decisions/2026-10-17-graceful-cluster-shutdown.md

@@ -0,0 +1,106 @@
+---
+date: 2026-10-17
+branch: feat/graceful-cluster-shutdown
+title: "Graceful node shutdown was never configured, and scaling a StatefulSet deleted its PVC"
+---
+
+## What changed
+
+All three nodes had to be powered off to move them onto a UPS. There was **no procedure for it**:
+`infra/cluster.sh stop` is `virsh`-based and only ever applied to the decommissioned dev cluster, so
+the whole sequence was improvised live. Two defects came out of doing it.
+
+**1. Kubelet graceful node shutdown was unconfigured on every prod node.** No `shutdownGracePeriod`
+anywhere in `infra/ansible/`, so `shutdown -h` stopped k3s, containerd went with it, and every pod
+was SIGKILLed where it stood — 9 CloudNativePG instances mid-checkpoint, the UniFi VM, and 25
+attached Longhorn volumes. `roles/k3s_server` now writes `kubelet-arg` into
+`/etc/rancher/k3s/config.yaml` with `shutdown-grace-period=90s` and
+`shutdown-grace-period-critical-pods=20s`.
+
+The half that is easy to miss and silently defeats the other half: **graceful node shutdown is
+enforced by logind, not by the kubelet.** The kubelet holds an inhibitor *delay* lock and systemd
+waits at most `InhibitDelayMaxSec` — **default 5 seconds** — before proceeding regardless. A grace
+period above that cap is truncated with no error, so the feature looks configured and still
+hard-kills pods. The role now ships a `logind.conf.d` drop-in setting it to 120, and **asserts**
+`k3s_logind_inhibit_delay_max_sec >= k3s_kubelet_shutdown_grace_period` rather than documenting the
+relationship, because the failure is invisible.
+
+**2. Scaling a StatefulSet to 0 DELETED its PVC and Longhorn volume.** `monitoring/loki` carries
+`persistentVolumeClaimRetentionPolicy: {whenDeleted: Delete, whenScaled: Delete}`, so the quiesce's
+`scale --replicas=0` destroyed `storage-loki-0` outright. Loki stores with `type: filesystem`, so
+that PVC was the only copy of its log data. This is the defect in this change set that actually
+destroyed something, and it was mine.
+
+New `infra/maintenance/quiesce.sh` (`quiesce` | `resume` | `status`) encodes the sequence that
+worked, and **refuses to scale any StatefulSet whose `whenScaled` is `Delete`** — it leaves it
+running, accepts that its volume hard-detaches at poweroff, and prints which volumes to expect
+`degraded`. A rebuild is a vastly better outcome than a deletion. Workload discovery is computed
+from the live cluster (every Deployment/StatefulSet whose pods mount a PVC, Longhorn or TrueNAS NFS)
+rather than hardcoded, so a newly onboarded service is covered without anyone remembering to add it.
+
+`runbooks/cluster-maintenance-shutdown.md` (new, registered in `runbooks/kustomization.yaml`) is the
+operator page: shutdown order, the TrueNAS-after-nodes constraint, power-on order, the
+un-hibernate-Postgres step Flux will not do for you, and a "what looks broken but is fine" section
+separating the `4/19`-Kustomizations-Ready cascade, the degraded-and-rebuilding volume and the
+self-recovering `keycloak-operator` from the one thing that genuinely needs a human (a stuck
+`oauth2-proxy` replica).
+
+## What I verified
+
+* **Graceful shutdown was genuinely absent**, not merely undocumented: `grep -rn
+  'shutdownGracePeriod|graceful-node-shutdown'` over `infra/ansible/` returns nothing, and no
+  `logind` or `InhibitDelay` setting exists anywhere in the tree.
+* **The whole shutdown/restart cycle was executed end to end on prod 2026-10-17** and the cluster
+  came back: 3/3 nodes Ready with etcd `healthz` ok, 19/19 Flux Kustomizations Ready,
+  `platform-config`'s `lastAppliedRevision` equal to the GitRepository artifact revision, all 3
+  CNPG clusters `healthy` with primaries elected, the UniFi VM `Running`, PiHole resolving
+  (`home.keithjackson.dev` → `192.168.2.20` via `192.168.2.23`), and the Gateway serving
+  `200/200/401` for apex/gitea/plex.
+* **The PVC-deletion mechanism is confirmed, not inferred:** `kubectl get sts loki -o
+  jsonpath={.spec.persistentVolumeClaimRetentionPolicy}` returns
+  `{"whenDeleted":"Delete","whenScaled":"Delete"}`, the PVC was `NotFound` after the cycle, and the
+  Longhorn volume count had gone 25 → 24.
+* **The damage was repaired and verified:** `scale sts loki --replicas=1` (restoring the replica
+  count the chart declares) recreated `storage-loki-0` as a fresh 50Gi Bound PVC, `loki-0` reached
+  `2/2 Running`, and the volume count returned to 25.
+* **The guard works against the live cluster**, tested both ways: `sts_deletes_pvc_on_scale
+  monitoring loki` returns true (would be skipped) and `pihole pihole` returns false (safe to
+  scale).
+* **The script's read-only paths run clean on prod:** `status` reports correctly, and the discovery
+  function returns the 13 workloads currently holding a PVC.
+* `bash -n` clean; the two edited Ansible YAML files parse.
+
+## What I did NOT verify
+
+* **The kubelet change has NEVER BEEN APPLIED OR TESTED.** This is the significant gap. I did not
+  run the role, did not restart k3s, and have **not** observed a node actually drain on
+  `shutdown -h`. Everything about it is reasoning from kubelet/systemd semantics plus the measured
+  absence of the setting. Applying it needs a **rolling** k3s restart (`serial: 1` — kube-vip keeps
+  the API up, etcd holds at 2/3), which is an operator action (CLAUDE.md §5). **Verify by draining
+  one node for real:** apply, then `shutdown -h now` on a single node and watch whether pods
+  terminate gracefully instead of vanishing.
+* **Whether 90s/20s are the right numbers.** Chosen to comfortably cover a Postgres fast shutdown
+  and a Longhorn flush; not measured against either. The budget is spent on every reboot, so if a
+  node takes noticeably longer to go down, this is why.
+* **Whether k3s accepts `kubelet-arg` in `config.yaml` as written.** The file already carries
+  `kube-apiserver-arg` as a list and `kubelet-arg` is the documented sibling, but I did not render
+  or apply it, so a typo would surface only at k3s restart — and a bad `config.yaml` is exactly the
+  kind of thing that makes k3s fail to come up. **Review this one before applying.**
+* **The `assert` task's `regex_replace` on the grace period** assumes a plain `90s`-style value; a
+  value expressed as `1m30s` would parse to the nonsense integer `130`. Fine for the committed
+  defaults, wrong if someone writes a compound duration.
+* **`resume`'s Flux-reconcile wait has never run**, and neither has `quiesce` as a script — the
+  2026-10-17 cycle was done with the equivalent commands by hand, so the script encodes a sequence
+  that worked but has not itself been executed end to end. Only `status` and the discovery and guard
+  functions have run.
+* **Loki's lost log window is gone for good.** Up to 72h of logs (its `retention_period`), destroyed
+  by my scale-down. Nothing recovers it; Velero's schedules cover the namespace but the PVC was
+  deleted, not corrupted, and I did not attempt a restore because the data self-expires anyway.
+* **No other `whenScaled: Delete` StatefulSet was audited.** The guard now catches them generically,
+  but I did not enumerate which other workloads carry the policy, so I cannot say loki was the only
+  one at risk. The runbook gives the one-liner to list them.
+* **TrueNAS and the router are entirely outside this change.** TrueNAS is not in the Ansible
+  inventory and refuses SSH, so its shutdown stays a web-UI step with no automation and no check.
+* **No runtime conformance.** `vars.CLUSTER_AVAILABLE` is still unset, so CI proves the L0/L1
+  offline subset only.
+* I did not re-measure branch protection or runner state (CLAUDE.md §2b).

infra/ansible/roles/k3s_server/defaults/main.yml

@@ -107,3 +107,31 @@ k3s_base_domain: "home.keithjackson.dev"
 
 # Derived, so the realm path is stated once. Override k3s_base_domain, not this.
 k3s_oidc_issuer_url: "https://keycloak.{{ k3s_base_domain }}/realms/homelab"
+
+# --- Graceful node shutdown (kubelet) ----------------------------------------------------------
+# MEASURED 2026-10-17, during the UPS move: graceful node shutdown was NOT configured on any prod
+# node, so `shutdown -h` did NOT drain pods. systemd stops k3s, containerd goes with it, and every
+# pod is SIGKILLed where it stands -- including 9 CloudNativePG instances mid-checkpoint, the UniFi
+# VM, and 25 attached Longhorn volumes. The whole-cluster shutdown that day had to quiesce
+# everything BY HAND first (runbooks/cluster-maintenance-shutdown.md), and the one volume that did
+# not finish detaching came back `degraded` and had to rebuild.
+#
+# With these set, the kubelet takes a systemd inhibitor lock and, on shutdown, evicts ordinary pods
+# first and critical ones last, so a plain `shutdown -h`/reboot drains the node. That makes the
+# manual scale-down in the runbook a belt-and-braces step for a PLANNED whole-cluster shutdown
+# rather than the only thing standing between a reboot and a hard kill.
+#
+# 90s/20s, not larger: the budget is spent on every reboot and node upgrade, and the kubelet waits
+# the FULL ordinary period before it starts on critical pods. Postgres does a fast shutdown in
+# well under 90s here, and Longhorn needs only enough time to flush and detach.
+k3s_kubelet_shutdown_grace_period: "90s"
+k3s_kubelet_shutdown_grace_period_critical_pods: "20s"
+
+# *** THE HALF THAT IS EASY TO MISS, AND SILENTLY BREAKS THE OTHER HALF. ***
+# Graceful node shutdown works by the kubelet holding a logind INHIBITOR DELAY lock. systemd caps
+# how long any inhibitor may delay shutdown at `InhibitDelayMaxSec`, which DEFAULTS TO 5 SECONDS.
+# If that cap is below the grace period above, systemd proceeds anyway and the drain is truncated
+# to ~5s -- i.e. the feature appears configured, reports no error, and still hard-kills pods. So
+# this MUST be >= k3s_kubelet_shutdown_grace_period; the role asserts it rather than trusting it.
+# Set a little above the kubelet's total (90s + 20s) to leave headroom.
+k3s_logind_inhibit_delay_max_sec: 120

infra/ansible/roles/k3s_server/handlers/main.yml

@@ -15,3 +15,12 @@
     port: "{{ k3s_api_port }}"
     timeout: 180
   listen: Restart k3s
+
+# logind re-reads InhibitDelayMaxSec only on restart. Restarting logind does NOT log users out or
+# disturb k3s -- it manages login sessions and inhibitor locks, not workloads. The kubelet picks up
+# the new cap when it next takes its lock, so no k3s restart is needed for THIS half.
+- name: Restart logind
+  ansible.builtin.systemd_service:
+    name: systemd-logind
+    state: restarted
+  listen: Restart logind

infra/ansible/roles/k3s_server/tasks/main.yml

@@ -86,6 +86,16 @@
       # k3s_base_domain (defaults/main.yml), whose [parity] contract with the cluster's
       # BASE_DOMAIN is documented there. Dev's default renders the value it already runs, so
       # config.yaml is unchanged and the Restart handler does not fire.
+      # ── Graceful node shutdown ──────────────────────────────────────────────────────────────
+      # Without these the kubelet takes no systemd inhibitor lock, so `shutdown -h` stops
+      # containerd and SIGKILLs every pod where it stands -- MEASURED on all three prod nodes
+      # 2026-10-17 (defaults/main.yml has the detail). The companion logind drop-in below raises
+      # InhibitDelayMaxSec, WITHOUT WHICH systemd caps the drain at ~5s and these values are
+      # quietly ignored.
+      kubelet-arg:
+        - "shutdown-grace-period={{ k3s_kubelet_shutdown_grace_period }}"
+        - "shutdown-grace-period-critical-pods={{ k3s_kubelet_shutdown_grace_period_critical_pods }}"
+
       kube-apiserver-arg:
         - "oidc-issuer-url={{ k3s_oidc_issuer_url }}"
         - "oidc-client-id=kubernetes"
@@ -183,3 +193,46 @@
     host: "127.0.0.1"
     port: "{{ k3s_api_port }}"
     timeout: 180
+
+# ── Graceful node shutdown: the systemd half — tag `shutdown` ──────────────────────────────────
+# The kubelet's shutdown-grace-period is ENFORCED BY logind, not by the kubelet: the kubelet holds
+# an inhibitor DELAY lock, and systemd will wait at most `InhibitDelayMaxSec` for it (default 5s)
+# before proceeding regardless. A grace period above that cap is therefore silently truncated --
+# the feature looks configured, logs no error, and still hard-kills pods. Assert the relationship
+# instead of documenting it, because the failure is invisible.
+- name: Assert the logind inhibitor cap can actually cover the kubelet grace period
+  ansible.builtin.assert:
+    that:
+      - (k3s_logind_inhibit_delay_max_sec | int) >= (k3s_kubelet_shutdown_grace_period | regex_replace('[^0-9]', '') | int)
+    fail_msg: >-
+      k3s_logind_inhibit_delay_max_sec ({{ k3s_logind_inhibit_delay_max_sec }}s) is below
+      k3s_kubelet_shutdown_grace_period ({{ k3s_kubelet_shutdown_grace_period }}). systemd would
+      stop waiting for the kubelet's inhibitor lock before the drain finished, so pods would be
+      SIGKILLed anyway and graceful node shutdown would be configured but ineffective.
+    quiet: true
+  tags: [shutdown]
+
+- name: Ensure /etc/systemd/logind.conf.d exists
+  ansible.builtin.file:
+    path: /etc/systemd/logind.conf.d
+    state: directory
+    owner: root
+    group: root
+    mode: "0755"
+  tags: [shutdown]
+
+# A drop-in, not an edit of logind.conf: the distro file stays pristine and `state: absent` here
+# would fully revert the change.
+- name: Raise the logind inhibitor delay cap so the kubelet can finish draining
+  ansible.builtin.copy:
+    dest: /etc/systemd/logind.conf.d/10-k3s-graceful-shutdown.conf
+    owner: root
+    group: root
+    mode: "0644"
+    content: |
+      # Managed by Ansible (roles/k3s_server). See defaults/main.yml.
+      # MUST stay >= kubelet shutdown-grace-period, or the drain is truncated to this value.
+      [Login]
+      InhibitDelayMaxSec={{ k3s_logind_inhibit_delay_max_sec }}
+  notify: Restart logind
+  tags: [shutdown]

infra/maintenance/quiesce.sh

@@ -0,0 +1,265 @@
+#!/usr/bin/env bash
+# =================================================================================================
+# quiesce.sh — bring the prod cluster to a safe standstill before powering nodes off, and bring it
+#              back afterwards. Companion to runbooks/cluster-maintenance-shutdown.md.
+# =================================================================================================
+# WHY THIS EXISTS. On 2026-10-17 all three nodes had to be powered off to move them onto a UPS, and
+# 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
+# day, so systemd stopped containerd and SIGKILLed every pod where it stood. roles/k3s_server now
+# 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="${TIMEOUT:-600}"
+
+# The three CloudNativePG clusters, as namespace/name. Hibernation is per-Cluster.
+CNPG=(keycloak/keycloak-db nextcloud-db/nextcloud-db semaphore-db/semaphore-db)
+
+log()  { printf '\033[34m[quiesce]\033[0m %s\n' "$*"; }
+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

runbooks/cluster-maintenance-shutdown.md

@@ -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`.

runbooks/kustomization.yaml

@@ -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