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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

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longhorn-capacity — A Longhorn volume or node is near its storage capacity

Alerts: LonghornVolumeCapacityHigh (warning, 30m) and LonghornNodeStorageHigh (warning, 30m) File: platform/monitoring/alerts.yaml, group platform-health.longhorn Expressions: (longhorn_volume_actual_size_bytes / longhorn_volume_capacity_bytes) > 0.85 (longhorn_node_storage_usage_bytes / longhorn_node_storage_capacity_bytes) > 0.85

What this means here

Either one volume is 85% full, or one node's Longhorn disk is 85% allocated. They are different problems with different fixes, so read the labels: volume means a workload is filling its own PVC; node means the cluster is running out of places to put replicas.

The node case is bounded by settings that are already conservative: storageReservedPercentageForDefaultDisk: 20, storageMinimalAvailablePercentage: 25, storageOverProvisioningPercentage: 200, defaultDataLocality: disabled, hard node anti-affinity. Measured headroom on prod is roughly 269 GiB scheduled against an 829 GiB ceiling, so the node alert firing means something has changed materially, not that the platform has slowly grown.

The severe consequence of running out of node storage is that a degraded volume cannot finish rebuilding — hard anti-affinity needs three distinct nodes with room, so one full node pins a volume at 2 replicas indefinitely. Cross-read /runbooks/longhorn-degraded.

Verify the alert can even fire (measured 2026-09-13)

Prometheus on prod scrapes 19 jobs: apiserver, cdi-prometheus-metrics, coredns, keycloak-discovery, keycloak-service, keycloak/keycloak-db, kube-prometheus-stack-alertmanager, kube-prometheus-stack-grafana, kube-prometheus-stack-operator, kube-prometheus-stack-prometheus, kube-state-metrics, kubelet, kubevirt-prometheus-metrics, nextcloud-db/nextcloud-db, node-exporter, oauth2-proxy, semaphore-db/semaphore-db, velero, velero/node-agent. There is no Longhorn, cert-manager, Flux-controller or Hubble/Cilium job. Check the series this rule depends on before you trust its silence:

infra/devcontainer/dev.sh run bash -c \
  'kubectl --context k3s-prod -n monitoring port-forward svc/kube-prometheus-stack-prometheus 19090:9090 & \
   sleep 5; curl -s -G --data-urlencode "query=count by (job) (up)" localhost:19090/api/v1/query'

These alerts are currently INERT. count(longhorn_volume_capacity_bytes) and count(longhorn_node_storage_capacity_bytes) both returned 0 series on prod on 2026-09-13 — Longhorn ships no ServiceMonitor here. Volume-fill coverage actually comes from kubelet_volume_stats_* instead, i.e. /runbooks/pvc-capacity, which is where the working alerts are. Use this runbook for the Longhorn-side (node allocation) half, and expect to reach it by hand.

Running the commands in this runbook

kubectl does not work on the operator workstation. The toolchain lives only in the pinned dev container, and the host's k3s-oidc context hangs on a browser prompt once its token expires — that hang is not the cluster being down. Every command below runs as:

infra/devcontainer/dev.sh run bash -c 'kubectl --context k3s-prod get nodes'

Always pass --context k3s-prod explicitly. dev.sh merges both clusters into one kubeconfig and defaults its current-context to k3s-dev, so a command without --context silently answers about the wrong cluster. (CLUSTER=prod infra/devcontainer/dev.sh run kubectl ... is equivalent.) Do not run two dev.sh invocations at once — they share one container and interfere.

USE FULLY-QUALIFIED RESOURCE NAMES, ALWAYS. Three CRDs on this cluster register the kind Backup: longhorn.io/v1beta2, postgresql.cnpg.io/v1 and velero.io/v1. The bare short name resolves to Longhorn's, which holds zero objects — so kubectl get backup -A prints "No resources found" on a cluster holding 6 Velero backups and 27 CNPG backups. Verified on prod 2026-09-13. Reading that as "the backups are gone" and acting on it turns a false negative into real data loss. Write backups.velero.io, backups.postgresql.cnpg.io, clusters.postgresql.cnpg.io, settings.longhorn.io, volumes.longhorn.io, nodes.longhorn.io.

Mutating kubectl (apply, patch, annotate, rollout) and flux reconcile are blocked for agents here: every durable change goes through git (git push origin main is the deploy). Where this runbook gives a mutating command it is for an operator, and it says so.

First commands

Node-level allocation (the half that has no substitute alert):

infra/devcontainer/dev.sh run bash -c \
  'kubectl --context k3s-prod -n longhorn-system get nodes.longhorn.io -o yaml | grep -E "name:|storageAvailable|storageMaximum|storageScheduled|allowScheduling"'

Volume sizes versus actual usage:

infra/devcontainer/dev.sh run bash -c \
  'kubectl --context k3s-prod -n longhorn-system get volumes.longhorn.io \
     -o custom-columns=NAME:.metadata.name,SPEC:.spec.size,ACTUAL:.status.actualSize,ROBUST:.status.robustness'

Which PVC each one is, so you know who is filling it:

infra/devcontainer/dev.sh run bash -c \
  'kubectl --context k3s-prod get pv -o custom-columns=PV:.metadata.name,CLAIM:.spec.claimRef.namespace/.spec.claimRef.name,SIZE:.spec.capacity.storage,SC:.spec.storageClassName'

The filesystem view, which is the alert that actually works:

infra/devcontainer/dev.sh run bash -c \
  'kubectl --context k3s-prod -n monitoring port-forward svc/kube-prometheus-stack-prometheus 19090:9090 & sleep 5; \
   curl -s -G --data-urlencode "query=topk(10, 1 - kubelet_volume_stats_available_bytes{job=\"kubelet\"} / kubelet_volume_stats_capacity_bytes{job=\"kubelet\"})" localhost:19090/api/v1/query'

On the node itself:

ssh k3s-prod-1 'df -h /data; du -xh --max-depth=1 /data/longhorn/replicas 2>/dev/null | sort -h | tail'

Likely causes, most likely first

1. A CNPG database is not recycling WAL (check this FIRST)

The only cause here that grows without bound. archive_mode=on plus a failing archive_command means Postgres will not recycle unarchived WAL; measured on prod keycloak-db at ~6.8 MiB/h with pg_wal sharing the data PVC (no walStorage: is configured on any Cluster) — about 29 days from 93% free to disk-full, ending in a postmaster PANIC. Go to /runbooks/cnpg-archiving. Never delete WAL by hand.

2. Snapshots and orphaned replicas accumulating

Longhorn snapshots are not free, and cleanup here is manual: orphanAutoDeletion: true in platform/longhorn/helmrelease.yaml has been silently inert since Longhorn 1.12 — it was renamed orphanResourceAutoDeletion (now a list) and the chart drops unknown defaultSettings keys with no error. Verify the key's current state in that file before citing it; then prune orphans and stale snapshots from the Longhorn UI.

3. A workload genuinely grew

Plex/Sonarr/Radarr media does not live on Longhorn — it is static NFS from 192.168.2.102:/mnt/Storage/plex, via the bulk tier. If a media volume is on longhorn, that is a misconfiguration worth fixing, not a capacity problem: the bulk StorageClass is a stub (provisioner: nfs.csi.k8s.io, server:/share: REPLACE-ME) and provisions nothing, so real bulk storage is static NFS PVs. Otherwise expand the PVC — all Longhorn classes have allowVolumeExpansion: true; change the size in git and push.

4. Replicas piled onto one node

replicaAutoBalance: best-effort should prevent this, and hard anti-affinity bounds it to one replica per volume per node. If one node is much fuller than the others, check whether a rebuild placed replicas there while another node was down.

5. The cluster has outgrown its disks

Prod's ceiling is ~829 GiB across three nodes. docs/plans/longhorn-ssd-tiering.md is the planned answer (a ~51 GB hot tier: Prometheus, CNPG, Loki, Gitea). Operator planning work.

When to escalate or stop

A node over 85% while any volume is degraded is urgent, because the rebuild cannot complete. Free space or restore the other node before anything else.
Never delete files under /data/longhorn or inside a Postgres pg_wal. Both are irreversible.
Do not expand a PVC as a reflex if the cause is unrecycled WAL — you are buying days and hiding the real fault.
Escalate for adding disks, the SSD tiering plan, or anything that needs a node reboot (each reboot degrades all ~18 volumes and triggers a rebuild storm).

Source of truth: runbooks/longhorn-capacity.md. Index: /runbooks/ Records: platform/longhorn/helmrelease.yaml (the settings above and the inert orphanAutoDeletion); platform/cnpg/alerts.yaml header (the WAL disk-full clock); docs/BULK-NFS-STORAGE.md.

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