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  jakman85andClaude Opus 5
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@@ -0,0 +1,106 @@
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---
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date: 2026-10-17
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branch: feat/graceful-cluster-shutdown
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title: "Graceful node shutdown was never configured, and scaling a StatefulSet deleted its PVC"
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---
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## What changed
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All three nodes had to be powered off to move them onto a UPS. There was **no procedure for it**:
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`infra/cluster.sh stop` is `virsh`-based and only ever applied to the decommissioned dev cluster, so
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the whole sequence was improvised live. Two defects came out of doing it.
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**1. Kubelet graceful node shutdown was unconfigured on every prod node.** No `shutdownGracePeriod`
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anywhere in `infra/ansible/`, so `shutdown -h` stopped k3s, containerd went with it, and every pod
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was SIGKILLed where it stood — 9 CloudNativePG instances mid-checkpoint, the UniFi VM, and 25
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attached Longhorn volumes. `roles/k3s_server` now writes `kubelet-arg` into
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`/etc/rancher/k3s/config.yaml` with `shutdown-grace-period=90s` and
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`shutdown-grace-period-critical-pods=20s`.
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The half that is easy to miss and silently defeats the other half: **graceful node shutdown is
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enforced by logind, not by the kubelet.** The kubelet holds an inhibitor *delay* lock and systemd
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waits at most `InhibitDelayMaxSec` — **default 5 seconds** — before proceeding regardless. A grace
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period above that cap is truncated with no error, so the feature looks configured and still
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hard-kills pods. The role now ships a `logind.conf.d` drop-in setting it to 120, and **asserts**
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`k3s_logind_inhibit_delay_max_sec >= k3s_kubelet_shutdown_grace_period` rather than documenting the
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relationship, because the failure is invisible.
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**2. Scaling a StatefulSet to 0 DELETED its PVC and Longhorn volume.** `monitoring/loki` carries
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`persistentVolumeClaimRetentionPolicy: {whenDeleted: Delete, whenScaled: Delete}`, so the quiesce's
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`scale --replicas=0` destroyed `storage-loki-0` outright. Loki stores with `type: filesystem`, so
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that PVC was the only copy of its log data. This is the defect in this change set that actually
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destroyed something, and it was mine.
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New `infra/maintenance/quiesce.sh` (`quiesce` | `resume` | `status`) encodes the sequence that
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worked, and **refuses to scale any StatefulSet whose `whenScaled` is `Delete`** — it leaves it
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running, accepts that its volume hard-detaches at poweroff, and prints which volumes to expect
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`degraded`. A rebuild is a vastly better outcome than a deletion. Workload discovery is computed
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from the live cluster (every Deployment/StatefulSet whose pods mount a PVC, Longhorn or TrueNAS NFS)
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rather than hardcoded, so a newly onboarded service is covered without anyone remembering to add it.
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`runbooks/cluster-maintenance-shutdown.md` (new, registered in `runbooks/kustomization.yaml`) is the
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operator page: shutdown order, the TrueNAS-after-nodes constraint, power-on order, the
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un-hibernate-Postgres step Flux will not do for you, and a "what looks broken but is fine" section
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separating the `4/19`-Kustomizations-Ready cascade, the degraded-and-rebuilding volume and the
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self-recovering `keycloak-operator` from the one thing that genuinely needs a human (a stuck
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`oauth2-proxy` replica).
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## What I verified
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* **Graceful shutdown was genuinely absent**, not merely undocumented: `grep -rn
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'shutdownGracePeriod|graceful-node-shutdown'` over `infra/ansible/` returns nothing, and no
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`logind` or `InhibitDelay` setting exists anywhere in the tree.
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* **The whole shutdown/restart cycle was executed end to end on prod 2026-10-17** and the cluster
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came back: 3/3 nodes Ready with etcd `healthz` ok, 19/19 Flux Kustomizations Ready,
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`platform-config`'s `lastAppliedRevision` equal to the GitRepository artifact revision, all 3
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CNPG clusters `healthy` with primaries elected, the UniFi VM `Running`, PiHole resolving
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(`home.keithjackson.dev` → `192.168.2.20` via `192.168.2.23`), and the Gateway serving
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`200/200/401` for apex/gitea/plex.
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* **The PVC-deletion mechanism is confirmed, not inferred:** `kubectl get sts loki -o
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jsonpath={.spec.persistentVolumeClaimRetentionPolicy}` returns
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`{"whenDeleted":"Delete","whenScaled":"Delete"}`, the PVC was `NotFound` after the cycle, and the
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Longhorn volume count had gone 25 → 24.
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* **The damage was repaired and verified:** `scale sts loki --replicas=1` (restoring the replica
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count the chart declares) recreated `storage-loki-0` as a fresh 50Gi Bound PVC, `loki-0` reached
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`2/2 Running`, and the volume count returned to 25.
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* **The guard works against the live cluster**, tested both ways: `sts_deletes_pvc_on_scale
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monitoring loki` returns true (would be skipped) and `pihole pihole` returns false (safe to
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scale).
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* **The script's read-only paths run clean on prod:** `status` reports correctly, and the discovery
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function returns the 13 workloads currently holding a PVC.
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* `bash -n` clean; the two edited Ansible YAML files parse.
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## What I did NOT verify
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* **The kubelet change has NEVER BEEN APPLIED OR TESTED.** This is the significant gap. I did not
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run the role, did not restart k3s, and have **not** observed a node actually drain on
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`shutdown -h`. Everything about it is reasoning from kubelet/systemd semantics plus the measured
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absence of the setting. Applying it needs a **rolling** k3s restart (`serial: 1` — kube-vip keeps
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the API up, etcd holds at 2/3), which is an operator action (CLAUDE.md §5). **Verify by draining
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one node for real:** apply, then `shutdown -h now` on a single node and watch whether pods
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terminate gracefully instead of vanishing.
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* **Whether 90s/20s are the right numbers.** Chosen to comfortably cover a Postgres fast shutdown
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and a Longhorn flush; not measured against either. The budget is spent on every reboot, so if a
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node takes noticeably longer to go down, this is why.
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* **Whether k3s accepts `kubelet-arg` in `config.yaml` as written.** The file already carries
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`kube-apiserver-arg` as a list and `kubelet-arg` is the documented sibling, but I did not render
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or apply it, so a typo would surface only at k3s restart — and a bad `config.yaml` is exactly the
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kind of thing that makes k3s fail to come up. **Review this one before applying.**
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* **The `assert` task's `regex_replace` on the grace period** assumes a plain `90s`-style value; a
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value expressed as `1m30s` would parse to the nonsense integer `130`. Fine for the committed
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defaults, wrong if someone writes a compound duration.
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* **`resume`'s Flux-reconcile wait has never run**, and neither has `quiesce` as a script — the
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2026-10-17 cycle was done with the equivalent commands by hand, so the script encodes a sequence
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that worked but has not itself been executed end to end. Only `status` and the discovery and guard
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functions have run.
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* **Loki's lost log window is gone for good.** Up to 72h of logs (its `retention_period`), destroyed
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by my scale-down. Nothing recovers it; Velero's schedules cover the namespace but the PVC was
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deleted, not corrupted, and I did not attempt a restore because the data self-expires anyway.
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* **No other `whenScaled: Delete` StatefulSet was audited.** The guard now catches them generically,
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but I did not enumerate which other workloads carry the policy, so I cannot say loki was the only
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one at risk. The runbook gives the one-liner to list them.
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* **TrueNAS and the router are entirely outside this change.** TrueNAS is not in the Ansible
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inventory and refuses SSH, so its shutdown stays a web-UI step with no automation and no check.
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* **No runtime conformance.** `vars.CLUSTER_AVAILABLE` is still unset, so CI proves the L0/L1
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offline subset only.
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* I did not re-measure branch protection or runner state (CLAUDE.md §2b).
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@@ -107,3 +107,31 @@ k3s_base_domain: "home.keithjackson.dev"
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# Derived, so the realm path is stated once. Override k3s_base_domain, not this.
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k3s_oidc_issuer_url: "https://keycloak.{{ k3s_base_domain }}/realms/homelab"
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# --- Graceful node shutdown (kubelet) ----------------------------------------------------------
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# MEASURED 2026-10-17, during the UPS move: graceful node shutdown was NOT configured on any prod
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# node, so `shutdown -h` did NOT drain pods. systemd stops k3s, containerd goes with it, and every
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# pod is SIGKILLed where it stands -- including 9 CloudNativePG instances mid-checkpoint, the UniFi
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# VM, and 25 attached Longhorn volumes. The whole-cluster shutdown that day had to quiesce
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# everything BY HAND first (runbooks/cluster-maintenance-shutdown.md), and the one volume that did
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# not finish detaching came back `degraded` and had to rebuild.
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#
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# With these set, the kubelet takes a systemd inhibitor lock and, on shutdown, evicts ordinary pods
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# first and critical ones last, so a plain `shutdown -h`/reboot drains the node. That makes the
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# manual scale-down in the runbook a belt-and-braces step for a PLANNED whole-cluster shutdown
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# rather than the only thing standing between a reboot and a hard kill.
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#
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# 90s/20s, not larger: the budget is spent on every reboot and node upgrade, and the kubelet waits
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# the FULL ordinary period before it starts on critical pods. Postgres does a fast shutdown in
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# well under 90s here, and Longhorn needs only enough time to flush and detach.
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k3s_kubelet_shutdown_grace_period: "90s"
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k3s_kubelet_shutdown_grace_period_critical_pods: "20s"
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# *** THE HALF THAT IS EASY TO MISS, AND SILENTLY BREAKS THE OTHER HALF. ***
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# Graceful node shutdown works by the kubelet holding a logind INHIBITOR DELAY lock. systemd caps
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# how long any inhibitor may delay shutdown at `InhibitDelayMaxSec`, which DEFAULTS TO 5 SECONDS.
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# If that cap is below the grace period above, systemd proceeds anyway and the drain is truncated
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# to ~5s -- i.e. the feature appears configured, reports no error, and still hard-kills pods. So
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# this MUST be >= k3s_kubelet_shutdown_grace_period; the role asserts it rather than trusting it.
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# Set a little above the kubelet's total (90s + 20s) to leave headroom.
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k3s_logind_inhibit_delay_max_sec: 120
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@@ -15,3 +15,12 @@
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port: "{{ k3s_api_port }}"
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timeout: 180
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listen: Restart k3s
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# logind re-reads InhibitDelayMaxSec only on restart. Restarting logind does NOT log users out or
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# disturb k3s -- it manages login sessions and inhibitor locks, not workloads. The kubelet picks up
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# the new cap when it next takes its lock, so no k3s restart is needed for THIS half.
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- name: Restart logind
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ansible.builtin.systemd_service:
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name: systemd-logind
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state: restarted
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listen: Restart logind
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@@ -86,6 +86,16 @@
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# k3s_base_domain (defaults/main.yml), whose [parity] contract with the cluster's
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# BASE_DOMAIN is documented there. Dev's default renders the value it already runs, so
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# config.yaml is unchanged and the Restart handler does not fire.
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# ── Graceful node shutdown ──────────────────────────────────────────────────────────────
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# Without these the kubelet takes no systemd inhibitor lock, so `shutdown -h` stops
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# containerd and SIGKILLs every pod where it stands -- MEASURED on all three prod nodes
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# 2026-10-17 (defaults/main.yml has the detail). The companion logind drop-in below raises
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# InhibitDelayMaxSec, WITHOUT WHICH systemd caps the drain at ~5s and these values are
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# quietly ignored.
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kubelet-arg:
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- "shutdown-grace-period={{ k3s_kubelet_shutdown_grace_period }}"
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- "shutdown-grace-period-critical-pods={{ k3s_kubelet_shutdown_grace_period_critical_pods }}"
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kube-apiserver-arg:
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- "oidc-issuer-url={{ k3s_oidc_issuer_url }}"
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- "oidc-client-id=kubernetes"
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@@ -183,3 +193,46 @@
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host: "127.0.0.1"
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port: "{{ k3s_api_port }}"
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timeout: 180
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|
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# ── Graceful node shutdown: the systemd half — tag `shutdown` ──────────────────────────────────
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# The kubelet's shutdown-grace-period is ENFORCED BY logind, not by the kubelet: the kubelet holds
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# an inhibitor DELAY lock, and systemd will wait at most `InhibitDelayMaxSec` for it (default 5s)
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# before proceeding regardless. A grace period above that cap is therefore silently truncated --
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# the feature looks configured, logs no error, and still hard-kills pods. Assert the relationship
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# instead of documenting it, because the failure is invisible.
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- name: Assert the logind inhibitor cap can actually cover the kubelet grace period
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ansible.builtin.assert:
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that:
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- (k3s_logind_inhibit_delay_max_sec | int) >= (k3s_kubelet_shutdown_grace_period | regex_replace('[^0-9]', '') | int)
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fail_msg: >-
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k3s_logind_inhibit_delay_max_sec ({{ k3s_logind_inhibit_delay_max_sec }}s) is below
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k3s_kubelet_shutdown_grace_period ({{ k3s_kubelet_shutdown_grace_period }}). systemd would
|
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stop waiting for the kubelet's inhibitor lock before the drain finished, so pods would be
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SIGKILLed anyway and graceful node shutdown would be configured but ineffective.
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quiet: true
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tags: [shutdown]
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|
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- name: Ensure /etc/systemd/logind.conf.d exists
|
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ansible.builtin.file:
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path: /etc/systemd/logind.conf.d
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state: directory
|
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owner: root
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group: root
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mode: "0755"
|
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tags: [shutdown]
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|
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# A drop-in, not an edit of logind.conf: the distro file stays pristine and `state: absent` here
|
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# would fully revert the change.
|
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- name: Raise the logind inhibitor delay cap so the kubelet can finish draining
|
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ansible.builtin.copy:
|
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dest: /etc/systemd/logind.conf.d/10-k3s-graceful-shutdown.conf
|
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owner: root
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group: root
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mode: "0644"
|
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content: |
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# Managed by Ansible (roles/k3s_server). See defaults/main.yml.
|
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# MUST stay >= kubelet shutdown-grace-period, or the drain is truncated to this value.
|
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[Login]
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InhibitDelayMaxSec={{ k3s_logind_inhibit_delay_max_sec }}
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notify: Restart logind
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tags: [shutdown]
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Executable
+265
@@ -0,0 +1,265 @@
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#!/usr/bin/env bash
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# =================================================================================================
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# quiesce.sh — bring the prod cluster to a safe standstill before powering nodes off, and bring it
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# back afterwards. Companion to runbooks/cluster-maintenance-shutdown.md.
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# =================================================================================================
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# WHY THIS EXISTS. On 2026-10-17 all three nodes had to be powered off to move them onto a UPS, and
|
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# there was NO procedure for it: `infra/cluster.sh stop` is `virsh`-based and only ever applied to
|
||||
# the decommissioned dev cluster. The whole sequence was improvised live. This script is that
|
||||
# sequence, so the next person does not improvise it.
|
||||
#
|
||||
# WHY IT IS NOT JUST `shutdown -h`. Graceful node shutdown was unconfigured on every prod node that
|
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# day, so systemd stopped containerd and SIGKILLed every pod where it stood. roles/k3s_server now
|
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# sets shutdown-grace-period (+ the logind InhibitDelayMaxSec cap that actually enforces it), which
|
||||
# makes a bare reboot safe. This script is still the right tool for a PLANNED whole-cluster
|
||||
# shutdown, for three reasons the kubelet's drain does not cover:
|
||||
# 1. The UniFi VM needs an ACPI guest shutdown, not an eviction.
|
||||
# 2. CloudNativePG wants hibernation, not pod deletion -- and hibernation is IMPERATIVE state
|
||||
# that Flux will not set or clear for you.
|
||||
# 3. Draining three nodes one at a time makes pods RESCHEDULE onto the survivors, churning
|
||||
# Longhorn replicas for no reason when the whole cluster is going down anyway. Scaling in
|
||||
# place avoids all of it.
|
||||
#
|
||||
# SAFE TO RE-RUN. Every step is idempotent and `resume` is the exact inverse of `quiesce`.
|
||||
#
|
||||
# WHAT IT DELIBERATELY DOES NOT DO: power anything off. Node poweroff is an operator action
|
||||
# (CLAUDE.md §5) and needs the become password; the runbook gives the ansible one-liner. It also
|
||||
# does not touch TrueNAS (not in the inventory, SSH refused -- web UI only) or the router.
|
||||
set -euo pipefail
|
||||
|
||||
CONTEXT="${CONTEXT:-k3s-prod}"
|
||||
KUBECTL=(kubectl --context "$CONTEXT" --request-timeout=30s)
|
||||
TIMEOUT="${TIMEOUT:-600}"
|
||||
|
||||
# The three CloudNativePG clusters, as namespace/name. Hibernation is per-Cluster.
|
||||
CNPG=(keycloak/keycloak-db nextcloud-db/nextcloud-db semaphore-db/semaphore-db)
|
||||
|
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log() { printf '\033[34m[quiesce]\033[0m %s\n' "$*"; }
|
||||
ok() { printf '\033[32m[ ok ]\033[0m %s\n' "$*"; }
|
||||
warn() { printf '\033[33m[warn]\033[0m %s\n' "$*"; }
|
||||
die() { printf '\033[31m[fail]\033[0m %s\n' "$*" >&2; exit 1; }
|
||||
|
||||
need() { command -v "$1" >/dev/null || die "$1 not on PATH — run this inside ./infra/devcontainer/dev.sh"; }
|
||||
|
||||
# ---------------------------------------------------------------- discovery
|
||||
# Every Deployment/StatefulSet whose pods mount a PVC — Longhorn OR the TrueNAS NFS bulk tier.
|
||||
# Computed from the LIVE cluster rather than hardcoded, so a newly onboarded service is covered
|
||||
# without anyone remembering to add it here. PROTECTED namespaces are excluded because scaling
|
||||
# them down would remove the very machinery that performs the detach (longhorn-system), keep the
|
||||
# API reachable (kube-system), or finish the hibernation and the VM shutdown (cnpg-system,
|
||||
# kubevirt).
|
||||
pvc_workloads() {
|
||||
"${KUBECTL[@]}" get pods -A -o json | python3 -c '
|
||||
import json,sys
|
||||
PROTECT={"longhorn-system","kube-system","cilium-secrets","cnpg-system","kubevirt","flux-system","cdi"}
|
||||
out={}
|
||||
for p in json.load(sys.stdin)["items"]:
|
||||
ns=p["metadata"]["namespace"]
|
||||
if ns in PROTECT: continue
|
||||
if not any(v.get("persistentVolumeClaim") for v in (p["spec"].get("volumes") or [])): continue
|
||||
ow=(p["metadata"].get("ownerReferences") or [])
|
||||
if not ow: continue
|
||||
k,n=ow[0]["kind"],ow[0]["name"]
|
||||
if k=="ReplicaSet": k,n="deployment",n.rsplit("-",1)[0]
|
||||
elif k=="StatefulSet": k="statefulset"
|
||||
else: continue # Jobs, and CNPG Clusters, are handled separately
|
||||
out[(ns,k,n)]=1
|
||||
for ns,k,n in sorted(out): print(ns,k,n)
|
||||
'
|
||||
}
|
||||
|
||||
# ---------------------------------------------------------------- the PVC-deletion guard
|
||||
# *** DO NOT REMOVE THIS CHECK. IT EXISTS BECAUSE SCALING A StatefulSet DESTROYED DATA. ***
|
||||
# A StatefulSet may carry `persistentVolumeClaimRetentionPolicy.whenScaled: Delete`, and then
|
||||
# scaling it to 0 DELETES ITS PVCs -- and with them the Longhorn volumes. MEASURED 2026-10-17: the
|
||||
# quiesce for the UPS move scaled `monitoring/loki` (whenScaled: Delete) to 0 and its
|
||||
# `storage-loki-0` PVC and volume were deleted outright. Loki stores with `type: filesystem`, so
|
||||
# that PVC was the only copy; 72h retention bounded the loss to a rolling window, but nothing about
|
||||
# the mechanism is bounded -- the same action on a Delete-policy StatefulSet holding real state
|
||||
# would be unrecoverable. The volume count going 25 -> 24 was the only visible symptom, and it was
|
||||
# first misread as a miscount.
|
||||
#
|
||||
# So: such a StatefulSet is NEVER scaled. It is left RUNNING and its volume hard-detaches at
|
||||
# poweroff, which costs a replica rebuild on restart (degraded -> healthy, automatic). A rebuild is
|
||||
# an enormously better outcome than a deletion, and that is the whole trade being made here.
|
||||
sts_deletes_pvc_on_scale() { # ns name -> 0 if scaling it would delete its PVCs
|
||||
local policy
|
||||
policy=$("${KUBECTL[@]}" -n "$1" get statefulset "$2" \
|
||||
-o jsonpath='{.spec.persistentVolumeClaimRetentionPolicy.whenScaled}' 2>/dev/null || true)
|
||||
[ "$policy" = "Delete" ]
|
||||
}
|
||||
|
||||
wait_for() { # wait_for <description> <shell-condition>
|
||||
local desc="$1" cond="$2" waited=0
|
||||
log "waiting: $desc (up to ${TIMEOUT}s)"
|
||||
until eval "$cond"; do
|
||||
(( waited += 10 )); (( waited >= TIMEOUT )) && { warn "TIMED OUT waiting: $desc"; return 1; }
|
||||
sleep 10
|
||||
done
|
||||
ok "$desc"
|
||||
}
|
||||
|
||||
# ---------------------------------------------------------------- quiesce
|
||||
do_quiesce() {
|
||||
need kubectl; need python3
|
||||
|
||||
# Refuse to start if Longhorn is already unhealthy. Powering off on top of a degraded volume is
|
||||
# how one replica becomes zero; better to stop here and let it rebuild first.
|
||||
local unhealthy
|
||||
unhealthy=$("${KUBECTL[@]}" -n longhorn-system get volumes.longhorn.io \
|
||||
-o jsonpath='{range .items[*]}{.status.robustness}{"\n"}{end}' | grep -cvE '^(healthy|unknown)$' || true)
|
||||
[ "$unhealthy" = "0" ] || die "$unhealthy Longhorn volume(s) are not healthy — fix or wait for rebuild BEFORE powering off"
|
||||
ok "Longhorn: all volumes healthy"
|
||||
|
||||
# 1. Flux first, or it reverts every scale-down below within its reconcile interval.
|
||||
log "suspending Flux Kustomizations"
|
||||
local k
|
||||
for k in $("${KUBECTL[@]}" -n flux-system get kustomizations -o name); do
|
||||
"${KUBECTL[@]}" -n flux-system patch "${k}" --type=merge -p '{"spec":{"suspend":true}}' >/dev/null
|
||||
done
|
||||
ok "all Kustomizations suspended"
|
||||
|
||||
# 2. The VM needs an ACPI shutdown of the GUEST. KubeVirt does that on running:false; a plain
|
||||
# pod eviction would be a power cut to the VM.
|
||||
if "${KUBECTL[@]}" -n unifi get vm unifi >/dev/null 2>&1; then
|
||||
log "ACPI-stopping the UniFi VM"
|
||||
"${KUBECTL[@]}" -n unifi patch vm unifi --type=merge -p '{"spec":{"running":false}}' >/dev/null
|
||||
fi
|
||||
|
||||
# 3. Postgres: hibernation is a clean smart shutdown that KEEPS the PVCs. CNPG does one instance
|
||||
# at a time, primary last-ish, so this is not instant.
|
||||
log "hibernating CloudNativePG clusters"
|
||||
local c ns name
|
||||
for c in "${CNPG[@]}"; do
|
||||
ns="${c%%/*}"; name="${c##*/}"
|
||||
"${KUBECTL[@]}" -n "$ns" annotate cluster.postgresql.cnpg.io "$name" \
|
||||
cnpg.io/hibernation=on --overwrite >/dev/null 2>&1 || warn "could not hibernate $c"
|
||||
done
|
||||
|
||||
# 4. Everything holding a PVC, scaled in place. NFS consumers first so nothing holds a hard
|
||||
# TrueNAS mount; PiHole last because it is the LAN resolver.
|
||||
log "scaling down PVC-holding workloads"
|
||||
local line ns2 kind nm deferred=() skipped_delete_policy=()
|
||||
while read -r ns2 kind nm; do
|
||||
[ -z "${ns2:-}" ] && continue
|
||||
if [ "$kind" = "statefulset" ] && sts_deletes_pvc_on_scale "$ns2" "$nm"; then
|
||||
warn "SKIPPING $ns2/$nm — whenScaled: Delete would DELETE its PVC (see the guard above)."
|
||||
warn " Left running; its volume hard-detaches at poweroff and rebuilds on restart."
|
||||
skipped_delete_policy+=("$ns2/$nm")
|
||||
continue
|
||||
fi
|
||||
if [ "$ns2" = "pihole" ]; then deferred+=("$ns2 $kind $nm"); continue; fi
|
||||
"${KUBECTL[@]}" -n "$ns2" scale "$kind" "$nm" --replicas=0 >/dev/null 2>&1 \
|
||||
&& printf ' scaled 0 %s/%s %s\n' "$ns2" "$kind" "$nm" \
|
||||
|| warn "could not scale $ns2/$kind/$nm"
|
||||
done < <(pvc_workloads)
|
||||
for line in "${deferred[@]:-}"; do
|
||||
[ -z "${line:-}" ] && continue
|
||||
# shellcheck disable=SC2086
|
||||
set -- $line
|
||||
"${KUBECTL[@]}" -n "$1" scale "$2" "$3" --replicas=0 >/dev/null 2>&1 \
|
||||
&& printf ' scaled 0 %s/%s %s (LAN DNS — expect name resolution to stop)\n' "$1" "$2" "$3"
|
||||
done
|
||||
|
||||
# 5. The only assertion that matters. An attached volume at poweroff comes back degraded and
|
||||
# rebuilds; this is what we are buying with all of the above.
|
||||
wait_for "UniFi VMI gone" \
|
||||
'[ "$('"${KUBECTL[*]}"' -n unifi get vmi --no-headers 2>/dev/null | wc -l)" = "0" ]' || true
|
||||
wait_for "all Postgres instances stopped" \
|
||||
'[ "$('"${KUBECTL[*]}"' get pods -A --no-headers 2>/dev/null | grep -cE "(keycloak|nextcloud|semaphore)-db-[0-9]")" = "0" ]' || true
|
||||
wait_for "all Longhorn volumes detached" \
|
||||
'[ "$('"${KUBECTL[*]}"' -n longhorn-system get volumes.longhorn.io -o jsonpath="{range .items[*]}{.status.state}{\"\n\"}{end}" 2>/dev/null | grep -c attached)" = "0" ]' || \
|
||||
warn "some volumes are STILL ATTACHED — they will come back degraded and rebuild; acceptable, but note which"
|
||||
|
||||
if [ "${#skipped_delete_policy[@]}" -gt 0 ]; then
|
||||
echo
|
||||
warn "NOT scaled down (whenScaled: Delete — scaling them would delete their PVCs):"
|
||||
printf ' %s\n' "${skipped_delete_policy[@]}"
|
||||
warn "Expect these volumes to come back 'degraded' and rebuild. That is correct and automatic."
|
||||
fi
|
||||
echo
|
||||
ok "QUIESCED. Safe to power off."
|
||||
cat <<'NEXT'
|
||||
|
||||
Next, from inside the devcontainer (it holds the become password):
|
||||
cd /work/infra/ansible && ansible -i inventory/hosts.ini k3s_prod -b \
|
||||
-m shell -a 'shutdown -h +1 "maintenance"'
|
||||
|
||||
THEN, in this order and not before:
|
||||
1. TrueNAS (192.168.2.30) — web UI only; not in the ansible inventory and SSH is refused.
|
||||
2. Router / switch last.
|
||||
NEXT
|
||||
}
|
||||
|
||||
# ---------------------------------------------------------------- resume
|
||||
do_resume() {
|
||||
need kubectl
|
||||
|
||||
# THE STEP THAT IS ALWAYS FORGOTTEN. Hibernation is imperative state: Flux neither sets nor
|
||||
# clears it, so resuming Flux alone leaves all three databases down and every app that needs
|
||||
# one looking broken for reasons that point nowhere near Postgres.
|
||||
log "un-hibernating CloudNativePG clusters"
|
||||
local c ns name
|
||||
for c in "${CNPG[@]}"; do
|
||||
ns="${c%%/*}"; name="${c##*/}"
|
||||
"${KUBECTL[@]}" -n "$ns" annotate cluster.postgresql.cnpg.io "$name" \
|
||||
cnpg.io/hibernation=off --overwrite >/dev/null 2>&1 || warn "could not un-hibernate $c"
|
||||
done
|
||||
|
||||
# Flux restores every replica count AND the VM's running:true from git, so nothing here needs to
|
||||
# undo the scale-downs by hand.
|
||||
log "resuming Flux Kustomizations"
|
||||
local k
|
||||
for k in $("${KUBECTL[@]}" -n flux-system get kustomizations -o name); do
|
||||
"${KUBECTL[@]}" -n flux-system patch "${k}" --type=merge -p '{"spec":{"suspend":false}}' >/dev/null
|
||||
done
|
||||
ok "all Kustomizations resumed"
|
||||
|
||||
wait_for "Flux fully reconciled" \
|
||||
'[ "$('"${KUBECTL[*]}"' -n flux-system get kustomizations --no-headers 2>/dev/null | grep -vc True)" = "0" ]' || \
|
||||
warn "some Kustomizations are not Ready — the graph serialises behind platform-config, so give it a few minutes before worrying"
|
||||
|
||||
echo
|
||||
ok "RESUMED."
|
||||
cat <<'NEXT'
|
||||
|
||||
Known cold-start race, not a fault in this script: oauth2-proxy performs OIDC discovery at
|
||||
startup and exits 1 on the 503 it gets while Keycloak is still coming up, then sits in
|
||||
exponential CrashLoopBackOff. If a replica is stuck, delete the pod once:
|
||||
kubectl --context k3s-prod -n oauth2-proxy delete pod <name>
|
||||
NEXT
|
||||
}
|
||||
|
||||
do_status() {
|
||||
need kubectl
|
||||
printf 'nodes: %s Ready\n' "$("${KUBECTL[@]}" get nodes --no-headers | grep -c ' Ready')"
|
||||
printf 'flux: %s/%s Ready\n' \
|
||||
"$("${KUBECTL[@]}" -n flux-system get kustomizations --no-headers | grep -c True)" \
|
||||
"$("${KUBECTL[@]}" -n flux-system get kustomizations --no-headers | wc -l)"
|
||||
printf 'longhorn: %s attached, %s detached, %s not healthy\n' \
|
||||
"$("${KUBECTL[@]}" -n longhorn-system get volumes.longhorn.io -o jsonpath='{range .items[*]}{.status.state}{"\n"}{end}' | grep -c attached)" \
|
||||
"$("${KUBECTL[@]}" -n longhorn-system get volumes.longhorn.io -o jsonpath='{range .items[*]}{.status.state}{"\n"}{end}' | grep -c detached)" \
|
||||
"$("${KUBECTL[@]}" -n longhorn-system get volumes.longhorn.io -o jsonpath='{range .items[*]}{.status.robustness}{"\n"}{end}' | grep -cvE '^(healthy|unknown)$' || true)"
|
||||
printf 'postgres: %s instance pod(s)\n' \
|
||||
"$("${KUBECTL[@]}" get pods -A --no-headers | grep -cE '(keycloak|nextcloud|semaphore)-db-[0-9]' || true)"
|
||||
printf 'unifi VM: %s VMI\n' "$("${KUBECTL[@]}" -n unifi get vmi --no-headers 2>/dev/null | wc -l)"
|
||||
}
|
||||
|
||||
case "${1:-}" in
|
||||
quiesce) do_quiesce ;;
|
||||
resume) do_resume ;;
|
||||
status) do_status ;;
|
||||
*) cat >&2 <<USAGE
|
||||
usage: $0 {quiesce|resume|status}
|
||||
|
||||
quiesce suspend Flux, ACPI-stop the UniFi VM, hibernate Postgres, scale down every
|
||||
PVC-holding workload, and wait for all Longhorn volumes to detach.
|
||||
Does NOT power anything off — see runbooks/cluster-maintenance-shutdown.md.
|
||||
resume the exact inverse: un-hibernate Postgres, resume Flux, wait for reconcile.
|
||||
status one-screen readout of nodes / Flux / Longhorn / Postgres / VM.
|
||||
|
||||
Run it inside the pinned toolbox, which supplies kubectl and the context:
|
||||
./infra/devcontainer/dev.sh run bash -c './infra/maintenance/quiesce.sh status'
|
||||
USAGE
|
||||
exit 2 ;;
|
||||
esac
|
||||
@@ -0,0 +1,162 @@
|
||||
# cluster-maintenance-shutdown — powering the whole cluster off, and back on
|
||||
|
||||
**Operator procedure, not an alert page.** Nothing links here from an alert.
|
||||
**Script:** `infra/maintenance/quiesce.sh` (`quiesce` | `resume` | `status`)
|
||||
**Related:** `/runbooks/update-rollback` is for rolling node work where the cluster stays up. This
|
||||
page is for taking **all three nodes down at once**.
|
||||
|
||||
First written after the 2026-10-17 UPS move, which was improvised live because no procedure
|
||||
existed — `infra/cluster.sh stop` is `virsh`-based and only ever applied to the decommissioned dev
|
||||
cluster, so it does nothing for these three baremetal nodes.
|
||||
|
||||
## Why you cannot just run `shutdown -h`
|
||||
|
||||
You mostly can now, and could not before.
|
||||
|
||||
Until 2026-10-17 **kubelet graceful node shutdown was unconfigured on every prod node**, so systemd
|
||||
stopped k3s, containerd went with it, and every pod was SIGKILLed where it stood — 9 Postgres
|
||||
instances mid-checkpoint, the UniFi VM, and 25 attached Longhorn volumes.
|
||||
`roles/k3s_server` now sets `shutdown-grace-period` (and, critically, the
|
||||
`InhibitDelayMaxSec` logind cap that actually enforces it — without that systemd stops waiting
|
||||
after 5s and the drain is silently truncated). A plain reboot of one node is therefore safe.
|
||||
|
||||
**A planned whole-cluster shutdown still wants `quiesce`**, for three things the kubelet's drain
|
||||
does not do:
|
||||
|
||||
1. **The UniFi VM needs an ACPI guest shutdown**, not an eviction. KubeVirt does that on
|
||||
`running: false`; an eviction is a power cut to the guest.
|
||||
2. **CloudNativePG wants hibernation**, not pod deletion — and hibernation is **imperative** state
|
||||
that Flux will neither set nor clear.
|
||||
3. **Draining three nodes one at a time makes pods reschedule onto the survivors**, churning
|
||||
Longhorn replicas for no reason when everything is going down anyway. Scaling in place avoids it.
|
||||
|
||||
## The hazard that bit us — read this before scaling anything by hand
|
||||
|
||||
**A StatefulSet can carry `persistentVolumeClaimRetentionPolicy.whenScaled: Delete`, and scaling it
|
||||
to 0 then DELETES its PVCs and their Longhorn volumes.**
|
||||
|
||||
On 2026-10-17 the hand-rolled quiesce scaled `monitoring/loki` (which has that policy) to 0, and
|
||||
`storage-loki-0` was deleted outright. Loki stores with `type: filesystem`, so that PVC was the only
|
||||
copy. Its 72h retention bounded the loss to a rolling window — nothing about the *mechanism* is
|
||||
bounded. The only visible symptom was the Longhorn volume count going 25 → 24, which was first
|
||||
misread as a miscount.
|
||||
|
||||
`quiesce.sh` now refuses to scale any such StatefulSet, leaves it running, and tells you which
|
||||
volumes to expect `degraded` on restart. **If you quiesce by hand, check the policy first:**
|
||||
|
||||
```bash
|
||||
kubectl --context k3s-prod get statefulset -A \
|
||||
-o custom-columns='NS:.metadata.namespace,NAME:.metadata.name,WHEN_SCALED:.spec.persistentVolumeClaimRetentionPolicy.whenScaled'
|
||||
```
|
||||
|
||||
A hard-detached volume comes back `degraded` and rebuilds itself automatically. That is a vastly
|
||||
better outcome than a deleted one — take the rebuild.
|
||||
|
||||
## Shutting down
|
||||
|
||||
Run everything through the pinned toolbox; it supplies `kubectl` and the context.
|
||||
|
||||
```bash
|
||||
# 0. Look before you leap. Refuses to proceed if any Longhorn volume is unhealthy —
|
||||
# powering off on top of a degraded volume is how one replica becomes zero.
|
||||
./infra/devcontainer/dev.sh run bash -c './infra/maintenance/quiesce.sh status'
|
||||
|
||||
# 1. Quiesce: suspend Flux, ACPI-stop the VM, hibernate Postgres, scale down every
|
||||
# PVC-holding workload (NFS consumers first, PiHole last), wait for detach.
|
||||
./infra/devcontainer/dev.sh run bash -c './infra/maintenance/quiesce.sh quiesce'
|
||||
```
|
||||
|
||||
**Expect DNS to stop** when PiHole scales down — it is the LAN resolver. `kubectl` is unaffected
|
||||
because the kubeconfig points at the kube-vip IP `192.168.2.9`, not a name.
|
||||
|
||||
```bash
|
||||
# 2. Power the nodes off. Inside the devcontainer, which holds the become password.
|
||||
./infra/devcontainer/dev.sh run bash -c \
|
||||
'cd /work/infra/ansible && ansible -i inventory/hosts.ini k3s_prod -b \
|
||||
-m shell -a "shutdown -h +1 \"maintenance\""'
|
||||
```
|
||||
|
||||
`+1` gives Ansible time to disconnect cleanly. The group resolves to all three nodes; confirm with
|
||||
`--list-hosts` if you want to see them first.
|
||||
|
||||
```bash
|
||||
# 3. Confirm they are actually down before touching anything else.
|
||||
for h in 192.168.2.10 192.168.2.11 192.168.2.12; do ping -c1 -W2 $h >/dev/null && echo "$h UP" || echo "$h down"; done
|
||||
```
|
||||
|
||||
**Then, in this order and not before:**
|
||||
|
||||
| # | Machine | How |
|
||||
|---|---|---|
|
||||
| 4 | **TrueNAS** `192.168.2.30` | **Web UI only.** Not in the ansible inventory, and SSH is **refused** (service disabled). `https://192.168.2.30` → power icon → Shut Down. Safe once the nodes are down, because every NFS consumer (`plex-media`, `*-media`, `qbittorrent-downloads`, `nextcloud-legacy-archive`) is already scaled to zero and nothing holds a hard mount. |
|
||||
| 5 | **Router / switch** | Last. |
|
||||
|
||||
TrueNAS must go **after** the k3s nodes: a hard NFS mount on a live node wedges kubelet in
|
||||
D-state (`/runbooks/nfs-export-latency`, and the load-average symptom in the 2026-10-?? note).
|
||||
|
||||
## Bringing it back
|
||||
|
||||
**Power on in the reverse order: router/switch → TrueNAS → all three nodes together.** etcd needs
|
||||
2 of 3 for quorum, so start the nodes as a group rather than one at a time.
|
||||
|
||||
```bash
|
||||
# 1. Nodes Ready, etcd quorum, storage reachable.
|
||||
./infra/devcontainer/dev.sh run bash -c 'kubectl --context k3s-prod get nodes'
|
||||
./infra/devcontainer/dev.sh run bash -c 'kubectl --context k3s-prod get --raw=/healthz/etcd'
|
||||
|
||||
# 2. Resume: un-hibernate Postgres, then resume Flux.
|
||||
./infra/devcontainer/dev.sh run bash -c './infra/maintenance/quiesce.sh resume'
|
||||
```
|
||||
|
||||
**Un-hibernating Postgres is the step everyone forgets.** The annotation is imperative and survives
|
||||
a Flux resume, so resuming Flux alone leaves all three databases down and Keycloak, Nextcloud and
|
||||
Semaphore looking broken for reasons that point nowhere near Postgres. `resume` does it first, for
|
||||
exactly that reason.
|
||||
|
||||
Flux restores every scaled-down replica count **and** the VM's `running: true` from git, so nothing
|
||||
needs undoing by hand.
|
||||
|
||||
### What "still broken" looks like when it is actually fine
|
||||
|
||||
* **`4/19` Kustomizations Ready for several minutes.** The dependency graph serialises behind
|
||||
`platform-config`; 15 of them report `dependency ... is not ready` until it finishes. Check
|
||||
`platform-config` itself is `Ready=True` and its `lastAppliedRevision` matches the GitRepository
|
||||
artifact — if it is, wait.
|
||||
* **One or more Longhorn volumes `degraded`.** Any volume that was still attached at poweroff
|
||||
rebuilds its lagging replica automatically. On 2026-10-17 it was Prometheus's 50Gi TSDB; it went
|
||||
healthy on its own. Worry only if it is still degraded after ~30 minutes.
|
||||
* **`keycloak-operator` crashlooping, then recovering.** It is the CRD reconciler, not in the
|
||||
request path; Keycloak's StatefulSet stays 2/2 and auth never goes down. See
|
||||
`/runbooks/keycloak-*` and the known OOM-at-450Mi behaviour.
|
||||
|
||||
### What is actually broken and needs you
|
||||
|
||||
* **An `oauth2-proxy` replica stuck in CrashLoopBackOff.** It performs OIDC discovery at startup and
|
||||
**exits 1** on the `503 no healthy upstream` it gets while Keycloak is still coming up, then sits
|
||||
in exponential backoff long after Keycloak is fine. It has no startup dependency on Keycloak.
|
||||
Delete the pod once and it comes up clean:
|
||||
|
||||
```bash
|
||||
./infra/devcontainer/dev.sh run bash -c \
|
||||
'kubectl --context k3s-prod -n oauth2-proxy delete pod <name>'
|
||||
```
|
||||
|
||||
* **Orphaned `Unknown`/`Error` Job pods** from CronJobs that were mid-run at poweroff. They never
|
||||
recover; delete them.
|
||||
|
||||
## Verifying you are actually back
|
||||
|
||||
```bash
|
||||
./infra/devcontainer/dev.sh run bash -c './infra/maintenance/quiesce.sh status'
|
||||
# nodes 3 Ready | flux 19/19 | longhorn 0 not healthy | postgres 9 pods | unifi 1 VMI
|
||||
|
||||
# DNS, through PiHole's VIP
|
||||
./infra/devcontainer/dev.sh run bash -c 'nslookup home.keithjackson.dev 192.168.2.23'
|
||||
|
||||
# The Gateway actually serving (401 on an auth-gated host is CORRECT)
|
||||
for h in home.keithjackson.dev gitea.home.keithjackson.dev plex.home.keithjackson.dev; do
|
||||
curl -s -o /dev/null -w "$h %{http_code}\n" -k --resolve $h:443:192.168.2.20 https://$h/
|
||||
done
|
||||
```
|
||||
|
||||
Expect `200`, `200`, `401`.
|
||||
@@ -52,6 +52,13 @@ configMapGenerator:
|
||||
- backup-failure=backup-failure.md
|
||||
- backup-missed=backup-missed.md
|
||||
- backup-partial=backup-partial.md
|
||||
# Operator procedure, not an alert page — nothing links here from an alert. Served because
|
||||
# the whole-cluster shutdown had NO written procedure until 2026-10-17 (infra/cluster.sh is
|
||||
# virsh-based and only ever applied to the decommissioned dev cluster), so the UPS move was
|
||||
# improvised live, and the one hazard it exposed -- a StatefulSet with
|
||||
# persistentVolumeClaimRetentionPolicy whenScaled: Delete loses its PVC when scaled to 0 --
|
||||
# destroyed monitoring/loki's volume before anyone noticed.
|
||||
- cluster-maintenance-shutdown=cluster-maintenance-shutdown.md
|
||||
- cdi-import-stuck=cdi-import-stuck.md
|
||||
- cert-expiry=cert-expiry.md
|
||||
- cert-issuance=cert-issuance.md
|
||||
|
||||
Reference in new issue
Block a user