Cilium was one of ~12 components inside a single `platform` Kustomization with wait:true,
so the CNI's health was indistinguishable from eleven unrelated components in the tier's
Ready condition, and the only emergency valve was freezing the whole platform tier. This
repo already set the precedent in reverse (oauth2-proxy and headlamp were split OUT so
unhealthy leaves would not gate a tier); Cilium is the mirror image — the one component
that legitimately SHOULD gate everything.
New clusters/base/cilium.yaml: path ./platform/cilium, wait:true, prune:true, interval 1h
(a CNI does not need a 10m re-render cadence; kustomize-controller is source-triggered so
a push still reconciles immediately — the interval is only the drift-correction floor),
timeout 10m (a 3-node DaemonSet rollout with wait exceeds the 5m default),
dependsOn:[flux-system], and postBuild.substituteFrom: cluster-vars — the last is
LOAD-BEARING, not decorative: helmrelease.yaml references ${K3S_API_HOST} and
kustomize-controller now runs --feature-gates=StrictPostBuildSubstitutions=true, so
without it this Kustomization would fail immediately.
*** THE HAZARD WAS FAR WORSE THAN "the CNI gets pruned" ***
platform/cilium/namespace.yaml is the ONLY declaration of Namespace/kube-system anywhere
under ./platform, and the live object carries kustomize.toolkit.fluxcd.io/name=platform.
With prune:true, the moment ./platform/cilium leaves platform's path the stale set is not
"the Cilium HelmRelease" — it is `kubectl delete namespace kube-system`, taking coredns,
metrics-server, local-path AND Cilium. A full cluster kill, not a CNI kill.
TWO INDEPENDENT PROTECTIONS, deliberately not trusting either alone:
1. prune:false on `platform` for this transition merge — Flux's documented Procedure 1 for
moving resources between Kustomizations. Chosen over the per-resource
`kustomize.toolkit.fluxcd.io/prune: disabled` annotation because that needs THREE merges
and leaves the new Kustomization owning resources it can never prune.
2. The pruner's own owner-label filter. In v1.4.0, prune() passes Inclusions:
GetOwnerLabels(obj.Name...), so platform only deletes objects whose LIVE labels still
say name=platform. The new cilium Kustomization relabels all three to name=cilium on
apply, and platform.dependsOn:[cilium] is REVISION-GATED, so platform provably cannot
reconcile revision N until cilium has APPLIED revision N. The relabel deterministically
precedes the prune.
Protection 2 alone would probably have sufficed. Not betting kube-system on "probably".
NOTED FOR THE FUTURE, in-file: anyone moving a platform/* component must first check
whether it is the sole declarer of a shared Namespace — that turns a component-scoped
prune into a cluster-scoped one.
Verified: `kubectl kustomize platform` goes 88 -> 85 documents, 3 removed / 0 added /
0 CHANGED, and `kubectl kustomize platform/cilium` reproduces those 3 byte-identical
(sha256-matched). A pure ownership move; no Cilium value touched. L0 substitution gate
103 assertions (was 102), new cilium row, 0 hazards. Server-side dry-run against the live
cluster accepted both CRs. clusters/prod renders clean off the same base.
MERGE 2 (restore prune:true) follows only after verifying: 13/13 Ready; kube-system, the
HelmRelease and the HelmRepository all relabelled to name=cilium; platform's inventory no
longer lists them; and Cilium pod ages/restarts UNCHANGED from
cilium-2f8h8 r=0 2026-09-01T05:55:27Z / cilium-425m8 r=1 2026-08-30T13:25:10Z /
cilium-54cww r=0 2026-09-01T05:55:26Z, HelmRelease v11.
Serves: R-PLAT-01, R-GITOPS-01.
Co-Authored-By: Claude Opus 5 (1M context) <[email protected]>
platform/
Cluster-wide platform services, Flux-managed (R-PLAT-01, R-GITOPS-01/02/03). Reconciled
by the platform Flux Kustomization defined in clusters/base/platform.yaml,
before apps/.
Governing spec: docs/05-gitops-and-delivery.md,
docs/01-architecture-overview.md.
Phase 0 scaffolding only. Every component here is a structurally-correct stub — a Flux HelmRelease and/or Kustomization with a values placeholder, a README citing the governing ADR/spec, and TODOs for the phase that fills it in. No cluster exists; nothing reconciles yet. Do not add working config, secrets, or provisioning under Phase 0 (spec
AGENTS.md§1/§5/§6,roadmap/phases.md).
Reconciliation flow (how a change lands)
git (source of truth)
│ operator PR → CI (lint · schema · Kyverno L0 · Chainsaw) → merge to tracked branch
▼
Flux GitRepository (clusters/base/flux-system.yaml)
▼
Flux Kustomization "platform" → ./platform (this dir) ── substituteFrom cluster-vars ──┐
│ prune=true (drift correction, R-GITOPS-03) · wait=true │ R-ENV-02
▼ │
Flux Kustomization "apps" → ./apps (dependsOn platform) ─ substituteFrom cluster-vars ──┘
Git is authoritative; the cluster conforms to git and drift is auto-corrected (R-GITOPS-01/03).
Manual kubectl apply of platform state is prohibited (spec AGENTS.md §5).
The dev ↔ prod overlay model (R-ENV-02)
Platform manifests are authored once. Every value that legitimately differs between environments
is a ${TOKEN} resolved from the cluster-vars ConfigMap via Flux postBuild.substituteFrom. The
clusters/dev and clusters/prod overlays differ only by the values they patch into
cluster-vars (issuer, replica counts, storage sizes, retention). See
clusters/README.md. Base manifests are never forked per environment.
Components (one directory each)
| Dir | Component | Governing ADR / spec | Serves |
|---|---|---|---|
cilium/ |
CNI + kube-proxy replacement + Gateway API + Egress Gateway + Hubble | ADR-0002, docs/03 | R-NET-* |
longhorn/ |
Replicated block storage; 3-replica default StorageClass + bulk tier | ADR-0003, docs/04 | R-STATE-* |
cert-manager/ |
TLS via Let's Encrypt DNS-01 (Cloudflare); staging + prod ClusterIssuers | ADR-0006, docs/08 | R-TLS-* |
externaldns/ |
Automatic DNS records for public services (Cloudflare) | docs/09 | R-DNS-* |
gateway/ |
Gateway API GatewayClass + shared HTTPS Gateway + wildcard cert | ADR-0002/ADR-0006, docs/09 | R-DNS-01, R-TLS-01 |
monitoring/ |
kube-prometheus-stack + Loki + Grafana Alloy + Alertmanager | docs/10 | R-OBS-* |
velero/ |
Off-cluster backup/DR of volumes + resource state | ADR-0003, docs/04 | R-STATE-03 |
kubevirt/ |
KubeVirt + CDI (IaaS: application VMs on the same K8s surface) | ADR-0005, docs/06 | R-PLAT-03 |
image-automation/ |
Flux image-update-automation (hands-off image tag advance) | ADR-0009, docs/11 | R-UPD-02 |
keycloak/ |
Platform IdP (OIDC + SAML), config-as-code, PostgreSQL on Longhorn | ADR-0014, docs/15 | R-IDP-* |
oauth2-proxy/ |
Forward-auth at the Gateway for non-OIDC apps → Keycloak | ADR-0014, docs/15 | R-IDP-* |
kyverno/ |
L0 policy-as-code gate — OWNED BY THE POLICY ENGINEER (WS-TEST). | ADR-0011, docs/14 | R-TEST-* |
⚠️ INTEGRATION TODO(PM): wire kyverno into the platform kustomization
platform/kyverno/ is authored by a different agent (the policy engineer, WS-TEST). This
workstream did not create any files under platform/kyverno/ and must not.
platform/kustomization.yaml intentionally omits - kyverno. Once the
policy engineer's files land, the PM must add - kyverno to that list (recommended first, so
policies are present before other components reconcile). The line is present as a commented TODO in
the kustomization.
Secrets
Every secret referenced below (Cloudflare API token, Velero backup-target creds, Keycloak admin/DB, oauth2-proxy cookie/client secrets) is referenced by name only and will be committed SOPS-encrypted (WS-SEC, ADR-0007). No plaintext secret appears anywhere in this tree.
Cross-workstream contracts surfaced by these stubs
- cilium (WS-NET ↔ WS-INFRA): Cilium's initial CNI install is done by Ansible at cluster bootstrap (docs/02, Phase 1). The HelmRelease here manages Cilium config thereafter; its Helm values MUST match the Ansible bootstrap values (kubeProxyReplacement, k8sServiceHost/Port, API server host) or reconciliation will fight the bootstrap. Contract owner: WS-NET + WS-INFRA.
- gateway + cert-manager + externaldns (WS-NET + WS-SEC): the shared Gateway listener, the
wildcard
*.home.keithjackson.devcert, and the ExternalDNS source all reference each other; they form the "Issuer + Gateway TLS" interface inroadmap/workstreams.md. - image-automation (WS-UPDATE): this dir holds only the cluster-wide ImageUpdateAutomation +
git write-back. Per-service
ImageRepository/ImagePolicyare rendered from each ServiceDefinition'supdateblock (WS-GITOPS/WS-UPDATE), living withapps/. - keycloak/oauth2-proxy (WS-SEC): the SSO/auth contract (
authblock → Keycloak client / oauth2-proxy protection) is owned by WS-SEC; these are placeholders pending that contract.