Files
home-network-k3s-impl/platform
jakman85andClaude Opus 5 16c6234696 feat(monitoring): alert when egress steering goes stale, not just when tun0 dies
`VPNTunnelDown` goes green the instant a tun0 exists, which is not the same as
vpn-class pods having egress: Cilium caches (egress IP, egress ifindex) at first
resolution, so after a reconnect the BPF egress map points at a destroyed
interface and the packets are dropped while tun0 looks perfectly healthy. Dev sat
in exactly that state for ~80 minutes with nothing alerting.

Two rules close it:

* VPNEgressSteeringStale (critical, for: 15m) — fires when the live tun0 was
  re-created more times in the last hour than the gateway node's `egress-uplink`
  label changed, i.e. Cilium was never told about a reconnect.
* VPNEgressUplinkLabelMissing (warning, for: 30m) — the watchdog for the
  watchdog: a gateway node whose uplink label never reaches kube-state-metrics is
  a cluster where the rule above is inert.

Both gated on a gateway node existing, reusing `VPNTunnelDown`'s
`kube_node_labels` guard — a cluster with no gateway cannot be made to fire them.

The direct label-vs-map comparison is NOT available and nothing was invented to
pretend otherwise: no `cilium_*`/`hubble_*` series exist on either cluster (the
cilium-agent exposes no metrics port, there is no ServiceMonitor), and Cilium OSS
publishes no series carrying egress-map contents at all — the map is readable only
via `cilium-dbg bpf egress list`. PromQL also cannot compare a metric value (the
live ifindex) against a number inside a label value, so the level-triggered
equality test is not expressible; the same invariant is counted over a window
instead. Both limits, and the textfile-collector/black-box-probe routes that would
lift them, are written down in the rule comments and the DECISIONS-LOG.

`egress-uplink` added to kube-state-metrics.metricLabelsAllowlist in the same
kustomization, because without it the first rule has nothing to compare.

Verified read-only against LIVE prod (port-forward + /api/v1/query), rendered expr
extracted from `kubectl kustomize platform-config`: empty when healthy; empty when
evaluated at a timestamp before prod had a gateway node; and FIRING when pointed at
a label that genuinely failed to follow prod's real 128 -> 129 tun0 flap earlier
today. Nothing on prod was disturbed to produce that.

Co-Authored-By: Claude Opus 5 <[email protected]>
2026-09-12 20:46:56 -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.