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2
Commits
| Author | SHA1 | Message | Date | |
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  jakman85andClaude Opus 5
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028853c87c |
feat(pihole): two replicas on different nodes, and fix a PVC mounted where pihole never writes
Phase 2 of making LAN DNS survive a node failure. Pihole was one pod on one node; measured 2026-10-04, losing that node meant roughly 6-10 minutes with no LAN resolution (tolerationSeconds 300 + NotReady detection + a Longhorn RWO force-detach), while losing the node holding the pihole-dns L2 lease -- a DIFFERENT node -- meant tens of seconds. Two of three nodes were single points of failure with wildly different blast radii. Adds `availability.replicas` to the ServiceDefinition schema (1.10.0). Intent only; the mechanism is render.py's, documented in the renderer contract. 1 or absent renders a Deployment exactly as before -- verified byte-identical across the whole apps/ tree. >1 renders a StatefulSet (a longhorn PVC is RWO, so a multi-replica Deployment never schedules the second pod), per-replica volumeClaimTemplates, REQUIRED hostname anti-affinity, podManagementPolicy Parallel, a minAvailable:1 PodDisruptionBudget, and an SLI that follows the rendered kind (a Deployment-shaped rule against a StatefulSet absent()s forever). Pinned by ~20 new --selftest assertions rather than a conformance change. ALSO FIXES A LIVE BUG. Pihole's config PVC was mounted at the renderer default /data/config, but pihole writes to /etc/pihole. Measured: /etc/pihole (7.1M -- gravity.db, pihole.toml, query DB) was on the OVERLAY, while the 2Gi Longhorn volume held lost+found and 24K of nothing. So every restart discarded all state and re-downloaded 72k gravity domains, and backup.policy has been backing up an empty volume while reporting success. Fixed here because otherwise the new per-replica volumes would hold nothing while state stayed ephemeral -- and because persisting gravity.db is what makes a restart cheap. The /etc/pihole mount is safe on the image's own evidence: start.sh is PID 1 as uid 0 and chowns the directory recursively (no fsGroup needed), and it calls migrate_gravity which creates the database when absent. The gate caught a real regression on the first run: the wave-0 alert unit test fed pihole a Deployment-shaped series. Updated; promtool SUCCESS. Touches no sensitive paths, so this one needs no override. Co-Authored-By: Claude Opus 5 (1M context) <[email protected]> |
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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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