jakman85andClaude Opus 5 b9f3143f42 feat(monitoring): name the CAUSE of node I/O pressure, not just the stall
NodeIOPressureCritical has now fired twice on k3s-prod-1 for opposite causes and
said the same thing both times. On 2026-09-14 02:40-02:45Z it fired at PSI(full)
20.98% — twice the threshold, four times the 2026-09-07 level — while every local
device was idle (0.09-0.27 utilisation) and fast (1.4-4.8 ms per write), NFS
retransmissions were zero and no Longhorn volume was degraded. Establishing that
took eight ad-hoc PromQL queries after the event had already recovered.

Adds the group platform-health.node-io-cause: eight rules, one per cause class,
each naming its cause in its own summary.

  NodeDiskDeviceSaturated        device saturation   >0.85 busy, 10m
  NodeDiskWriteLatencyHigh       device latency      >20ms/write, 10m
  NodeDiskWriteLatencyCritical   device latency      >50ms/write, 5m
  NodeDiskReadLatencyHigh        device latency      >250ms/read, 15m
  NodeNFSRetransmissionRateHigh  NFS transport       >1% retransmitted, 10m
  NodeIOPressureNotLocalDisk     not local disk      PSI>10% with all of the above absent
  NodeEtcdRequestsSlow           etcd                >0.5% of etcd requests over 1s
  ContainerIOStallHigh           which workload      per-container PSI >15%

Every threshold is measured on prod over 24-48h, not guessed, and each rule
records its headroom. The PSI thresholds themselves are deliberately unchanged:
the 21% stall was real, it fired twice in 24h for two real events on the one node
that has a problem, and raising the bar would also have raised it above the 11.36%
at which prod-1 was already losing etcd on 2026-09-07.

Context reaches the operator at page time three ways: the summary states the cause
class; every rule carries a diagnostic_query annotation with the exact companion
PromQL; and node-pressure-dashboard.yaml gains a WHY row (seven panels) plotting
saturation, write/read service time, NFS retransmissions, our own NFS op rate,
the etcd slow-request fraction and per-container PSI side by side. runbooks/node-io.md
gains a 10-row triage table with the real healthy / 2026-09-14 / 2026-09-07 columns,
which turns those eight queries into a two-minute read.

etcd and NFS metric availability, verified on prod rather than assumed:
  * etcd SERVER disk metrics do NOT exist. etcd_disk_wal_fsync_duration_seconds and
    etcd_disk_backend_commit_duration_seconds are absent (kubeEtcd disabled for k3s);
    a query for etcd_disk_*/etcd_server_*/etcd_mvcc_* returns nothing at all.
    NodeEtcdRequestsSlow uses the apiserver's client-side view of its own local
    member instead, and says in its own description that it is a proxy.
  * node_nfs_* DOES exist — the nfs collector is on by default, host-wide via
    /proc/net/rpc/nfs, confirmed on all three nodes. It gives op counts and
    retransmissions and NO latency, so it can see a dropping export but not a slow
    one. The mountstats collector is enabled here to close that gap; NO rule
    references node_mountstats_* yet, because the series do not exist until the
    HelmRelease rolls out and the collector's visibility through the node-exporter
    mount namespace must be verified on prod first. The runbook records the check
    and says to revert if it comes back empty.

Proof, per the repo's two shipped alerting failure modes:
  * platform/monitoring/tests/node-io-cause.test.yaml — 7 fixtures, all from
    measured profiles: healthy (all 8 quiet), 2026-09-14 (NotLocalDisk fires and
    names sonarr), 2026-09-07 re-queried at offset 164h (write-latency and etcd
    fire, NotLocalDisk correctly silent), rebuild storm, NFS transport, read
    latency, and the `unless` semantics.
  * 10 mutations of the shipped rules, all killed. The mutation run found a real
    gap: the etcd threshold could be changed without failing any test, because it
    was only pinned by a promql_expr_test that restated the threshold in the test
    file. An alert_rule_test now pins it.
  * All 11 referenced metrics verified to return series on prod with
    `promtool query instant`, and all 8 expressions verified quiet on today's state.

Also extends the alert-metrics-have-scrape-targets owner table for container_*
(the kubelet ServiceMonitor's cAdvisor path, which this entry already claimed in
its title) and for etcd_request_duration_seconds_* by EXACT NAME, deliberately not
by an etcd_ prefix, so a future rule on the unscraped etcd_disk_* names still fails
the gate.

Co-Authored-By: Claude Opus 5 <[email protected]>
2026-09-13 22:35:19 -05:00

home-network-k3s-impl

Implementation of the home k3s + Longhorn platform. This repo holds the reconciled artifacts (Flux config, Kustomize overlays, KubeVirt/Helm manifests, ServiceDefinitions, Kyverno policies, Chainsaw conformance tests, CI). It is driven by — and subordinate to — the read-only specification at ../home-network-k3s.

Rules (from the spec — non-negotiable)

  • The spec is read-only. Never modify anything under ../home-network-k3s. Implement against it; escalate spec problems, don't edit them (spec AGENTS.md §11, R-TEST-06).
  • Done = a green, reproducible, requirement-tagged conformance test — never "merged," never a manual demo (spec docs/14, agents/definition-of-done.md).
  • No work on main. Every change is a feature branch merged into main (spec CONTRIBUTING.md).
  • No plaintext secrets — SOPS-encrypted only (spec docs/07).
  • Phase discipline — only build what the active roadmap phase authorizes (spec roadmap/phases.md).

Layout

infra/          node provisioning: OpenTofu (Proxmox VE) + cloud-init + Ansible, and the
                pinned dev container that carries the whole toolchain
bootstrap/      one-time cluster bootstrap: Flux install, SOPS/age key, host Gitea
platform/       platform CONTROLLERS (Flux HelmReleases / operator bases): kyverno, cilium,
                longhorn, external-snapshotter, cert-manager, externaldns, gateway, coredns,
                vpn-egress, monitoring, cnpg, keycloak, oauth2-proxy, kubevirt
platform-config/ platform CONFIGS — the custom resources of the CRDs installed above
                (ClusterIssuers, Gateway, Kyverno policies, KubeVirt/CDI CRs, Keycloak CRs).
                Split out because CRs and the CRDs they use cannot apply in one pass.
apps/           application tier, reconciled as dependency-ordered WAVES:
                  wave-0/ wave-1/ wave-2/   rendered container apps (see DESIGN-waves.md)
                  vms/                      KubeVirt VirtualMachines (non-gating tier)
catalog/        ServiceDefinition entries (the onboarding surface) + render.py
schemas/        ServiceDefinition JSON Schema + renderer contract
clusters/       Flux entrypoints + dev/ and prod/ overlays
conformance/    Chainsaw behavior/conformance suite + harness + coverage report
ci/             the gate as scripts (lint · schema · Kyverno L0 · L1 render · decision)
.gitea/         Gitea Actions CI running that gate on an in-cluster runner

Status

Roadmap phases 0–6 are delivered, and Phase 7 (Production Readiness) is OPEN and in progress. clusters/prod is no longer a design-only overlay: prod is the live cluster, serving the apex home.keithjackson.dev. The dev cluster was decommissioned on 2026-09-12 (full migration: dev out, prod onto the apex — see the DECISIONS-LOG), so phases 0–6 are now exercised on prod hardware rather than on Proxmox VMs.

Phase 7 exit criteria — prod runs the same config via the prod overlay; DR proven; monitoring + alerts live:

criterion state
prod runs the prod overlay met — 3× mini-PC bare metal, one Flux tree, prod overlay only
monitoring + alerts live met 2026-09-13 — see the note below; this was not true before that date
DR proven R-STATE-03 PROVEN on prod 2026-09-14 — off-cluster restore from Cloudflare R2. R-STATE-02 (node-loss) is still dev-only

DR restore is proven on prod. R-STATE-03 reads proven in --status as of 2026-09-14 — the first requirement in this repo to reach that state. Both of its verifiers are recorded: dr-restore (L3, run 20260914T021505Z-24b8111, sentinel DR_RESTORED_FROM_OFF_CLUSTER_BACKUP_OK) and placeholder-guard-coupling (L0). The L3 drill seeds a canary on the replicated longhorn class, backs the namespace and volume data up off-cluster, destroys every in-cluster copy (namespace, PVC and PV), restores into a clean namespace, and asserts the restored PVC binds a different PersistentVolume — so an in-cluster survival cannot pass as a restore.

What remains for Phase 7: R-STATE-02 (node-loss) is still proven only on the decommissioned dev cluster. That drill takes a real node down on a live cluster, so it is a deliberate, scheduled exercise rather than something to run in passing.

Read --coverage-only and --status as two different questions; the earlier PROVEN: 0 was not a bug but the honest answer, because proofs are claims about a specific tree on a specific cluster.

Phase Delivered
0 Foundations ServiceDefinition schema + renderer, Kyverno L0 gate, conformance harness, CI
1 Cluster bring-up 3-node k3s HA, embedded etcd, kube-vip VIP, Cilium, Flux, SOPS. Originally Proxmox VMs; now 3× mini-PC bare metal (k3s-prod-1/2/3, 192.168.2.10/.11/.12, k3s v1.36.4+k3s1, Debian 13)
2 Platform core Cilium · Longhorn · cert-manager (LE-prod wildcard) · ExternalDNS · Gateway API · split-horizon CoreDNS
3 Egress / VPN ADR-0015 node-level OpenVPN split-tunnel + Cilium egress-gateway steering + host kill-switch
4 Observability kube-prometheus-stack · Loki · Alloy · Alertmanager. Velero unblocked 2026-09-13 — backs up to Cloudflare R2 (OQ-BKP closed; the velero-plugin-for-aws tagging incompatibility needed a pinned plugin). Longhorn has no backup target by decision: volume data is protected by Velero + kopia to R2. image-automation authored but disabled
5 IaaS KubeVirt + CDI on real nested KVM; live-migratable RWX VM storage. The UniFi VM runs, but UniFi OS Server is not yet installed in the guest
6 Identity + CI Keycloak (Operator + CNPG) · oauth2-proxy forward-auth · Grafana OIDC · kubectl OIDC SSO with group→RBAC · in-cluster Gitea Actions merge gate
7 Production readiness IN PROGRESS (DR restore proven 2026-09-14; node-loss outstanding). Prod live on bare metal serving the apex; dev decommissioned; CNPG HA 3 instances with primaries spread one per node; NFS bulk media + legacy Nextcloud mounted; VPN egress on prod. Alerting made real 2026-09-13 (Longhorn, cert-manager, Flux and twelve app SLIs had all been unable to fire). Open: node-loss (R-STATE-02) re-proven on prod.

Conformance: 51 / 51 requirements covered (100%), 0 gaps, 0 safety-critical gaps (closed 2026-09-13; R-C2-01/R-C2-02 were the last two). Regenerate with ./conformance/run.sh --coverage-only; the full report is conformance/_artifacts/coverage/coverage.md.

Coverage is not proof. A requirement is covered when an executable test exists for it, and PROVEN only when a recorded run of that test is in conformance/runs/ledger.jsonl at the current SHA on the cluster it claims. Read both numbers: --coverage-only for the first, --status for the second.

The running narrative — decisions, root causes, incidents, follow-ups — is DECISIONS-LOG.md. It, not this table, is the authoritative record.

Working on this repo

Everything the gate needs is baked into the pinned dev container — do not install the toolchain on the host:

infra/devcontainer/dev.sh build            # once
infra/devcontainer/dev.sh run make -C ci gate   # the same gate CI runs
infra/devcontainer/dev.sh                  # interactive shell (sops, flux, kubectl, tofu, ansible)

The container mounts the repo at /work, your age keyring, and the sibling spec repo read-only so the spec-immutability check can actually run. See infra/devcontainer/README.md.

A green run prints MERGE GATE: PASS. The L2/L3 conformance layers stay SKIPPED unless CLUSTER_AVAILABLE=true — the static gate never pretends to have run them.

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