Commit Graph
6 Commits
Author SHA1 Message Date
jakman85andClaude Opus 5 f663e7c801 fix(longhorn): the I/O caps a runbook promised were never declared — declare them
`runbooks/longhorn-degraded.md` told operators that, after the 2026-09-07 etcd
I/O-starvation incident, `concurrentVolumeBackupRestorePerNodeLimit` and
`snapshotHeavyTaskConcurrentLimit` had been tightened 5 -> 1. Measured live on
prod today: both read **5**, and neither name appeared anywhere in this
repository — so nothing declared them and nothing would have restored them.
Fourth instance of config that looked applied and was not.

Landed in `platform/longhorn/helmrelease.yaml` `defaultSettings` (the path Flux
reconciles; `values.yaml` is the reference mirror), NOT by `kubectl patch` —
a hand-applied Setting is exactly how this gap arose and Helm would silently
rewrite it on its next upgrade.

  concurrentVolumeBackupRestorePerNodeLimit      5 -> 1
  snapshotHeavyTaskConcurrentLimit              5 -> 1
  replicaReplenishmentWaitInterval              600     PINNED, unchanged
  backupConcurrentLimit / restoreConcurrentLimit  2 / 2 PINNED, unchanged
  concurrentAutomaticEngineUpgradePerNodeLimit  0       PINNED, unchanged
  nodeDrainPolicy  block-if-contains-last-replica       PINNED — it was in
      force only as Longhorn's OWN DEFAULT, declared in no manifest and in no
      rendered ConfigMap, so an upstream default change would have moved it
      silently while two runbooks reasoned about drain safety from it.

EVERY KEY PROVEN TO LAND, not assumed. `helm template longhorn/longhorn
--version 1.12.1` (the version this chart range resolves to, per the
HelmRelease's own lastAttemptedRevision) on this branch's spec.values,
substituted as clusters/prod substitutes them, emits all eight into the rendered
`longhorn-default-setting` ConfigMap in kebab-case. Diffed against the LIVE
ConfigMap the change is purely ADDITIVE: 8 keys added, none altered, none lost.
The chain to the Settings is verified read-only on prod — all 115
settings.longhorn.io carry `longhorn.io/configmap-resource-version: 7917`
(= that ConfigMap's resourceVersion) with `status.applied: true`, and every key
in the ConfigMap equals its Setting's value. The two targets sit at 5 with the
key absent, i.e. Longhorn defaults, as measured.

`orphanAutoDeletion: true` REMOVED, verified inert two independent ways against
the deployed 1.12.1: the render emits no orphan key at all (Longhorn 1.9 renamed
it `orphanResourceAutoDeletion`, a list, and the chart drops unknown
defaultSettings keys with no error), and live, `setting/orphan-auto-deletion` is
NotFound while `orphan-resource-auto-deletion` reads "". Deliberately NOT
replaced — orphan deletion is extra writes on the constrained partition and buys
only space. Orphan cleanup stays manual by decision; the two runbooks that cite
the key by name are corrected rather than left to go stale.

BOTH NEW CAPS ARE 1, AND 1 COSTS SOMETHING — stated, not waved at.
`concurrentVolumeBackupRestorePerNodeLimit: 1` costs nothing TODAY: Longhorn has
no backup target (the `backup-target` Setting does not exist; still the
WS-STORAGE Phase-4 TODO), and velero's nightly run is not a Longhorn backup —
`snapshotVolumes: false` + `defaultVolumesToFsBackup: true` is kopia
file-system backup through velero's node-agent, which this Setting does not
gate; CNPG base backups are barman-level and ungated too. Its only consumer is
an R-STATE-03 restore, where serialising ~24 volumes beats losing etcd
mid-restore. Revisit when a Longhorn backup target lands.
`snapshotHeavyTaskConcurrentLimit: 1` rather than 2 because purge work is
generated by rebuild cleanup (auto-cleanup-system-generated-snapshot true, NO
RecurringJobs, 24 volumes / 24 snapshots) and rebuild is already serialised to
1 per node — so 1 keeps pace with its own generator, where 2 buys backlog drain
at the price of a second heavy writer during the exact rebuild that starved
etcd. The cost: space reclaims serially after a rebuild storm — real here (a
37.7 GiB snapshot once pinned a volume at 97.3% allocated), but instrumented by
LonghornDiskAllocationHigh and recoverable by hand, where a wedged etcd is not.
Headroom on the record: I/O PSI full is 0.30/0.62/0.37 % now, and 3.79 under a
full 18-replica rebuild after node 1's drive replacement, against a 5% warning
threshold. These caps are a BOUND, not a fix — etcd and Longhorn still share one
ext4 filesystem and nothing arbitrates the jbd2 journal fdatasync waits on.

NOT PORTED, deliberately: the same unmerged branch's node-level I/O arbitration
(`roles/etcd_io_priority` — BFQ on the shared device, nr_requests 64 -> 32,
systemd IOWeight drop-ins). The 2011 C400 it was written for was replaced on
2026-09-07 and the same load class measured 11.36 -> 3.79 I/O PSI with the node
Ready throughout; the role was never run against any cluster, its author
recorded it as unproven with a node-3-first sequenced rollout, and its own
README concedes it does not separate the two tenants. Node-wide blast radius,
low ceiling, stale measurements (node 1 reinstalled, founder moved to node 2).
It stays an operator option if I/O PSI climbs back toward 5% — which, unlike in
September, we would now be told about. Nothing under infra/ansible/ is touched.

ALSO ALREADY DONE, so skipped: that branch's NodeIOPressureHigh/Critical and the
dashboard I/O row are on main already (efc6db6) with runbooks/node-io.md.
Verified live, not by reading the file: both rules loaded in
platform-health.nodes, health ok, state inactive, and
ALERTS{alertname=~"NodeIOPressure.*"} returns no samples.

Runbooks corrected in both directions: longhorn-degraded.md's prominent "DO NOT
RELY ON THAT: it was never applied" block becomes an accurate statement of what
is now declared, what to verify before trusting it, what it cannot do, and what
it costs; longhorn-capacity.md / node-disk.md stop citing a key that no longer
exists; node-io.md gains the one line an operator needs mid-incident.

No new ${...} substitution variables and not one dollar sign added anywhere in
the diff, so neither StrictPostBuildSubstitutions nor the L0 doubled-dollar guard
is affected.

Co-Authored-By: Claude Opus 5 <[email protected]>
2026-09-13 17:48:42 -05:00
jakman85andClaude Opus 5 d96165e8fb fix(monitoring,runbook): 5 GiB is not compaction headroom, and a runbook claimed an I/O cap that was never applied
gate / gate (push) Has been cancelled
gate / conformance (push) Has been cancelled
Two things found while reviewing the Longhorn alert work.

Prometheus retentionSize was 45GiB of a 50Gi PVC, under a comment already
naming the right intent — 'headroom for WAL + head + compaction scratch'.
5 GiB is not that: retentionSize counts only persisted blocks, and a large
compaction can need roughly the size of the blocks being merged. ENOSPC on
/prometheus wedges every WAL commit, so scrapes keep succeeding while nothing
is stored and every absent()/==0 alert fires falsely at once. Lowered to
36GiB, which costs no history: the TSDB is 11.2 GiB at 30d, so 30d remains
the binding limit.

runbooks/longhorn-degraded.md asserted that concurrentVolumeBackupRestore-
PerNodeLimit and snapshotHeavyTaskConcurrentLimit 'was actually tightened
5 -> 1'. Both read 5 on prod and neither name appears anywhere in this repo —
the work is on the unmerged fix/etcd-io-priority branch. The page is read
during etcd I/O starvation on a node whose WAL shares a device with Longhorn,
so it was telling an operator mid-incident that the cap they depend on is in
place when it is not. Corrected, with the two mitigations that ARE real named
and a command to verify any of them.

Co-Authored-By: Claude Opus 5 <[email protected]>
2026-09-13 17:27:20 -05:00
jakman85andClaude Opus 5 4687521d65 fix(monitoring): delete the Longhorn rule that measured allocation and called it capacity
LonghornVolumeCapacityHigh went pending within minutes of the Longhorn scrape
landing today. Re-measured on prod: it read 0.9731 on the Prometheus TSDB volume
(actual_size 52243681280 / capacity 53687091200) while the kubelet reported the
SAME filesystem 20.8% used. actual_size is head + pinned snapshots, and one
user_created=false system snapshot from prod-1's replica rebuild holds 40510484480
bytes (37.7 GiB) of it; Longhorn returns no freed blocks without discard/TRIM, and
retentionSize 45GiB on a 50Gi volume targets 90% by design. The ratio is pinned
near 1.0 and cannot fall back under 0.85 — a permanently-firing alert, the same
shape as CNPGNoRecoverabilityPoint.

DELETED, not re-thresholded. Raising the threshold would tune away a true
statement about allocation. Redundancy proven, not asserted: of 24 Longhorn
volumes on prod, 23 appear in kubelet_volume_stats_inodes > 0 and so fall inside
MonitoringVolumeFillingUp (namespace="monitoring") or PersistentVolumeFillingUp /
PersistentVolumeAlmostFull. The 24th is unifi/unifi-rootdisk, volumeMode Block —
no filesystem for anyone to measure, and the deleted rule was not covering it
either.

AND A SECOND INERTNESS the scrape did not fix. longhorn_volume_robustness on
longhorn 1.12.1 is one-hot over a `state` label with values 0/1, not the 0-3 enum
the rules assumed:
  count(longhorn_volume_robustness)                  => 96  (24 volumes x 4 states)
  count by (state) (longhorn_volume_robustness == 1) => {state="healthy"} 24
  count(longhorn_volume_robustness == 2)             => (empty)
  count(longhorn_volume_robustness == 3)             => (empty)
So a FAULTED volume would still have alerted nobody. Re-keyed to the label; the
"44 series / 72 unknown(0, detached)" note in platform/longhorn/helmrelease.yaml
was the same misreading and is corrected in place.

The allocation question moved to where allocation is a budget. LonghornNodeStorageHigh
fired at 0.85, but storage-minimal-available-percentage is 25 on this cluster, so a
disk leaves the scheduling pool at 75% used — the old threshold could only fire
after scheduling had already been refused. Replaced by:
  LonghornDiskAllocationHigh  (longhorn_disk_usage_bytes / longhorn_disk_capacity_bytes) > 0.70, 30m
  LonghornDiskUnschedulable   longhorn_disk_status{condition="schedulable"} == 0, 15m
Per DISK, not per node: longhorn_node_storage_usage_bytes sums a node's disks, so
one full disk could hide behind a half-empty sibling. Measured prod usage
0.2254 / 0.2306 / 0.2369 on prod-1/2/3.

PROVEN NEITHER PERMANENTLY FIRING NOR INERT. platform/monitoring/tests/longhorn.test.yaml
adds 6 cases pinning every rule quiet on today's measured prod state and firing on
a constructed bad state, with every `for:` asserted, plus regression assertions that
the old `== 2`/`== 3` forms match nothing and that per-disk 0.72 is visible where the
node-summed 0.475 is not. Mutation-checked 11 ways; each turns the suite RED. Live on
prod: all four new expressions return empty, while the sum of their selector
cardinalities is 54. The L0 UNTESTED_ALERTS register shrinks by seven (7/56 -> 14/58
alert rules unit-tested), which also brings MonitoringVolumeFillingUp,
PersistentVolumeFillingUp and PersistentVolumeAlmostFull under test since the
redundancy claim rests on them.

REPORTED, NOT CHANGED (DECISIONS-LOG, owner decisions): retentionSize 45GiB on a
50Gi volume is too tight — recommend 36GiB, with reasoning; and discard/TRIM on the
longhorn StorageClass is feasible but not advisable now — remove-snapshots-during-
filesystem-trim reads false on prod, so trim would not have reclaimed the 37.7 GiB
anyway, and continuous discard on nodes where the etcd WAL shares the spindle points
at this cluster's known failure mode.

Co-Authored-By: Claude Opus 5 <[email protected]>
2026-09-13 17:19:03 -05:00
jakman85andClaude Opus 5 bce8778096 docs(runbooks): forward-auth IS enforced — correct the posture note
The serving route's comment claimed that because no Gateway ext-authz
attachment exists, every forward-auth route is 'in practice reachable
unauthenticated today'. That is wrong, and wrong in a dangerous direction
for a document an operator reads during an incident.

Enforcement here is PER-POD, not gateway-level: each of the five services
declaring auth: forward-auth (pihole, jackett, qbittorrent, radarr, sonarr)
publishes both its app port and 4180 on its Service, and its HTTPRoute
targets :4180 — the oauth2-proxy sidecar. Verified on prod. The app port
remains reachable in-cluster on purpose, which is how sonarr/radarr drive
qBittorrent's API, and Cilium default-deny governs that path.

The public-by-design decision for this route is unchanged and still correct;
what changes is that it is genuinely the exception rather than one open route
among many. Headlamp's exclusion is likewise deliberate (native OIDC with
per-user id_token forwarding and no ServiceAccount cluster rights).

Co-Authored-By: Claude Opus 5 <[email protected]>
2026-09-13 00:10:24 -05:00
jakman85andClaude Opus 5 b7341b329b fix(runbooks): declare whole-repo scope, drop the bespoke l0 stage, +cnpg-primary-spread
Three corrections after rebasing onto main.

1. THE GUARD CAUGHT A REAL ONE ON ITS FIRST CONTACT WITH main. main had gained
   `CNPGPrimariesCoLocated` (platform/cnpg/alerts.yaml) pointing at
   /runbooks/cnpg-primary-spread, with no runbook. The check failed the rebase exactly as
   designed — 46 annotations, 35 names, 34 present — naming both the missing file AND the
   missing configMapGenerator entry. runbooks/cnpg-primary-spread.md now exists: what
   co-located primaries actually cost here (blast radius, not an outage, because
   instances: 3 + required anti-affinity), why the drift is uncorrectable-by-declaration
   (CNPG has no primary-placement field), the readiness gate that keeps the rule quiet
   during a real node outage, and the ~9s-per-database switchover rebalance, one cluster
   at a time. The 2026-09-07 outage in which all three primaries sat on one node is the
   reason the alert exists at all.

2. WHOLE-REPO SCOPE, NOT A HAND-WRITTEN STAGE. main's refactor replaced ci/l0.sh's
   per-check "UNCONDITIONAL" stages with a declaration:
   `conformance.home.k3s/scope: "whole-repo"`, unioned into every gate run by Stage 3b's
   `--include-scope`. My +38-line Stage 3f is removed (ci/l0.sh is now byte-identical to
   main) and the annotation is declared instead. Assertion (7) of the check was rewritten
   to match: it no longer asserts its own path appears in ci/l0.sh — it asserts the test
   DECLARES the scope and that ci/l0.sh still passes --include-scope, since neither half
   alone makes the check load-bearing. That matters here because
   ci/touched-requirements.sh maps platform/monitoring/* to "R-OBS-01 R-OBS-02", not
   R-OBS-04, and maps platform/kubevirt/* and runbooks/* to nothing at all.

3. A FACTUAL CORRECTION IN ALL 35 RUNBOOKS. Every page claimed `dev.sh` defaults its
   current-context to k3s-dev. main's `9b4744d fix(devcontainer): dev.sh defaults to
   prod` made that false, and a runbook that misstates which cluster a command talks to is
   worse than one that says nothing. The pages now say what is durably true: the default
   has already changed once, so naming `--context k3s-prod` is what makes a command mean
   the same thing next month, and the per-invocation banner is there to be read. The
   check's own failure message was corrected the same way.

Re-verified after all three: check green at 374 assertions (46 annotations, 35/35 runbooks
present, 35/35 projected), re-applied to prod, and re-probed in-cluster through the
Gateway — node-down, keycloak-down, keycloak-client-secrets, cnpg-archiving,
longhorn-faulted, vpn-down, node-io and cnpg-primary-spread all HTTP 200 with
text/plain; charset=utf-8 and 8.9-12.1 KB of real body; /runbooks/ index 200; an unknown
name 404s with a pointer rather than a blank page; and homepage still answers the apex `/`,
confirming Gateway API longest-path precedence.

Full merge gate: PASS (spec-immutability, lint, l0, render-golden, l1 all green;
prom-rules SKIPPED for want of promtool in the image; L2/L3 SKIPPED, no cluster).

Co-Authored-By: Claude Opus 5 <[email protected]>
2026-09-13 00:00:24 -05:00
jakman85andClaude Opus 5 44983095e1 feat(runbooks): make the 42 alert runbook_url annotations resolve
Every platform-health alert rule carries
`runbook_url: "https://${BASE_DOMAIN}/runbooks/<name>"` — 42 annotations over 34
distinct names, across platform/monitoring/alerts.yaml,
platform/monitoring/pvc-capacity-alerts.yaml, platform/cnpg/alerts.yaml and
platform/kubevirt/alerts.yaml. There was no runbooks/ directory and no HTTPRoute
serving that path: an in-cluster probe of
https://home.keithjackson.dev/runbooks/node-down returned HTTP 404. Every alert that
reached a human handed them a dead link at the exact moment the documentation is read,
and the annotation made it look solved — the same green-surface-over-absent-mechanism
class as the import Job that reported success while storing placeholder secrets.

No alerts.yaml is touched and no runbook_url value changes. The existing URL scheme is
made to resolve instead.

WHAT LANDS
- runbooks/<34>.md — one per name, each grounded in this cluster's real topology and,
  where one exists, its real incident history: the 2026-09-07 k3s-prod-1 etcd I/O
  starvation (measured PSI 11.36 vs 0.75/1.29, the exact journal lines, the four
  mechanisms proven inert), the Longhorn reboot tax and the freeze/thaw of
  concurrent-replica-rebuild-per-node-limit, Cilium's once-resolved egress interface
  cache (Ifindex 3 against a live 1780) and the absence of OSS failover, the CNPG
  38-hour ContinuousArchiving=False with its measured 6.8 MiB/h disk-full clock and the
  2026-09-12 aggregation-scope fix, the 2026-09-06 Keycloak lockout in which all 12
  clients held literal placeholder secrets behind an entirely green cluster, the Velero
  R2 x-amz-tagging NotImplemented incompatibility and its v1.14.3-rc.2 pin, and swap
  re-enabling itself across reboots via systemd-gpt-auto-generator.
  Each page states what the alert means HERE, the first diagnostic commands, likely
  causes ordered by probability with a remediation each, and when to escalate or stop.
- Every page uses FULLY-QUALIFIED resource names and says why: three CRDs register the
  kind `Backup` here, the bare short name resolves to Longhorn's (zero objects), so
  `kubectl get backup -A` prints "No resources found" on a cluster holding 6 Velero and
  27 CNPG backups. Acting on that false negative is how a CLI quirk becomes data loss.
- Every page states that kubectl only works via
  `infra/devcontainer/dev.sh run bash -c '...'` with an explicit `--context k3s-prod`,
  because dev.sh defaults its current-context to k3s-dev.
- Pages also record which alert groups are INERT today (measured 2026-09-13: no
  Longhorn, cert-manager, Flux-controller or Hubble scrape job exists, so 13 rules
  evaluate against nothing) so nobody reads their silence as health.

SERVING — runbooks/serving/ plus clusters/base/runbooks.yaml
A two-replica nginx-unprivileged serving a ConfigMap generated from runbooks/*.md, at
the apex `/runbooks` prefix, in its own non-gating post-platform Flux tier
(dependsOn platform-config, wait:false) — the platform/homepage pattern, file for file.
- The service catalog cannot express this route: ingressRoutes[].host is pattern-bound
  to a single DNS label plus the apex, so the bare apex is unrepresentable, and there is
  no path field.
- Rejected: redirecting to the Gitea web UI. A runbook is read when the platform is
  broken, and Gitea is an app-tier workload whose own dependencies several of these
  runbooks document; Gateway API's RequestRedirect also has no "append .md" modifier,
  so it would need 34 hand-maintained ReplaceFullPath rules.
- configMapGenerator maps each file to an EXTENSIONLESS key (node-down=node-down.md),
  so /runbooks/node-down is a plain static lookup with no rewrite rule. Served as
  text/plain: the namespace has DNS-only egress, so a CDN markdown renderer could not
  load anyway.
- The tier declares NO postBuild.substituteFrom, deliberately: envsubst would run over
  the prose and silently empty every ${...} shell example (it fails open — the 2026-09-01
  emptied Cilium k8sServiceHost). The HTTPRoute omits `hostnames:` and inherits the
  https-apex listener's, so nothing needs substituting.

AUTH — PUBLIC, deliberately
auth-mode=none. Gating these pages behind oauth2-proxy/Keycloak would make
runbooks/keycloak-down unreadable when Keycloak is down and
runbooks/keycloak-client-secrets unreadable during the exact 2026-09-06 failure mode.
An operator who cannot log in is this route's primary reader. Content is operational
procedure only, no secrets. The rationale is recorded in an annotation on the HTTPRoute
so the route is left OUT of the Gateway ext-authz attachment when forward-auth
enforcement lands.

PROVEN — in-cluster probe through the Gateway on prod
  /runbooks/node-down        HTTP 200   8613 bytes  text/plain; charset=utf-8
  /runbooks/keycloak-down    HTTP 200   9378 bytes  text/plain; charset=utf-8
  /runbooks/cnpg-archiving   HTTP 200  11729 bytes  text/plain; charset=utf-8
  /runbooks/longhorn-faulted HTTP 200   9135 bytes  text/plain; charset=utf-8
  /runbooks/vpn-down         HTTP 200  11092 bytes  text/plain; charset=utf-8
  /runbooks/backup-failure   HTTP 200   9604 bytes  text/plain; charset=utf-8
HTTPRoute Accepted by io.cilium/gateway-controller on sectionName https-apex; the
`/runbooks` prefix wins over homepage's apex `/` by Gateway API longest-path precedence.

GUARD — conformance/tests/l0-static/alert-runbooks-resolvable (R-OBS-04)
363 offline assertions. It checks BOTH halves, because the regression is silent in both
directions: an alert with a new runbook_url and no runbook links to a 404, AND a runbook
committed without its configMapGenerator entry is in git, reviewed, merged, and still
404s in the cluster. Also asserts a quality floor so a stub cannot make the link look
fixed, and that route/listener/nginx prefix agree with the annotations.
Proven to fail, then reverted: a bogus runbook_url (2 FAIL), a runbook removed from the
generator (1 FAIL), and a 31-byte stub (7 FAIL).

Co-Authored-By: Claude Opus 5 <[email protected]>
2026-09-12 23:49:58 -05:00