Files
home-network-k3s-impl/platform
jakman85andClaude Opus 5 21491f901b fix(cnpg): scope DR alerts to the CLUSTER, not the pod — stop a permanent false positive
CNPGNoRecoverabilityPoint has been firing continuously on prod against six
pods — keycloak-db-1/-3, nextcloud-db-1/-3, semaphore-db-1/-3 — i.e. exactly
the REPLICAS of all three Clusters, while the databases themselves are fine:
every Cluster reports firstRecoverabilityPoint=2026-09-07T07:0x, a
lastSuccessfulBackup within the last few hours, ContinuousArchiving=True and
LastBackupSucceeded=True.

Root cause is aggregation scope, not archiving. `cnpg_collector_first_recoverability_point`
reads the backup CATALOGUE, which only the primary owns; a replica reports a
hard 0 for as long as it is a replica. The metric carries no cnpg.io/cluster
label (its label set on prod is container/endpoint/instance/job/namespace/pod),
so `max by (namespace, pod)` evaluated each replica as its own subject and an
`== 0` comparison then held forever. The rule went from correct to permanently
wrong the moment the Clusters went to `instances: 3`; nothing about the
expression changed.

WHY THIS IS WORSE THAN HAVING NO ALERT. An alert that is always firing has
zero information content: its value is identical in the healthy state and in
the failure state, so it cannot distinguish them. It is worse than silence in
two specific ways. First, it trains the operator to delete the notification on
sight, so the day a base backup genuinely stops the seventh identical email is
discarded with the other six — the alert actively MASKS the failure it was
written to catch, which for a DR alarm means discovering the loss at restore
time. Second, it is indistinguishable from a broken alert, so nobody can tell
whether the absence of new alerts means health or means the rule rotted. This
file exists because a real 38-hour archiving failure told nobody; a rule that
cries wolf about six healthy replicas rebuilds exactly the blindness it was
supposed to remove. This repo has been here before — see the permanently-firing
critical VPNTunnelDown post-mortem in platform/monitoring/alerts.yaml.

Fix: group by (namespace, job) and aggregate `pod` away. The CNPG operator
creates one PodMonitor per Cluster, named after the Cluster, in the Cluster's
namespace, so prometheus-operator derives job="<namespace>/<cluster>" —
keycloak/keycloak-db, nextcloud-db/nextcloud-db, semaphore-db/semaphore-db —
which identifies the CNPG Cluster uniquely. `job` rather than bare `namespace`
deliberately: namespace alone works today (one Cluster per namespace, verified
live) but would let two Clusters in one namespace mask each other, since the
healthy one's non-zero value would satisfy `max` for both. The alert now
states what its summary always claimed — this CLUSTER has no recoverability
point — and fires only when no instance of that Cluster reports one.

Proven live against prod Prometheus, read-only (promtool query instant):
  OLD  max by (namespace, pod) (...) == 0  -> 6 series, and 6 ALERTS firing
  NEW  max by (namespace, job) (...) == 0  -> empty
The new expression is not vacuous: forcing the metric to 0 for one cluster's
primary only yields exactly one series, {job="keycloak/keycloak-db"}, so a
genuine single-cluster loss of DR still alerts, per cluster. `promtool check
rules` passes on all 5 rules.

CNPGNoRecentBaseBackup carried the same defect and is fixed the same way.
`cnpg_collector_last_available_backup_timestamp` is also primary-only: on prod
the primaries read 3.1h/2.1h/0.1h old while all six replicas read 0, i.e.
time()-0 = ~56.7 YEARS. It was not firing only because the `> 0` guard was
load-bearing — a single clause was all that stood between this rule and six
more permanent false positives, too thin a margin for a DR alarm. Aggregating
`pod` away removes the dependence: `max` takes the primary's timestamp as the
cluster's answer, and the guard now means "this cluster has had at least one
backup". Verdict unchanged live (old empty, new empty).

The other three rules were audited and deliberately left on `by (namespace, pod)`:
  * CNPGWALArchiveBacklog — every instance reports archive_status and the shape
    is `> 0`, so a replica at 0 never fires and no pod can mask another; `pod`
    names the instance whose archiver is stuck.
  * CNPGWALVolumeNotRecycling — per-pod is REQUIRED, not merely safe:
    aggregating it away would compare one instance's WAL count against
    another's max_wal_size.
  * CNPGMetricsCollectorErroring — unchanged in meaning AND grouping. Its
    grouping is already correct: cnpg_last_error is genuinely per-instance, and
    prod proves it discriminates rather than tracking role — all three
    nextcloud-db pods report 1 while all six keycloak/semaphore pods report 0.
    It is a true positive (the nextcloud 42501 CONNECT grant) owned by separate
    work; nothing here silences or rescopes it.

The general rule, recorded in the file: `== 0`/staleness shapes must aggregate
`pod` away or every structurally-silent pod fires forever; `> 0` shapes are
safe per-pod and keep the instance name.

Co-Authored-By: Claude Opus 5 <[email protected]>
2026-09-12 23:09:53 -05:00
..

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.dev cert, and the ExternalDNS source all reference each other; they form the "Issuer + Gateway TLS" interface in roadmap/workstreams.md.
  • image-automation (WS-UPDATE): this dir holds only the cluster-wide ImageUpdateAutomation + git write-back. Per-service ImageRepository/ImagePolicy are rendered from each ServiceDefinition's update block (WS-GITOPS/WS-UPDATE), living with apps/.
  • keycloak/oauth2-proxy (WS-SEC): the SSO/auth contract (auth block → Keycloak client / oauth2-proxy protection) is owned by WS-SEC; these are placeholders pending that contract.