INCIDENT FIX. Prod's external-dns DELETED EVERY ONE OF DEV'S PUBLIC DNS RECORDS. Both
clusters ran policy: sync against the SAME Cloudflare zone with the SAME implicit
txtOwnerId (`default`), so prod believed it owned dev's records, found no matching sources,
and removed them plus their TXT registry entries. Dev recovered ~30s after prod was scaled
to 0; verified restored against Cloudflare directly (my first check went through a pfSense
override and falsely showed healthy — local resolvers are not evidence about public DNS).
THE MISS WAS MINE, and it was a failure of imagination in how I briefed every agent. I put
"never touch dev" in brief after brief and enforced it — separate kubeconfigs, verified
--limit, sha-checked dev's kubeconfig before and after. Every one of those guards held. NONE
of them covered SHARED EXTERNAL RESOURCES. Prod reconciling its OWN correctly-authored
manifests reached across a third party and destroyed dev's state. Cluster-to-cluster
isolation was verified; the dependency that mattered was cluster-to-Cloudflare.
Operator's architecture: dev -> *.dev.home.keithjackson.dev, prod ->
*.prod.home.keithjackson.dev, apex CNAME <svc>.home -> <svc>.prod.home.
PHASE 1 ONLY (this commit): prod moves to its own subdomain. DEV IS NOT MIGRATED and its
effective hostname stays home.keithjackson.dev, so dev renders byte-identically and nothing
live moves. That alone ends the collision and unblocks prod. Phase 2 (dev -> dev.home. +
apex CNAMEs) is deferred to when the operator is present: it relocates Keycloak's issuer and
12 clients' redirect URIs, forces a rolling k3s restart and kubectl SSO re-issue for every
user, and moves gitea.home. — which is BOTH the GitOps source and the current push target.
BASE_DOMAIN WAS A DEAD KNOB — it existed in cluster-vars but the status report flagged it as
referenced by nothing, because hostnames were hardcoded throughout. Now real: 141 refs.
Searched the AUTHORITATIVE reconciled set by resolving each Flux spec.path transitively via
conformance/lib/status.py — the same resolver the L0 gate uses, so "what Flux reconciles"
has one definition. 185 occurrences across 47 files in 154 reconciled files. Tokenized:
Gateway listeners, the wildcard Certificate, coredns-custom, external-dns, Keycloak
instance/realm (26 redirect URIs), oauth2-proxy, Grafana OIDC, all HTTPRoutes, Homepage's 15
links, 30 runbook_urls, unifi cloud-init, render.py's ZONE constant (which drove
--oidc-issuer-url/--cookie-domain/--whitelist-domain on every forward-auth sidecar) and 11
catalog/ ServiceDefinitions re-rendered canonically. Left alone: 43 comment/prose
occurrences and non-reconciled paths.
TWO THAT CANNOT BE TOKENIZED, flagged not forced:
- headlamp's OIDC URLs live inside a SOPS-encrypted Secret; re-encrypting rewrites the MAC
over every value and the OFFLINE harness cannot verify it (kustomize does not decrypt),
so an error would break live-dev SSO with no pre-flight proof. Prod needs its own copy
anyway — client secrets are realm-scoped.
- kube-apiserver --oidc-issuer-url is a k3s SERVER FLAG, not a manifest, so Flux can never
reach it. Done on the inventory seam instead (k3s_base_domain -> k3s_oidc_issuer_url,
overridden in group_vars/k3s_prod). Verified per host: dev keeps the default, prod gets
prod.home.
EXTERNAL-DNS OWNER, the actual incident cause: txtOwnerId is now explicit per environment —
dev renders exactly `default` (the chart default it was already using, so its existing
records stay recognised) and prod gets `prod`. The BASE default is a NON-COLLIDING SENTINEL,
deliberately not `default`, so a future environment that forgets the knob owns nothing and
can delete nothing rather than silently inheriting dev's identity.
I OVERRODE ONE AGENT DECISION against our own prior finding: it narrowed prod's
domainFilters to prod.home.keithjackson.dev as defence in depth. FINDING F-DNS1
(DECISIONS-LOG 2026-08-17) already proved a subdomain filter DROPS THE PARENT ZONE —
ExternalDNS generates the record then skips it with "no hosted zone matching record DNS
Name". Prod would have published NOTHING. Set to the ZONE (keithjackson.dev) like dev.
Isolation comes from the subdomain split plus txtOwnerId, which is what the incident
actually needed and what a domain filter cannot provide.
DEV PROVEN UNCHANGED: 11 of 12 substituting paths byte-identical; the 12th differs by
exactly one line, `+ txtOwnerId: default` — the value dev was already using implicitly.
POSITIVE CONTROLS confirm the harness is not blind: perturbing BASE_DOMAIN moves 10 of 12
hashes (the 2 that don't provably contain no hostname), perturbing the owner id moves
exactly 1. Prod's rendered output has ZERO home.keithjackson.dev references outside prod.,
and its cert renders *.prod.home.keithjackson.dev — no overlap with dev's.
L0 substitution assertions 106 -> 254; BASE_DOMAIN is no longer flagged dead. Gate PASS.
PROD REMAINS SUSPENDED (platform + 10 downstream tiers) pending review; nothing applied.
Serves: R-ENV-02, R-DNS-01, R-DNS-02, R-DNS-03, R-TLS-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.