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]>
jakman85andClaude Opus 5
44983095e1