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]>
decisions/ — the handoff log, one file per entry
This directory is the decision log. ../DECISIONS-LOG.md is the frozen archive of
everything written before 2026-09-29 and is never edited again (see "The archive is
frozen" below).
Why this exists
DECISIONS-LOG.md was append-only in a single file, and every agent appended to its
tail. Two branches that both append hit the same last hunk, so git cannot
auto-merge them: the second one to be reviewed conflicts, and so does the third, and
the fourth. Measured on 2026-09-29: four of the five open PRs were unmergeable, and
DECISIONS-LOG.md was the only conflicting file in all four:
#22 fix/crafty-oauth2-proxy-signin CONFLICT (content): DECISIONS-LOG.md
#20 feat/conformance-job-template CONFLICT (content): DECISIONS-LOG.md
#19 feat/conformance-trigger-kubeconfig CONFLICT (content): DECISIONS-LOG.md
#18 feat/conformance-runner-image CONFLICT (content): DECISIONS-LOG.md
#17 feat/ci-is-the-approver clean (it touched no log entry)
Nothing was wrong with any of those changes. The log's storage format serialised work that was otherwise parallel, and it got worse with every concurrent branch: N branches produce N-1 rebases, each of which invalidates any gate run that preceded it.
The fix is the obvious one for concurrent appenders: stop sharing a file. Each
handoff is its own file. Two agents writing handoffs touch disjoint paths, so there is
nothing for git to merge and nothing to conflict. This scales to any number of parallel
branches with zero coordination — which is the point, since the agents are deliberately
isolated from each other in separate worktrees (required by CLAUDE.md §0) and cannot
coordinate.
There is deliberately no index file and no counter. An index would be a shared
mutable file — exactly the thing that just failed — and a sequence number would have
two agents racing for 0043. The directory listing is the index.
Writing an entry
One file per handoff, named:
decisions/YYYY-MM-DD-<slug>.md
<slug> is lowercase [a-z0-9-]. Use your branch name's last segment — it is
already unique per unit of work, which is precisely the property the filename needs.
A branch fix/crafty-oauth2-proxy-signin handed off on 2026-09-29 writes:
decisions/2026-09-29-crafty-oauth2-proxy-signin.md
The file is YAML frontmatter followed by three required sections:
---
date: 2026-09-29
branch: fix/crafty-oauth2-proxy-signin
title: The Keycloak gate works — Crafty's own login was the wall
---
## What changed
Prose. What you actually did, and why.
## What I verified
The measurements, with their numbers. Quote the field you read, not the prose you
believed. Name the gate result and its exit code.
## What I did NOT verify
Everything else. An honest "UNVERIFIED" is worth more than an optimistic "green" —
this repo has been burned by the difference more than once.
All three headings are required and enforced (ci/decisions-log.sh). They are
CLAUDE.md §7's contract; making them a checked structure is what stops an entry
degrading into "done ✅".
Reading the log
The whole log, oldest first:
ls decisions/[0-9]*.md | sort
The current PM handoff — the newest entry. Ties within a day are broken by what landed
on main last, which is the honest answer, so ask git rather than the filename:
git log --diff-filter=A --format='%H' --name-only -- 'decisions/[0-9]*.md' \
| grep '^decisions/' | head -1
For a quick skim of who said what:
grep -H '^title:' decisions/[0-9]*.md | sort
The archive is frozen
DECISIONS-LOG.md is read-only history. Its SHA-256 is pinned in
decisions/ARCHIVE.sha256 and ci/decisions-log.sh fails the merge gate if the file
changes. That is not ceremony: without it, the next agent to read runbooks/ or an old
CLAUDE.md habit appends to the tail again and re-creates the conflict for everybody
else, silently, one PR at a time.
If the archive genuinely must change (a leaked credential to redact, say), that is a
deliberate, reviewed act: change it, run sha256sum DECISIONS-LOG.md > decisions/ARCHIVE.sha256,
and say in your handoff entry why. Re-pinning is visible in the diff. Appending is not.