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Commits
| Author | SHA1 | Message | Date | |
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  jakman85andClaude Opus 5
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cf7d97e546 |
fix(obs): twelve app SLI rules read a signal that exists; kill the dead ServiceMonitors
Twelve `<app>-down` SLI rules were STRUCTURALLY INERT. Each read `up{job="<app>"} == 0`,
and the ServiceMonitor rendered beside it named `endpoints[].port: metrics` — a port NO
rendered app Service defined. Every monitor discovered ZERO targets, so no `up{job="<app>"}`
series existed and the rule could not fire. Verified on prod before this change:
`count by (job) (up)` listed 24 jobs and not one of the twelve appeared; `up{job="plex"}`
and `up{job="gitea"}` both returned nothing. `PrometheusTargetsMissing` could not see it
either — a target that was never discovered has no `up` series to be 0.
THE PORT NAME WAS NEVER THE MISSING PIECE. Ground truth per app: Plex, Pi-hole, Jackett,
qBittorrent, Sonarr, Radarr, Seerr, Semaphore and Nextcloud export NO Prometheus metrics
without a separate exporter sidecar; Gitea can but only with app.ini metrics enabled;
Keycloak does, on the operator's management port, already scraped by
platform/keycloak/servicemonitor.yaml; vm-demo is a KubeVirt VM with no Service at all, so
its monitor selected nothing whatsoever. `metrics: true` was asserting a fact none of them
had. There was also a THIRD layer of inertness nobody had hit yet: every app namespace ships
default-deny with `ingress: []` and the renderer emitted no monitoring allow, so even a
correct port would have been dropped by policy — while renderer-contract.md claimed the
baseline carried such an allow.
FIXED IN THE GENERATOR, not in twelve rendered files:
* `slis: [up]` now renders a `<app>-down` alert against kube-state-metrics readiness of the
service's own workload object —
`kube_deployment_status_replicas_available{namespace,deployment} == 0 or absent(...)`,
`kube_statefulset_status_replicas_ready` for a StatefulSet, and
`absent(kubevirt_vmi_info{namespace,name,phase="running"})` for a VM. The same idiom
KeycloakDown has used since it was fixed. kube-state-metrics IS scraped, so this needs no
exporter and no new target. The `or absent(...)` half is load-bearing: the signal
DISAPPEARING now fires the alert instead of silencing it.
* schema 1.6.0 adds `observability.metricsEndpoint` — WHERE metrics are served. A
ServiceMonitor is rendered ONLY from it, and it renders all three halves of a working
scrape together: the named Service port, the monitor endpoint, and the
monitoring-namespace CiliumNetworkPolicy allow. No catalog entry declares one, so twelve
dead ServiceMonitors are gone. `metrics: true` keeps meaning logs-to-Loki plus
kube-state-metrics liveness.
* schema 1.6.0 also adds `observability.livenessWorkload`, and catalog/keycloak.yaml uses
it. Keycloak's server is a StatefulSet run by the operator; the default Deployment shape
would have made its `absent()` half fire FOREVER — the other failure mode this repo has
shipped.
* renderer selftest gains cases 9/9a/9b/9c: no metricsEndpoint => no monitor; the up SLI
must not read `up{job=...}`; endpoint port must exist on the Service; the metrics port
must NOT reach the Gateway allow; an unknown livenessWorkload.kind is REFUSED.
PROOF, both directions, for all twelve (apps/wave-{0,1,2}/tests/app-slis.test.yaml, run by
platform/monitoring/tests/run.sh over the RENDERED manifests):
* quiet on the healthy state; firing on no-ready-replica; firing when the series is ABSENT;
the VM asserted both gone and in a non-running phase; per-app isolation asserted, and
keycloak asserted un-maskable by its neighbours (keycloak-operator Deployment,
keycloak-db StatefulSet ready in the same namespace).
* mutation-checked: six mutations, each turning its suite red — reverting plex to
`up{job=...} == 0`; dropping seerr's `absent()` half; pointing keycloak at a Deployment;
capitalising the VMI phase to `Running`; widening keycloak's matcher to the namespace;
inverting plex's `== 0` to `!= 0`. Control run green.
* live on prod with `promtool query instant`: all ten deployed app Deployments export
`kube_deployment_status_replicas_available`,
`kube_statefulset_status_replicas_ready{namespace="keycloak",statefulset="keycloak"}` = 2,
`kubevirt_vmi_info` present with a lowercase `phase="running"`; and evaluating the twelve
SHIPPED expressions returns no series for eleven (quiet, not permanently firing). The
twelfth is vm-demo, which is not in apps/wave-0/kustomization.yaml and so is not deployed
— its rule is not applied either.
DELETION WAS NOT THE ANSWER, and the evidence is recorded rather than assumed:
kube-prometheus-stack's `kubernetes-apps` group IS live on prod (17 rules, KubePodNotReady /
KubeDeploymentReplicasMismatch among them), so app pods are not unmonitored — but that is a
generic warning keyed to a namespace, not the per-service CRITICAL SLI R-OBS-01 declares.
platform/monitoring/alerts.yaml carries no generic app-readiness rule at all.
GUARD SO IT CANNOT RECUR SILENTLY: new whole-repo L0 invariant
conformance/tests/l0-static/servicemonitor-ports-resolve. It walks the MONITORS, not the
alerts, so it needs no `up{job=...}` rule to reach one, and resolves each endpoint by SELECTOR
across the whole tree rather than by same-file adjacency. Fixing the alerts DELETED the only
thing that made the broken monitors visible to the sibling check, which is exactly why this
axis needed its own home. It declares `conformance.home.k3s/scope: whole-repo` and adds no
ci/l0.sh stage. Proven to FAIL on the pre-fix tree: 15 failures — eleven port disagreements,
vm-demo's monitor matching no Service at all, and the three generator/contract assertions —
and to pass after. Its resolver is additionally proven on in-check fixtures (agreeing pair
accepted, disagreeing pair rejected, target-less endpoint rejected), because after the fix
there are zero in-repo monitors left for it to judge and a guard whose only evidence is
"nothing failed" cannot be told apart from one that stopped working. It also asserts
r_servicemonitor does not HARDCODE a port name — the mechanism by which one edit gave twelve
services the same wrong one.
Also fixed, found on the way:
* platform/monitoring/tests/run.sh discovered the SUITE convention only inside
platform/monitoring/tests/ while documenting it as general — a suite added anywhere else
was never run and still looked like coverage. Now discovered tree-wide; a misplaced
*.test.yaml fails loudly instead of vanishing.
* KNOWN_UNWIRED_JOBS in alert-metrics-have-scrape-targets is now EMPTY, and the twelve
apps/* entries in alert-rules-unit-tested's UNTESTED_FILES are gone — both because the
gaps were CLOSED, not waived. Both registers are shrink-only and a stale entry fails.
* renderer-contract.md claimed the default-deny baseline carried a standing monitoring
scrape allow. It never did; the claim is corrected and the allow is now real, per declared
metrics endpoint and scoped to that one port.
Co-Authored-By: Claude Opus 5 <[email protected]>
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jakman85andClaude Opus 5
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a92fa11701 |
feat(monitoring): scrape Longhorn + cert-manager — 8 alerts were structurally inert
An alert rule whose metric is never scraped is not a broken alert, it is an ABSENT
alert that reads as a present one. `longhorn_volume_robustness == 2` over a TSDB
with no longhorn_* series returns no vector: permanently quiet, permanently
"healthy", indistinguishable from a correct rule. It survives review (the PromQL is
right), it survives `promtool test rules` (the unit test supplies the series
itself), and it appears on no dashboard.
VERIFIED ABSENT ON PROD before this change (re-verified 2026-09-13 21:0xZ, ~15h
after the first audit, because a stale reading is not evidence):
count(longhorn_volume_robustness) => (empty) 4 rules inert
count({__name__=~"certmanager.*"}) => (empty) 3 rules inert
count(hubble_drop_total) / {__name__=~"cilium.*"} => (empty) 1 rule inert
count by (job) (up) => 20 jobs, none of them
Longhorn, cert-manager,
Cilium or Hubble
Consequence: storage health was unmonitored on the cluster whose prod-1 had just
had a failing SSD, and TLS expiry was unmonitored with the live `wildcard-home`
wildcard 89 days from expiry on an ACME DNS-01 renewal that can fail silently.
WHAT THIS CHANGES
* platform/longhorn: `metrics.serviceMonitor.enabled: true` (the supported chart
way — rendering longhorn 1.12.1 emits exactly 1 ServiceMonitor with the flag and
0 without), plus networkpolicy-metrics.yaml. The NetworkPolicy is LOAD-BEARING,
not belt-and-braces: measured with the monitor applied and no allowance, all 3
targets were DISCOVERED and every scrape failed `context deadline exceeded`
after 10.0s — a drop, not a refusal — while curling the endpoint from inside
the manager pod returned 200 in 0.031s. Longhorn 1.12.1 ships 6 NetworkPolicies
of its own, guarded on `networkPolicies.restrictInternalTraffic` (default TRUE)
and NOT on `networkPolicies.enabled`, so they are effectively unconditional and
the manager policy admits only same-namespace Longhorn components. The one-line
alternative (restrictInternalTraffic: false) was rejected: it deletes the
internal-traffic restriction across all six components to open one port to one
namespace, trading an R-SEC-02 control for an observability one when the two do
not conflict. This policy is Ingress-only, ns monitoring -> app=longhorn-manager,
TCP 9500 only; 9502/9503 (webhook, recovery backend) stay closed.
* platform/cert-manager: `prometheus.servicemonitor.enabled: true`. Chart default
already serves 9402; only the monitor was missing. No NetworkPolicy needed —
neither ns cert-manager nor ns monitoring carries one. NOT paired with
prometheus.podmonitor.enabled: the chart calls `fail` if both are set.
* platform/kubevirt: KubeVirtVMLaunchFailing queried
`kubevirt_vmi_phase_count{phase="Failed"}`, which DOES NOT EXIST on the deployed
KubeVirt — a different flavour of the same defect, with the scrape target up and
healthy. Prod has only `kubevirt_vmi_info` and `kubevirt_vmi_number_of_outdated`;
the only phase-bearing names are the phase_transition_time histograms. Corrected
to `kubevirt_vmi_info{phase="failed"}` — LOWERCASE, because KubeVirt lowercases
the value (observed `phase="running"` for the unifi VMI) and a capital-F matcher
would select nothing and be exactly as inert.
PROVEN, NOT ASSERTED. The rendered ServiceMonitors were applied to prod by hand and
the metrics observed to land, then REMOVED again so the merge's Helm upgrade creates
and owns them rather than colliding with an unowned object:
count(up{job="longhorn-backend"}) => 3 (all three managers, up==1)
count({__name__=~"longhorn.*"}) => 8717 (was empty)
count(longhorn_volume_robustness) => 44
up{namespace="cert-manager"} => 3 targets, all 1
count({__name__=~"certmanager.*"}) => 104 (was empty)
wildcard-home days to expiry => 89.2, ready_status{condition="True"}=1
All 58 alert rules in the repo were then evaluated against prod one by one: every
one returns a result without error, and exactly ONE fires.
TRIAGE OF THE ONE NEWLY-FIRING ALERT — A TRUE POSITIVE, NOT TUNED AWAY.
LonghornVolumeCapacityHigh on the Prometheus TSDB volume:
`longhorn_volume_actual_size_bytes / longhorn_volume_capacity_bytes` = 0.971
(48.6 GiB allocated of 50 GiB) while the kubelet's view of the same filesystem is
only 20.4% used. Longhorn is not reclaiming freed blocks, so ~48.6 GiB x 3 replicas
is committed for ~10 GiB of real data. On a cluster whose failure mode is disk
pressure and whose etcd WAL shares a spindle with Longhorn, that is worth knowing
and was invisible until now. The threshold is left alone; the follow-up is
filesystem trim, not a bigger number.
THE GUARD (conformance/tests/l0-static/alert-metrics-have-scrape-targets)
Whole-repo L0 invariant, 118 assertions. It crosses from each alert to the scrape
config that makes its metric exist: every metric name is claimed by exactly one
declared owner, and each owner's enabling declaration is re-proven against the
working tree on every gate run, including the negative conditions that defeat an
enablement without deleting it. `up{job="X"}` is audited on its own axis, because
`up` always exists: where this repo authors a Service and a ServiceMonitor in the
same file, the monitor's endpoint port must be a port that Service defines.
It DECLARES conformance.home.k3s/scope: "whole-repo" and adds NO ci/l0.sh stage —
the whole-repo-invariants-wired meta-test fails the gate if one reappears.
PROVEN ABLE TO FAIL, five ways, each reverted:
1. an alert on a fabricated metric -> FAIL "claimed by NO entry"
2. longhorn metrics.serviceMonitor removed -> FAIL "no longer matches"
3. networkpolicy-metrics.yaml unwired -> FAIL "the monitor alone is NOT enough"
4. cert-manager podmonitor also enabled -> FAIL "FORBIDDEN pattern"
5. a register entry made stale / removed -> FAIL in both directions
TWO SHRINK-ONLY REGISTERS, because a blanket fail would make the gate red until
work that is not this change lands, and a disabled gate protects nothing:
* KNOWN_UNWIRED_METRICS (1): hubble_drop_total. See below.
* KNOWN_UNWIRED_JOBS (12): every apps/* `<app>-down` SLI rule is ALSO inert, and
this was found by the re-audit, not previously known. The rendered
ServiceMonitors name `port: metrics` and NOT ONE of the twelve app Services
defines a port of that name (zero occurrences of `name: metrics` across all
twelve manifests); prod confirms none of the twelve jobs appears in `up`. This
is the nastiest variant of the class: `up` exists in abundance so nothing looks
wrong, and PrometheusTargetsMissing cannot see it either, because a target that
was never discovered has no up series to be 0. Closing it needs an exporter per
app (Plex, Pi-hole, Jackett, qBittorrent, Sonarr, Radarr, Seerr speak no
Prometheus) — except keycloak, where the live jobs are keycloak-service /
keycloak-discovery and the rule is a rename away from being live.
NOT DONE HERE, DELIBERATELY: Hubble. hubble.metrics.enabled RECONFIGURES THE CNI —
it opens 9965 on every cilium-agent and rolls the DaemonSet across all three nodes,
serialised by this repo's own maxUnavailable: 1 (set after the 2026-09-01
k8sServiceHost outage, where a CNI roll deadlocked 2 of 3 agents). It also needs a
matching edit to roles/cilium/templates/cilium-values.yaml.j2 in the same commit,
because platform/cilium/helmrelease.yaml carries a [parity] contract against it and
a rebuilt node would otherwise bootstrap a CNI config that disagrees with the
reconciled one. Recommended as its own change on the cilium Kustomization, with the
Ansible parity edit, a narrow labelsContext, and a one-node canary — not smuggled in
here.
ALSO FOUND, NOT FIXED HERE: kube-state-metrics is OOMKilled every ~10 minutes on
prod (90 restarts in 16h against a 128Mi limit) while its logs show the
custom-resource-state factory reloading every 3 seconds. Thirteen alert rules read
kube_* metrics, so those rules are INTERMITTENTLY inert — the same defect class,
arriving through a crashloop rather than a missing monitor. Needs its own change.
Co-Authored-By: Claude Opus 5 <[email protected]>
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