home-network-k3s-impl/runbooks/README.md

# Alert runbooks — home-network-k3s prod

This is the index page served at `https://home.keithjackson.dev/runbooks/`.

Every alert rule in this platform carries an annotation of the form

    runbook_url: "https://${BASE_DOMAIN}/runbooks/<name>"

46 of them, over 35 names. Until this directory existed, that path returned **HTTP 404** on the
live cluster: every alert that reached a human handed them a dead link at the exact moment they needed
help. These pages are what makes the link resolve.

## How to run the commands in these runbooks

`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.

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

Always pass `--context k3s-prod`. `dev.sh` merges BOTH clusters into one kubeconfig and picks a
current-context per invocation, and **that default has already changed once** — k3s-dev until dev was
decommissioned on 2026-09-13, k3s-prod now. A command that names its context still means the same thing
next month; one that relies on the default does not, and the failure is silent. `CLUSTER=prod
infra/devcontainer/dev.sh run kubectl ...` selects it explicitly, and every invocation prints a banner
naming the cluster — read it. Do not run two `dev.sh` invocations at once; they share one container.

**Use fully-qualified resource names, always.** Three CRDs on this cluster register the kind `Backup` —
`longhorn.io/v1beta2`, `postgresql.cnpg.io/v1`, `velero.io/v1` — and the bare short name resolves to
Longhorn's, which holds zero objects. `kubectl get backup -A` therefore prints **"No resources found"** on
a cluster holding 6 Velero and 27 CNPG backups (verified on prod 2026-09-13). Acting on that false
negative is how a CLI quirk becomes real data loss. Write `backups.velero.io`,
`backups.postgresql.cnpg.io`, `clusters.postgresql.cnpg.io`, `settings.longhorn.io`,
`volumes.longhorn.io`, `nodes.longhorn.io`.

Merging a PR into `main` **is** the deploy; there is no other apply step. `main` is protected, so a
direct push is rejected — durable changes go through a branch, a PR, and a green gate.

## Alerts you should not trust the silence of (measured 2026-09-13)

The Longhorn and cert-manager scrapes were ENABLED on 2026-09-13, so the Longhorn row below is no
longer inert — and re-keying the two robustness rules the same day fixed a SECOND inertness the
scrape had left in place (the metric is one-hot over a `state` label, not a 0–3 enum). Take the
Longhorn row as history; the rest of this table still holds, and Flux-controller and Hubble/Cilium
rule groups still evaluate against nothing and **cannot fire**:

| Missing scrape job | Inert alerts |
|---|---|
| Longhorn | `LonghornVolumeDegraded`, `LonghornVolumeFaulted`, `LonghornDiskAllocationHigh`, `LonghornDiskUnschedulable` |
| cert-manager | `CertificateExpiringSoon`, `CertificateExpiryImminent`, `CertificateNotReady` |
| Flux (`gotk_*`) | `FluxReconciliationFailure`, `FluxResourceSuspended`, `ImageUpdateAutomationFailing`, `ImagePolicyStalled`, `UpdateHealthGateFailed` |
| Hubble (`hubble_drop_total`) | `HubbleDeniedFlowSpike` |
| etcd (`kubeEtcd` disabled for k3s, deliberately) | no etcd fsync alerting exists at all |

Each affected runbook says so on its own page and gives the by-hand equivalent. See `targets-down`.

## The runbooks

### Nodes
- **`node-down`** — a node's node-exporter is unscrapable; the node may be gone, or its kubelet may have
  stopped posting status while the host stays up (the 2026-09-07 shape).
- **`node-io`** — disk I/O pressure/starvation. The etcd WAL shares a partition with Longhorn replicas;
  this is the alert that would have called the 2026-09-07 outage and did not exist at the time.
- **`node-memory`** — memory pressure. Includes why `SwapTotal == 0` is not evidence swap is off.
- **`node-disk`** — a node filesystem filling up. `/data` is the one that matters.
- **`node-cpu`** — CPU PSI and run-queue depth, and how to tell CPU contention from I/O contention.

### Storage
- **`longhorn-degraded`** — a volume has lost redundancy. Normal after any reboot, and the rebuild is the
  expensive part. Freeze/thaw commands here.
- **`longhorn-faulted`** — no usable replica. Data at risk; stop before anything destructive.
- **`longhorn-capacity`** — a node's Longhorn disk running out of room for replicas (allocation, not PVC fill; for PVC fill see `pvc-capacity` / `monitoring-capacity`).
- **`pvc-capacity`** — PVC filling up / almost full / predicted to fill. These rules work.
- **`monitoring-capacity`** — Prometheus or Loki running out of disk; don't let the monitor blind itself.

### GitOps and updates
- **`flux-reconcile`** — a Flux resource stuck at Ready=False. Which tier decides the blast radius.
- **`flux-suspended`** — reconciliation turned off and forgotten. Drift becomes silent.
- **`update-rollback`** — a HelmRelease failed its health gate and is rolling back.
- **`image-automation`** — the git write-back engine is failing (feature is disabled here).
- **`image-policy-stalled`** — an ImagePolicy/ImageRepository cannot resolve a tag.

### Certificates
- **`cert-issuance`** — ACME issuance failing. The DNS-01 self-check is the usual cause.
- **`cert-expiry`** — a certificate is expiring. Almost always a late symptom of `cert-issuance`.

### Networking
- **`vpn-down`** — the egress VPN tunnel. Explains what the kill-switch actually does, and the silent
  egress-gateway staleness this alert cannot see — which now has its own alerts and page below.
- **`vpn-egress-stale`** — the tunnel is UP but `egress-class=vpn` pods have no egress: Cilium's cached
  ifindex outlived a reconnect. Also covers the watchdog for that rule going inert.
- **`denied-flows`** — policy-denied flow spike. The Cilium hairpin/identity regression class.

### Backups and DR
- **`backup-failure`** — a Velero backup failed. The R2 object-tagging incompatibility is documented here.
- **`backup-partial`** — a Velero backup completed with partial failures, and which skips are deliberate.
- **`backup-missed`** — no successful Velero backup in 24h.
- **`cnpg-archiving`** — WAL archiving stuck / no recoverability point. **An availability incident, not
  just a backup one.**
- **`cnpg-backup-missed`** — no recent CNPG base backup. Velero does not cover these databases.
- **`cnpg-wal-growth`** — `pg_wal` not being recycled. Never delete WAL by hand.
- **`cnpg-exporter`** — the CNPG SQL exporter erroring: a blind spot that looks exactly like health.
- **`cnpg-primary-spread`** — two or more CNPG primaries on one node. Blast radius, not an outage,
  and the rebalance costs ~9s of writes per database — one cluster at a time.

### Identity
- **`keycloak-down`** — the IdP is down. Blast radius, and the break-glass path that still works.
- **`keycloak-db`** — Keycloak's CloudNativePG database is unavailable.
- **`keycloak-client-secrets`** — the client/URL reconciler failing or silent. The 2026-09-06 lockout that
  every green signal missed.

### Operator procedures (no alert links here)
- **`plex-claim`** — claiming the Plex Media Server. **Claimed 2026-09-29**; the page now only
  applies after a `/config` wipe. The claim token is short-lived — read the countdown on
  plex.tv/claim — so it is a timed sequence, scripted as `infra/plex/claim-ship.sh`:
  token → `sops` → PR → gate → merge → **forced** `flux reconcile` → pod roll (~2m45s measured).
  Includes why a changed Secret does not restart anything, and why an expired token is harmless.

### Virtualisation
- **`kubevirt-control-plane`** — VM lifecycle operations will fail; running VMs keep running.
- **`kubevirt-launch-failed`** — a VMI reached the Failed phase. The three k3s-specific launch traps.
- **`kubevirt-crashloop`** — a virt-launcher pod restarting repeatedly.
- **`cdi-import-stuck`** — a DataVolume import not progressing. Check node I/O before restarting it.

## Editing a runbook

Each page is `runbooks/<name>.md` in the `home-network-k3s-impl` repo. Edit it, push to `main`, and Flux
re-renders the ConfigMap and rolls the two-replica server; kustomize's content hash on the generated
ConfigMap name is what triggers the roll.

Adding a **new** alert with a `runbook_url` requires the matching `runbooks/<name>.md` **and** its
`<name>=<name>.md` entry in `runbooks/kustomization.yaml`. Both are enforced by
`conformance/tests/l0-static/alert-runbooks-resolvable`, which runs unconditionally in the merge gate —
"the file exists in git" and "the URL resolves in the cluster" are different claims, and it checks both.

Every page must carry the four operator sections (*What this means here*, *First commands*, *Likely
causes, most likely first*, *When to escalate or stop*), mention `dev.sh`, and pass `--context k3s-prod`.
The check enforces that too, because a stub that makes the link resolve while helping nobody is worse than
the 404 it replaced — it looks fixed.

## Why this route has no login

Deliberately public. The UIs that declare forward-auth (pihole, jackett, qbittorrent, radarr, sonarr)
really are closed: enforcement is per-pod, each one's HTTPRoute targeting its oauth2-proxy sidecar on
:4180 rather than the app port. If
these pages did too, `keycloak-down` would be unreadable exactly when Keycloak is down,
`keycloak-db` unreadable when its database is down, and `keycloak-client-secrets` unreadable during the
precise failure that broke all 12 OIDC clients on 2026-09-06 behind an entirely green cluster. An
operator who cannot log in is this route's primary reader. The content is operational procedure — metric
names, thresholds, kubectl invocations, topology — and no secrets. See
`runbooks/serving/httproute.yaml` for the full reasoning, including how forward-auth is actually
enforced here and the instruction to leave this route **out** of any Gateway-level ext-authz attachment
if one is ever introduced.

The running narrative of real incidents on this cluster is `DECISIONS-LOG.md`.