jakman85andClaude Opus 5
b7d6ba3d5f
Prod's UniFi VM has no disk. `DataVolume unifi/unifi-rootdisk` stuck in
ImportScheduled for hours, because Kyverno denied CDI's own generated pod:
validate.kyverno.svc-fail denied Pod/unifi/importer-prime-<uid>
require-auth-mode-label (R-IDP-02)
require-egress-class-label (R-NET-05)
Both policies match any Pod in an `app-namespace: "true"` namespace with no
exclusion, and CDI generates `importer-*` itself — it cannot carry repo labels.
A COLD-START defect, not a prod quirk: dev's identical import Succeeded 9 days
ago, before the policies enforced, so dev has never exercised it and would hit it
on any rebuild. Fourth bug of this shape in two days.
MECHANISM: a MUTATE ClusterPolicy that ADDS
`egress-class: internet` + `auth-mode: none` (add-if-absent anchor) to Pods on
CREATE in app namespaces WHEN the requesting subject is ServiceAccount
`cdi/cdi-sa`. Both validate policies are untouched — no exclude, no exception,
`background: true` preserved on them.
Why mutate beats exempting: the requirement stays literally true ("every pod in an
app namespace declares both labels") and the values are HONEST — the importer does
pull over the default WAN path, and `internet` is the least-reach class (it does
not grant the VPN path); a transient worker pod with no UI genuinely is
`auth-mode: none`.
THE MATCH IS IDENTITY, NOT A NAME. `subjects: ServiceAccount cdi/cdi-sa` is the
AdmissionReview userInfo, taken from the real prod denial
(`system:serviceaccount:cdi:cdi-sa`, name importer-prime-…, op CREATE). A name
prefix is attacker-choosable; a requesting ServiceAccount is not — and the test
proves it, with a fixture `importer-prime-forged-by-an-app` that copies both the
name prefix AND CDI's labels and is still DENIED. Covers every CDI worker kind
(importer/uploader/cloner) without enumerating names that change per release.
Confirmed on prod that cdi-sa is the only cdi-namespace SA that can create pods.
REJECTED, and the first one is a trap worth recording:
* PolicyException — the CRD EXISTS (v2/v2beta1, from the pre-applied bundle) but
all controllers run `--enablePolicyException=false` (verified live on prod:
admission, background and reports controllers all carry the flag). An exception
would apply cleanly through Flux and be SILENTLY IGNORED. Enabling the gate is a
cluster-wide capability change for no gain over the mutate.
* `exclude` scoped to cdi-sa — sound identity, worse consequences: any userInfo
match forces `background: false`, which would drop background scanning and
policy-report coverage of R-NET-05/R-IDP-02 for ALL EXISTING PODS to fix one pod
class. It also leaves the importer with no labels at all — the unlabelled
fall-through that require-egress-class-label's own header calls a fail-open leak.
* name-prefix / CDI-label matching — attacker-choosable, and proven walkable.
TWO-WAY PROOF, non-vacuous by construction — same resource, different requester,
opposite outcomes (verified by me, not just reported):
userinfo cdi-sa -> mutate pass, require-egress-class pass, require-auth-mode pass
userinfo ordinary -> mutate SKIP, require-egress-class FAIL, require-auth-mode FAIL
Kyverno L0 went 17 -> 29 tests passed, 0 failed. The mutate policy is deliberately
kept OUT of the existing tests/kyverno-test.yaml: that suite declares no userinfo,
and without userinfo the offline engine does not discriminate on subjects — it
mutates everything, which would have silently turned its negative rows into passes.
platform-config/kustomization.yaml is the live apply path for these ClusterPolicies;
without it the policy never reaches a cluster.
RESIDUAL TRADE-OFF, reversible by deleting one file: anything created by cdi-sa in
an app namespace now has these labels supplied rather than being rejected for not
declaring them — including a pod that is not a CDI worker. That identity already
holds `pods create/delete` cluster-wide via ClusterRole `cdi`, so it is not a new
capability; what changes is that for that one identity the declaration is assumed
rather than demanded. restrict-host-namespaces, the namespace default-deny baseline
and the CiliumNetworkPolicies all still apply.
FIRST resource-mutating policy on this cluster: kyverno-resource-mutating-webhook-cfg
holds 0 webhooks today; with autoUpdateWebhooks=true Kyverno registers
mutate.kyverno.svc-fail for Pods within seconds of this applying. Prod's
forceFailurePolicyIgnore=false makes it failurePolicy: Fail — same posture as the
validating webhook already in that path.
CDI retries importer creation on a loop, so the stuck import should proceed once
this lands. The detached prime-be3f9d1c-… 40 GiB scratch PVC is separate operator
cleanup; untouched, as is the DataVolume.
VERIFIED: full CI gate PASS. Nothing applied to any cluster.
Refs R-IDP-02, R-NET-05, R-PLAT-01.
Co-Authored-By: Claude Opus 5 <[email protected]>
platform/kyverno — L0 policy-as-code gate & admission enforcer (T-0.5)
Kyverno is the platform's L0 static/policy gate (in CI, no cluster) and its
in-cluster admission enforcer (ADR-0011, docs/14, docs/07). The policies here
encode spec invariants as code: they run in CI as a merge gate today (Phase 0, no
cluster) and the same policies are wired to run in-cluster as an admission controller
later (Phase 2, admission/).
Enforcement complements, never replaces, behavior tests. A policy admitting a manifest is not proof the runtime behaves (R-TEST-01). The L2/L3 Chainsaw behavior + fault-injection tests remain mandatory. See
admission/README.md.
Layout
platform/kyverno/
├── README.md # this file: policy→requirement map + CI entrypoint
├── labels.md # label/annotation convention (PROPOSED contract — escalated)
├── policies/ # ClusterPolicies (authored once; CI + admission)
│ ├── require-default-deny-baseline.yaml # R-NET-01 (generate baseline)
│ ├── validate-default-deny-shape.yaml # R-NET-01 (reject malformed baseline)
│ ├── disallow-plaintext-secrets.yaml # R-SEC-01 (CI-only: sops block required)
│ ├── restrict-host-namespaces.yaml # R-SEC-02 (+R-NET-01 bypass guard)
│ ├── require-egress-class-label.yaml # R-NET-05
│ ├── require-auth-mode-label.yaml # R-IDP-02
│ └── label-cdi-worker-pods.yaml # R-NET-05+R-IDP-02 (mutate: CDI's own worker pods)
├── servicedefinition/ # ServiceDefinition shape validation (kyverno-json)
│ ├── validate-servicedefinition.yaml # R-GITOPS-02
│ ├── payloads/ (valid-* / invalid-*) # pass & fail fixtures
│ └── README.md
├── tests/ # `kyverno test` suite — runnable L0 tests NOW, no cluster
│ ├── kyverno-test.yaml # policies × fixtures × expected results
│ ├── resources/ (good-* / bad-* fixtures + generated golden)
│ └── controller-worker-pods/ # the CDI-worker mutation, proven BOTH ways
│ ├── kyverno-test.yaml # 2 Tests: cdi-sa requester vs ordinary requester
│ ├── userinfo-cdi-sa.yaml / userinfo-ordinary.yaml
│ └── resources/ + patched/ # real + FORGED importer pods; expected patch
├── admission/ # in-cluster enforcing bundle (scaffolding, T-2.7)
│ ├── namespace.yaml · helmrelease.yaml · kustomization.yaml
│ ├── secret-provenance.yaml # R-SEC-01 admission variant (provenance)
│ └── README.md
└── scripts/run-l0.sh # the single-command CI entrypoint for the gate
Policy → requirement map
| Policy / artifact | Rule(s) | Requirement | Spec source | Behaves |
|---|---|---|---|---|
require-default-deny-baseline |
generate-default-deny |
R-NET-01 | docs/03 default-deny baseline | Every app namespace auto-gets a deny-all (ingress+egress, DNS-only) NetworkPolicy |
validate-default-deny-shape |
baseline-must-deny-both-directions |
R-NET-01 | docs/03 | A baseline that leaves a direction open is rejected |
disallow-plaintext-secrets |
secrets-must-be-sops-encrypted |
R-SEC-01 | docs/07, docs/05, ADR-0007 | Committed Secrets must be SOPS-encrypted (sops block); plaintext rejected. CI-only |
restrict-host-namespaces |
disallow-host-namespaces, disallow-privileged-containers |
R-SEC-02 (+R-NET-01) | docs/07 least reach | App pods can't use hostNetwork/PID/IPC or privileged (would bypass default-deny) |
require-egress-class-label |
require-egress-class |
R-NET-05 | docs/03, docs/13 | App pods must declare egress-class ∈ {internet,vpn} |
require-auth-mode-label |
require-auth-mode |
R-IDP-02 | docs/13, docs/15 | App pods must declare auth-mode ∈ {oidc,forward-auth,native,none} |
label-cdi-worker-pods (mutate) |
add-worker-pod-labels |
R-NET-05, R-IDP-02 | docs/03, docs/13 | CDI's controller-generated worker pods (importer-*/uploader-*/cloner-*, created by SA cdi/cdi-sa) get egress-class: internet + auth-mode: none added, so they satisfy the two policies above instead of being exempted from them. Matched on the generating ServiceAccount, never a pod-name prefix |
validate-servicedefinition (kyverno-json) |
shape / dependencies / storage | R-GITOPS-02 | docs/13 (+03,15) | ServiceDefinition is schema/invariant valid before render; public⇒not none auth |
admission/secret-provenance |
secrets-must-be-flux-managed |
R-SEC-01 | docs/07 | Admission-only variant: app-ns Secrets must come from Flux/SOPS (see below) |
Coverage of the T-0.5 requirement set: R-TEST-01 (behavior-tagged, reproducible
tests — this whole suite), R-NET-01, R-SEC-01, R-SEC-02, R-IDP-02,
R-NET-05, R-GITOPS-02. Every policy carries its R-* IDs in the
homelab.keithjackson.dev/requirements annotation so the coverage report can pick
them up automatically.
CI entrypoint (the L0 gate)
CI (WS-GITOPS .gitea/workflows, then Gitea Actions) runs the single command:
platform/kyverno/scripts/run-l0.sh
which performs, with pinned tool versions (KYVERNO_VERSION, KYVERNO_JSON_VERSION):
# 1) ClusterPolicy tests — offline, no cluster
kyverno test platform/kyverno/tests
# 2) ServiceDefinition validation — offline, no cluster
kyverno-json scan --policy platform/kyverno/servicedefinition/validate-servicedefinition.yaml \
--payload <each catalog/ ServiceDefinition and the valid-* fixtures> # must pass
# plus each invalid-* fixture must be REJECTED (script asserts non-zero exit)
kyverno test emits pass/fail per policy×rule×resource and supports JUnit output for
the coverage/merge gate:
kyverno test platform/kyverno/tests --output junit > results/kyverno-l0.junit.xml
Exit non-zero fails the merge gate (docs/14 gating rules). Deterministic, hermetic,
self-contained — no cluster, no external state (reproducibility contract, R-TEST-02).
Notes / handoffs
- Label keys are a proposed contract (
labels.md) shared with WS-NET / WS-SEC / WS-GITOPS. Values are spec-fixed; keys need owner sign-off (coordination-protocol §2). - Controller-generated pods are a cold-start hazard. A policy that matches any Pod in an
app namespace also matches pods that no manifest in git authors. Prod hit this on 2026-09-06:
require-auth-mode-label+require-egress-class-labeldenied CDI's ownimporter-prime-*pod, soDataVolume unifi/unifi-rootdiskstuck inImportScheduledand the UniFi VM had no disk. Fix:policies/label-cdi-worker-pods.yamlmutates those pods to carry truthful labels (matched on the generating ServiceAccountcdi/cdi-sa), rather than excluding them.virt-launcher-*pods need nothing — they inherit the VM pod-template labels. KubeVirt hotplug (hp-volume-*) and export (virt-export-*) pods do not inherit them and are unused here; extend the same policy if either is adopted. PolicyExceptionis NOT usable in this install: the Kyverno admission/background/reports controllers all run--enablePolicyException=false(chart default, verified on prod 2026-09-06). The CRD exists (from the pre-applied CRD bundle) so aPolicyExceptionwould APPLY cleanly and be silently ignored — a policy hole that looks like a fix and isn't.- Secrets CI vs admission divergence is deliberate and documented in
admission/README.mdandpolicies/disallow-plaintext-secrets.yaml. - The ServiceDefinition JSON Schema (WS-GITOPS T-0.3) is the complementary structural
contract; this Kyverno policy encodes the invariants from
docs/13. - Tool availability: neither
kyvernonorkyverno-jsonis installed on the WS-TEST workstation, so this suite was authored but not executed here; the CI agent (T-0.2/T-0.4 harness) runsscripts/run-l0.shas the gate.