) only deletes policies carrying a "custom policy" label, and this one never had it — so already-deployed clusters keep the stale policy object indefinitely, undoing part of the isolation fix.

This PR adds k8sutil.RemoveLegacyIntraNamespaceEgressPolicy, called once from the agent's existing startup bootstrap path in backendk8scache.go, scoped to a single hardcoded policy name in the shared nvcf-backend namespace only. It never touches MiniService/Helm per-instance namespaces, where the same policy is legitimate and retained.

Split into a separate PR from the base fix so the operational impact of an automated startup deletion (versus a manual/SBOM-driven remediation) can be evaluated on its own, independent of the underlying NetworkPolicy scoping fix.

For the Reviewer

• internal/util/k8sutil/netpol.go: RemoveLegacyIntraNamespaceEgressPolicy — the only new function, a straightforward delete-if-exists.
• pkg/nvca/backendk8scache.go: call site, added right after the existing per-namespace ensureNetworkPolicies bootstrap loop at agent startup.
• Please weigh in on whether an automated startup delete is acceptable here, or whether this should instead be a manual/tooled remediation step outside NVCA.

For QA (optional for docs, build, test, refactor, ci, chore, style, and revert PRs)

• go build ./..., go vet ./... — clean.
• go test ./internal/util/k8sutil/... ./pkg/nvca/... — all green.
• Not yet done: live verification against a cluster with a pre-existing allow-egress-intra-namespace policy in nvcf-backend, confirming the agent removes it on startup.

Issues

NO-REF

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 network policy behavior so function-specific namespaces allow intended same-namespace communication.
  • Shared pod-instance namespaces no longer receive unintended intra-namespace access.
  • Improved monitoring access rules for Prometheus and related services.
  • Legacy network policy configuration is removed during startup when possible, with cleanup issues logged without blocking startup.

• Documentation

  • Clarified policy names, internet egress exclusions, monitoring behavior, and namespace applicability in cluster configuration guides.

[github-actions]

🌿 Preview your docs: https://nvidia-preview-fix-nvca-cleanup-legacy-intra-namespace-netpol.docs.buildwithfern.com/nvcf

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• src/compute-plane-services/nvca/pkg/nvca/backendk8scache.go

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📝 Walkthrough

Walkthrough

Network policy reconciliation now distinguishes isolated function namespaces from the shared nvcf-backend namespace. Startup removes the legacy shared-namespace egress policy. Tests and documentation reflect the namespace-specific behavior.

Changes

Network policy namespace behavior

Layer / File(s)	Summary
Namespace-specific policy reconciliation src/compute-plane-services/nvca/internal/util/k8sutil/netpol.go, src/compute-plane-services/nvca/internal/util/k8sutil/netpol_test.go, src/compute-plane-services/nvca/pkg/nvca/k8scomputebackend_test.go	Function namespaces receive intra-namespace egress and same-namespace monitoring ingress. Shared nvcf-backend namespaces do not receive these rules. Tests validate both cases and preserve unowned policies.
Legacy policy cleanup at startup src/compute-plane-services/nvca/pkg/nvca/backendk8scache.go, src/compute-plane-services/nvca/pkg/nvca/backendk8scache_test.go	The migration helper deletes the legacy intra-namespace egress policy. Missing policies are accepted. Other cleanup failures are logged as warnings, and startup continues. Tests verify deletion.
Policy behavior documentation and validation docs/ngc-managed/cluster-management/configuration.md, docs/user/cluster-management/configuration.md, src/compute-plane-services/nvca/internal/util/k8sutil/netpol_test.go	Documentation corrects policy names and describes namespace-specific egress and monitoring ingress. Tests use Kubernetes NotFound handling for absent policies.

Estimated code review effort: 3 (Moderate) | ~20 minutes

Merge Risk: ⚪ Minimal · up to cb55b

This PR adds a localized startup cleanup for a stale NetworkPolicy in the shared backend namespace, with the stated build and test checks passing. No actionable merge-blocking risk remains beyond normal review.

Suggested reviewers: kristinapathak

🚥 Pre-merge checks | ✅ 4 | ❌ 1

❌ Failed checks (1 warning)

Check name	Status	Explanation	Resolution
Docstring Coverage	⚠️ Warning	Docstring coverage is 30.77% which is insufficient. The required threshold is 80.00%. Docstring coverage is scoped to functions touched by this diff. Analyzed 13 functions across 5 files.	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 follows Conventional Commits with the scoped type fix(nvca) and accurately describes the primary change: removing the legacy intra-namespace egress NetworkPolicy from nvcf-backend at sta…
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.

Full details: Title check

Explanation

The title follows Conventional Commits with the scoped type fix(nvca) and accurately describes the primary change: removing the legacy intra-namespace egress NetworkPolicy from nvcf-backend at startup.

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🔧 golangci-lint (2.12.2)

level=error msg="Running error: context loading failed: failed to load packages: failed to load packages: failed to load with go/packages: err: exit status 1: stderr: go: inconsistent vendoring in /src/compute-plane-services/nvca:\n\tgithub.com/NVIDIA/KAI-scheduler@v0.12.6: is explicitly required in go.mod, but not marked as explicit in vendor/modules.txt\n\tgithub.com/NVIDIA/k8s-dra-driver-gpu@v0.0.0-20251017125642-cfe35ffd3d2c: is explicitly required in go.mod, but not marked as explicit in vendor/modules.txt\n\tgithub.com/NVIDIA/nvcf/src/libraries/go/lib@v0.0.0-20260722095202-f5e2792f5630: is explicitly required in go.mod, but not marked as explicit in vendor/modules.txt\n\tgithub.com/aws/aws-sdk-go@v1.55.5: is explicitly required in go.mod, but not marked as explicit in vendor/modules.txt\n\tgithub.com/bombsimon/logrusr/v4@v4.1.0: is explicitly required in go.mod, but not marked as explicit in vendor/modules.txt\n\tgithub.com/evanphx/json-patch/v5@v5.9.11: is explicitly required in

... [truncated 21721 characters] ...

i: is replaced in go.mod, but not marked as replaced in vendor/modules.txt\n\tk8s.io/apiextensions-apiserver: is replaced in go.mod, but not marked as replaced in vendor/modules.txt\n\tk8s.io/apimachinery: is replaced in go.mod, but not marked as replaced in vendor/modules.txt\n\tk8s.io/client-go: is replaced in go.mod, but not marked as replaced in vendor/modules.txt\n\tk8s.io/component-base: is replaced in go.mod, but not marked as replaced in vendor/modules.txt\n\tsigs.k8s.io/controller-runtime: is replaced in go.mod, but not marked as replaced in vendor/modules.txt\n\tgolang.org/x/crypto: is replaced in go.mod, but not marked as replaced in vendor/modules.txt\n\n\tTo ignore the vendor directory, use -mod=readonly or -mod=mod.\n\tTo sync the vendor directory, run:\n\t\tgo mod vendor\n"

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Actionable comments posted: 1

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Inline comments:
In `@src/compute-plane-services/nvca/pkg/nvca/backendk8scache.go`:
- Around line 748-754: Add a startup migration test covering an existing
allow-egress-intra-namespace policy: seed that policy in c.podInstanceNamespace
before BackendK8sCacheBuilder.Start, start the builder, and assert the policy is
deleted. Extend the existing shared-namespace test setup without changing
unrelated behavior, and use the repository’s native Go test tooling as
appropriate.

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📥 Commits

Reviewing files that changed from the base of the PR and between 7cde8df and ee72855.

📒 Files selected for processing (6)

• docs/ngc-managed/cluster-management/configuration.md
• docs/user/cluster-management/configuration.md
• src/compute-plane-services/nvca/internal/util/k8sutil/netpol.go
• src/compute-plane-services/nvca/internal/util/k8sutil/netpol_test.go
• src/compute-plane-services/nvca/pkg/nvca/backendk8scache.go
• src/compute-plane-services/nvca/pkg/nvca/k8scomputebackend_test.go

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