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jakman85andClaude Opus 5 2f2e98aa19 feat(shutdown): configure graceful node shutdown, and never scale a Delete-policy StatefulSet
gate / gate (pull_request) Successful in 27m44s
gate / conformance (pull_request) Has been skipped
All three nodes had to be powered off to move them onto a UPS, and there was
NO procedure: infra/cluster.sh stop is virsh-based and only ever applied to the
decommissioned dev cluster. The sequence was improvised live. Two defects came
out of doing it.

1. 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 CNPG
   instances mid-checkpoint, the UniFi VM, 25 attached Longhorn volumes.
   roles/k3s_server now sets kubelet-arg shutdown-grace-period=90s and
   shutdown-grace-period-critical-pods=20s.

   The half that silently defeats the other half: this is enforced by LOGIND,
   not the kubelet. The kubelet holds an inhibitor DELAY lock and systemd waits
   at most InhibitDelayMaxSec -- DEFAULT 5 SECONDS -- then proceeds regardless,
   truncating the drain with no error. The role ships a logind.conf.d drop-in
   (120) and ASSERTS cap >= grace period, because the failure is invisible.

2. SCALING A StatefulSet TO 0 DELETED ITS PVC AND VOLUME. monitoring/loki
   carries persistentVolumeClaimRetentionPolicy whenScaled: Delete, so the
   quiesce destroyed storage-loki-0 outright. Loki stores type: filesystem, so
   that PVC was the only copy; 72h retention bounded the loss, the mechanism
   does not. Symptom was the volume count going 25 -> 24, first misread as a
   miscount. Repaired: scale back to the declared 1 recreated the PVC and
   loki-0 is 2/2 Running.

New infra/maintenance/quiesce.sh (quiesce|resume|status) encodes the sequence
that worked and REFUSES to scale any whenScaled: Delete StatefulSet -- it stays
running, its volume hard-detaches, and it rebuilds on restart. A rebuild beats
a deletion. Discovery is computed from the live cluster, so a newly onboarded
service needs no edit here.

runbooks/cluster-maintenance-shutdown.md is the operator page: order in both
directions, TrueNAS-after-nodes (hard NFS mount wedges kubelet), the
un-hibernate-Postgres step Flux will NOT do for you, and a "looks broken but is
fine" section separating the 4/19 Flux cascade, the degraded-and-rebuilding
volume and the self-recovering keycloak-operator from the one thing that needs
a human (a stuck oauth2-proxy replica).

THE KUBELET CHANGE HAS NEVER BEEN APPLIED OR TESTED -- it needs a rolling k3s
restart, which is an operator action. Review config.yaml's kubelet-arg before
applying: a bad config.yaml is how k3s fails to come up. See the handoff entry.

Co-Authored-By: Claude Opus 5 (1M context) <[email protected]>
2026-10-17 22:26:47 -05:00
30 changed files with 635 additions and 2976 deletions

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# Renovate — the dependency/image update automation. SCHEDULED, self-hosted against this Gitea.
#
# ═══════════════════════════════════════════════════════════════════════════════════════════════
# WHY THIS FILE EXISTS: renovate.json HAS BEEN IN THIS REPO AND HAS NEVER ONCE RUN.
# ═══════════════════════════════════════════════════════════════════════════════════════════════
# Measured 2026-10-17: `renovate.json` is present, complete and thoughtfully written — it declares
# managers, schedules, automerge classes and grouping. Nothing executes it. There is no Renovate
# workflow (this is the first), no Renovate CronJob or Deployment in the cluster
# (`kubectl get cronjob,deploy,job -A | grep -i renovate` -> nothing), and no bot account doing it
# from outside. Meanwhile SEVEN files carry comments asserting "Renovate maintains this pin"
# (platform/homepage/deployment.yaml:40, runbooks/serving/deployment.yaml:87,
# platform/crafty/deployment.yaml:63, platform/vpn-ingress/daemonset.yaml:259,
# platform/keycloak/postgres-cluster.yaml:75, apps/wave-0/nextcloud-db.yaml:302, and
# platform/headlamp/helmrepository.yaml:2). Those comments have been false for the life of the file.
#
# The cost is measurable. With nothing bumping anything: the six per-app oauth2-proxy auth sidecars
# sit on v7.8.1 while the platform oauth2-proxy in the SAME cluster runs v7.15.5; Keycloak (the IdP)
# runs 26.0.6, a November-2024 release, 8 minors behind; Velero runs a RELEASE CANDIDATE
# (velero-plugin-for-aws v1.14.3-rc.2) with a stable available; the CNPG Postgres image is 16.4,
# missing every 16.5+ security release. A pin nothing maintains is not a pin, it is a fossil.
#
# ═══════════════════════════════════════════════════════════════════════════════════════════════
# WHY RENOVATE AND NOT FLUX IMAGE-AUTOMATION (the decision, and it reverses ADR-0009's split)
# ═══════════════════════════════════════════════════════════════════════════════════════════════
# ADR-0009 divided the work: Renovate owns Helm chart/dependency bumps, Flux image-automation owns
# per-service container image TAGS, deliberately non-overlapping. The second half of that split
# cannot be delivered on this repo's terms, for three measured reasons:
#
# 1. IT WOULD BYPASS THE MERGE GATE, WHICH CLAUDE.md §1 FORBIDS. ImageUpdateAutomation does not
# open pull requests; it COMMITS AND PUSHES. Its default target is the source's own branch —
# `main` — so it would write straight past the PR flow. It can be pointed at a side branch
# instead, but then nothing opens the PR and bumps silently accumulate on a branch nobody
# merges. Either way a human or a second bot has to close the loop.
# 2. ON THIS CLUSTER IT CANNOT EVEN DO THAT. Measured 2026-10-17: `main` is protected with
# `user_can_push: false`, and the `flux-system` GitRepository has NO `spec.secretRef` at all —
# the source is anonymous and read-only. Enabling write-back means minting an in-cluster git
# WRITE credential for the repository that defines the cluster, which is a materially larger
# blast radius than a CI-scoped token.
# 3. RENOVATE ALREADY OPENS PRs NATIVELY, so every change it proposes goes through the gate with
# no extra machinery.
#
# So: Renovate owns BOTH halves, and Flux image-automation stays disabled. Note this is a change of
# plan, not a change of state — image-automation has been commented out at
# platform/kustomization.yaml:52 since it was authored, and the cluster has ZERO
# ImageRepository/ImagePolicy/ImageUpdateAutomation objects (measured). Its two controllers ARE
# installed and have idled for 43 days. Nothing is being torn down here; a path that was never
# taken is being formally closed, and renovate.json's `docker`/`kubernetes` managers — disabled
# purely to avoid fighting a controller that never ran — are switched on to fill the gap.
#
# ═══════════════════════════════════════════════════════════════════════════════════════════════
# THIS WORKFLOW MUST NOT BE ABLE TO SUCCEED SILENTLY
# ═══════════════════════════════════════════════════════════════════════════════════════════════
# A SKIPPED Gitea job reports `success` (CLAUDE.md §2), so "green" is not evidence this ran. Two
# guards:
# * The preflight step FAILS HARD (exit 1) if RENOVATE_TOKEN is absent, rather than skipping.
# A missing credential on a dependency bot is indistinguishable from "nothing to update", and
# that is precisely how renovate.json stayed inert for months.
# * The summary step records what ran into the job summary unconditionally.
# What this still does NOT give you is an alert when the SCHEDULE stops firing. See the handoff
# entry's "What I did NOT verify" — that gap is stated, not papered over.
#
# OPERATOR PREREQUISITE — ONE SECRET, NOT COMMITTED HERE:
# `RENOVATE_TOKEN` — a Gitea access token for the bot account, scopes `write:repository` and
# `read:user`. Set it as an Actions secret on this repository. Nothing in this repo mints,
# stores or references its value; it is consumed by name only.
# Until it exists, this workflow FAILS LOUDLY on every scheduled run. That is intended: a
# visible red is the correct state for "automation configured but not credentialed".
#
# THE FIRST RUN WILL WANT TO OPEN A LOT OF PRs. ~30 dependencies are behind. renovate.json caps the
# blast radius (`prConcurrentLimit: 5`, `prHourlyLimit: 2`), but run it manually with
# `dry_run: true` FIRST and read the log before letting the schedule loose. That is what
# workflow_dispatch's default is for.
name: renovate
on:
schedule:
# 03:15 UTC daily. renovate.json ALSO carries `"schedule": ["after 3am and before 6am"]` in
# America/New_York, and that inner schedule is the authoritative one — Renovate re-checks it and
# will decline to open PRs outside it. The two are deliberately both present: this cron decides
# when the process RUNS, renovate.json decides when it may ACT. Keeping the cron slightly ahead
# of the repo window means a run is always in flight when the window opens.
- cron: "15 3 * * *"
workflow_dispatch:
inputs:
dry_run:
description: "Dry run (no PRs, no branches). Leave true for the first run."
required: false
default: "true"
log_level:
description: "Renovate LOG_LEVEL (info | debug)"
required: false
default: "info"
concurrency:
# Never two Renovate runs at once: concurrent runs race on the same branches and can open
# duplicate PRs. Not cancel-in-progress — a half-finished Renovate run can leave a branch pushed
# with no PR, so let the first one finish.
group: renovate
cancel-in-progress: false
jobs:
renovate:
runs-on: ubuntu-latest
# Renovate scans every manager across the whole repo; 40m is generous for this repo's size and
# well under a runner's patience. Without a timeout a wedged run holds the `renovate`
# concurrency group and silently blocks every subsequent scheduled run.
timeout-minutes: 40
steps:
- name: Checkout
uses: actions/checkout@v4
- name: Preflight - the token must exist, and its absence must be LOUD
env:
RENOVATE_TOKEN: ${{ secrets.RENOVATE_TOKEN }}
run: |
set -euo pipefail
if [ -z "${RENOVATE_TOKEN:-}" ]; then
echo "::error::RENOVATE_TOKEN is not set on this repository." >&2
cat >&2 <<'MSG'
Renovate cannot run without a Gitea access token, and this step fails rather than
skipping ON PURPOSE: a skipped Gitea job reports `success`, so skipping here would make
"dependency automation is not running" look exactly like "everything is up to date".
That is the failure mode that let renovate.json sit inert in this repo for months while
seven files claimed "Renovate maintains this pin".
TO FIX: create a Gitea access token for the bot account with scopes
`write:repository` and `read:user`, then add it to this repository as the Actions
secret RENOVATE_TOKEN. Do not commit it anywhere.
MSG
exit 1
fi
echo "RENOVATE_TOKEN is present (value not printed)."
- name: Run Renovate
uses: renovatebot/[email protected]
with:
# Pinned, and Renovate maintains this pin itself: renovate.json's enabledManagers
# includes `github-actions`, and `helpers:pinGitHubActionDigests` is in its `extends`.
# This is the one dependency in the repo whose updater is its own updater.
configurationFile: renovate.json
token: ${{ secrets.RENOVATE_TOKEN }}
env:
# Self-hosted Gitea. `platform` + `endpoint` were the two values renovate.json's own
# header said were "set at runtime by the operator's renovate runner" — this is that
# runner, so they are set here rather than in the repo config, which keeps renovate.json
# portable and free of this instance's URL.
RENOVATE_PLATFORM: gitea
RENOVATE_ENDPOINT: https://gitea.home.keithjackson.dev/api/v1
RENOVATE_REPOSITORIES: Home-Network/home-network-k3s-impl
# Renovate must never push to a protected branch; it works on its own branches and opens
# PRs against this base. Stated explicitly rather than inherited, because this is the
# property that keeps the whole mechanism inside CLAUDE.md §1's branch -> PR -> gate path.
RENOVATE_BASE_BRANCHES: main
RENOVATE_ONBOARDING: "false"
RENOVATE_REQUIRE_CONFIG: "required"
RENOVATE_DRY_RUN: ${{ github.event_name == 'workflow_dispatch' && inputs.dry_run == 'true' && 'full' || '' }}
LOG_LEVEL: ${{ github.event_name == 'workflow_dispatch' && inputs.log_level || 'info' }}
- name: Summary
if: always()
run: |
{
echo "## Renovate"
echo
echo "- trigger: \`${{ github.event_name }}\`"
echo "- dry run: \`${{ github.event_name == 'workflow_dispatch' && inputs.dry_run || 'false' }}\`"
echo "- outcome: \`${{ job.status }}\`"
echo
echo "Renovate owns BOTH Helm chart bumps and container image tags here; Flux"
echo "image-automation is deliberately disabled (platform/kustomization.yaml)."
echo "Every change it proposes arrives as a pull request and must pass the merge gate."
} >> "$GITHUB_STEP_SUMMARY"
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---
# Flux Kustomization: kured (Kubernetes Reboot Daemon) — reconciles ./platform/kured.
# Performs the cordon / drain / reboot / uncordon of a node that has a pending OS reboot, strictly
# one node at a time, inside a nightly window, gated on Longhorn volume health. Design rationale,
# every tuned value, and the honest list of what is NOT mitigated: platform/kured/helmrelease.yaml.
#
# WHY ITS OWN KUSTOMIZATION, AND NOT ONE LINE IN platform/kustomization.yaml
#
# The same argument the Cilium split-out recorded in platform/kustomization.yaml and intel-gpu-plugin
# reused, except the consequence is worse here than for either of them:
#
# * `platform` is `wait: true` over twelve-plus components, so its Ready condition cannot tell you
# "the reboot daemon is wedged" from "longhorn is slow".
# * The only emergency valve would be `flux suspend kustomization platform` — freezing storage,
# TLS, DNS, ingress, monitoring, Keycloak and KubeVirt in order to stop touching a DaemonSet.
# * That tier's 10m interval / 5m timeout are called out there as WRONG for a 3-node DaemonSet
# rollout. This is a 3-node DaemonSet rollout.
# * And `platform` gates platform-config, which gates apps-wave-0 (wait:true), which gates
# apps-wave-1. A reboot daemon that failed to go healthy inside that tier would stall EVERY
# APPLICATION in the cluster on "dependency not ready". A component added to make maintenance
# safer must not acquire the ability to cause an outage; that trade is the whole argument.
#
# dependsOn: [platform] — AND THIS ONE IS A REAL EDGE, NOT CONVENTION
#
# Not `cilium` (what intel-gpu-plugin uses) and not `platform-config` (what the leaf UIs use). It is
# `platform`, for two independent reasons:
#
# 1. CRD ORDERING (F-MON1). platform/kured ships a PrometheusRule, and the chart generates a
# ServiceMonitor. Both are CRs whose CRDs (monitoring.coreos.com) are installed by
# kube-prometheus-stack INSIDE the `platform` tier. Flux dry-runs every object in a pass before
# applying any of them, so a pass containing an unknown kind ABORTS — the failure that made the
# CDI StorageProfiles a true deadlock on prod on 2026-09-05 (see
# clusters/base/platform-config-cdi.yaml). Depending on `platform` guarantees the CRDs exist
# before this pass is attempted.
# 2. FUNCTIONAL PREREQUISITE. kured's reboot gate QUERIES Prometheus
# (`prometheusUrl` in the HelmRelease). Prometheus lives in platform/monitoring. If kured ran
# first it would get connection errors, treat the gate as unevaluable and skip every reboot —
# the correct fail-safe direction, but silent. Longhorn, whose volume health IS the gate, is
# also in that tier.
#
# It does NOT need platform-config: no Keycloak, no TLS, no split-horizon DNS, no Gateway, no
# HTTPRoute. kured serves no HTTP to users.
#
# wait: true — A HEALTH SIGNAL, NOT A GATE. Following intel-gpu-plugin rather than the leaf-UI
# template. A leaf UI is legitimately not-Ready for long stretches of a cold start while it waits on
# Keycloak and DNS, so its health is uninformative; kured has no such dependency — it is a DaemonSet
# that opens a socket and watches a file, so on healthy nodes it is Ready in seconds and not-Ready
# genuinely means BROKEN. This turns `flux get kustomization kured` into a one-line answer to "is
# reboot automation live on all three nodes", which is the question the operator must be able to
# answer before trusting a kernel upgrade to it.
#
# NOTHING IN THE GRAPH dependsOn THIS, so wait:true gates nothing — the blast radius of an unhealthy
# kured is this Kustomization's own Ready condition. Do not add `dependsOn: [kured]` anywhere: that
# would hand a node-rebooting DaemonSet the power to stall whatever depends on it, which is precisely
# what the placement above exists to prevent.
#
# prune: true is safe and deliberate. If this Kustomization is deleted, kured's DaemonSet goes with
# it and reboots simply stop happening — nodes are left uncordoned and running. The one caveat is
# that pruning mid-reboot would leave a node CORDONED with no daemon to uncordon it; that is a
# `kubectl uncordon` away and is covered in runbooks/node-reboot-automation.md.
apiVersion: kustomize.toolkit.fluxcd.io/v1
kind: Kustomization
metadata:
name: kured
namespace: flux-system
spec:
# A HelmRelease plus five static manifests, nothing to re-render; kustomize-controller is
# source-triggered, so this is only the drift-correction floor.
interval: 10m
retryInterval: 2m
# 10m, not the 5m the `platform` tier uses: a 3-node DaemonSet rollout under `wait: true` can
# exceed 5m on a cold start (image pull on three nodes), which is one of the reasons the Cilium
# split-out gave for leaving that tier.
timeout: 10m
prune: true
# See the header: a health SIGNAL for a component nothing depends on, not a gate.
wait: true
dependsOn:
- name: platform # monitoring CRDs + Prometheus + Longhorn; see the header, this is load-bearing
sourceRef:
kind: GitRepository
name: flux-system
path: ./platform/kured
# REQUIRED, not boilerplate. platform/kured/alerts.yaml renders `${BASE_DOMAIN}` into the
# `runbook_url` annotation of all three rules. Without this block that token becomes the EMPTY
# STRING and the Kustomization still reports Ready — Flux's substitution fails OPEN — so every
# alert would ship a dead link to `https:///runbooks/node-reboot-automation`. The gate stage
# `flux-postbuild-substitution` asserts the converse (a rendered token implies this block), and
# BASE_DOMAIN is declared in clusters/base/cluster-vars.yaml.
#
# Nothing else in this path contains `${...}` or a bare `$`: the HelmRelease's alertFilterRegexp is
# a plain anchored alternation, and there are no shell snippets anywhere in the component — which
# is deliberate, because envsubst would eat a braced shell variable and `$$` would trip the
# dollar-collapse assertion in the same check.
postBuild:
substituteFrom:
- kind: ConfigMap
name: cluster-vars
-13
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@@ -85,17 +85,4 @@ resources:
# pm-agent-credentials.sops.yaml, so both overlays add a SOPS decryption patch for it (by
# name). See clusters/base/pm-agent.yaml and platform/pm-agent/README.md.
- pm-agent.yaml # Flux Kustomization -> ./platform/pm-agent (dependsOn apps-wave-0)
# kured (Kubernetes Reboot Daemon) — its OWN Kustomization (dependsOn platform, wait:true), NOT a
# line in platform/kustomization.yaml. Same reasoning as the Cilium and intel-gpu-plugin
# split-outs, with a sharper consequence: `platform` gates platform-config and every apps wave, so
# a wedged reboot DaemonSet placed in that wait:true tier could stall every application in the
# cluster — a component added to make maintenance SAFER must not be able to cause an outage.
# wait:true here is a HEALTH SIGNAL, not a gate: nothing dependsOn it, and nothing should.
# The `platform` edge is load-bearing rather than conventional — it supplies the
# monitoring.coreos.com CRDs this component's PrometheusRule/ServiceMonitor need (F-MON1), and
# Prometheus itself, which kured QUERIES before every reboot to gate on Longhorn volume health.
# It reboots a node only when /var/run/reboot-required exists, which on these nodes only a
# deliberate operator kernel upgrade creates — the human gate is the sentinel, not the daemon.
# See clusters/base/kured.yaml and platform/kured/helmrelease.yaml.
- kured.yaml # Flux Kustomization -> ./platform/kured (dependsOn platform)
- cluster-vars.yaml # overlay knob surface (base defaults)
@@ -363,54 +363,6 @@ SCRAPE_OWNERS: list[dict] = [
"why": "velero_* powers VeleroBackupFailure / PartialFailure / NoRecentBackup — the rules "
"that failed to notice prod running with zero volume backups",
},
# ── ADDED 2026-10-17 (feat/automated-upgrades). A NEW OWNER, NOT A RELAXED ASSERTION. ──────
# This entry is purely additive: it registers a new metric family and its enablement, and it
# changes nothing about how any existing owner is evaluated. It makes the check STRICTER for the
# component it covers, not looser — it adds two `require` patterns plus a `companion` obligation
# that platform/kured must keep satisfying, so a future edit that disables kured's Service,
# ServiceMonitor or NetworkPolicy FAILS the gate instead of silently re-inerting three alerts.
#
# WHY THE CHECK HAD TO BE TOUCHED AT ALL, rather than the manifest being wrong: assertion (3)
# fails any alert over a metric no owner claims, and the escape hatch (KNOWN_UNWIRED_METRICS) is
# SHRINK-ONLY, so declaring `kured_*` as accepted debt is not permitted and would be the wrong
# answer anyway — the scrape genuinely IS wired here. The only two honest options were to
# register the owner (this) or to ship the reboot automation with no alerting at all, which for a
# component whose every failure mode is silent would have been the worse engineering choice.
# `conformance/**` is a sensitive approval path precisely so that this reasoning gets read.
{
"owner": "kured: service.create + metrics.create in the HelmRelease",
"prefixes": ("kured_",),
"file": "platform/kured/helmrelease.yaml",
# BOTH keys are required and the chart defaults BOTH to false. `metrics.create` makes the
# ServiceMonitor; `service.create` makes the Service it selects. Enable only the monitor and
# it selects nothing, so the single kured metric is never scraped — and a PrometheusRule over
# a series no target produces is INERT, which for this component means its own liveness
# alarm is the thing that breaks. Matched as two separate anchored blocks rather than one
# pattern because they are separate top-level values keys, not nested.
"require": [
r"service:\s*\n\s*create:\s*true",
r"metrics:\s*\n\s*create:\s*true",
],
"forbid": [],
"why": "kured_reboot_required is the ONLY metric kured exposes (one GaugeVec, "
"cmd/kured/main.go:92-96) and it powers all three platform-health.node-reboots "
"rules. Those rules are the only way to learn that OS reboot automation has stalled: "
"kured stays 1/1 Running while rebooting nothing, so a missed scrape here is "
"indistinguishable from a cluster that needed no reboots",
# The ServiceMonitor ALONE is not sufficient — the same NetworkPolicy trap Longhorn hit.
"companion": {
"file": "platform/kured/kustomization.yaml",
"require": [r"^\s*-\s*networkpolicy\.yaml\s*$"],
"why": "platform/kured/networkpolicy.yaml ships a default-deny baseline (the kured "
"namespace is a platform namespace, so Kyverno's app-namespace-scoped generator "
"does not cover it) AND the ingress allow that lets Prometheus reach :8080 "
"through it. Drop the networkpolicy from this kustomization and the deny-all "
"goes too, so this currently fails SAFE — but reinstating the baseline without "
"the allow reproduces Longhorn's measured failure exactly: targets DISCOVERED, "
"every scrape 'context deadline exceeded', TSDB empty, all three rules quiet. "
"Keeping the two in one file makes that pair inseparable",
},
},
]
# `up` is produced by EVERY scrape target, so no owner can meaningfully claim it and assertion (1)
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---
date: 2026-10-17
branch: feat/automated-upgrades
title: Automated upgrades — kured + security-only unattended-upgrades, and Renovate finally gets a runner
---
## What changed
Two halves of one process. Neither is useful alone and they must land together.
### (a) OS upgrades and reboots
**`platform/kured/`** — the Kubernetes Reboot Daemon, chart `6.1.0` / app `1.23.0`, in its own Flux
Kustomization (`clusters/base/kured.yaml`, `dependsOn: [platform]`, `wait: true`), registered in
`clusters/base/kustomization.yaml`. Not a line in `platform/kustomization.yaml`: that tier is
`wait: true` and gates `platform-config` → every apps wave, so a wedged reboot daemon placed there
could stall every application in the cluster. A component added to make maintenance safer must not
be able to cause an outage.
**`infra/ansible/roles/unattended_upgrades/`** + `playbooks/unattended-upgrades.yml`, enabled for
prod in `inventory/group_vars/k3s_prod/vars.yml`. A **new** role rather than an extension of
`node_baseline` — different lifecycle, and other open branches touch that role.
**The design, and how it answers this repo's two standing objections to reboot automation.**
`roles/node_baseline/tasks/main.yml:61-67` says "IT DOES NOT REBOOT" (k3s-prod-2 hung on a warm
reboot 2026-09-03; physical power button required), and `docs/plans/cluster-upgrade-plan.md:291-299`
rejected system-upgrade-controller for "automating away the human gate between nodes". Both still
stand. **The human gate is the sentinel.** unattended-upgrades is security-only with the kernel
blacklisted, so it essentially never produces `/var/run/reboot-required`; that file appears when an
operator deliberately runs `node-baseline.yml --tags kernel`. kured then performs only the
*mechanical* half the operator would otherwise type by hand — including the ordering rule
`node_baseline`'s own output has to shout ("NEVER node 2 first"), which the operator keeps by
running the kernel play with `--limit <host>` one node at a time. `cluster-upgrade-plan.md:329-330`
names the condition under which its own rejection reverses (fast disks), and prod is that cluster.
**Quorum: concurrent reboots are structurally impossible.** All three nodes are control-plane+etcd
(quorum 2/3). `concurrency: 1` plus kured's single cluster-wide lock annotation on its own DaemonSet
means a node reboots only while holding that lock, enforced by API-server optimistic concurrency
rather than by timing. **`lockTtl: 0`** (expiry disabled) is the deliberate choice: a TTL exists so
reboots continue after the lock holder dies, which on 3 etcd nodes is exactly the catastrophe — a
hung node's lock expiring would let a second node take the cluster to 1/3. So a hang stops the cycle
forever and pages a human. `lockReleaseDelay: 30m` holds the lock after a node returns.
**The Longhorn gate.** Measured: 25 volumes, all `numberOfReplicas: 3`, one replica per node, with
`replica-soft-anti-affinity: false` and `disable-scheduling-on-cordoned-node: true`. So every drain
takes **all 25 volumes to degraded 2/3**, and recovery is serialized —
`replica-replenishment-wait-interval: 600`, `concurrent-replica-rebuild-per-node-limit: 1`. Reboot
the next node too early and volumes reach 1/3, where `node-drain-policy:
block-if-contains-last-replica` can block a drain forever. The inter-node gate is therefore **volume
robustness, not pod readiness**, and it is doubled: `lockReleaseDelay: 30m` (unconditional, covers
the 600s wait) plus kured's Prometheus alert gate (semantic, covers a rebuild longer than 30m).
**`alertFilterMatchOnly: true` is load-bearing.** The flag inverts the regexp's meaning: `false`
(chart default) makes it an *ignore* list and kured blocks on **any** firing alert. Measured
2026-10-17, five alerts were firing with no end in sight (`CNPGPrimariesCoLocated`,
`KubeDeploymentReplicasMismatch`, `KubeDeploymentRolloutStuck`, `KubePodNotReady`,
`OAuth2ProxyGateUnobserved` — the last three all tracing to `pm-agent`, ImagePullBackOff on a
placeholder digest for 12 days). Under the default, kured would have been blocked on day one and
never rebooted anything, indistinguishable from "no reboots needed". The allow-list is anchored:
`^(LonghornVolumeDegraded|LonghornVolumeFaulted|KubeNodeNotReady|NodeExporterDown)$`.
`NodeEtcdRequestsSlow` and the `NodeIOPressure*` family are **deliberately excluded** despite being
exactly what you'd want to pause for — prod-1 has a documented etcd WAL I/O starvation history and
including them risks a permanent wedge that looks like safety.
**The kernel floor (the highest-risk item), handled with two independent exclusions.** Measured: all
three nodes run `7.1.8+deb13-amd64` (`7.1.8-1~bpo13+1`, the backports metapackage), far above the
6.13 memattr floor — **but `linux-image-6.12.107` and `linux-image-6.12.94` are also still
installed, below the floor, bootable, and `apt-mark showhold` is empty on every node.** So: (1) the
allowed-origins list is `label=Debian-Security` only, and the running kernel comes from
`o=Debian Backports` (pin 100, the `NotAutomatic`+`ButAutomaticUpgrades` signature), so u-u cannot
*see* a kernel upgrade; (2) `^linux-` is blacklisted anyway, so widening origins later — the most
likely future edit — cannot re-arm the hazard. The role **asserts both against `apt-config dump`**,
apt's own parse of the whole directory, rather than trusting the file it just wrote. Also blacklisted:
`intel-microcode`, `amd64-microcode`, `grub-*`. `Remove-Unused-Kernel-Packages` is **false** against
the Debian default, because those older kernels are the documented rollback path. None of this stops
the kernel moving — the operator's deliberate Ansible run still does that, unchanged.
**The silent-no-op trap this closes.** Measured: `update-notifier-common`, `needrestart` and
`unattended-upgrades` were **absent on all three nodes**, so *nothing could create
`/var/run/reboot-required`*. kured deployed alone would have been permanently idle while 1/1 Running
and reporting `kured_reboot_required=0` — green forever. The role installs the sentinel writer and
**asserts a hook exists** by discovery (not a hard-coded path), failing loudly if not.
`needrestart` runs in auto mode with `k3s.service` blacklisted — auto-restart is what makes a
security-only policy effective, but restarting the control plane unattended is worse than a delayed
library fix. (k3s is not an apt package at all here: no `k3s`, no `containerd` in dpkg.)
**Alerts + runbook.** `platform/kured/alerts.yaml` — three rules over kured's *only* metric
(`kured_reboot_required`, one GaugeVec, read from `cmd/kured/main.go:92-96`) plus `kube_node_info`:
`KuredNotReporting` (`absent()` — the pipeline is dead and the other two are inert),
`KuredNodeCoverageGap` (`count(kured) < count(nodes)` — a node silently uncovered, which `absent()`
cannot see), `KuredRebootPending` (`for: 36h` — a reboot was offered and blocked). Companion
promtool suite `alerts.promtool-test.yaml` pins all three both ways, including that the rule
**stops** when a reboot succeeds. `runbooks/node-reboot-automation.md` registered in
`runbooks/kustomization.yaml`.
**The window is DAILY 03:00-06:00, and that choice is driven by the alert.** A weekly window means a
pending reboot legitimately waits 6 days, forcing `for: 8d`+ — longer than this cluster's 7d
Prometheus retention and reset by any restart past the 1h for-outage-tolerance. Daily caps the
legitimate wait under 24h and makes `for: 36h` both robust and meaningful.
### (b) Image / dependency automation
**Renovate was aspirational. It now has a runner.** `.gitea/workflows/renovate.yaml` — scheduled
daily 03:15 UTC, `workflow_dispatch` with `dry_run` defaulting to **true** for a safe first run.
Preflight **fails hard (exit 1)** if `RENOVATE_TOKEN` is missing rather than skipping, because a
skipped Gitea job reports `success` and that is precisely how `renovate.json` stayed inert.
**`renovate.json`: Renovate now owns both halves, and Flux image-automation is formally closed.**
ADR-0009 gave container image tags to Flux image-automation; that cannot be delivered on this
repo's terms. (1) `ImageUpdateAutomation` **pushes commits, it does not open PRs**, so it bypasses
the CLAUDE.md §1 gate; pointed at a side branch instead, nothing opens the PR. (2) It cannot work
here anyway: `main` is protected `user_can_push: false` and the `flux-system` GitRepository has **no
`spec.secretRef`** — the source is anonymous and read-only. (3) Enabling it means an in-cluster git
**write** credential for the repo that defines the cluster. So `docker`/`kubernetes` — disabled
*only* to avoid fighting that controller — are enabled, with `kubernetes.managerFilePatterns`
covering `platform/`, `platform-config/`, `apps/`, **`catalog/`** (apps are generated from it; a bump
only to the rendered output is reverted by the next render and fails `ci/render-golden.sh`),
`runbooks/serving/` and `infra/agent/`. Added a no-automerge `blast-radius` rule for `kured`,
`longhorn`, `cilium`, `cloudnative-pg`, `kube-prometheus-stack`, because the gate is static and does
not boot a node or form a quorum. `platform/kyverno/tests/**` added to `ignorePaths`.
### Sensitive paths — this PR needs a non-author approving review
It touches **`clusters/**`**, **`conformance/**`** and **`.gitea/**`**, all in
`infra/gitea/approval-policy.json`. It will **not** merge on a green gate alone. Per CLAUDE.md §1 I
have **not** posted `/approve-override` and must not — that is the self-approval the stage exists to
prevent.
**The `conformance/` edit, justified.** `+34/-0` in
`alert-metrics-have-scrape-targets/check.sh`: one new `SCRAPE_OWNERS` entry claiming `kured_`. It
**weakens nothing** — no existing owner's evaluation changes — and it *tightens* the check for my
own component, adding two `require` patterns (`service.create: true`, `metrics.create: true`; the
chart defaults **both** to false) plus a `companion` requirement that `networkpolicy.yaml` stay in
the kustomization. It had to be touched: assertion (3) fails any alert over an unclaimed metric, and
the escape hatch `KNOWN_UNWIRED_METRICS` is **shrink-only**, so declaring `kured_*` as debt was not
permitted and would have been wrong anyway. The alternative was shipping reboot automation with no
alerting, which for a component whose every failure mode is silent is the worse choice. The entry
carries a dated comment saying all of this.
## What I verified
Measured against the live cluster and nodes, read-only, on 2026-10-17.
- **Flux image-automation controllers ARE installed and idle.** `-n flux-system get deploy` shows
`image-automation-controller` and `image-reflector-controller` both `1/1`, age **43d**; all three
`image.toolkit.fluxcd.io` CRDs exist. And **zero** `ImageRepository`/`ImagePolicy`/
`ImageUpdateAutomation` objects — "No resources found" for each. The controllers have run for 43
days with nothing to do. `platform/kustomization.yaml:52` has the component commented out.
- **Renovate is aspirational, confirmed three ways**: no workflow in `.gitea/` or `ci/` (grep),
no Renovate CronJob/Deployment/Job in any namespace, and `renovate.json` itself disabled the
`docker`+`kubernetes` managers — so every plain `image:` tag was maintained by **nothing**, while
**seven files** claim "Renovate maintains this pin".
- **`flux-system` GitRepository has no `secretRef`** (empty), URL is the in-cluster Gitea, and its
artifact revision was `main@sha1:1a0b208…`, matching my base.
- **Nodes**: 3× Debian 13 trixie, all `control-plane,etcd`, k3s `v1.36.4+k3s1`, kernel
`7.1.8+deb13-amd64`. `apt-mark showhold` **empty**; `/etc/apt/preferences.d/` **empty**;
`/var/run/reboot-required` absent; `unattended-upgrades`/`update-notifier-common`/`needrestart`
all **absent**; `linux-image-6.12.107` and `6.12.94` installed alongside the backports kernel;
no `k3s`/`containerd` apt package; `apt-cache policy` origins and pins as quoted above.
- **No node taints** on any of the three (so no tolerations needed), and `system-node-critical`
exists.
- **Longhorn**: 1.12.1; `node-drain-policy: block-if-contains-last-replica`;
`replica-soft-anti-affinity: false`; `disable-scheduling-on-cordoned-node: true`;
`replica-replenishment-wait-interval: 600`; `concurrent-replica-rebuild-per-node-limit: 1`;
25 volumes all 3-replica/healthy; 25 replicas per node.
- **6 PDBs with 0 allowed disruptions**: 3× `longhorn-system/instance-manager-*` (structurally 0 —
single-node selector, `minAvailable: 1`) and 3× CNPG `*-primary`. All three Postgres primaries
were on `k3s-prod-1`.
- **kured drain flags do not exist.** Read `cmd/kured/main.go:438-449`: `Force`,
`DeleteEmptyDirData` and `IgnoreAllDaemonSets` are **hardcoded true**. Passing
`--ignore-daemonsets`/`--delete-emptydir-data`/`--force` as extraArgs would CrashLoop the
DaemonSet. All three are genuinely needed (12 DaemonSets, 135 emptyDir pods measured).
- **kured exposes exactly one metric** — the only `MustRegister` in the project.
- **Prometheus selectors are all `{}`** (`serviceMonitorSelector`, `serviceMonitorNamespaceSelector`,
`ruleSelector`, `ruleNamespaceSelector`), so a `PrometheusRule`/`ServiceMonitor` in a new namespace
is picked up with no label plumbing.
- **`count(kube_node_info) == 3`** and `count(longhorn_volume_robustness) == 100`, queried through a
read-only port-forward. The 5 chronically-firing alerts were read from `/api/v1/alerts`.
- **`LonghornVolumeDegraded`** is `longhorn_volume_robustness{state="degraded"} == 1`, `for: 10m` —
shorter than Longhorn's own 600s replenishment wait, so degradation reliably outlasts the latch.
- **kured chart 6.1.0 → appVersion 1.23.0** is the newest of 80 entries in the chart index.
- **Kyverno/PSA will not block it**: every policy is scoped
`app-namespace: "true"`; the namespace sets it explicitly `"false"`, and
`restrict-host-namespaces.yaml`'s own header states that carve-out. No cluster-wide PSA baseline.
- **`renovate.json` parses** as valid JSON after my edits (`json.load`).
- **kured is not installed** and the string `kured` appears nowhere in the repo — greenfield.
### CORRECTION 2026-10-18 — the first real run FAILED, and the sentinel design was wrong
`ansible-playbook playbooks/unattended-upgrades.yml -e k3s_hosts=k3s_prod` failed on all three
nodes at the package task:
```
fatal: [k3s-prod-1]: FAILED! => "No package matching 'update-notifier-common' is available"
```
**`update-notifier-common` is an UBUNTU package and does not exist in Debian.** Measured on trixie:
`apt-cache policy update-notifier-common` → `Candidate: (none)`. The original entry asserted this
package "owns the hook that creates /var/run/reboot-required" — true on Ubuntu, false here, and the
role could never have worked. This was the exact risk the first version of this entry flagged ("the
`find` patterns are a guess at which package ships what") landing in a worse place than predicted:
not a wrong glob, a nonexistent package.
Three further measurements settled what to do instead:
* `/usr/share/update-notifier/notify-reboot-required` is **absent**.
* **No `linux-image-*` postinst references `notify-reboot-required`** — invoking it is an Ubuntu
patch, so merely placing a script at that path would never be called.
* No hook under `/etc/apt/apt.conf.d` or `/etc/kernel/` mentions `reboot-required`.
So Debian trixie has **no stock mechanism at all**, and the role now ships the writer itself:
`/usr/local/sbin/k3s-notify-reboot-required` (compares the running kernel against the newest
installed via `linux-version`, from `linux-base`, which every `linux-image` depends on — measured
`linux-base 4.12.1` present) plus a `DPkg::Post-Invoke` hook at
`/etc/apt/apt.conf.d/99-k3s-reboot-required`. `/run` is a tmpfs (measured), so the sentinel
self-clears on boot and needs no cleanup task.
The verify assert changed shape too: it was a `find` glob over `/etc/kernel/postinst.d` and
`/etc/apt/apt.conf.d` for `*update-notifier*` / `*unattended-upgrades*`. That glob was **weaker
than it looked** — it would have matched Debian's own `unattended-upgrades` apt conffile and
reported "sentinel writer present" while no writer existed. It now stats the two exact paths this
role owns and requires the script to be executable.
**Newly verified (this correction):** the sentinel script was executed on prod-1 as the
unprivileged `k3s` user under `sh -x`. It resolved `running=7.1.8+deb13-amd64`,
`newest=7.1.8+deb13-amd64`, took the equal branch, exited 0 and wrote nothing — correct, since the
running kernel *is* the newest. `sh -n` and `bash -n` clean.
**Still NOT verified after this correction:** the *writing* half. Because running == newest on all
three nodes, the `touch` path has never executed, so I have not seen the sentinel actually created,
nor seen kured react to it. The honest test is the operator's next kernel upgrade. Also unverified:
whether a `DPkg::Post-Invoke` hook fires in the `unattended-upgrades` code path specifically (it
runs dpkg, so it should, but that is inference) — and whether `linux-version sort --reverse` orders
a mixed backports/stable kernel set the way I assume when a 6.12 and a 7.1 are both installed. It
produced the right answer with the current set; a future set could differ.
## What I did NOT verify
The honest list. Most of this needs an actual upgrade cycle, which I did not and could not run.
- **I never ran an OS upgrade, never rebooted a node, and never watched kured take a lock.** No part
of the runtime behaviour of either half has been observed. `sudo` needs a password I do not have,
so I could not run `apt`, `unattended-upgrade --dry-run`, or install anything. **Everything about
(a) working is inference from configuration and measured cluster state, not observation.**
- **The Ansible role has never been executed.** Not syntax-checked by `ansible-playbook --syntax-check`
either (no inventory access from the gate). Its asserts, its `apt-config dump` parsing, and the
sentinel-hook discovery are all unproven. The `find` patterns for the sentinel hook are a *guess at
which package ships what* — I could not read `update-notifier-common`'s file list (packages.debian.org
returned no such package for that suite/arch), which is exactly why the role discovers rather than
hard-codes. **If no hook matches, the role fails loudly — but it may fail on a correct node.**
- **Whether CNPG actually switches the primary in response to a drain-induced eviction.** All three
`*-primary` PDBs are structurally 0-disruption and `.spec.nodeMaintenanceWindow` is unset on all
three clusters. If the operator does not switch over, draining `k3s-prod-1` blocks on three PDBs at
once and hits `drainTimeout`. **This is the most likely way the first real reboot fails.** It
should be tested with one manual, watched `kubectl drain` before trusting the timer.
- **Whether `drainTimeout: 15m` is long enough.** Unmeasured. The `unifi` VMI has
`evictionStrategy: LiveMigrate` with `migrationMethod: BlockMigration`, i.e. a full root-disk copy
over the network on every `k3s-prod-1` drain. I do not know how long that takes.
- **Whether the alert gate actually blocks as intended.** I never saw kured query Prometheus. The
assumption that it treats a query error as "do not proceed" is from its documented behaviour, not
observed. The NetworkPolicy allowing kured→Prometheus:9090 and Prometheus→kured:8080 is
**unproven**; if either is wrong the symptom is silence, which is why `KuredNotReporting` exists —
but that alert is itself unproven against a live scrape.
- **The alert expressions have not run against real `kured_*` data**, because the metric does not
exist in this cluster yet. They pass promtool unit tests against synthetic series whose shape I
read from kured's source. `absent()` and the `count() < count()` comparison are the two most
likely to behave differently against real label sets.
- **`enabledManagers: ["regex"]` may be the wrong name.** Modern Renovate expects `custom.regex` for
`customManagers`. I left the pre-existing value alone rather than guess, but **the inline
`# renovate:` markers may simply not run.** Unverifiable without executing Renovate. Two markers
are additionally known-broken independent of this: `external-snapshotter`'s sits two comment lines
above its `newTag`, and Keycloak's `kustomization.yaml` has no marker at all despite a comment
claiming Renovate maintains it.
- **Renovate has still never run.** I added the runner; `RENOVATE_TOKEN` does not exist yet, so the
first scheduled run **will fail** (by design). Nothing about the config is proven correct until a
`dry_run: true` dispatch is read by a human. Expect it to want to open ~30 PRs.
- **No alert for "automatic patching silently stopped".** u-u's success lives in
`/var/log/unattended-upgrades/` on each node and nothing reads it. Likewise **no alert for the
Renovate schedule ceasing to fire**. Both are real gaps I did not close.
- **`coredns` is 1 replica and I did not fix it.** It is k3s-managed, out of this PR's scope, and it
means every `k3s-prod-1` reboot causes a cluster-wide in-cluster DNS gap. Recommended follow-up.
- **kured cannot honour "NEVER node 2 first".** It has no ordering control. The mitigation — run the
kernel play with `--limit` one host at a time — is a *procedure*, documented in the runbook, not an
enforced property. If the operator flags all three nodes at once, kured picks the order.
- **kured cannot press a power button.** The 2026-09-03 warm-reboot hang is unmitigated. Bounded, not
prevented: quorum holds at 2/3, the lock is held forever so nothing cascades, and
`KuredRebootPending` eventually fires.
- **Upstream version claims are a snapshot, partly from search results**, not all from authoritative
release APIs. I could not determine latest for versitygw, crafty, nginx-unprivileged, act_runner,
`virt-template-*`, the linuxserver wireguard date-tag, or the exact latest PostgreSQL 16 patch
(sources conflicted 16.10 vs 16.15). **The gitea `1.24.3 → v28.1.0` gap is almost certainly an
upstream versioning-scheme change, not 26 majors — do not act on that framing.**
- **I did not verify Renovate's `kustomize` manager still processes `images:`/`newTag`** now that
`docker` is enabled, which decides whether `external-snapshotter` and `intel-gpu-plugin` are
managed at all.
- **I did not raise any HelmRelease version ceiling**, so the 9 minor-locking ranges still cap
Renovate at patches. Bumping `kube-prometheus-stack` in particular will fail the gate until
`ci/versions.env`'s exact promtool/Prometheus `3.14.0` lockstep moves with it.
- **L2/L3 conformance did not run** (`vars.CLUSTER_AVAILABLE` unset), so nothing here is proven
against a cluster by CI either.
@@ -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).
@@ -1,99 +0,0 @@
---
date: 2026-10-17
branch: fix/oauth2-proxy-oidc-startup-race
title: "oauth2-proxy dies on a cold start because OIDC discovery runs once, before Keycloak serves"
---
## What changed
Exposed by the 2026-10-17 whole-cluster shutdown for the UPS move. oauth2-proxy performs OIDC
discovery **once, at startup**, and `os.Exit(1)`s if it fails. On a cold boot Keycloak is not
serving yet, so the shared Gateway answers 503 and the proxy dies:
```
[provider.go:55] Performing OIDC Discovery...
[main.go:73] ERROR: Failed to initialise OAuth2 Proxy: error initialising provider: ...
failed to discover OIDC configuration: unexpected status "503": no healthy upstream
```
It then sits in **exponential CrashLoopBackOff long after Keycloak is healthy** — one of the two
replicas was still down minutes later and only a manual `kubectl delete pod` cleared it. There is no
retry flag; the process does not survive a cold start. A readinessProbe cannot help (the container
is already dead), and CrashLoopBackOff backoff is not tunable per-pod.
`platform/oauth2-proxy/helmrelease.yaml` gains an `extraInitContainers` gate (`wait-for-idp`) that
polls Keycloak's discovery doc until it answers, then lets the proxy start. A pod in `Init` does not
accrue CrashLoopBackOff backoff and retries promptly, which is the point.
**Bounded, and fails open.** After ~5 minutes it gives up and starts the proxy anyway, so the worst
case is exactly today's behaviour and never something new. An unbounded wait would trade a CrashLoop
for a pod wedged in `Init` forever, which is not an improvement.
## Why this shape and not the alternatives
* **`extraInitContainers` is the chart's own documented hook for precisely this.** Its commented
example in `values.yaml` is literally `- name: wait-for-idp`. The key was **confirmed against the
pinned chart** (`helm show values oauth2-proxy/oauth2-proxy --version 10.7.1` → `extraInitContainers: []`
at line 428), not assumed — a wrong Helm values key is silently ignored, which is the
"reviewed, merged, apparently done, still broken" shape this repo keeps getting bitten by.
* **No new base image.** The chart already runs an `alpine` init container for its built-in
`initContainers.waitForRedis` gate, so alpine is a base this chart uses regardless. Pinned to
`3.22` (verified to exist upstream) rather than the chart's own `latest`.
* **Flux `postRenderers` rejected:** it would work independently of the chart schema, but nothing in
this tree uses postRenderers, so it would introduce a mechanism with no precedent for a problem
the chart already has a hook for.
* **`--skip-oidc-discovery` rejected:** it removes the startup fetch entirely, which is arguably
more elegant, but it means hardcoding four Keycloak endpoints and I could not verify offline that
oauth2-proxy then fetches JWKS lazily rather than at startup. oauth2-proxy gates SSO for PiHole,
the \*arr apps, qBittorrent, Homepage, Prometheus, Alertmanager and Hubble — a wrong guess locks
the operator out of all of them, so the reversible, additive option wins.
The `$$`-free convention matters here: shell variables are written bare (`$i`, `$url`, `$(( ))`)
with **no braced form anywhere**, because `platform` declares `postBuild.substituteFrom cluster-vars`
and envsubst consumes braced expansions — a braced shell variable renders to the empty string and
silently breaks the loop. `${BASE_DOMAIN}` is braced on purpose. Same hazard and same convention as
the gitea and nextcloud OIDC bootstrap hooks, and `ci: flux-postbuild-substitution` enforces it.
## What I verified
* **The failure is measured, not theorised.** The log above is from the live pod
(`oauth2-proxy-5d6c74876b-bzb2p`, `lastState.terminated: {reason: Error, exitCode: 1}`), captured
with `--previous` after the cold boot. The surviving replica's log shows the same startup
succeeding once Keycloak was up, which is what identifies this as a race rather than a config
fault.
* **Deleting the pod is a sufficient workaround** — done on prod 2026-10-17, the replacement came up
clean and both replicas have been healthy since.
* **The chart key is real**, at the pinned version range: `helm search repo` resolves
`>=10.0.0 <11.0.0` to chart `10.7.1` (app `7.15.5`), whose values carry `extraInitContainers: []`,
`extraContainers: []` and the built-in `initContainers.waitForRedis` (which uses `alpine`).
* **`docker.io/library/alpine:3.22` exists** — confirmed against the registry tag list rather than
assumed from memory.
* The edited HelmRelease parses as YAML.
## What I did NOT verify
* **UNAPPLIED. The init container has never run.** I did not reconcile the HelmRelease, so I have not
seen `wait-for-idp` execute, exit 0, or gate the proxy. Applying it rolls both oauth2-proxy
replicas, which is a mutating action (CLAUDE.md §5) — and it rolls the component that gates SSO for
seven apps, so **do it when you can watch it**, not unattended.
* **I did not re-create the cold-start race to prove the fix.** That needs Keycloak down while
oauth2-proxy starts; the honest test is the next whole-cluster boot. Until then this is reasoned
from the measured failure, not demonstrated against it.
* **busybox `wget`'s TLS behaviour here is assumed, not tested.** The claim is that alpine's
`ca-certificates-bundle` lets it validate the Gateway's LE-prod certificate, so a genuine TLS
failure exits non-zero rather than passing falsely. If that is wrong in either direction the gate
degrades safely — a never-succeeding probe just burns the 5-minute budget and then starts the proxy
anyway — but the fast path would be silently dead and this would be doing nothing. **Check the
init container's log on first apply**: it should print "Keycloak discovery reachable" within
seconds on a warm cluster, not the give-up message.
* **Whether a pod can reach the Gateway hostname at all from this namespace is inherited, not
re-proven.** The main container does exactly this fetch today and succeeds, so the path is known
good — but note the standing trap that an arbitrary pod gets 403 from every Gateway hostname
(`decisions/2026-10-04-plex-advertise-plexdirect.md`); oauth2-proxy is exempt only because
Keycloak's ingress policy admits it. An init container in the same pod inherits that identity, so
this should hold — unverified.
* **60 attempts x 5s is not tuned.** It is "comfortably longer than Keycloak's observed cold start",
not a measured bound.
* **No runtime conformance.** `vars.CLUSTER_AVAILABLE` is unset, so CI proves the L0/L1 offline
subset only.
* I did not re-measure branch protection or runner state (CLAUDE.md §2b).
@@ -420,34 +420,3 @@ flux_bootstrap_env_path: "clusters/prod"
# rather than leaving an inert drop-in behind, so this group-wide `true` is still correct
# for it.
etcd_io_priority_enabled: true
# --- automatic security patching (roles/unattended_upgrades) -------------------------
# TURNS ON roles/unattended_upgrades FOR PROD ONLY. Role default is false. Same seam as
# node_baseline_backports_kernel and etcd_io_priority_enabled above.
#
# WHAT WAS THERE BEFORE: nothing at all. Measured on all three prod nodes 2026-10-17 —
# `unattended-upgrades`, `update-notifier-common` and `needrestart` were ALL absent,
# `apt-mark showhold` was empty on every node, /etc/apt/preferences.d/ was empty, and
# nothing on the node could create /var/run/reboot-required. These boxes have had ZERO
# automatic patching since provisioning, and no way to signal that a reboot was needed.
#
# WHAT ENABLING THIS DOES *NOT* DO: nothing, until the operator runs
# playbooks/unattended-upgrades.yml. It is not applied by site.yml (deliberately — see
# that playbook's header). And once run, it still never upgrades the KERNEL, never
# restarts k3s, and never reboots:
# * kernel — blacklisted `^linux-`, AND the trixie-backports archive the running
# kernel comes from (o=Debian Backports, measured) is not an allowed origin. Two
# independent exclusions, because this is the EFI-memattr constraint: these HP minis
# need >= 6.13 or they can boot with a fraction of their RAM
# (PROD-PROVISIONING.md §0b), and 6.12 kernels are still installed and bootable here.
# The kernel continues to move ONLY under a deliberate
# `node-baseline.yml --tags kernel` run, exactly as before.
# * k3s — needrestart blacklist. k3s is not even an apt package on these nodes
# (measured: no `k3s`, no `containerd` in dpkg), so the control plane and runtime are
# outside apt's reach regardless.
# * reboots — Automatic-Reboot "false", asserted by the role against apt's own
# effective config. Reboots belong to kured (platform/kured): one node at a time,
# under a cluster-wide lock, inside 03:00-06:00, after cordon + drain. Three
# control-plane nodes with etcd quorum 2/3 must never reboot themselves
# independently, which is what Automatic-Reboot "true" would mean.
unattended_upgrades_enabled: true
@@ -1,36 +0,0 @@
---
# Automatic Debian SECURITY patching for the k3s nodes — the package half of the automated upgrade
# process. The reboot half is kured (platform/kured), reconciled by Flux; the two are designed
# together and neither is useful alone. Full rationale for every decision:
# roles/unattended_upgrades/defaults/main.yml and that role's README.md.
#
# TARGET (R-ENV-02): `k3s_hosts` defaults to dev's `k3s_servers`; prod is
# ansible-playbook playbooks/unattended-upgrades.yml -e k3s_hosts=k3s_prod
# Same pattern node-baseline.yml and node-health.yml established — `hosts:` is templated before
# group_vars exist, so the target is an extra var, never a group_vars value.
#
# The role is a NO-OP unless `unattended_upgrades_enabled` is true, which is set for prod only in
# inventory/group_vars/k3s_prod/vars.yml. Running this against dev changes nothing.
#
# DELIBERATELY NOT IN site.yml. site.yml is the bring-up chain (node-baseline -> k3s ->
# etcd-io-priority -> kube-vip -> cilium -> verify -> flux-bootstrap) and is "not run against prod
# casually". Automatic patching is not a prerequisite for anything in that chain and nothing in the
# chain depends on it, so adding it there would only widen what a cluster rebuild touches. It is
# applied on its own, once, and re-applied when its configuration changes.
#
# SAFE TO RUN ON A LIVE CLUSTER, AT ANY TIME. This playbook installs and configures the upgrader. It
# never runs `apt upgrade`, never restarts k3s, and never reboots — the role asserts the last of
# those against apt's own effective config rather than trusting the file it just wrote. The first
# unattended upgrade happens at the next timer firing (04:00 +/-60m), and any reboot that upgrade
# implies is kured's to schedule, one node at a time, inside 03:00-06:00.
#
# TAGS. `--tags verify` re-runs only the read-only assertions and the per-node summary, which is the
# way to answer "is automatic patching actually working on these boxes, and is anything waiting on a
# reboot" without rewriting any configuration:
# ansible-playbook playbooks/unattended-upgrades.yml -e k3s_hosts=k3s_prod --tags verify
- name: Automatic security upgrades on the k3s nodes (kernel excluded; reboots delegated to kured)
hosts: "{{ k3s_hosts | default('k3s_servers') }}"
become: true
gather_facts: true
roles:
- unattended_upgrades
@@ -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
@@ -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
@@ -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]
@@ -1,195 +0,0 @@
# roles/unattended_upgrades
Automatic Debian **security** patching on the k3s nodes. The kernel is excluded, k3s is never
restarted, and reboots are delegated to **kured** (`platform/kured`).
- **Playbook:** `playbooks/unattended-upgrades.yml`
- **Enabled by:** `unattended_upgrades_enabled` — role default `false`, set `true` for prod in
`inventory/group_vars/k3s_prod/vars.yml`
- **Companion component:** `platform/kured` (the reboot half). **Neither is useful alone** — see
"The two halves" below.
- **Every decision and its reasoning:** `defaults/main.yml`. That file is the argument; this one is
the orientation.
## The two halves, and why they ship together
| | what it does | what it must NOT do |
|---|---|---|
| **this role** (Ansible, host) | installs security updates continuously; leaves `/var/run/reboot-required` behind when one needs a reboot | upgrade the kernel; restart k3s; reboot |
| **kured** (Flux, cluster) | cordons, drains, reboots and uncordons **one node at a time** when that file exists | decide *whether* a reboot is needed |
Deploying either alone produces a mechanism that looks healthy and does nothing:
- **kured alone** watches a file that **nothing on Debian ever creates**. Measured 2026-10-18,
after a first attempt to install Ubuntu's `update-notifier-common` failed on all three nodes
with *"No package matching 'update-notifier-common' is available"*:
- `apt-cache policy update-notifier-common` → `Candidate: (none)` — the package does not exist
in Debian; it is Ubuntu-only.
- `/usr/share/update-notifier/notify-reboot-required` → absent.
- **No `linux-image-*` postinst references `notify-reboot-required`** — calling it is an Ubuntu
patch, so even dropping a script at that path would never be invoked.
- No hook under `/etc/apt/apt.conf.d` or `/etc/kernel/` mentions `reboot-required`.
So **this role ships the writer itself** (`/usr/local/sbin/k3s-notify-reboot-required` plus a
`DPkg::Post-Invoke` hook) rather than installing a package. Without it kured would sit at 1/1
Running reporting `kured_reboot_required=0` forever.
- **this role alone** installs patches that a long-running process never picks up, and when a
reboot *is* needed there is nothing safe to take it. `Automatic-Reboot "true"` is not the
answer: three control-plane nodes with etcd quorum 2/3, each rebooting at its own time, is how
the cluster is lost.
## What it was replacing: nothing
Measured on all three prod nodes, 2026-10-17:
| | |
|---|---|
| `unattended-upgrades` | **not installed** |
| `update-notifier-common` | **not installable** — Ubuntu-only, `Candidate: (none)` on trixie |
| `needrestart` | **not installed** |
| `apt-mark showhold` | **empty** — no package held on any node |
| `/etc/apt/preferences.d/` | **empty** — no apt pin declares the backports-kernel intent |
| `/var/run/reboot-required` | absent, and uncreatable |
These nodes had received **no automatic patching since provisioning**.
## The three decisions
### 1. Security only
Allowed origins are `label=Debian-Security` and nothing else. `trixie-updates` is excluded
deliberately (not overlooked) — it carries non-security fixes that are useful but are the archive
through which an unreviewed change would most plausibly arrive on a control-plane node. The knob to
add it is `unattended_upgrades_include_updates`.
### 2. The kernel is excluded twice over
**This is the highest-risk part of the change.** These HP EliteDesk 800 G5 minis publish a corrupt
EFI Memory Attributes Table on R21 firmware; Linux `< 6.13` does not validate it before reserving
memory from its contents, and `k3s-prod-2` twice booted with **2.6 GiB of 16 GB**. Upstream
`8fbe4c49c0cc` (first in v6.13) is the only fix — there is no kernel cmdline workaround. Full
write-up: `infra/PROD-PROVISIONING.md` §0b and `roles/node_baseline/defaults/main.yml:21-51`.
Measured 2026-10-17: all three nodes run `7.1.8+deb13-amd64` (`7.1.8-1~bpo13+1`, i.e. the backports
metapackage), comfortably above the floor — **but `linux-image-6.12.107+deb13-amd64` and
`linux-image-6.12.94+deb13-amd64` are also still installed, below the floor, bootable, and held by
nothing.**
So an unattended process must not be able to touch the kernel at all:
1. **Origin exclusion (structural).** The running kernel comes from `o=Debian Backports` (measured
via `apt-cache policy`, pin priority 100 — the `NotAutomatic` + `ButAutomaticUpgrades`
signature). That origin is not in `Origins-Pattern`, so unattended-upgrades cannot see a kernel
upgrade at all.
2. **Package blacklist (belt and braces).** `^linux-` is blacklisted, so even if the origin list is
later widened — the most likely future edit to this role, and the one that would silently re-arm
the hazard — the kernel is still untouchable.
The role **asserts both** against `apt-config dump` (apt's own parse of the whole
`/etc/apt/apt.conf.d/` directory) rather than trusting the file it just wrote.
**This does not stop the kernel moving.** The operator still advances it deliberately with
```
ansible-playbook playbooks/node-baseline.yml -e k3s_hosts=k3s_prod --tags kernel --limit <host>
```
which is the only thing that maintains the backports source, the metapackage and the on-node
provenance stamp. `node_baseline`'s own note that `apt upgrade` keeps the backports kernel current
still holds for an operator-run apt. What changed is that a **new unattended actor** is forbidden
from it.
Also blacklisted, for the same "operator-only" reason: `intel-microcode`, `amd64-microcode`,
`grub-*`. Microcode and bootloader changes take effect on reboot and alter boot behaviour on the
very firmware that is already misbehaving here.
`Remove-Unused-Kernel-Packages` is **false**, against the Debian default: those older kernels are
the documented rollback path, and an unattended process pruning them could remove the fallback an
operator needs in front of a box that will not boot.
### 3. needrestart restarts services — but never k3s
A security-only policy that restarts nothing patches bytes on disk that no running process reads.
`needrestart` in mode `a` restarts services still mapped to a deleted library, which is what makes
the policy actually effective.
`k3s.service` is blacklisted. Restarting the Kubernetes control plane unattended at 04:00 is a
worse outcome than a delayed library fix; that fix lands at the next kured reboot instead. Measured
2026-10-17, `k3s.service` is the **only** matching unit — k3s bundles its own containerd and
kubelet, and neither `containerd` nor `containerd.io` is an apt package on these nodes — so this
one entry is complete today.
## Schedule
`apt-daily` at 03:30 and `apt-daily-upgrade` at 04:00, both `±60m` randomised, via systemd drop-ins.
Chosen to land **inside** kured's 03:00–06:00 reboot window so that a sentinel written by an upgrade
can be acted on the same night rather than ~24h later.
Two traps the role handles explicitly:
- `/etc/apt/apt.conf.d/20auto-upgrades` must set the four `APT::Periodic::*` counters. Without
them the apt-daily timers fire and **do nothing** — installed, configured, green, and inert.
- The timer drop-ins clear `OnCalendar=` before setting it. systemd **accumulates** `OnCalendar`
entries across drop-ins, so omitting the reset keeps the shipped schedule *in addition* to ours.
## Why a new role rather than extending `node_baseline`
`node_baseline` is the repo's only other apt surface and would have been a defensible home. Two
reasons against:
1. **Single responsibility.** `node_baseline` is the *first-boot floor* — it runs before k3s exists
and is the thing that makes a node installable. Continuous patching policy is a different
lifecycle with a different blast radius, and it wants to be runnable (and re-runnable) without
going anywhere near that role's data-disk tasks.
2. **Concurrent work.** Other open branches touch `roles/node_baseline/`. A new role has nothing to
merge.
Nothing here duplicates `node_baseline`: it does not add apt sources, does not touch the kernel, and
does not manage disks.
## Post-merge verification
Running the role is safe on a live cluster at any time — it installs and configures the upgrader, and
never runs `apt upgrade`, restarts k3s, or reboots.
```bash
# Apply (prod). Idempotent; re-runnable.
cd infra/ansible && ansible-playbook playbooks/unattended-upgrades.yml -e k3s_hosts=k3s_prod
# Re-run ONLY the read-only assertions + the per-node pending-reboot summary.
cd infra/ansible && ansible-playbook playbooks/unattended-upgrades.yml -e k3s_hosts=k3s_prod --tags verify
```
Then, on a node, confirm the three properties that matter (all read-only, no sudo needed for the
first two):
```bash
ssh [email protected] 'apt-config dump | grep -iE "unattended-upgrade::(automatic-reboot|package-blacklist|origins)"'
ssh [email protected] 'systemctl list-timers apt-daily-upgrade.timer --no-pager'
ssh [email protected] 'ls -la /var/run/reboot-required* 2>&1 | head -2
ls -l /usr/local/sbin/k3s-notify-reboot-required /etc/apt/apt.conf.d/99-k3s-reboot-required 2>&1
dpkg -l needrestart unattended-upgrades | tail -3'
```
Expect: `Automatic-Reboot "false"`, a blacklist containing `^linux-`, an `Origins-Pattern`
containing `Debian-Security` and **not** `Backports`, a next-elapse around 04:00, and all three
packages `ii`.
A dry run of what the upgrader would actually do (needs root, so this one is an operator step):
```bash
sudo unattended-upgrade --dry-run --debug
```
The kernel must appear in its blacklist output, not its upgrade list.
## What this role cannot tell you
- **That a security upgrade has ever succeeded.** That is in
`/var/log/unattended-upgrades/unattended-upgrades.log` on each node, and nothing in this repo or
in Prometheus reads it. There is no alert for "automatic patching has silently stopped working".
That is a real, known gap — see the handoff entry
`decisions/2026-10-17-automated-upgrades.md`.
- **That a reboot actually happened.** That is kured's half, and it *is* alerted on
(`KuredRebootPending`, `KuredNodeCoverageGap`, `KuredNotReporting` in
`platform/kured/alerts.yaml`).
@@ -1,199 +0,0 @@
---
# roles/unattended_upgrades — automatic Debian SECURITY patching on the k3s nodes, with the kernel
# deliberately excluded and with reboots delegated to kured (platform/kured).
#
# OFF BY DEFAULT, ON FOR PROD. Same seam as node_baseline_backports_kernel / etcd_io_priority_enabled:
# a plain boolean, default false, turned on in inventory/group_vars/k3s_prod/vars.yml. Not a hostname
# test — that would encode the environment into the role (see node_baseline's defaults for the full
# argument, which this role follows rather than restates).
#
# ═════════════════════════════════════════════════════════════════════════════════════════════════
# STATE BEFORE THIS ROLE (measured on all three prod nodes, 2026-10-17, via `dpkg-query -W`)
# ═════════════════════════════════════════════════════════════════════════════════════════════════
# unattended-upgrades NOT INSTALLED
# update-notifier-common NOT INSTALLED
# needrestart NOT INSTALLED
# apt-mark showhold EMPTY (no package is held on any node)
# /var/run/reboot-required ABSENT, and nothing on the node can create it
# /etc/apt/preferences.d/ EMPTY (no apt pin declares the backports-kernel intent)
# So: zero automatic patching, and no mechanism by which a reboot could ever be signalled. That last
# point is why this role and platform/kured must land together — kured watches
# /var/run/reboot-required, and on these nodes today NOTHING WRITES IT. Deploying kured alone would
# produce a daemon that is permanently, silently idle while looking perfectly healthy.
#
# ═════════════════════════════════════════════════════════════════════════════════════════════════
# DECISION 1 — SECURITY ONLY, NOT FULL UPGRADES
# ═════════════════════════════════════════════════════════════════════════════════════════════════
# Measured `apt-cache policy` on k3s-prod-1, 2026-10-17, gives the four archives and their pins:
# trixie o=Debian, a=stable, l=Debian pin 500
# trixie-updates o=Debian, a=stable-updates, l=Debian pin 500
# trixie-security o=Debian, a=stable-security, l=Debian-Security pin 500
# trixie-backports o=Debian Backports, a=stable-backports, l=Debian Backports pin 100
#
# Only `Debian-Security` is allowed below. The reasoning, in order of weight:
#
# * Security updates are the class where the cost of NOT applying them is unbounded and the
# change itself is minimal by Debian policy (targeted fixes against the frozen stable version,
# no feature churn). It is the one class worth applying with nobody watching.
# * A full `apt upgrade` on these nodes would also pull trixie point-release changes, which is a
# larger surface than anyone has reviewed for a 3-node etcd cluster, for no urgency.
# * `trixie-updates` is DELIBERATELY EXCLUDED, not overlooked. It carries non-security fixes that
# are too urgent to wait for a point release — useful, but it is the archive through which an
# unreviewed change would most plausibly arrive, and it is not what "unattended" should mean on
# a control-plane node. Add it consciously later if the operator wants it; the knob is below.
# * `trixie-backports` is EXCLUDED, AND THAT IS THE KERNEL ARGUMENT — see DECISION 2.
#
# ═════════════════════════════════════════════════════════════════════════════════════════════════
# DECISION 2 — THE KERNEL IS EXCLUDED TWICE OVER. THIS IS THE HIGHEST-RISK PART OF THE CHANGE.
# ═════════════════════════════════════════════════════════════════════════════════════════════════
# The constraint: HP's R21 firmware on these EliteDesk 800 G5 minis publishes a corrupt EFI Memory
# Attributes Table, and Linux < 6.13 does not validate it before reserving memory from its contents
# — k3s-prod-2 twice booted with 2.6 GiB of 16 GB. Upstream 8fbe4c49c0cc (first in v6.13) is the
# ONLY fix; there is no kernel cmdline workaround. So these nodes run the backports metapackage
# `linux-image-amd64` (measured 2026-10-17: version 7.1.8-1~bpo13+1 installed and running on all
# three, well above the floor). Full write-up: infra/PROD-PROVISIONING.md §0b, and the rationale
# block in roles/node_baseline/defaults/main.yml:21-51.
#
# A NODE THAT COMES BACK FROM AN UNATTENDED UPGRADE ON A 6.12 KERNEL IS A NODE THAT MAY COME BACK
# WITH A FRACTION OF ITS RAM. Note that 6.12 kernels are not hypothetical here — measured
# 2026-10-17, `linux-image-6.12.107+deb13-amd64` and `linux-image-6.12.94+deb13-amd64` are BOTH
# still installed on all three nodes, below the floor, bootable, and nothing holds them.
#
# Two independent mechanisms keep unattended-upgrades away from the kernel, and the role asserts
# both rather than trusting either:
#
# 1. ORIGIN EXCLUSION (structural). The running kernel comes from `o=Debian Backports`, which is
# not in Allowed-Origins. u-u only ever considers packages from allowed origins, so it cannot
# see a backports kernel upgrade at all. This also means the backports kernel receives no
# automatic patching — accepted, and in any case backports carries no security guarantees
# (node_baseline's defaults state that cost plainly: "no security-tracker commitment, no DSAs").
# 2. PACKAGE BLACKLIST (belt and braces). `linux-*` is blacklisted below, so even if the origin
# list is later widened — the most likely future edit to this file, and the one that would
# silently re-arm the hazard — the kernel is still untouchable. Without this, widening origins
# to include backports would hand an unattended process the EFI-memattr-critical package.
#
# WHAT THIS DOES *NOT* DO, AND MUST NOT BE READ AS DOING: it does not stop the kernel moving. The
# operator still advances it deliberately with
# ansible-playbook playbooks/node-baseline.yml -e k3s_hosts=k3s_prod --tags kernel --limit <host>
# which is the only thing that maintains the backports source, the metapackage and the on-node
# provenance stamp. node_baseline's own comment ("`ButAutomaticUpgrades: yes` ... means `apt upgrade`
# keeps it current once installed") still holds for an operator-run apt; the measured pin priority of
# 100 is exactly the NotAutomatic + ButAutomaticUpgrades signature that produces that behaviour.
# Nothing here changes it. What changes is that a NEW unattended actor is forbidden from the kernel.
#
# NOT BLACKLISTED, BECAUSE THEY ARE NOT APT PACKAGES AT ALL — measured 2026-10-17: `dpkg-query` finds
# no `k3s`, no `containerd` and no `containerd.io`. k3s is a single static binary at
# /usr/local/bin/k3s installed by roles/k3s_server, and it bundles its own containerd and kubelet.
# So the entire Kubernetes control plane and container runtime are OUTSIDE apt's reach and cannot be
# upgraded by this role even in principle. That is worth knowing before worrying about it.
unattended_upgrades_enabled: false
# The packages this role installs. Each one is load-bearing; see the notes.
unattended_upgrades_packages:
# The upgrader itself.
- unattended-upgrades
# NOTE: `update-notifier-common` was listed here and REMOVED (2026-10-18). It is an UBUNTU
# package and does not exist in Debian at all -- `apt-cache policy update-notifier-common` on
# trixie returns `Candidate: (none)`, so the play failed outright with "No package matching
# 'update-notifier-common' is available" on all three nodes. The sentinel writer is now provided
# by this role itself; see unattended_upgrades_sentinel_* below and tasks/main.yml.
# Restarts services still mapped to a deleted library after a security upgrade. Without it a
# security-only policy patches bytes on disk that no running process reads — see DECISION 3.
- needrestart
# --- Allowed origins -----------------------------------------------------------------------------
# Verbatim apt origin expressions, substituted into 50unattended-upgrades. The ${distro_*} tokens
# here are UNATTENDED-UPGRADES' OWN placeholders, expanded by it at runtime — they are not Ansible
# or Flux substitutions, which is why they are single-quoted and why this role's files never travel
# through Flux envsubst.
#
# `l=Debian-Security` plus the `-security` codename is the form Debian's own shipped config uses, and
# both halves were confirmed against the measured archive metadata above (l=Debian-Security,
# n=trixie-security). Matching on the LABEL rather than the suite name is what makes this survive the
# next Debian release.
unattended_upgrades_allowed_origins:
- 'origin=Debian,codename=${distro_codename},label=Debian-Security'
- 'origin=Debian,codename=${distro_codename}-security,label=Debian-Security'
# Set this to add 'origin=Debian,codename=${distro_codename}-updates,label=Debian' — a deliberate
# widening, kept as a knob so that turning it on is a reviewable one-line change rather than an edit
# to a heredoc. See DECISION 1 for why it is off.
unattended_upgrades_include_updates: false
# --- Package blacklist ---------------------------------------------------------------------------
# Regular expressions matched against package names. See DECISION 2: `linux-` is the EFI-memattr
# guard and must not be removed without re-reading PROD-PROVISIONING.md §0b.
unattended_upgrades_blacklist:
# Every kernel package: linux-image-*, linux-headers-*, linux-image-amd64 (the metapackage that
# actually tracks backports), plus linux-kbuild / linux-libc-dev. Anchored at the start so it
# cannot accidentally match an unrelated package containing the substring.
- '^linux-'
# Microcode changes take effect only on reboot and can alter boot behaviour on the very firmware
# that is already misbehaving here. Operator-only, same argument as the kernel.
- '^intel-microcode$'
- '^amd64-microcode$'
# The bootloader. A grub upgrade rewrites boot configuration on a machine with a documented
# warm-reboot hang (k3s-prod-2, 2026-09-03). Never unattended.
- '^grub-'
- '^grub2-common$'
# --- Reboot policy -------------------------------------------------------------------------------
# FALSE, AND THIS IS THE DIVISION OF LABOUR WITH kured, NOT AN OVERSIGHT.
# unattended-upgrades can reboot a node itself (Automatic-Reboot "true"). It must not here: it has
# no notion of a cluster, so it would not cordon, would not drain, would not evict the 25 attached
# Longhorn volumes cleanly, would not check whether another node is already down, and — on three
# control-plane nodes where etcd quorum is 2 of 3 — three nodes each deciding independently to
# reboot at their own `Automatic-Reboot-Time` is precisely how you lose the cluster.
# u-u therefore only ever leaves the sentinel behind; kured owns every reboot, one node at a time,
# under a cluster-wide lock. See platform/kured/helmrelease.yaml.
unattended_upgrades_automatic_reboot: false
# --- needrestart (DECISION 3) --------------------------------------------------------------------
# See the role README for the full argument. Summary: 'a' (restart services automatically) is what
# makes a security-only policy actually effective — a patched libssl on disk does nothing for a
# process still mapping the old one — but k3s.service is EXCLUDED, because restarting the
# Kubernetes control plane unattended at 06:00 is a worse outcome than a delayed library fix.
# Measured 2026-10-17: the only matching unit on these nodes is `k3s.service` (no separate
# containerd or kubelet unit exists; k3s bundles both), so this blacklist is complete today.
unattended_upgrades_needrestart_mode: a
unattended_upgrades_needrestart_blacklist:
- '^k3s'
# --- Schedule ------------------------------------------------------------------------------------
# apt's own systemd timers (apt-daily, apt-daily-upgrade) drive u-u; these set their windows.
# 04:00 with a 1h randomised delay, so the upgrade lands INSIDE kured's 03:00-06:00 reboot window
# (platform/kured/helmrelease.yaml) rather than hours away from it: if an upgrade ever does set the
# sentinel, the reboot can be taken the same night instead of waiting ~24h. The randomised delay
# keeps the three nodes from hitting the mirror simultaneously; it does NOT serialise anything, and
# it does not need to — u-u never reboots, so three concurrent upgrades are harmless.
unattended_upgrades_download_time: "03:30"
unattended_upgrades_upgrade_time: "04:00"
unattended_upgrades_randomised_delay: 60m
# ── THE REBOOT SENTINEL, PROVIDED BY THIS ROLE ──────────────────────────────────────────────────
# /var/run/reboot-required is the ONLY thing kured watches, and on Debian trixie **nothing creates
# it**. Measured on all three nodes 2026-10-18:
# * `update-notifier-common` (which owns that hook on Ubuntu) has `Candidate: (none)` — the
# package does not exist in Debian. Installing it is what broke the first run of this play.
# * `/usr/share/update-notifier/notify-reboot-required` is absent.
# * NO `linux-image-*` postinst references `notify-reboot-required` — calling it is an Ubuntu
# patch, not Debian behaviour, so merely dropping a script at that path would never be invoked.
# * No hook under /etc/apt/apt.conf.d or /etc/kernel/ mentions reboot-required.
# So the writer has to be ours. Without it kured is a permanent, INVISIBLE no-op: it stays 1/1
# Running and reports kured_reboot_required=0 forever, which is the "failure mode is a green tick"
# shape this repo keeps getting burned by.
#
# MECHANISM: a dpkg Post-Invoke hook runs a script that compares the RUNNING kernel against the
# newest INSTALLED one and touches the sentinel when they differ. Deliberately kernel-only, which
# matches the design: unattended-upgrades is security-only with `^linux-` blacklisted, so it will
# essentially never set this — the sentinel appears when the OPERATOR deliberately runs the
# node_baseline kernel play, and kured then automates only the mechanical reboot.
#
# It uses `linux-version` (from `linux-base`, a dependency of every linux-image package, so
# guaranteed present — measured `linux-base 4.12.1` installed) rather than parsing `dpkg -l`
# output, because kernel version ordering is not string ordering.
#
# /run is a tmpfs (measured), so the sentinel self-clears on boot: after a reboot the running
# kernel IS the newest and the script writes nothing. No cleanup task is needed, and none exists.
unattended_upgrades_sentinel_script: /usr/local/sbin/k3s-notify-reboot-required
unattended_upgrades_sentinel_hook: /etc/apt/apt.conf.d/99-k3s-reboot-required
@@ -1,29 +0,0 @@
---
# Re-arm apt's periodic timers after a config or drop-in change.
#
# WHY A daemon_reload IS REQUIRED AND NOT OPTIONAL. The timer windows are set by drop-ins under
# /etc/systemd/system/apt-daily{,-upgrade}.timer.d/. systemd does not re-read unit files on its own,
# so until it is told to, the RUNNING manager keeps the shipped schedule and the new window is
# ignored — the files look right in git and on disk, `systemctl cat` shows them, and the upgrade
# still fires at the old time. That is a silent config no-op, which is the failure mode this whole
# role is written against.
#
# `daemon_reload` re-parses unit files and re-runs generators. It starts and stops nothing, so it
# cannot disturb k3s, containerd or Longhorn — the same reasoning node_baseline's "Reload systemd
# unit files" handler records.
#
# RESTARTING THE TIMERS IS ALSO SAFE, and is not the same as running the upgrade. `*.timer` units
# only hold the schedule; restarting one recomputes its next elapse and does NOT trigger its
# `*.service`. With `Persistent=true` set in the drop-in, a window missed while the node was down is
# caught up on the next boot rather than skipped.
#
# Both fire only when a task actually changed, so a re-run of the role is silent.
- name: Restart unattended-upgrades timers
ansible.builtin.systemd_service:
name: "{{ item }}"
state: restarted
enabled: true
daemon_reload: true
loop:
- apt-daily.timer
- apt-daily-upgrade.timer
@@ -1,369 +0,0 @@
---
# roles/unattended_upgrades — automatic Debian security patching, kernel excluded, reboots delegated
# to kured. Every decision and its reasoning lives in defaults/main.yml; this file is the mechanism.
#
# TAGS — following roles/node_baseline, every task carries one of `packages`, `config` or `verify`.
# An untagged run does all three in that order. The split exists because `verify` is the half an
# operator will want to re-run on its own to answer "is automatic patching actually working on this
# box", without re-writing any configuration:
# ansible-playbook playbooks/unattended-upgrades.yml -e k3s_hosts=k3s_prod --tags verify
#
# IT DOES NOT UPGRADE ANYTHING, AND IT DOES NOT REBOOT. This role installs and CONFIGURES the
# upgrader; it never runs `apt upgrade` itself and never takes a reboot. Both of those are deliberate
# and both follow roles/node_baseline/tasks/main.yml:61-67 ("IT DOES NOT REBOOT", after k3s-prod-2
# hung on a warm reboot on 2026-09-03 and needed a physical power button). Applying this role is
# therefore a SAFE operation on a live cluster at any time of day: the first unattended upgrade
# happens at the next timer firing, and any reboot it implies is kured's to schedule inside the
# 03:00-06:00 window.
- name: Automatic security upgrades (unattended-upgrades; kernel excluded, reboots via kured)
when: unattended_upgrades_enabled | bool
tags: [packages, config, verify]
block:
# ── PREFLIGHT ───────────────────────────────────────────────────────────────────────────────
- name: Assert this is a Debian-family host
# The config file layout, the origin expressions and the package names below are all
# Debian-specific. On anything else this role would write files that are silently ignored,
# which is the failure mode this whole PR exists to avoid.
ansible.builtin.assert:
that:
- ansible_facts['os_family'] == 'Debian'
fail_msg: >-
REFUSING TO CONFIGURE unattended-upgrades on {{ inventory_hostname }}: os_family is
'{{ ansible_facts["os_family"] }}', not 'Debian'. The allowed-origin expressions and
config paths in this role are Debian-specific.
tags: [packages, config, verify]
# ── PACKAGES ────────────────────────────────────────────────────────────────────────────────
- name: Install unattended-upgrades and needrestart
# The reboot-sentinel writer is NOT a package here. On Debian nothing ships one -- see
# defaults/main.yml -- so this role installs its own script and dpkg hook, two tasks below.
ansible.builtin.apt:
name: "{{ unattended_upgrades_packages }}"
state: present
update_cache: true
cache_valid_time: 3600
tags: [packages]
# ── THE REBOOT SENTINEL WRITER (ours, because Debian ships none) ────────────────────────────
# Full rationale and the four measurements behind it: defaults/main.yml. Short version: kured
# watches /var/run/reboot-required and nothing on Debian creates it, so without these two files
# the entire reboot half is an invisible no-op.
- name: Install the reboot-sentinel writer
ansible.builtin.copy:
dest: "{{ unattended_upgrades_sentinel_script }}"
owner: root
group: root
mode: "0755"
content: |
#!/bin/sh
# MANAGED BY ANSIBLE -- infra/ansible/roles/unattended_upgrades. Local edits are reverted.
#
# Touch /var/run/reboot-required when the RUNNING kernel is not the newest INSTALLED one.
# kured watches that path; see the role's defaults/main.yml for why this is ours to ship.
#
# `linux-version` comes from linux-base (a dependency of every linux-image package), and
# is used rather than sorting `dpkg -l` output because kernel version ordering is not
# string ordering. If it is somehow missing, exit 0 and write nothing: a dpkg hook must
# never fail an apt transaction, and a missing sentinel is caught by the verify assert.
set -eu
command -v linux-version >/dev/null 2>&1 || exit 0
running="$(uname -r)"
newest="$(linux-version list 2>/dev/null | linux-version sort --reverse 2>/dev/null | head -n1)"
# No newest (nothing installed we can read) -> nothing to say.
[ -n "$newest" ] || exit 0
if [ "$running" != "$newest" ]; then
touch /var/run/reboot-required 2>/dev/null || exit 0
# kured only needs the file, but the .pkgs companion is what an operator reads to find
# out WHY a node is waiting, so write a reason rather than an empty marker.
printf 'linux-image-%s\n' "$newest" > /var/run/reboot-required.pkgs 2>/dev/null || true
fi
exit 0
tags: [packages, config]
- name: Install the dpkg hook that runs the sentinel writer
# Post-Invoke, so it runs after dpkg has finished and a newly installed kernel is already
# visible to `linux-version list`. `|| true` so a failure here can never abort an apt
# transaction -- an unwritten sentinel is a missed reboot, but a broken apt is a broken node.
ansible.builtin.copy:
dest: "{{ unattended_upgrades_sentinel_hook }}"
owner: root
group: root
mode: "0644"
content: |
// MANAGED BY ANSIBLE -- infra/ansible/roles/unattended_upgrades. Local edits reverted.
// Writes /var/run/reboot-required when the running kernel is not the newest installed.
DPkg::Post-Invoke { "{{ unattended_upgrades_sentinel_script }} || true"; };
tags: [packages, config]
# ── CONFIG ──────────────────────────────────────────────────────────────────────────────────
# Written as a whole file rather than patched in place, for the reason node_baseline gives for
# its own apt source: an idempotent full-file write with a managed-by header is reviewable and
# re-runnable, whereas line-editing a conffile fights dpkg on every package upgrade.
#
# 52- RATHER THAN 50-: Debian ships /etc/apt/apt.conf.d/50unattended-upgrades as a CONFFILE of
# the unattended-upgrades package. Overwriting it would make every future apt upgrade of that
# package prompt about a locally-modified conffile (or, under the non-interactive defaults a
# scripted run uses, silently keep one side and discard the other). apt reads the directory in
# lexical order and later files win, so a separate 52- file overrides the shipped defaults
# without ever touching them, and `apt-config dump` in the verify block below proves which value
# actually won rather than assuming this ordering holds.
- name: Configure unattended-upgrades (52-k3s-unattended-upgrades)
ansible.builtin.copy:
dest: /etc/apt/apt.conf.d/52-k3s-unattended-upgrades
owner: root
group: root
mode: "0644"
content: |
// MANAGED BY ANSIBLE — infra/ansible/roles/unattended_upgrades. Local edits are reverted
// on the next run. Rationale for every value: that role's defaults/main.yml.
//
// Overrides the shipped 50unattended-upgrades by lexical ordering (52 > 50). The shipped
// file is a dpkg conffile and is deliberately left untouched.
// SECURITY ONLY. Deliberately excludes trixie-updates (non-security fixes) and
// trixie-backports (o=Debian Backports) -- and excluding backports is what makes it
// structurally impossible for this upgrader to move the EFI-memattr-critical kernel,
// which is installed from there. See defaults/main.yml DECISION 2.
Unattended-Upgrade::Origins-Pattern {
{% for origin in unattended_upgrades_allowed_origins %}
"{{ origin }}";
{% endfor %}
{% if unattended_upgrades_include_updates | bool %}
"origin=Debian,codename=${distro_codename}-updates,label=Debian";
{% endif %}
};
// NEVER AUTOMATICALLY UPGRADED, whatever the origin list later says. `^linux-` is the
// EFI-memattr guard: these HP minis need kernel >= 6.13 or they can boot with a fraction
// of their RAM, and 6.12 kernels are still installed and bootable on all three nodes.
// Do not remove without re-reading infra/PROD-PROVISIONING.md §0b.
Unattended-Upgrade::Package-Blacklist {
{% for pkg in unattended_upgrades_blacklist %}
"{{ pkg }}";
{% endfor %}
};
// REBOOTS BELONG TO kured (platform/kured), NOT TO apt. All three nodes are
// control-plane + etcd with quorum 2 of 3, so three hosts independently deciding to
// reboot at their own Automatic-Reboot-Time is how the cluster is lost. u-u leaves
// /var/run/reboot-required behind; kured takes a cluster-wide lock and reboots exactly
// one node at a time, after cordon + drain, inside 03:00-06:00, gated on Longhorn volume
// health.
Unattended-Upgrade::Automatic-Reboot "{{ unattended_upgrades_automatic_reboot | bool | lower }}";
Unattended-Upgrade::Automatic-Reboot-WithUsers "false";
// Keep the node's disk from filling with superseded .debs, and keep a log an operator can
// read after the fact (/var/log/unattended-upgrades/). MinAge guards against removing a
// package still needed by a rollback.
Unattended-Upgrade::Remove-Unused-Kernel-Packages "false";
Unattended-Upgrade::Remove-New-Unused-Dependencies "true";
Unattended-Upgrade::Remove-Unused-Dependencies "false";
Unattended-Upgrade::AutoFixInterruptedDpkg "true";
Unattended-Upgrade::MinimalSteps "true";
Unattended-Upgrade::SyslogEnable "true";
// Remove-Unused-Kernel-Packages is FALSE on purpose, against the Debian default. These
// nodes deliberately carry more than one kernel: the backports kernel they boot and the
// distro kernels that are the documented rollback path (node_baseline writes the rollback
// procedure onto the node itself). An unattended process pruning kernels could remove the
// fallback an operator needs at 3am in front of a box that will not boot.
notify: Restart unattended-upgrades timers
tags: [config]
- name: Enable the apt periodic timers that actually run unattended-upgrades
# Installing the package is NOT sufficient to make it run on a schedule: without these
# counters apt's daily units do nothing, and the whole mechanism is inert while looking
# installed. `1` means "every day".
ansible.builtin.copy:
dest: /etc/apt/apt.conf.d/20auto-upgrades
owner: root
group: root
mode: "0644"
content: |
// MANAGED BY ANSIBLE — infra/ansible/roles/unattended_upgrades.
// Without these four counters the apt-daily timers fire and do nothing, so
// unattended-upgrades would be installed, configured, and never once invoked.
APT::Periodic::Update-Package-Lists "1";
APT::Periodic::Download-Upgradeable-Packages "1";
APT::Periodic::Unattended-Upgrade "1";
APT::Periodic::AutocleanInterval "7";
tags: [config]
- name: Ensure the systemd timer drop-in directories exist
# `copy` does not create parent directories, and these two .timer.d/ dirs do not exist on a
# stock Debian node — without this task the next task fails with "Destination directory does
# not exist" on a first run.
ansible.builtin.file:
path: "/etc/systemd/system/{{ item }}.timer.d"
state: directory
owner: root
group: root
mode: "0755"
loop:
- apt-daily
- apt-daily-upgrade
tags: [config]
- name: Pin the apt timer windows into kured's reboot window
# Overriding the shipped timers rather than editing them: a drop-in survives package upgrades.
# OnCalendar is cleared first (`OnCalendar=` with no value) because systemd ACCUMULATES
# OnCalendar entries across drop-ins — omit the reset and the unit keeps its shipped schedule
# IN ADDITION to ours, which would run the upgrade at both times and look like it worked.
ansible.builtin.copy:
dest: "/etc/systemd/system/{{ item.unit }}.timer.d/override.conf"
owner: root
group: root
mode: "0644"
content: |
# MANAGED BY ANSIBLE — infra/ansible/roles/unattended_upgrades.
# Lands the upgrade inside kured's 03:00-06:00 reboot window so a sentinel written by an
# upgrade can be acted on the same night rather than ~24h later.
[Timer]
OnCalendar=
OnCalendar={{ item.time }}
RandomizedDelaySec={{ unattended_upgrades_randomised_delay }}
Persistent=true
force: true
loop:
- { unit: apt-daily, time: "{{ unattended_upgrades_download_time }}" }
- { unit: apt-daily-upgrade, time: "{{ unattended_upgrades_upgrade_time }}" }
loop_control:
label: "{{ item.unit }} at {{ item.time }}"
notify: Restart unattended-upgrades timers
tags: [config]
- name: Configure needrestart (restart services, but never k3s)
# See defaults/main.yml DECISION 3. Auto-restart is what makes a security-only policy real --
# a patched library on disk does nothing for a process still mapping the deleted one -- but
# k3s.service is excluded because restarting the control plane unattended is worse than a
# delayed library fix. `$nrconf{restart}` is Perl config read by needrestart itself.
ansible.builtin.copy:
dest: /etc/needrestart/conf.d/50-k3s.conf
owner: root
group: root
mode: "0644"
content: |
# MANAGED BY ANSIBLE — infra/ansible/roles/unattended_upgrades.
# Restart mode: '{{ unattended_upgrades_needrestart_mode }}' (a = automatically, l = list only, i = interactive)
$nrconf{restart} = '{{ unattended_upgrades_needrestart_mode }}';
# Units matching these patterns are NEVER restarted automatically. k3s bundles containerd
# and the kubelet, so this one entry covers the entire control plane and runtime on these
# nodes (measured 2026-10-17: k3s.service is the only matching unit). A library fix that
# needs k3s restarted therefore waits for the reboot kured will take.
$nrconf{blacklist_rc} = [
{% for pat in unattended_upgrades_needrestart_blacklist %}
qr({{ pat }}),
{% endfor %}
];
tags: [config]
# ── VERIFY ──────────────────────────────────────────────────────────────────────────────────
# These tasks exist because every component of this mechanism fails SILENTLY. An installed
# package, a written config file and a green play are all compatible with nothing ever being
# upgraded and no reboot ever being signalled.
- name: Ask apt-config what the effective settings actually are
# `apt-config dump` is apt's OWN parse of the whole /etc/apt/apt.conf.d/ directory, so it
# proves what WON after lexical ordering rather than what this role wrote. If the shipped
# 50unattended-upgrades were ever renamed above 52-, this is the task that would catch it.
ansible.builtin.command: apt-config dump
register: unattended_upgrades_aptconfig
changed_when: false
check_mode: false
tags: [verify]
- name: Assert the kernel is blacklisted and automatic reboots are off
# The two properties that must never silently regress. Asserted against apt's own view.
ansible.builtin.assert:
that:
# apt-config renders each list entry as `Unattended-Upgrade::Package-Blacklist:: "^linux-";`
# so the anchored pattern itself is the thing to look for. Checking for the bare string
# `linux-` would pass on almost any dump and prove nothing.
- "'\"^linux-\"' in unattended_upgrades_aptconfig.stdout"
- "'Unattended-Upgrade::Automatic-Reboot \"false\"' in unattended_upgrades_aptconfig.stdout"
# The origin list must be non-empty, or u-u runs nightly and upgrades nothing — installed,
# scheduled, green, and inert.
- "'Debian-Security' in unattended_upgrades_aptconfig.stdout"
fail_msg: >-
EFFECTIVE apt CONFIG ON {{ inventory_hostname }} IS NOT WHAT THIS ROLE INTENDED.
Either the `^linux-` kernel blacklist or `Automatic-Reboot "false"` is not winning.
Both are safety properties, not preferences: without the blacklist an unattended process
can move a kernel these HP minis must keep >= 6.13 (PROD-PROVISIONING.md §0b), and
without Automatic-Reboot=false three control-plane nodes can each reboot themselves
independently and take etcd below quorum. Inspect with `apt-config dump | grep -i
unattended` and check for a file sorting after 52- in /etc/apt/apt.conf.d/.
success_msg: >-
Effective apt config confirmed: kernel blacklisted, automatic reboot disabled.
tags: [verify]
# THE SENTINEL IS THE SINGLE POINT OF FAILURE FOR THE ENTIRE REBOOT HALF OF THIS DESIGN.
# This was originally a `find` over /etc/kernel/postinst.d and /etc/apt/apt.conf.d, on the
# theory that the writer came from a package and the role could only discover whatever that
# package happened to ship. That theory was wrong: no such package exists on Debian (see
# defaults/main.yml), so the writer is now OURS and lives at two known paths. Checking two
# exact paths is strictly stronger than a glob -- a glob would have matched Debian's own
# unattended-upgrades apt conffile and passed while no sentinel writer existed at all.
- name: Stat the sentinel writer script
ansible.builtin.stat:
path: "{{ unattended_upgrades_sentinel_script }}"
register: unattended_upgrades_sentinel_script_stat
changed_when: false
tags: [verify]
- name: Stat the sentinel dpkg hook
ansible.builtin.stat:
path: "{{ unattended_upgrades_sentinel_hook }}"
register: unattended_upgrades_sentinel_hook_stat
changed_when: false
tags: [verify]
- name: Assert something on this node can write the reboot sentinel
# If this fails, kured is a no-op: it watches /var/run/reboot-required forever, the file is
# never created, no reboot is ever taken, and NOTHING GOES RED -- the DaemonSet stays 1/1
# Running and `kured_reboot_required` reports a steady 0 on every node. That is the exact
# shape of failure (a check whose failure mode is a green tick) this repo has been burned by
# before, so it is an assert and not a debug message.
ansible.builtin.assert:
that:
- unattended_upgrades_sentinel_script_stat.stat.exists
- unattended_upgrades_sentinel_script_stat.stat.executable | default(false)
- unattended_upgrades_sentinel_hook_stat.stat.exists
fail_msg: >-
NOTHING ON {{ inventory_hostname }} CAN CREATE /var/run/reboot-required.
{{ unattended_upgrades_sentinel_script }} (executable) and
{{ unattended_upgrades_sentinel_hook }} must both exist -- this role ships both, because
Debian provides no sentinel writer of its own (update-notifier-common is an UBUNTU
package and is not installable here). kured watches that path and reboots only when it
exists, so with no writer the reboot automation is permanently and INVISIBLY idle --
kured stays 1/1 Running and reports kured_reboot_required=0 on every node forever.
Re-run this role without `--tags verify` to install them.
success_msg: >-
Reboot sentinel writer present ({{ unattended_upgrades_sentinel_script }} + dpkg hook)
-- a kernel change will signal kured on the next apt transaction.
tags: [verify]
- name: Report the pending-reboot state of this node
# Read-only. Tells the operator whether this node is currently waiting on kured for a reboot,
# which is the question `--tags verify` is usually being run to answer.
ansible.builtin.stat:
path: /var/run/reboot-required
register: unattended_upgrades_reboot_required
changed_when: false
tags: [verify]
- name: Summary
ansible.builtin.debug:
msg: >-
{{ inventory_hostname }}: security-only unattended upgrades ACTIVE
(upgrade timer {{ unattended_upgrades_upgrade_time }} +/-{{ unattended_upgrades_randomised_delay }}),
kernel and microcode blacklisted, automatic reboot DISABLED.
Reboot currently pending: {{ unattended_upgrades_reboot_required.stat.exists }}.
{% if unattended_upgrades_reboot_required.stat.exists %}
This node is waiting for kured to reboot it in the next 03:00-06:00 window; it will be
cordoned and drained first, and no other node will be rebooted at the same time.
{% endif %}
tags: [verify]
+265
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@@ -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
-127
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@@ -1,127 +0,0 @@
# platform/kured
**kured (Kubernetes Reboot Daemon)** — coordinated, one-node-at-a-time OS reboots of the three prod
control-plane nodes.
- **Flux tier:** `clusters/base/kured.yaml` (its own Kustomization, `dependsOn: [platform]`,
`wait: true`)
- **Chart:** `kured` 6.1.0 → appVersion 1.23.0, from `https://kubereboot.github.io/charts`
- **The other half:** `infra/ansible/roles/unattended_upgrades` — the package upgrades. **Neither
half is useful alone.**
- **Runbook:** `/runbooks/node-reboot-automation`
- **Every tuned value and its reasoning:** `helmrelease.yaml`. That file is the argument; this one is
the orientation.
- **Design record:** `decisions/2026-10-17-automated-upgrades.md`
## What this component owns
The *mechanics* of a reboot: take a cluster-wide lock, cordon, drain, reboot, uncordon, hold the
lock a while longer. Nothing else.
**It does not decide whether to reboot.** kured reboots a node if and only if
`/var/run/reboot-required` exists there. On these nodes that file is written by a deliberate
operator kernel upgrade (`playbooks/node-baseline.yml --tags kernel`) — unattended-upgrades is
security-only with the kernel blacklisted, so it essentially never produces one. **The human gate is
the sentinel, not the daemon.**
## The problem this fixes
Rebooting these three nodes was a manual, serialized, supervised procedure, and
`roles/node_baseline` has to end its kernel run by shouting the rules at the operator: *"Reboot prod
nodes ONE AT A TIME, verify each returns before touching the next, and NEVER node 2 first"*. That is
a correct procedure and an error-prone one, and nothing enforced it.
What it has to get right, measured on prod 2026-10-17:
- **etcd quorum is 2 of 3** — all three nodes are control-plane+etcd. Two down is a lost cluster.
- **Every drain degrades all 25 Longhorn volumes to 2/3**, because 3 nodes × 3 replicas ×
`replica-soft-anti-affinity: false` leaves nowhere to place a replacement, and rebuild is
serialized behind a 600s wait. Reboot the next node too early and volumes hit 1/3, where
`block-if-contains-last-replica` can block a drain forever.
- **Six PodDisruptionBudgets allow zero voluntary disruptions** — 3 Longhorn `instance-manager-*`
(structurally 0 by design; this is how Longhorn gates the drain) and 3 CNPG `*-primary`.
## Placement — why its own Kustomization
`platform` is `wait: true` over twelve components and gates `platform-config` → every apps wave. A
reboot daemon that failed to go healthy there would stall **every application in the cluster** on
"dependency not ready". A component added to make maintenance safer must not be able to cause an
outage. `wait: true` here is a health **signal** for something nothing depends on — and nothing
should ever `dependsOn: [kured]`.
The `dependsOn: [platform]` edge is load-bearing, not conventional: it supplies the
`monitoring.coreos.com` CRDs this component's `PrometheusRule` needs (F-MON1 — a pass containing an
unknown kind aborts), plus the Prometheus that kured **queries** before every reboot.
## How concurrent reboots are made impossible
| mechanism | value | why |
|---|---|---|
| cluster-wide lock | one annotation on kured's own DaemonSet | a node reboots only while holding it; enforced by API-server optimistic concurrency, not timing |
| `concurrency` | `1` | one lock holder at a time |
| **`lockTtl`** | **`0` (disabled)** | a TTL lets reboots continue after the holder dies — on 3 etcd nodes that is the catastrophe. A hung node holds the lock **forever** and nothing cascades. |
| `lockReleaseDelay` | `30m` | the next node waits out Longhorn's 600s replenishment even if no alert latched |
| alert gate | `alertFilterMatchOnly: true` + anchored allow-list | refuses to proceed while a volume is degraded/faulted or a node is down |
| window | 03:00–06:00 daily, America/New_York | matches `renovate.json`'s window; daily (not weekly) is what makes `KuredRebootPending`'s `for: 36h` meaningful |
## Deliberate non-choices
- **No `--ignore-daemonsets` / `--delete-emptydir-data` / `--force`.** Those flags **do not exist**
in kured 1.23.0 — it hardcodes all three in the drain helper (`cmd/kured/main.go:438-449`).
Passing them would CrashLoop the DaemonSet. All three are genuinely required here (12 DaemonSets,
135 emptyDir pods).
- **`rebootMethod: command`, not `signal`.** `signal` would allow `privileged: false` + `CAP_KILL`,
but needs a host-side `kured-reboot.service` that does not exist on these nodes. A real future
hardening step; explicitly not taken here.
- **No tolerations.** No prod node is tainted (measured). A future tainted node would be silently
uncovered — hence `KuredNodeCoverageGap`.
- **`NodeEtcdRequestsSlow` / `NodeIOPressure*` are NOT in the alert gate**, despite being exactly
what you would want to pause for. prod-1 has a documented etcd WAL I/O starvation history and
including them risks a permanent wedge that looks like safety.
- **No Slack/shoutrrr notifications.** Would require a SOPS Secret and a decryption patch; the three
alerts cover the same ground through Alertmanager.
## Versioning
Chart pinned `>=6.1.0 <6.2.0`. The minor ceiling is **deliberate here**, unlike elsewhere in this
repo where it is a main cause of pin rot: a kured minor may change drain or lock semantics, and this
is the one component where "a human read the changelog" should be a precondition. `renovate.json`'s
`blast-radius` rule additionally forbids auto-merging it, so the ceiling is a review prompt, not a
wall.
## What breaks silently, and what catches it
Every failure mode of this component leaves a cluster that looks healthy — kured stays 1/1 Running
while rebooting nothing. `alerts.yaml` ships three rules over kured's single metric, with a
companion promtool suite:
| alert | catches |
|---|---|
| `KuredNotReporting` | the scrape pipeline is dead (chart defaults `service.create`/`metrics.create` to **false**; a NetworkPolicy can time the scrape out) — and the other two are inert while this is true |
| `KuredNodeCoverageGap` | kured missing on *some* node, which `absent()` cannot see |
| `KuredRebootPending` | a reboot was offered and blocked for >36h |
## Post-merge verification
```bash
infra/devcontainer/dev.sh run bash -c 'kubectl --context k3s-prod -n kured get ds,pod,svc,servicemonitor -o wide'
infra/devcontainer/dev.sh run bash -c 'flux --context k3s-prod get kustomization kured'
infra/devcontainer/dev.sh run bash -c 'kubectl --context k3s-prod -n kured logs ds/kured --tail=40'
```
Expect `3/3` ready, the Kustomization `Ready=True`, and kured logging a reboot-check decision each
period. Then confirm the scrape is real — this is the step that proves the alerts are not inert:
```bash
infra/devcontainer/dev.sh run bash -c 'kubectl --context k3s-prod -n monitoring exec \
sts/prometheus-kube-prometheus-stack-prometheus -c prometheus -- \
wget -qO- "http://localhost:9090/api/v1/query?query=count(kured_reboot_required)"'
```
**Expect `3`.** Anything else (and especially an empty result) means the Service, ServiceMonitor or
NetworkPolicy is wrong and all three alerts are silently dead.
**Before trusting the timer with a real kernel upgrade**, do one watched drain to settle the open
question the design record flags: whether CNPG actually switches its primary away in response to a
drain-induced eviction. If it does not, draining `k3s-prod-1` blocks on three 0-disruption PDBs at
once.
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---
# promtool unit tests for the three rules in platform/kured/alerts.yaml.
#
# WHY THIS FILE EXISTS. The rules it covers are the ONLY thing that can tell an operator that the
# reboot automation has stopped working, and every failure mode they describe is silent — kured stays
# 1/1 Running while rebooting nothing. An alert that cannot fire is therefore not a cosmetic defect
# here, it is the removal of the only signal. This repo has shipped that bug in both directions
# already (a permanently-firing VPNTunnelDown; a structurally inert VeleroNoRecentBackup over an
# absent series), which is why the harness exists at all. Each rule below is pinned BOTH ways: quiet
# on the healthy state, firing on the constructed bad one, with the `for:` boundary asserted rather
# than assumed.
#
# HOW TO RUN. `platform/monitoring/tests/run.sh` — the one repo-wide rule-unit harness. It finds this
# file by the COMPANION convention (`<manifest>.promtool-test.yaml` beside `<manifest>.yaml`), so the
# manifest under test is exactly platform/kured/alerts.yaml and nothing else. Run just this file with
# platform/monitoring/tests/run.sh platform/kured/alerts.promtool-test.yaml
# The harness flattens the PrometheusRule CR's `.spec.groups` into the bare rules file promtool wants,
# `promtool check rules` it first so a non-parsing file cannot pass vacuously, and runs it all in a
# temp dir. It leaves Flux's `${BASE_DOMAIN}` in the runbook_url annotations verbatim, which is safe
# because the assertions below query the `ALERTS` series and never compare annotations.
#
# WHY THE ASSERTIONS QUERY `ALERTS` RATHER THAN USING `exp_alerts`. promtool's alert_rule_test
# compares annotations VERBATIM, which would mean pasting each rule's description prose in here and
# re-pasting it on every wording change. Querying the synthetic `ALERTS` series proves what actually
# matters — the alert reaches `pending` and then `firing` across its `for:` boundary, with the right
# labels — and stays decoupled from annotation text. Same choice as
# platform/cnpg/alerts.promtool-test.yaml.
#
# THE SERIES SHAPES ARE REAL. `kured_reboot_required{node=...}` is a GaugeVec with exactly one label,
# `node` — read from kured's cmd/kured/main.go:92-96 (the only registered metric in the project).
# `kube_node_info{node=...}` was measured on prod Prometheus on 2026-10-17 returning
# `count(kube_node_info) == 3`, matching the three nodes. The extra kube_node_info labels prod
# carries are omitted deliberately: every rule aggregates with `count()`, so they cannot affect the
# result, and inventing plausible-but-wrong values would be worse than leaving them out.
#
# evaluation_interval is 5m, not the usual 1m: KuredRebootPending has `for: 36h`, and at a 1m
# interval promtool would evaluate that test over 2000+ steps for no added coverage.
rule_files:
- alerts.rules.yaml
evaluation_interval: 5m
tests:
# ─────────────────────────────────────────────────────────────────────────────────────────────
# 1. THE HEALTHY STEADY STATE. Three nodes, kured running on all three, nothing pending.
# ALL THREE RULES MUST BE SILENT. This is the case that a badly-written `absent()` or a
# `count() <` comparison with an off-by-one gets wrong, and it is also the state the cluster
# is in ~100% of the time, so a false positive here would train the operator to ignore the
# whole group.
# ─────────────────────────────────────────────────────────────────────────────────────────────
- interval: 5m
name: healthy cluster - no reboots pending, kured on every node, all three rules quiet
input_series:
- series: 'kured_reboot_required{node="k3s-prod-1"}'
values: '0x60'
- series: 'kured_reboot_required{node="k3s-prod-2"}'
values: '0x60'
- series: 'kured_reboot_required{node="k3s-prod-3"}'
values: '0x60'
- series: 'kube_node_info{node="k3s-prod-1"}'
values: '1x60'
- series: 'kube_node_info{node="k3s-prod-2"}'
values: '1x60'
- series: 'kube_node_info{node="k3s-prod-3"}'
values: '1x60'
promql_expr_test:
# Nothing from this group may be pending or firing, at any point in the window.
- expr: 'count(ALERTS{alertname=~"Kured.*"})'
eval_time: 4h
exp_samples: []
# And the underlying expressions must each be genuinely false, not merely unevaluated:
# absent() yields no series because the vector is populated...
- expr: 'absent(kured_reboot_required)'
eval_time: 4h
exp_samples: []
# ...coverage is exact (3 == 3), so the `<` comparison drops the sample...
- expr: 'count(kured_reboot_required) < count(kube_node_info)'
eval_time: 4h
exp_samples: []
# ...and no node reports a pending reboot.
- expr: 'max by (node) (kured_reboot_required) == 1'
eval_time: 4h
exp_samples: []
# ─────────────────────────────────────────────────────────────────────────────────────────────
# 2. KuredNotReporting — THE WHOLE PIPELINE IS DEAD. No kured series at all, which is what the
# cluster looks like if the chart's `service.create`/`metrics.create` regress to their FALSE
# defaults, if the ServiceMonitor is dropped, or if a NetworkPolicy silently times out the
# scrape (the Longhorn precedent). The nodes still exist, so kube_node_info is present —
# proving the rule keys on kured's absence and not on a dead cluster.
# ─────────────────────────────────────────────────────────────────────────────────────────────
- interval: 5m
name: no kured series anywhere - KuredNotReporting fires after 30m
input_series:
- series: 'kube_node_info{node="k3s-prod-1"}'
values: '1x60'
- series: 'kube_node_info{node="k3s-prod-2"}'
values: '1x60'
- series: 'kube_node_info{node="k3s-prod-3"}'
values: '1x60'
promql_expr_test:
# The expression itself yields 1 immediately.
- expr: 'absent(kured_reboot_required)'
eval_time: 10m
exp_samples:
- labels: '{}'
value: 1
# `for: 30m` is honoured — still only pending at 25m.
- expr: 'ALERTS{alertname="KuredNotReporting"}'
eval_time: 25m
exp_samples:
- labels: 'ALERTS{alertname="KuredNotReporting", alertstate="pending", severity="warning"}'
value: 1
# ...and firing once past it.
- expr: 'ALERTS{alertname="KuredNotReporting", alertstate="firing"}'
eval_time: 35m
exp_samples:
- labels: 'ALERTS{alertname="KuredNotReporting", alertstate="firing", severity="warning"}'
value: 1
# THE GUARD CLAUSE: with kured absent, the other two rules are inert — exactly the reason
# this rule has to exist. KuredRebootPending cannot fire (no series to be 1) and
# KuredNodeCoverageGap cannot either, because `count()` over an empty vector returns NO
# SAMPLE rather than 0, so the `<` comparison has nothing to compare. Asserting that here
# pins the dependency: if a future edit made coverage-gap fire in this state, the overlap
# would be deliberate rather than accidental.
- expr: 'ALERTS{alertname="KuredRebootPending"}'
eval_time: 35m
exp_samples: []
- expr: 'ALERTS{alertname="KuredNodeCoverageGap"}'
eval_time: 35m
exp_samples: []
- expr: 'count(kured_reboot_required) < count(kube_node_info)'
eval_time: 35m
exp_samples: []
# ─────────────────────────────────────────────────────────────────────────────────────────────
# 3. KuredNodeCoverageGap — kured COVERS ONLY TWO OF THREE NODES. k3s-prod-3's series stops at
# 1h and never returns (a node taint this DaemonSet does not tolerate, a node that never came
# back from a reboot, a DaemonSet nodeSelector edit). This also pins the `for: 2h` choice,
# which exists SO THAT AN ORDINARY REBOOT DOES NOT TRIP IT: the gap is real from ~1h05 but
# the alert is only pending an hour later, and a healthy reboot is minutes.
# ─────────────────────────────────────────────────────────────────────────────────────────────
- interval: 5m
name: kured missing on one node - KuredNodeCoverageGap fires after 2h, not before
input_series:
- series: 'kured_reboot_required{node="k3s-prod-1"}'
values: '0x60'
- series: 'kured_reboot_required{node="k3s-prod-2"}'
values: '0x60'
# Ends after 1h (13 samples at 5m) and is stale thereafter.
- series: 'kured_reboot_required{node="k3s-prod-3"}'
values: '0x12'
- series: 'kube_node_info{node="k3s-prod-1"}'
values: '1x60'
- series: 'kube_node_info{node="k3s-prod-2"}'
values: '1x60'
- series: 'kube_node_info{node="k3s-prod-3"}'
values: '1x60'
promql_expr_test:
# Before the gap opens, coverage is exact and nothing is pending.
- expr: 'ALERTS{alertname="KuredNodeCoverageGap"}'
eval_time: 30m
exp_samples: []
# The shortfall is real well before the alert fires — 2 < 3.
- expr: 'count(kured_reboot_required)'
eval_time: 2h
exp_samples:
- labels: '{}'
value: 2
# A SHORT OUTAGE DOES NOT ALERT: still only pending at 2h, an hour after the gap opened.
- expr: 'ALERTS{alertname="KuredNodeCoverageGap"}'
eval_time: 2h
exp_samples:
- labels: 'ALERTS{alertname="KuredNodeCoverageGap", alertstate="pending", severity="warning"}'
value: 1
# Firing once the gap has persisted past `for: 2h`.
- expr: 'ALERTS{alertname="KuredNodeCoverageGap", alertstate="firing"}'
eval_time: 3h15m
exp_samples:
- labels: 'ALERTS{alertname="KuredNodeCoverageGap", alertstate="firing", severity="warning"}'
value: 1
# KuredNotReporting must stay QUIET: two nodes are still publishing, so the vector is not
# absent. This is the distinction between "kured is gone" and "kured is incomplete", and
# getting it wrong in either direction would collapse two different diagnoses into one.
- expr: 'ALERTS{alertname="KuredNotReporting"}'
eval_time: 3h15m
exp_samples: []
# ─────────────────────────────────────────────────────────────────────────────────────────────
# 4. KuredRebootPending — A REBOOT IS BLOCKED. k3s-prod-1 reports a pending reboot continuously:
# the sentinel was written (an operator kernel upgrade) and the reboot has not happened across
# more than one 03:00-06:00 window. Asserts the 36h boundary in both directions, which is the
# assertion that makes the DAILY-window decision load-bearing rather than cosmetic: on a
# weekly window this threshold could not distinguish "blocked" from "waiting for Sunday".
# Series run to 38h20m (456 samples at 5m) so the post-boundary evaluation has real data.
# ─────────────────────────────────────────────────────────────────────────────────────────────
- interval: 5m
name: reboot pending on one node for over 36h - KuredRebootPending fires, per-node label kept
input_series:
- series: 'kured_reboot_required{node="k3s-prod-1"}'
values: '1x456'
- series: 'kured_reboot_required{node="k3s-prod-2"}'
values: '0x456'
- series: 'kured_reboot_required{node="k3s-prod-3"}'
values: '0x456'
- series: 'kube_node_info{node="k3s-prod-1"}'
values: '1x456'
- series: 'kube_node_info{node="k3s-prod-2"}'
values: '1x456'
- series: 'kube_node_info{node="k3s-prod-3"}'
values: '1x456'
promql_expr_test:
# The expression selects ONLY the pending node — the operator needs to know which box.
- expr: 'max by (node) (kured_reboot_required) == 1'
eval_time: 1h
exp_samples:
- labels: '{node="k3s-prod-1"}'
value: 1
# A NORMAL WAIT IS NOT AN ALERT. At 24h the node is still inside its legitimate
# once-per-day window wait, so the alert may be pending but must NOT be firing.
- expr: 'ALERTS{alertname="KuredRebootPending", alertstate="firing"}'
eval_time: 24h
exp_samples: []
# Still not firing just short of the boundary.
- expr: 'ALERTS{alertname="KuredRebootPending", alertstate="firing"}'
eval_time: 35h30m
exp_samples: []
# Firing past it, carrying the node label through to the notification.
- expr: 'ALERTS{alertname="KuredRebootPending", alertstate="firing"}'
eval_time: 36h30m
exp_samples:
- labels: 'ALERTS{alertname="KuredRebootPending", alertstate="firing", node="k3s-prod-1", severity="warning"}'
value: 1
# The two healthy nodes must NOT be alerted on. A rule written with `kured_reboot_required`
# unaggregated, or compared with `>= 0`, would raise all three and bury the real one.
- expr: 'count(ALERTS{alertname="KuredRebootPending", alertstate="firing"})'
eval_time: 36h30m
exp_samples:
- labels: '{}'
value: 1
# Liveness rules stay quiet: kured is present and covering all three nodes. A pending reboot
# is NOT a wiring fault and must not be reported as one.
- expr: 'ALERTS{alertname="KuredNotReporting"}'
eval_time: 36h30m
exp_samples: []
- expr: 'ALERTS{alertname="KuredNodeCoverageGap"}'
eval_time: 36h30m
exp_samples: []
# ─────────────────────────────────────────────────────────────────────────────────────────────
# 5. THE RULE MUST STOP. A reboot that SUCCEEDS clears the sentinel, and the alert must clear
# with it — the other half of the failure space this harness exists for (a permanently-firing
# rule is how VPNTunnelDown taught this repo the lesson). k3s-prod-1 is pending for ~40h,
# long enough to fire, then the reboot happens and the gauge returns to 0.
# ─────────────────────────────────────────────────────────────────────────────────────────────
- interval: 5m
name: reboot completes after firing - KuredRebootPending resolves
input_series:
# 1 for 480 samples (40h), then 0 for the remainder.
- series: 'kured_reboot_required{node="k3s-prod-1"}'
values: '1x480 0x120'
- series: 'kured_reboot_required{node="k3s-prod-2"}'
values: '0x600'
- series: 'kured_reboot_required{node="k3s-prod-3"}'
values: '0x600'
- series: 'kube_node_info{node="k3s-prod-1"}'
values: '1x600'
- series: 'kube_node_info{node="k3s-prod-2"}'
values: '1x600'
- series: 'kube_node_info{node="k3s-prod-3"}'
values: '1x600'
promql_expr_test:
# Firing while the reboot is still outstanding.
- expr: 'ALERTS{alertname="KuredRebootPending", alertstate="firing"}'
eval_time: 39h
exp_samples:
- labels: 'ALERTS{alertname="KuredRebootPending", alertstate="firing", node="k3s-prod-1", severity="warning"}'
value: 1
# Cleared once the sentinel is gone. If this assertion ever fails, the rule has become
# self-sustaining and the operator will start ignoring it.
- expr: 'ALERTS{alertname=~"Kured.*"}'
eval_time: 45h
exp_samples: []
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---
# Alert rules for the kured reboot automation.
#
# WHY THESE THREE, AND WHY THEY ARE NOT OPTIONAL. Reboot automation's characteristic failure is
# SILENCE, not noise. Every way this component can break leaves a cluster that looks perfectly
# healthy: a sentinel nothing writes, a Service the chart did not create, a NetworkPolicy that drops
# the scrape, a taint that excludes a node, a drain wedged on a PodDisruptionBudget, a cluster lock
# held forever by a node that hung on warm reboot. In none of those cases does anything turn red on
# its own. kured itself stays 1/1 Running throughout.
#
# kured EXPOSES EXACTLY ONE METRIC. Read from cmd/kured/main.go:92-96 and :113 on 2026-10-17 — the
# only `prometheus.MustRegister` in the tree is a GaugeVec `Subsystem: "kured"`, `Name:
# "reboot_required"`, labelled `{node}`. So the full vocabulary available is
# `kured_reboot_required{node="..."}`, 1 when the sentinel exists and 0 when it does not. Each rule
# below is built from that one series plus `kube_node_info` (kube-state-metrics), and nothing else.
# There is deliberately no rule over an invented metric name: this repo has shipped a
# structurally-inert alert before (VeleroNoRecentBackup over an absent series, which is why
# platform/monitoring/tests/run.sh exists), and an alert that cannot fire is worse than no alert
# because it also removes the suspicion that would have caught it.
#
# THESE RULES LIVE HERE, NOT IN platform/monitoring/alerts.yaml, for two reasons. (1) The unit-test
# harness treats a `<manifest>.promtool-test.yaml` COMPANION as covering just its sibling, whereas a
# `tests/*.test.yaml` SUITE covers every PrometheusRule in its directory — so shipping them beside
# the component keeps the test obligation local and legible (the platform/cnpg precedent). (2)
# platform/monitoring/alerts.yaml is concurrently edited by other open branches; adding 3 rules to
# its tail would create a merge conflict for no benefit.
apiVersion: monitoring.coreos.com/v1
kind: PrometheusRule
metadata:
name: kured
namespace: kured
labels:
app.kubernetes.io/name: kured
spec:
groups:
- name: platform-health.node-reboots
rules:
# ── 1. IS THE MECHANISM ALIVE AT ALL? ────────────────────────────────────────────────
- alert: KuredNotReporting
# `absent()` yields a series only when the ENTIRE vector is empty, so this fires when no
# node at all is publishing — kured gone, or its Service/ServiceMonitor/NetworkPolicy
# regressed so nothing is scraped. It stays quiet while a single node is mid-reboot
# (the other two still report), which is what makes it specific to a wiring failure
# rather than to a reboot in progress.
#
# THIS IS THE RULE THAT GUARDS THE OTHER TWO. Both of them read `kured_reboot_required`,
# so if that series stops existing they go quiet and look like good news. This one turns
# the absence itself into the signal. The specific regression it is aimed at: the kured
# chart defaults `service.create` and `metrics.create` to FALSE, and Longhorn has already
# demonstrated on this cluster (see the companion note in
# conformance/tests/l0-static/alert-metrics-have-scrape-targets/check.sh) that a
# NetworkPolicy can let targets be DISCOVERED while every scrape times out and the TSDB
# stays empty.
expr: absent(kured_reboot_required)
# 30m absorbs a HelmRelease upgrade rolling the DaemonSet and a Prometheus restart,
# without tolerating a real wiring break for more than one quiet night's worth of time.
for: 30m
labels:
severity: warning
annotations:
summary: kured is publishing no reboot_required series on any node
description: >-
No node is reporting kured_reboot_required, so the reboot automation is either not
running or not being scraped. While this is true, OS reboots are not happening and
the two alerts that would say so (KuredRebootPending, KuredNodeCoverageGap) are
themselves inert. Nodes will silently accumulate pending kernel upgrades.
runbook_url: "https://${BASE_DOMAIN}/runbooks/node-reboot-automation"
# ── 2. IS IT ALIVE ON *EVERY* NODE? ──────────────────────────────────────────────────
- alert: KuredNodeCoverageGap
# A per-node agent that silently covers only some nodes is the subtler half of the
# liveness question, and `absent()` cannot see it. kured publishes one series per node it
# runs on; kube-state-metrics publishes one `kube_node_info` per node that exists
# (measured 2026-10-17: 3, matching the 3 nodes). A shortfall means at least one node has
# no reboot automation — most likely a new or re-provisioned node carrying a taint this
# DaemonSet does not tolerate (it declares none, because no prod node is tainted today).
# That node would then never reboot, with nothing else to indicate it.
expr: count(kured_reboot_required) < count(kube_node_info)
# 2h, chosen to sit comfortably ABOVE the duration of a healthy reboot. A node being
# rebooted stops publishing for a few minutes and legitimately creates a shortfall; a
# node that is still missing after two hours is either genuinely uncovered or has hung on
# reboot, and both of those want a human.
for: 2h
labels:
severity: warning
annotations:
summary: kured is not running on every node
description: >-
Fewer nodes are reporting kured_reboot_required than exist in the cluster, so at
least one node has no reboot automation and will never be rebooted by it. Most
likely a node carries a taint this DaemonSet does not tolerate, or has hung during
a reboot.
runbook_url: "https://${BASE_DOMAIN}/runbooks/node-reboot-automation"
# ── 3. IS A REBOOT STUCK? ────────────────────────────────────────────────────────────
- alert: KuredRebootPending
# A node has wanted a reboot for longer than a full maintenance window plus margin, so
# the reboot was OFFERED and did not happen. The causes are all real and all invisible
# otherwise: the Prometheus alert gate is blocking on a degraded Longhorn volume that is
# not recovering; the drain hit `drainTimeout` against a 0-disruption PDB; another node
# holds the cluster lock and never released it (`lockTtl: 0` means a lock held by a hung
# node is held FOREVER — that is deliberate, see helmrelease.yaml, and this is the alert
# that makes the resulting stall visible).
expr: max by (node) (kured_reboot_required) == 1
# 36h, and the window being DAILY is what makes this number meaningful — see the window
# block in helmrelease.yaml. With a 03:00-06:00 window every day, a pending reboot waits
# at most ~24h legitimately, so 36h means at least one full window elapsed without the
# reboot completing. On a weekly window this threshold would have to exceed 7 days, which
# is longer than this cluster's 7d Prometheus retention and is reset by any Prometheus
# restart past the 1h for-outage-tolerance — i.e. unreliable in the one direction that
# matters. Note this alert can still be LATE for that reason, but it cannot be spurious.
for: 36h
labels:
severity: warning
annotations:
summary: Node {{ $labels.node }} has needed a reboot for over 36h
description: >-
kured reports a pending reboot on {{ $labels.node }} that has survived at least one
full 03:00-06:00 maintenance window. The reboot is being blocked, not merely
waiting: likely a degraded Longhorn volume holding the Prometheus alert gate, a
drain timing out against a PodDisruptionBudget, or a stale cluster lock held by a
node that did not come back. The kernel or security update that needed the reboot is
installed but NOT running.
runbook_url: "https://${BASE_DOMAIN}/runbooks/node-reboot-automation"
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---
# kured (Kubernetes Reboot Daemon) — coordinated, one-node-at-a-time reboots of the three prod
# control-plane nodes.
#
# ═══════════════════════════════════════════════════════════════════════════════════════════════
# READ THIS FIRST: kured DOES NOT DECIDE *WHETHER* TO REBOOT. IT ONLY DECIDES *WHEN* AND *HOW*.
# ═══════════════════════════════════════════════════════════════════════════════════════════════
# kured reboots a node if and only if the file `/var/run/reboot-required` exists on it. On these
# nodes exactly one thing creates that file: a deliberate operator run of
# `playbooks/node-baseline.yml --tags kernel` (which advances the backports kernel). The
# unattended-upgrades role this PR also adds installs SECURITY updates only and BLACKLISTS
# `linux-image-*`/`linux-headers-*`, so it can never produce a reboot-required sentinel on its own —
# see infra/ansible/roles/unattended_upgrades/defaults/main.yml for that argument in full.
#
# That is the whole answer to this repo's two standing objections to reboot automation:
#
# * infra/ansible/roles/node_baseline/tasks/main.yml:61-67 — "IT DOES NOT REBOOT." k3s-prod-2 hung
# on a warm reboot on 2026-09-03 (powered, off the LAN ~38 minutes, physical power button
# required), so rebooting was made "a SERIALIZED, SUPERVISED operator step ... and a role cannot
# enforce that." STILL TRUE, and nothing here changes it: node_baseline continues not to reboot.
# * docs/plans/cluster-upgrade-plan.md:291-299 — system-upgrade-controller was rejected because it
# "automates away the human gate between nodes", and the operator's hard requirement is an
# explicit PASS/STOP verification BETWEEN every node.
#
# THE HUMAN GATE IS PRESERVED, AND IT IS THE SENTINEL. The operator decides whether a kernel moves
# and on which hosts (`--limit k3s-prod-1`), which is what writes the sentinel on those hosts and
# only those hosts. kured then performs the cordon/drain/reboot/uncordon that the operator would
# otherwise have typed by hand — the error-prone mechanical half, including the ordering rule
# node_baseline's own message has to shout ("NEVER node 2 first"). Run the kernel play one host at a
# time and the operator keeps per-node PASS/STOP control exactly as before; run it on all three and
# kured still does them strictly one at a time, just in an order it chooses. Both are safe for
# quorum; only the first preserves the ordering preference. See runbooks/node-reboot-automation.md.
#
# cluster-upgrade-plan.md:329-330 and :545-548 name the condition under which its own rejection
# reverses — "SUC becomes viable once the cluster is on fast disks ... where drain-driven rebuild is
# cheap" — and prod is that cluster. This component takes that clause up, but NOT its drain
# assumption: see the Longhorn section below, where drain-driven rebuild is measurably NOT free even
# on SSD, and is gated on explicitly rather than waved through.
#
# WHAT IS STILL UNMITIGATED, STATED PLAINLY: kured cannot press a power button. If a node hangs on
# warm reboot the way k3s-prod-2 did in September, kured will not recover it. The blast radius is
# bounded by design rather than by luck — `concurrency: 1` plus `lockTtl: 0` means the hung node
# keeps the cluster lock forever, so NO second node is ever rebooted behind it; etcd keeps 2/3 quorum
# and the cluster stays up, degraded, until a human attends. The KuredRebootPending alert in
# alerts.yaml is what tells them. That is strictly better than the previous automation story (none)
# but it is NOT the same as "safe to ignore at 3am on a Sunday".
apiVersion: helm.toolkit.fluxcd.io/v2
kind: HelmRelease
metadata:
name: kured
namespace: kured
spec:
interval: 30m
chart:
spec:
chart: kured
# Chart 6.1.0 -> appVersion 1.23.0 (published 2026-06-30; newest of the 80 entries in
# https://kubereboot.github.io/charts/index.yaml, read 2026-10-17).
#
# THE `<6.2.0` CEILING IS A DELIBERATE CHOICE HERE, NOT THE REFLEX IT IS ELSEWHERE. This PR's
# own audit found that 9 of 12 HelmReleases in this repo pin a minor-locking range, and that
# this is a MAIN CAUSE of pin rot: Renovate can then only ever offer patches inside a line it
# has been told not to leave (kube-prometheus-stack is stuck 4 chart majors back that way).
# For a component whose job is to reboot control-plane nodes, that ceiling is worth paying on
# purpose: a kured MINOR may change drain or lock semantics, and this is the one component
# where "a human looked at the changelog" should be a precondition, not a nice-to-have.
# Renovate will raise the minor as a non-automerged PR (see the kured packageRule in
# renovate.json), so the ceiling is a review prompt, not a wall.
version: ">=6.1.0 <6.2.0"
sourceRef:
kind: HelmRepository
name: kured
namespace: kured
install:
remediation:
retries: 3
upgrade:
remediation:
retries: 3
values:
# ── IDENTITY / PLACEMENT ───────────────────────────────────────────────────────────────────
# No tolerations. Measured 2026-10-17: all three prod nodes carry `spec.taints` EMPTY (k3s does
# not taint its servers), so a DaemonSet reaches every node untainted. If a future node IS
# tainted, kured silently stops covering it and that node then never reboots — invisible,
# because the other two keep reporting. KuredNodeCoverageGap in alerts.yaml is the detector: it
# compares kured's per-node series count against the node count rather than merely asking
# whether kured exists.
priorityClassName: system-node-critical
# The chart's defaults are kept: `hostPID: true` and `containerSecurityContext.privileged: true`
# with `readOnlyRootFilesystem: true`. Both are load-bearing and neither is reducible:
# `rebootMethod: command` runs the reboot by nsenter'ing /proc/1/ns/mnt, which needs the host PID
# namespace to see PID 1 and the privilege to enter its mount namespace. The documented
# lower-privilege alternative (privileged:false + CAP_KILL) applies ONLY to
# `rebootMethod: signal`, which signals a host-side kured-reboot.service that does not exist on
# these nodes. Choosing `signal` would mean shipping and maintaining that unit via Ansible for a
# capability reduction on a DaemonSet that is already cluster-admin-adjacent by function; it is a
# reasonable future hardening step and is explicitly NOT taken here.
resources:
requests:
cpu: 10m
memory: 32Mi
limits:
# No CPU limit on purpose (the repo's node-pressure work treats CPU limits on tiny system
# agents as a throttling hazard). Memory is capped: kured holds no state beyond one
# annotation and a gauge, and 128Mi is ~4x its idle RSS upstream reports.
memory: 128Mi
configuration:
# ── THE QUORUM CONSTRAINT: TWO NODES MUST NEVER BE DOWN AT ONCE ──────────────────────────
# All three prod nodes are control-plane + etcd (measured 2026-10-17: every node reports
# `control-plane,etcd`). etcd quorum is 2 of 3, so one node down is degraded-but-up and two
# nodes down is a LOST CLUSTER that does not self-heal. Everything in this block exists to
# make the second case structurally unreachable rather than merely unlikely.
#
# concurrency: 1 — kured's cluster-wide lock is a single annotation
# (`weave.works/kured-node-lock`) on kured's OWN DaemonSet object, and a node reboots only
# while it holds that lock. One lock + concurrency 1 = one reboot, enforced by the API server's
# optimistic concurrency rather than by timing. This is the chart default; it is written out
# explicitly because it is the single most important value in this file.
concurrency: 1
# lockTtl: 0 (DISABLED) — THIS IS A SAFETY DECISION, NOT A DEFAULT WE FORGOT TO TUNE.
# A TTL makes the lock EXPIRE, which exists for the case "the lock holder died and we want
# reboots to continue". On a 3-node etcd cluster that is precisely the catastrophe: if node A
# has hung on a warm reboot (which has happened here — see the header) and its lock expires,
# node B becomes eligible and takes the cluster from 2/3 to 1/3. We would rather the reboot
# cycle STOP FOREVER and page a human than have it step over a corpse. The cost is that a
# genuinely stale lock needs manual clearing; runbooks/node-reboot-automation.md has the
# procedure, and KuredRebootPending is the alert that surfaces it.
lockTtl: 0
# lockReleaseDelay: 30m — hold the lock for 30 minutes AFTER this node is back and uncordoned,
# before any other node may take it. See the Longhorn section: this is the STRUCTURAL half of
# the inter-node gate, deliberately not dependent on an alert's `for:` timer having latched.
lockReleaseDelay: 30m
# ── THE MAINTENANCE WINDOW: 03:00-06:00 EVERY DAY, America/New_York ──────────────────────
# The timezone and the 03:00-06:00 band match renovate.json's existing
# `"schedule": ["after 3am and before 6am"]` / `"timezone": "America/New_York"`, so every
# unattended change in this repo lands in the same quiet 3-hour window.
#
# DAILY, NOT WEEKLY, AND THE REASON IS THE ALERT — not impatience. A weekly (`- sun`) window
# was the first draft and it breaks the only alert that can tell you this mechanism has
# stalled. With a Sunday-only window, a kernel upgraded on a Monday legitimately waits six
# days, so "a reboot has been pending too long" cannot be distinguished from "it is Tuesday"
# until the threshold exceeds a full 7-day cycle. That forces `for: 8d`+, which is longer than
# this cluster's Prometheus retention (MONITORING_PROMETHEUS_RETENTION is 7d) and is reset by
# any Prometheus restart beyond the 1h default for-outage-tolerance — i.e. the alert would be
# unreliable in exactly the direction that matters. A daily window caps the legitimate wait at
# under 24h, which makes KuredRebootPending's `for: 36h` both robust and meaningful: 36 hours
# with a sentinel still set means at least one full window passed and SOMETHING BLOCKED IT.
#
# Daily does NOT weaken the quorum guarantee — that is `concurrency: 1` plus the lock, not the
# calendar. It does mean a 3-node kernel rollout can finish in one to three nights instead of
# three weeks, with each node still gated on the previous one's Longhorn rebuilds (below).
rebootDays:
- su
- mo
- tu
- we
- th
- fr
- sa
startTime: "03:00"
endTime: "06:00"
timeZone: America/New_York
# How often to re-evaluate (sentinel + window + alerts + lock). 1h is the chart default; at a
# 3h window that is three evaluation opportunities per node per night.
period: 1h
# ── THE SENTINEL ─────────────────────────────────────────────────────────────────────────
# Written ONLY by a deliberate operator kernel upgrade (see the header). `update-notifier-common`
# — the package that owns /etc/kernel/postinst.d and actually creates this file on Debian — was
# measured ABSENT on all three nodes on 2026-10-17, which is why the unattended_upgrades role
# installs it. Without that package nothing ever writes this path, kured correctly never
# reboots, every probe looks healthy, and the entire mechanism is a silent no-op. That failure
# mode is the reason KuredNotReporting exists.
#
# THE PATH kured LOGS IS NOT THIS PATH, and that trips people debugging it. The chart
# defaults `useRebootSentinelHostPath: true` (kept), which bind-mounts the DIRNAME of this
# value onto /sentinel read-only and renders the flag as
# `--reboot-sentinel=/sentinel/reboot-required` (daemonset.yaml:134). So the container watches
# /sentinel/reboot-required and the host file is /var/run/reboot-required. Same file, two
# names. Set this value as the HOST path, as below.
rebootSentinel: /var/run/reboot-required
# ── THE LONGHORN GATE: WHY POD READINESS IS NOT A SUFFICIENT INTER-NODE SIGNAL ────────────
# Measured on prod 2026-10-17, and this is the finding that shaped this file:
# * 25 Longhorn volumes, ALL `numberOfReplicas: 3`, all healthy, with exactly 25 replicas on
# each of the 3 nodes. So there is no single-replica volume to lose today.
# * BUT `replica-soft-anti-affinity: false` (replicas may not share a node) and
# `disable-scheduling-on-cordoned-node: true`. With 3 nodes and 3 replicas, cordoning ONE
# node leaves nowhere to place a replacement — so every drain takes ALL 25 volumes to
# degraded 2/3 for the whole reboot.
# * Recovery is slow and serialized: `replica-replenishment-wait-interval: 600` (10 minutes
# before a rebuild even starts) and `concurrent-replica-rebuild-per-node-limit: 1`.
# Therefore: if the next node is rebooted before rebuilds finish, those volumes go to 1/3, and
# the drain after that genuinely CAN hit Longhorn's `node-drain-policy:
# block-if-contains-last-replica` and block forever. The inter-node gate must be VOLUME
# ROBUSTNESS, not "are the pods Ready again".
#
# It is gated twice, on purpose, because each half covers the other's blind spot:
# 1. lockReleaseDelay: 30m (above) — unconditional. Covers the 600s replenishment wait with
# margin and does not depend on any alert having fired.
# 2. The Prometheus alert gate below — semantic. Covers a rebuild that takes LONGER than 30
# minutes (25 serialized rebuilds on one node can), which a fixed delay cannot.
prometheusUrl: http://kube-prometheus-stack-prometheus.monitoring.svc.cluster.local:9090
# Only consider alerts that are FIRING, not merely pending. A `pending` alert is a 10-minute
# guess; blocking a weekly reboot on one would make the gate fire on noise.
alertFiringOnly: true
# ── alertFilterMatchOnly: true IS LOAD-BEARING. DO NOT DROP IT. ──────────────────────────
# kured's two alert modes are near-opposites and the flag name does not advertise it:
# * false (the chart default): alertFilterRegexp is an IGNORE list — kured blocks on ANY
# firing alert except those matching.
# * true: alertFilterRegexp is an ALLOW list — kured blocks ONLY on alerts that match.
# We need `true`, because this cluster always has something firing. Measured via the Prometheus
# API on 2026-10-17, these five were firing with no reboot pending and no end in sight:
# CNPGPrimariesCoLocated, KubeDeploymentReplicasMismatch, KubeDeploymentRolloutStuck,
# KubePodNotReady, OAuth2ProxyGateUnobserved (the last three all trace to the pm-agent pod,
# ImagePullBackOff on a placeholder digest for 12 days). Under the default `false`, kured would
# have been blocked by those on day one and would never have rebooted anything — a silent
# no-op indistinguishable, from outside, from "no reboots were needed".
alertFilterMatchOnly: true
# The ALLOW list: the conditions under which rebooting ANOTHER node risks data or quorum.
# Anchored and explicit — a prefix match here would silently re-admit the chronic five above.
# LonghornVolumeDegraded — the inter-node gate (see above). `longhorn_volume_robustness
# {state="degraded"} == 1`, for: 10m, in platform/monitoring/alerts.yaml.
# LonghornVolumeFaulted — data already at risk; never reboot into this.
# KubeNodeNotReady — a node is already down. Rebooting a second one loses quorum. This
# is the single most important entry for the etcd constraint.
# NodeExporterDown — a node we cannot see the health of. Treated as "assume the worst".
# DELIBERATELY NOT INCLUDED: NodeEtcdRequestsSlow and the NodeIOPressure* family. They are
# exactly the conditions you would want to pause for, but prod-1 has a documented history of
# etcd WAL I/O starvation, so including them risks a permanent wedge that looks like safety.
# Revisit once those are quiet for a sustained period; KuredRebootPending makes a wedge visible
# either way.
alertFilterRegexp: ^(LonghornVolumeDegraded|LonghornVolumeFaulted|KubeNodeNotReady|NodeExporterDown)$
# ── THE DRAIN ────────────────────────────────────────────────────────────────────────────
# NOTE ON FLAGS THAT DO NOT EXIST: there is no `--ignore-daemonsets`, no
# `--delete-emptydir-data` and no `--force` in kured 1.23.0. Read from
# cmd/kured/main.go:438-449 on 2026-10-17, kured HARDCODES
# `IgnoreAllDaemonSets: true`, `DeleteEmptyDirData: true` and `Force: true` in the drain
# helper. Passing them as extraArgs would CrashLoop the DaemonSet on an unknown flag. This
# matters because all three are genuinely REQUIRED here and it is easy to assume they must be
# configured: 12 DaemonSets and 135 emptyDir-carrying pods were measured on 2026-10-17, and a
# drain without those three settings refuses to start.
#
# drainTimeout: 15m — the chart/kured default is 0, meaning INFINITE, and infinite is the wrong
# answer here. Measured 2026-10-17, six PodDisruptionBudgets currently allow ZERO voluntary
# disruptions, and a plain drain loops on them indefinitely:
# * 3x longhorn-system/instance-manager-* — one per node, `minAvailable: 1` against a
# selector pinned to a single node's single pod, so disruptionsAllowed is STRUCTURALLY 0
# forever. This is the mechanism by which Longhorn's node-drain-policy blocks: the
# longhorn-manager deletes the node's instance-manager PDB only once it judges the drain
# safe. The drain is SUPPOSED to wait on this one.
# * 3x CNPG `<cluster>-primary` (keycloak-db, nextcloud-db, semaphore-db) — `minAvailable: 1`
# against a selector matching exactly one pod (the primary), so again structurally 0 until
# the CNPG operator switches the primary away. All three primaries were on k3s-prod-1.
# With a timeout, a drain that is genuinely stuck ABORTS, the lock is released, and kured
# retries next period instead of holding the cluster lock forever on a wedged node. 15m is
# chosen to be longer than a CNPG switchover and longer than the `unifi` VM's eviction (below)
# usually needs, while still being well inside the 3h window.
drainTimeout: 15m
# Taint a node PreferNoSchedule while its reboot is pending, so the scheduler stops placing new
# pods on a node that is about to go away. With concurrency 1 this is a small win (there is no
# second rebooting node to shed pods onto) but it is free and it shortens the drain.
preferNoScheduleTaint: weave.works/kured-node-reboot
# Record reboot state on the Node objects (`weave.works/kured-reboot-in-progress`,
# `weave.works/kured-most-recent-reboot-needed`). Off by default. Turned on because the only
# other observability kured offers is ONE gauge, and during an incident `kubectl get node -o
# yaml` is the thing an operator can reach without Prometheus.
annotateNodes: true
logFormat: json
# ── METRICS: BOTH OF THESE MUST BE true OR THE ALERTS IN alerts.yaml CANNOT FIRE ───────────
# The chart ships `service.create: false` AND `metrics.create: false`. Leaving either at its
# default means no Service, or a ServiceMonitor with nothing to select, so `kured_reboot_required`
# is never scraped — and a PrometheusRule over a series that no target produces is INERT: quiet
# forever, indistinguishable from healthy. This repo has shipped that exact bug twice
# (VeleroNoRecentBackup over an absent series; the inert gotk_* rules in
# runbooks/image-automation.md), which is why platform/monitoring/tests/run.sh exists at all.
# KuredNotReporting (alerts.yaml) is the standing detector for this pair regressing.
# Prometheus selects ServiceMonitors cluster-wide: measured 2026-10-17, `serviceMonitorSelector`
# and `serviceMonitorNamespaceSelector` are both `{}`, so no label plumbing is needed here.
service:
create: true
port: 8080
metrics:
create: true
interval: 60s
-12
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@@ -1,12 +0,0 @@
---
# HelmRepository for the official kured chart (github.com/kubereboot/charts). Renovate maintains the
# pinned chart version in helmrelease.yaml via its `flux` manager, whose managerFilePatterns already
# cover `platform/**` (renovate.json). Same Flux source pattern as platform/headlamp.
apiVersion: source.toolkit.fluxcd.io/v1
kind: HelmRepository
metadata:
name: kured
namespace: kured
spec:
interval: 1h
url: https://kubereboot.github.io/charts
-36
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@@ -1,36 +0,0 @@
---
# platform/kured — the Kubernetes Reboot Daemon.
#
# Rendered by its OWN Flux Kustomization (clusters/base/kured.yaml, dependsOn platform), NOT by a
# line in platform/kustomization.yaml. The reasoning is the same one the Cilium split-out wrote down
# and intel-gpu-plugin reused: inside the shared `wait: true` platform tier, this component's health
# would be indistinguishable from eleven others, the only emergency valve would be suspending the
# whole tier, and that tier's 5m timeout is wrong for a 3-node DaemonSet rollout. It matters more
# than usual here, because `platform` gates platform-config which gates every apps wave — so a wedged
# reboot daemon placed there could stall every application in the cluster. A component whose entire
# purpose is to make maintenance safer must not be able to cause an outage.
#
# `namespace: kured` applies to every resource below, so none of them repeats it. Keep it: the
# CiliumNetworkPolicy in networkpolicy.yaml is a CR whose namespace kustomize would otherwise leave
# to chance.
#
# NO SECRET OF ANY KIND. kured authenticates to the API server with its own ServiceAccount token and
# talks to nothing off-cluster — no registry credential, no webhook URL, no notification token. So
# neither clusters/dev nor clusters/prod adds a SOPS decryption patch for this tier (same as
# homepage/runbooks/intel-gpu-plugin). If Slack or shoutrrr notifications are ever wanted, the chart
# takes them via `configuration.notifyUrl`, and THAT would need a SOPS-encrypted Secret plus a
# decryption patch — do not inline a webhook URL here.
apiVersion: kustomize.config.k8s.io/v1beta1
kind: Kustomization
namespace: kured
resources:
- namespace.yaml
- helmrepository.yaml
- helmrelease.yaml # chart installs the DaemonSet / RBAC / SA / Service / ServiceMonitor
# default-deny baseline + the Prometheus scrape ingress + the apiserver/Prometheus egress.
# The scrape ingress is NOT optional decoration: without it the ServiceMonitor's targets are
# discovered and every scrape times out, leaving the TSDB empty and all three rules in alerts.yaml
# permanently quiet. See the header in that file for the measured Longhorn precedent.
- networkpolicy.yaml
# Three rules over kured's single metric, with a companion promtool unit test beside them.
- alerts.yaml
-34
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@@ -1,34 +0,0 @@
---
# kured — namespace for the Kubernetes Reboot Daemon DaemonSet.
#
# PLATFORM INFRA, NOT AN APPLICATION NAMESPACE, and here that distinction is the difference between
# a working component and an admission rejection. kured runs `hostPID: true` with a `privileged: true`
# container (it `nsenter`s /proc/1/ns/mnt to run `/bin/systemctl reboot` on the host). Both are
# forbidden by platform/kyverno/policies/restrict-host-namespaces.yaml — but that policy, like every
# other policy in this repo, is scoped by
# `namespaceSelector: matchLabels: homelab.keithjackson.dev/app-namespace: "true"`
# and its own header states the carve-out: "platform components that do [need these] live in platform
# namespaces that do NOT carry the app-namespace label, so they are out of scope."
# Verified by reading the policies on this branch, not assumed:
# * restrict-host-namespaces.yaml rule `disallow-host-namespaces` (hostPID)
# * restrict-host-namespaces.yaml rule `disallow-privileged-containers` (privileged)
#
# We set the label EXPLICITLY to "false" rather than leaving it unset, following
# platform/intel-gpu-plugin/namespace.yaml and platform/vpn-egress: an unset label and a deliberate
# "false" are identical to the admission engine but not to a reviewer, and this component's
# correctness depends entirely on the answer.
#
# NO PodSecurity labels. There is no cluster-wide PSA baseline in this repo — `pod-security.*`
# appears only where a namespace opts IN (conformance/incluster, platform/kyverno/admission,
# platform/pm-agent), all at `enforce: restricted`. Adding them here would reject this DaemonSet for
# the same reasons Kyverno would. Leaving them off is the convention for a privileged platform
# namespace (platform/vpn-ingress/namespace.yaml sets none either).
#
# NO `gateway-access` label. kured serves no HTTP to users and attaches no HTTPRoute; its only
# listener is the :8080 metrics endpoint, reached in-cluster by Prometheus. See networkpolicy.yaml.
apiVersion: v1
kind: Namespace
metadata:
name: kured
labels:
homelab.keithjackson.dev/app-namespace: "false"
-125
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@@ -1,125 +0,0 @@
---
# Default-deny baseline (R-NET-01): deny all ingress + egress, allow only DNS. `kured` is a PLATFORM
# namespace, so Kyverno's generator — scoped to `app-namespace=true` — does not produce this; we ship
# it explicitly, as crafty/headlamp/homepage/runbooks all do.
#
# THESE POLICIES DO APPLY TO kured, UNLIKE platform/vpn-ingress'. That component's identical-looking
# baseline is honest-but-inert because its DaemonSet runs `hostNetwork: true` and therefore has no
# Cilium endpoint for any policy to select. kured's chart defaults to `hostNetwork: false` and we
# keep that default (it needs the host PID namespace to reboot, not the host network stack), so it
# has a normal pod identity and every rule here is enforced.
#
# Cilium enforces the UNION of these policies (allow if ANY policy allows), so the CiliumNetworkPolicy
# below adds the kube-apiserver path on top of this deny-all floor.
apiVersion: networking.k8s.io/v1
kind: NetworkPolicy
metadata:
name: default-deny
namespace: kured
labels:
homelab.keithjackson.dev/baseline: default-deny
spec:
podSelector: {}
policyTypes:
- Ingress
- Egress
ingress: []
egress:
- to:
- namespaceSelector:
matchLabels:
kubernetes.io/metadata.name: kube-system
ports:
- protocol: UDP
port: 53
- protocol: TCP
port: 53
---
# ═══════════════════════════════════════════════════════════════════════════════════════════════
# PROMETHEUS MUST REACH :8080, OR EVERY RULE IN alerts.yaml IS INERT.
# ═══════════════════════════════════════════════════════════════════════════════════════════════
# This is not a theoretical hazard in this repo, it is a measured one. From the Longhorn entry in
# conformance/tests/l0-static/alert-metrics-have-scrape-targets/check.sh: with the ServiceMonitor
# applied and no NetworkPolicy allowance, all three targets were DISCOVERED and every scrape failed
# with "context deadline exceeded" after 10.0s — "a drop, not a refusal" — and the TSDB stayed
# empty. Target discovery succeeding is therefore NOT evidence the scrape works, and the alerts
# would have been quiet rather than broken. KuredNotReporting is the standing detector for exactly
# this regression, and it can only work if this policy is correct.
#
# THE WHOLE `monitoring` NAMESPACE, NOT THE PROMETHEUS POD LABELS — following the same choice
# longhorn/networkpolicy-metrics.yaml made and for the same reason: the prometheus-operator owns
# those pod labels and rewrites them on upgrade (measured 2026-10-17, the pod carries
# `app.kubernetes.io/name: prometheus` plus five operator-managed labels including a
# controller-revision-hash), so selecting on them makes the scrape silently fail on a chart bump.
# The namespace holds only the monitoring stack.
apiVersion: networking.k8s.io/v1
kind: NetworkPolicy
metadata:
name: kured-allow-prometheus-scrape
namespace: kured
labels:
app.kubernetes.io/name: kured
spec:
podSelector:
matchLabels:
# Set by the chart's `kured.matchLabels` helper (_helpers.tpl:70-71) with release name `kured`.
app.kubernetes.io/name: kured
policyTypes:
- Ingress
ingress:
- from:
- namespaceSelector:
matchLabels:
kubernetes.io/metadata.name: monitoring
ports:
- protocol: TCP
# The container port the chart names `metrics` (daemonset.yaml:211-213), from
# `configuration.metricsPort`, which we leave at the chart default of 8080 and mirror in
# the HelmRelease's `service.port`.
port: 8080
---
# Egress allows. kured talks to exactly two things and nothing else; both are required and the
# component is useless without either.
#
# 1. THE KUBE-APISERVER — the lock annotation on its own DaemonSet (`weave.works/kured-node-lock`),
# cordon/uncordon (`nodes` patch), the node annotations, listing pods, and creating
# `pods/eviction` objects during the drain. Reached via the `kube-apiserver` Cilium entity
# rather than an IP: on this cluster the API is fronted by a kube-vip VIP that moves between
# nodes on every reboot, so any CIDR-based rule here would break during the exact operation
# this component exists to perform. Same construct as platform/headlamp/networkpolicy.yaml.
#
# 2. PROMETHEUS, on 9090 — the alert gate. The HelmRelease sets
# `prometheusUrl: http://kube-prometheus-stack-prometheus.monitoring.svc.cluster.local:9090`
# and `alertFilterMatchOnly: true`, so before taking the cluster lock kured asks Prometheus
# whether any of LonghornVolumeDegraded / LonghornVolumeFaulted / KubeNodeNotReady /
# NodeExporterDown is firing. IF THIS EGRESS IS BLOCKED, kured cannot evaluate the gate.
# It treats the query error as "do not proceed" and skips the reboot — which is the correct
# fail-safe direction, but it fails SILENTLY and indefinitely: reboots simply stop happening
# and nothing goes red except, eventually, KuredRebootPending. Do not remove this rule
# thinking it is only for metrics; metrics ingress is the policy above, this is the gate.
#
# NOTHING ELSE. No egress to the internet (kured pulls no content at runtime), no DNS beyond the
# baseline above, no Longhorn or etcd access — kured reads Longhorn's health THROUGH Prometheus
# alerts, never from Longhorn's own API, which is why that allow is absent here.
apiVersion: cilium.io/v2
kind: CiliumNetworkPolicy
metadata:
name: kured-allow-egress
namespace: kured
labels:
app.kubernetes.io/name: kured
spec:
endpointSelector:
matchLabels:
app.kubernetes.io/name: kured
egress:
- toEntities:
- kube-apiserver
- toEndpoints:
- matchLabels:
io.kubernetes.pod.namespace: monitoring
app.kubernetes.io/name: prometheus
toPorts:
- ports:
- port: "9090"
protocol: TCP
-69
View File
@@ -63,75 +63,6 @@ spec:
# gets oauth2-proxy's HTML sign-in page (HTTP 403) instead of an immediate redirect (docs/15 UX).
skip-provider-button: "true"
scope: "openid email profile"
# ── Cold-start gate: do not start the proxy until Keycloak's discovery doc answers ──────────
# MEASURED on prod 2026-10-17, during the UPS move: oauth2-proxy performs OIDC discovery ONCE at
# startup and EXITS 1 if it fails. On a whole-cluster cold boot Keycloak is not serving yet, so
# the Gateway answers 503 and the proxy dies:
#
# [provider.go:55] Performing OIDC Discovery...
# [main.go:73] ERROR: Failed to initialise OAuth2 Proxy: ... failed to discover OIDC
# configuration: unexpected status "503": no healthy upstream
#
# It then sits in exponential CrashLoopBackOff long after Keycloak is healthy -- one replica was
# still down minutes later and only a manual pod delete cleared it. There is no retry flag; the
# process simply does not survive a cold start. A readinessProbe cannot help (the container is
# already dead), and CrashLoopBackOff backoff is not tunable per-pod.
#
# `extraInitContainers` is the chart's OWN documented hook for this -- its commented example in
# values.yaml is literally `- name: wait-for-idp` -- and the chart already uses an alpine init
# container for its built-in waitForRedis gate, so this adds no new base image to the platform.
# A pod in Init does not accrue CrashLoopBackOff backoff and retries promptly, which is the whole
# point.
#
# BOUNDED, AND FAILS OPEN. After ~5 minutes it gives up and starts the proxy anyway: the worst
# case is then exactly today's behaviour, never something new. An unbounded wait would trade a
# CrashLoop for a pod wedged in Init forever, which is not an improvement.
#
# SHELL VARIABLES ARE WRITTEN BARE ($i, $url, $(( ))), WITH NO BRACED FORM ANYWHERE. This file is
# rendered through Flux envsubst (platform declares postBuild.substituteFrom cluster-vars), which
# CONSUMES braced expansions -- so a braced shell variable renders to the empty string and
# silently breaks the loop. BASE_DOMAIN below is braced ON PURPOSE: it is a real cluster-vars
# knob and must be substituted. Same hazard, and the same convention, as the gitea and nextcloud
# OIDC bootstrap hooks. (ci: flux-postbuild-substitution enforces it.)
extraInitContainers:
- name: wait-for-idp
image: docker.io/library/alpine:3.22
imagePullPolicy: IfNotPresent
command: ["/bin/sh", "-c"]
args:
- |
set -u
url=https://keycloak.${BASE_DOMAIN}/realms/homelab/.well-known/openid-configuration
i=0
while [ "$i" -lt 60 ]; do
# busybox wget validates against alpine's ca-certificates-bundle, so a real TLS
# failure is a non-zero exit here rather than a false pass.
if wget -q -O /dev/null --timeout=5 "$url" 2>/dev/null; then
echo "[wait-for-idp] Keycloak discovery reachable; starting oauth2-proxy"
exit 0
fi
i=$(( i + 1 ))
sleep 5
done
echo "[wait-for-idp] discovery still unreachable after ~5m; starting anyway so this" >&2
echo "[wait-for-idp] gate can never be worse than the un-gated behaviour it replaces" >&2
exit 0
securityContext:
allowPrivilegeEscalation: false
runAsNonRoot: true
runAsUser: 65534
runAsGroup: 65534
readOnlyRootFilesystem: true
capabilities:
drop:
- ALL
resources:
requests:
cpu: 10m
memory: 16Mi
limits:
memory: 32Mi
# Metrics for the ServiceMonitor (../oauth2-proxy servicemonitor in platform-config).
metrics:
enabled: true
+5 -31
View File
@@ -1,6 +1,6 @@
{
"$schema": "https://docs.renovatebot.com/renovate-schema.json",
"_comment": "Renovate config — Phase 4 automated updates (ADR-0009, R-UPD-01/02). AS OF 2026-10-17 RENOVATE OWNS BOTH HALVES: Helm chart/dependency bumps AND per-service container image tags. It opens PRs for everything; allowed low-risk classes auto-merge on green CI. The ADR-0009 split that gave image tags to Flux image-automation is formally closed — see .gitea/workflows/renovate.yaml for the three measured reasons (it pushes commits rather than opening PRs, so it bypasses the CLAUDE.md §1 gate; `main` is protected with user_can_push:false and the flux-system GitRepository has no secretRef, so it cannot write anyway; and enabling it would need an in-cluster git WRITE credential for the repo that defines the cluster). image-automation has been commented out at platform/kustomization.yaml:52 since it was authored and the cluster holds zero ImagePolicy/ImageRepository/ImageUpdateAutomation objects, so nothing is being torn down. CONSEQUENCE: the `docker` and `kubernetes` managers, previously disabled ONLY to avoid fighting that controller, are now ENABLED — without them every plain `image: repo/name:tag` line in this repo was maintained by nothing at all, which is how the oauth2-proxy auth sidecars reached 7 minors behind the oauth2-proxy running in the same cluster. RUNNER: .gitea/workflows/renovate.yaml (scheduled daily); platform/endpoint are set there, not here.",
"_comment": "Renovate config — Phase 4 automated updates (ADR-0009, R-UPD-01/02). Renovate owns HELM CHART + DEPENDENCY bumps (opens PRs; allowed classes auto-merge on green CI). Flux image-automation owns per-service container IMAGE TAGS (the $imagepolicy setters). The two do NOT overlap: this config DISABLES image-tag updates so Renovate never fights Flux over a running version. Self-hosted against the bootstrap Gitea; platform: gitea set at runtime by the operator's renovate runner.",
"extends": [
"config:recommended",
":dependencyDashboard",
@@ -15,24 +15,13 @@
"labels": ["dependencies", "automated-update"],
"ignoreUnstable": true,
"respectLatest": true,
"enabledManagers": ["flux", "kustomize", "helmv3", "kubernetes", "regex", "github-actions"],
"enabledManagers": ["flux", "kustomize", "helmv3", "regex", "github-actions"],
"flux": {
"managerFilePatterns": ["/(^|/)platform/.+\\.ya?ml$/", "/(^|/)apps/.+\\.ya?ml$/"]
},
"kustomize": {
"managerFilePatterns": ["/(^|/)kustomization\\.ya?ml$/"]
},
"_kubernetes_comment": "ADDED 2026-10-17. The `kubernetes` manager reads plain `image:` fields out of Kubernetes manifests, and it is NOT auto-detected — it only looks at files matched here, which is why this block is as broad as it is. Scope covers every place this repo writes a container image: platform components, the rendered app waves, the ServiceDefinition catalog that generates them, the runbooks web server and the pm-agent job template. `catalog/` matters as much as `apps/`: apps/wave-*/*.yaml are GENERATED by catalog/render.py, so a bump applied only to the rendered output is reverted by the next render and would also fail ci/render-golden.sh. Renovate will raise BOTH, and both must land together.",
"kubernetes": {
"managerFilePatterns": [
"/(^|/)platform/.+\\.ya?ml$/",
"/(^|/)platform-config/.+\\.ya?ml$/",
"/(^|/)apps/.+\\.ya?ml$/",
"/(^|/)catalog/.+\\.ya?ml$/",
"/(^|/)runbooks/serving/.+\\.ya?ml$/",
"/(^|/)infra/agent/.+\\.ya?ml$/"
]
},
"customManagers": [
{
"customType": "regex",
@@ -71,29 +60,14 @@
"matchFileNames": ["ci/versions.env", "infra/devcontainer/versions.env"],
"automerge": false,
"addLabels": ["ci-tooling"]
},
{
"description": "ADDED 2026-10-17. NEVER AUTO-MERGE THE BLAST-RADIUS COMPONENTS, not even a patch. The default rule above auto-merges minor/patch/digest on a green gate, which is right for an app image: a bad Sonarr bump inconveniences one pod. It is wrong for these five, because the gate is a STATIC check — it renders manifests and lints them, it does not boot a node, drain a volume or form an etcd quorum (vars.CLUSTER_AVAILABLE is unset, so L2/L3 conformance does not run in CI at all). So for anything whose failure mode is the CLUSTER rather than a service, a green gate is not evidence and a human must read the changelog. kured is here because it reboots control-plane nodes; longhorn because a storage-engine bump migrates live volume data; cilium because it is the CNI and a bad bump is a total partition (and its version is DUAL-PINNED in infra/ansible/roles/cilium/defaults/main.yml, which Renovate does not see, so the two would silently desync); cloudnative-pg because it drives Postgres switchovers; kube-prometheus-stack because ci/versions.env asserts an exact promtool/Prometheus lockstep and a chart bump that moves Prometheus fails the gate until that file moves with it.",
"matchPackageNames": [
"kured",
"longhorn",
"cilium",
"cloudnative-pg",
"kube-prometheus-stack"
],
"automerge": false,
"addLabels": ["needs-review", "blast-radius"]
}
],
"_unmanageable_comment": "WHAT RENOVATE STILL CANNOT FIX, so nobody mistakes a working bot for full coverage. A FLOATING tag has no version to compare, so Renovate skips it silently — it does not pin it and does not warn. As of 2026-10-17 that is: plexinc/pms-docker:latest, lscr.io/linuxserver/jackett:latest, pihole/pihole (NO TAG AT ALL), quay.io/keycloak/keycloak (no tag), nextcloud:31-apache and docker:27-dind. Those must be pinned BY HAND to a concrete version before any automation can maintain them, and until then they drift on every pull with nothing recording what is running. Separately, the HelmRelease minor-locking ranges (9 of 12, e.g. `>=88.0.0 <89.0.0` on kube-prometheus-stack) cap Renovate at patches inside a line it has been told not to leave; raising those ceilings is deliberate per-component work and is NOT part of enabling the bot. Both lists are in decisions/2026-10-17-automated-upgrades.md.",
"ignorePaths": [
"**/*.example",
"**/*.sops.yaml",
"conformance/**",
"platform/image-automation/per-service/**",
"platform/kyverno/tests/**"
"platform/image-automation/per-service/**"
],
"_ignorePaths_comment": "platform/kyverno/tests/** ADDED 2026-10-17: those Kyverno policy fixtures pin `alpine:latest` and a `conformance-runner:latest`, which are test inputs whose whole point is to be a fixed shape, not software to keep current. `conformance/**` was already ignored for the same reason; this closes the matching hole that enabling the `kubernetes` manager would otherwise have opened.",
"_docker_comment": "The `docker` manager (Dockerfiles, docker-compose) and the `kubernetes` manager above were BOTH previously `enabled: false`, solely so Renovate would not fight Flux image-automation over a running tag. That controller was never enabled and never will be here (see _comment), so the only thing those two flags were achieving was leaving every plain `image:` tag in the repo unmanaged. `docker` is left out of enabledManagers because this repo contains no Dockerfile that ships to the cluster; `kubernetes` is now ON and is the one that matters.",
"docker": { "enabled": true }
"docker": { "enabled": false },
"kubernetes": { "enabled": false }
}
+162
View File
@@ -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`.
+7 -3
View File
@@ -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
@@ -85,9 +92,6 @@ configMapGenerator:
- node-io=node-io.md
- node-memory=node-memory.md
- node-memory-swap=node-memory-swap.md
# Covers all three platform-health.node-reboots rules (KuredRebootPending,
# KuredNodeCoverageGap, KuredNotReporting) from platform/kured/alerts.yaml.
- node-reboot-automation=node-reboot-automation.md
# Linked from OAuth2ProxyGateUnobserved, and the diagnostic procedure for any gated app
# that "is up but does not work" — the gate answers an unauthenticated XHR with a 302,
# not a 401, so the failure arrives as an HTTP 200 carrying the wrong body.
-254
View File
@@ -1,254 +0,0 @@
# Node reboot automation (kured)
**Alerts:** `KuredRebootPending`, `KuredNodeCoverageGap`, `KuredNotReporting`
**File:** `platform/kured/alerts.yaml`
**Expressions:** `max by (node) (kured_reboot_required) == 1` / `count(kured_reboot_required) < count(kube_node_info)` / `absent(kured_reboot_required)`
## What this means here
These three alerts cover the OS reboot half of the automated upgrade process. The design is two
pieces that only work together:
- **`roles/unattended_upgrades`** (Ansible, on the host) installs Debian **security** updates
nightly. It never upgrades the kernel, never restarts k3s, and never reboots. When something it
installed needs a reboot, it leaves `/var/run/reboot-required` behind.
- **kured** (`platform/kured`, a DaemonSet) watches that file. When it exists, kured takes a
**cluster-wide lock**, cordons the node, drains it, reboots it, and uncordons it — then holds the
lock for a further 30 minutes before any other node may go.
**kured does not decide whether to reboot.** On these nodes the sentinel is written almost
exclusively by a deliberate operator kernel upgrade
(`playbooks/node-baseline.yml --tags kernel`), because the kernel is blacklisted from unattended
upgrades. So a pending reboot normally means *a human already asked for this*.
Which alert you have tells you which half is wrong:
| alert | meaning |
|---|---|
| `KuredRebootPending` | The mechanism is alive and a reboot was offered, but it did not happen for >36h. **Something is blocking it.** |
| `KuredNodeCoverageGap` | kured is not running on every node. The uncovered node will never be rebooted, silently. |
| `KuredNotReporting` | kured is publishing nothing at all. Reboots are not happening, **and the other two alerts are inert.** Treat this as the most serious of the three. |
**All three nodes are control-plane + etcd, so quorum is 2 of 3.** One node down is degraded but
up; two is a lost cluster. Everything below is written to protect that. `concurrency: 1` plus
`lockTtl: 0` means a node that hangs on reboot keeps the lock **forever** and no second node is ever
rebooted behind it. That is deliberate: the cycle stops and pages a human rather than stepping over
a corpse.
**A reboot is not seamless.** Most workloads here are single-replica, so each reboot cycle takes a
brief outage of whatever runs on that node — including `coredns` (1 replica), which means a
cluster-wide DNS gap while it reschedules. See "Expected outage per cycle" below.
## Running the commands in this runbook
`kubectl` does not work on the operator workstation. The toolchain lives only in the pinned dev
container. Every command below runs as:
infra/devcontainer/dev.sh run bash -c 'kubectl --context k3s-prod get nodes'
Always pass `--context k3s-prod` explicitly. `dev.sh` merges both clusters into one kubeconfig and
picks a current-context per invocation, and that default has already changed once. Do not run two
`dev.sh` invocations at once; they share one container and interfere.
Mutating kubectl (`apply`, `patch`, `annotate`, `uncordon`, `rollout`) and `flux reconcile` are
operator actions, not agent actions. Where this runbook gives a mutating command it is for an
operator, and it says so.
## First commands
Start here, in order. The first question is always *which half is broken*.
# 1. Is kured running at all, and on how many nodes?
infra/devcontainer/dev.sh run bash -c 'kubectl --context k3s-prod -n kured get ds,pod -o wide'
# 2. Which node is asking for a reboot, and who holds the lock?
# The lock is an annotation on kured's OWN DaemonSet. An empty/absent value means no holder.
infra/devcontainer/dev.sh run bash -c 'kubectl --context k3s-prod -n kured get ds kured \
-o jsonpath="{.metadata.annotations}"; echo'
# 3. Is a node cordoned, and is a reboot in progress?
infra/devcontainer/dev.sh run bash -c 'kubectl --context k3s-prod get nodes \
-o custom-columns=NAME:.metadata.name,SCHEDULABLE:.spec.unschedulable,TAINTS:.spec.taints'
infra/devcontainer/dev.sh run bash -c 'kubectl --context k3s-prod get nodes \
-o jsonpath="{range .items[*]}{.metadata.name}{\" \"}{.metadata.annotations.weave\.works/kured-reboot-in-progress}{\"\n\"}{end}"'
# 4. What is kured itself saying? It logs its decision every period (1h).
infra/devcontainer/dev.sh run bash -c 'kubectl --context k3s-prod -n kured logs ds/kured --tail=80'
# 5. Is the gate blocking it? These are the ONLY alerts kured blocks on.
infra/devcontainer/dev.sh run bash -c 'kubectl --context k3s-prod -n longhorn-system \
get volumes.longhorn.io -o custom-columns=NAME:.metadata.name,STATE:.status.state,ROBUSTNESS:.status.robustness' \
| grep -v healthy
# 6. Does the node actually want a reboot? (read-only; SSH as k3s, no sudo needed)
ssh -o BatchMode=yes 192.168.2.10 'ls -la /var/run/reboot-required; cat /var/run/reboot-required.pkgs 2>/dev/null'
## Likely causes, most likely first
### 1. The Longhorn gate is holding it (the common `KuredRebootPending` cause)
kured queries Prometheus before taking the lock and refuses to proceed while
`LonghornVolumeDegraded`, `LonghornVolumeFaulted`, `KubeNodeNotReady` or `NodeExporterDown` is
firing. This is working as designed and it is the **most likely** cause.
Why it lingers: there are 3 nodes, every volume has 3 replicas, and
`replica-soft-anti-affinity: false` means replicas may not share a node. So cordoning one node
leaves nowhere to put a replacement and **every volume goes degraded 2/3** for the duration.
Recovery is slow on purpose: `replica-replenishment-wait-interval` is 600s before a rebuild even
starts, and `concurrent-replica-rebuild-per-node-limit` is 1, so ~25 volumes rebuild one at a time.
Check progress, then wait:
infra/devcontainer/dev.sh run bash -c 'kubectl --context k3s-prod -n longhorn-system \
get volumes.longhorn.io -o json' | python3 -c 'import json,sys,collections; \
v=json.load(sys.stdin)["items"]; print(collections.Counter(x["status"]["robustness"] for x in v))'
If volumes are rebuilding, **do nothing**. If a volume is stuck `degraded` or `faulted` with no
rebuild progressing, that is a storage problem to fix first — see `/runbooks/longhorn-degraded`.
Rebooting another node while a volume is at 1/3 is how you lose data.
### 2. The drain timed out against a PodDisruptionBudget
Six PDBs currently allow **zero** voluntary disruptions, and two kinds matter:
- **`longhorn-system/instance-manager-*`** (one per node). `minAvailable: 1` against a selector
pinned to a single node's single pod, so `disruptionsAllowed` is structurally **always 0**.
Longhorn's `longhorn-manager` *deletes* the PDB when its `node-drain-policy`
(`block-if-contains-last-replica`) judges the drain safe. The drain is **supposed** to wait here.
- **CNPG `<cluster>-primary`** (`keycloak-db`, `nextcloud-db`, `semaphore-db`). Also structurally 0
until the CNPG operator switches the primary to another instance. If all three primaries are on
the node being drained, three switchovers must happen.
kured's `drainTimeout` is 15m: a genuinely stuck drain **aborts**, releases the lock, and is retried
next period rather than wedging forever. Repeated timeouts show in kured's logs.
infra/devcontainer/dev.sh run bash -c 'kubectl --context k3s-prod get pdb -A -o wide' | awk '$NF==0 || NR==1'
infra/devcontainer/dev.sh run bash -c 'kubectl --context k3s-prod get clusters.postgresql.cnpg.io -A \
-o custom-columns=NS:.metadata.namespace,NAME:.metadata.name,PRIMARY:.status.currentPrimary'
If CNPG will not switch over, an **operator** can move the primary deliberately before the next
window rather than fighting the drain.
### 3. A node hung on reboot and still holds the lock
`k3s-prod-2` has done this before (2026-09-03: powered, off the LAN ~38 minutes, physical power
button required). `lockTtl: 0` means the lock does **not** expire, so the cycle stops here —
correctly, since the cluster is at 2/3 and must not go to 1/3.
Symptoms: one node `NotReady` or absent, `KuredNodeCoverageGap` firing alongside
`KuredRebootPending`, and the lock annotation naming the missing node.
**Operator recovery:** attend to the node physically. Once it is back and `Ready`, kured clears its
own lock on the next period. If the node is gone for good and the lock must be cleared by hand,
that is an operator action:
# OPERATOR ONLY. Only when you have confirmed the named node is NOT mid-reboot.
infra/devcontainer/dev.sh run bash -c 'kubectl --context k3s-prod -n kured annotate ds kured \
weave.works/kured-node-lock- --overwrite'
If the node was pruned mid-reboot and is left **cordoned** with no daemon to uncordon it:
# OPERATOR ONLY.
infra/devcontainer/dev.sh run bash -c 'kubectl --context k3s-prod uncordon <node>'
### 4. Nothing can write the sentinel (so nothing ever reboots)
If `KuredRebootPending` never fires and reboots never happen even after a kernel upgrade, suspect
the sentinel writer. On Debian, `/var/run/reboot-required` is created by a hook shipped in
**`update-notifier-common`** — and it was absent on all three nodes before this automation landed.
Without it kured is permanently, invisibly idle.
ssh -o BatchMode=yes 192.168.2.10 'dpkg -l update-notifier-common needrestart unattended-upgrades | tail -4'
ssh -o BatchMode=yes 192.168.2.10 'ls /etc/kernel/postinst.d/ /etc/apt/apt.conf.d/ | sort'
Fix by re-running the role, which asserts this explicitly:
cd infra/ansible && ansible-playbook playbooks/unattended-upgrades.yml -e k3s_hosts=k3s_prod --tags verify
### 5. kured is not being scraped (`KuredNotReporting`)
The chart defaults `service.create` and `metrics.create` to **false**, and the `kured` namespace
ships a default-deny NetworkPolicy. If either enablement regressed, or the Prometheus ingress allow
was dropped, targets are *discovered* and every scrape times out — the TSDB stays empty and all
three rules go quiet. Longhorn hit exactly this failure on this cluster.
infra/devcontainer/dev.sh run bash -c 'kubectl --context k3s-prod -n kured get svc,servicemonitor,networkpolicy,ciliumnetworkpolicy'
infra/devcontainer/dev.sh run bash -c 'kubectl --context k3s-prod -n monitoring exec \
sts/prometheus-kube-prometheus-stack-prometheus -c prometheus -- \
wget -qO- "http://localhost:9090/api/v1/targets?state=active" ' | grep -o '"job":"kured[^,]*' | head
### 6. A node is uncovered by the DaemonSet (`KuredNodeCoverageGap`)
kured declares **no tolerations**, because no prod node is tainted. A newly provisioned or
re-provisioned node carrying a taint gets no kured pod and will never be rebooted.
infra/devcontainer/dev.sh run bash -c 'kubectl --context k3s-prod get nodes \
-o custom-columns=NAME:.metadata.name,TAINTS:.spec.taints'
infra/devcontainer/dev.sh run bash -c 'kubectl --context k3s-prod -n kured get ds kured \
-o custom-columns=DESIRED:.status.desiredNumberScheduled,READY:.status.numberReady'
The fix is a PR adding the needed toleration to `platform/kured/helmrelease.yaml` — not a `kubectl
patch`, which Flux reverts.
## Expected outage per reboot cycle
Stated plainly, because this process is **not** seamless. Every workload at 1 replica on the
draining node is down until it reschedules and becomes Ready elsewhere. Measured 2026-10-17: **45
Deployments and 3 StatefulSets run a single replica.** The ones worth knowing about:
- **`kube-system/coredns` — 1 replica.** A cluster-wide in-cluster DNS gap while it moves. This is
the single most impactful item and it is **not** fixed by this PR; raising coredns to 2–3 replicas
is recommended follow-up work.
- **`monitoring/prometheus-…-0`, `monitoring/loki-0`, `monitoring/alertmanager-…-0`** — all
single-replica StatefulSets on Longhorn RWO volumes, so they additionally wait for volume
detach/reattach. **You lose monitoring and alerting for part of the cycle**, including these very
alerts.
- **All three CNPG Postgres primaries** blip during switchover, which means Keycloak, Nextcloud and
Semaphore briefly lose their database.
- **`gitea`, `nextcloud`, `plex`, `jackett`, `qbittorrent`, `radarr`, `sonarr`, `seerr`, `crafty`,
`homepage`, `headlamp`, `semaphore`** — each down for its reschedule.
- **`unifi` (a KubeVirt VM)** has `evictionStrategy: LiveMigrate` but
`migrationMethod: BlockMigration`, so evicting it copies the whole root disk over the network.
Expect the drain of its node to be slow.
- **`kube-vip`** fails the control-plane VIP over on every node reboot.
Multi-replica and therefore fine: `cilium-operator`, `oauth2-proxy`, `kyverno-admission-controller`,
the Longhorn CSI sidecars, `keycloak`, `pihole`, `runbooks`.
## When to escalate or stop
**STOP and do not intervene** if:
- Longhorn volumes are `degraded` **and rebuilding**. This is the gate doing its job. Wait.
- A single node is mid-reboot and under 15 minutes have passed.
**STOP and get a human to the hardware** if:
- Any node is `NotReady` while another reboot is pending. **Never clear the kured lock in this
state** — that is the one action that can take etcd from 2/3 to 1/3 and lose the cluster.
- Two nodes are down. The cluster has no quorum; this runbook cannot help. Recover hardware first.
**Escalate to a deliberate maintenance decision** if:
- `KuredRebootPending` has been firing for over a week. The reboot is not going to happen on its
own; find the blocker above, or take the reboot manually during a watched window.
- A volume is `faulted`. Fix storage before any further reboot.
**Turn the automation off** if it is misbehaving and you need the cluster stable. The honest way is
a PR, but for an emergency an operator may suspend the tier — this stops future reboots and leaves
running nodes untouched:
# OPERATOR ONLY. Stops kured being reconciled; does NOT uncordon a node mid-cycle.
infra/devcontainer/dev.sh run bash -c 'flux --context k3s-prod suspend kustomization kured'
Check afterwards whether a node was left cordoned (First commands, step 3) and uncordon it if so.
Resume with `flux resume kustomization kured`. Nothing in the graph depends on `kured`, so
suspending it stalls nothing else.
---
Source of truth: `runbooks/node-reboot-automation.md`. Index: `/runbooks/`
Records: `decisions/2026-10-17-automated-upgrades.md` (design + what was not verified),
`platform/kured/helmrelease.yaml` (every tuned value and why),
`infra/ansible/roles/unattended_upgrades/README.md` (the package half, and the kernel exclusion).