felhom.eu/REPORT-r87-spike.md

REPORT — R-87 spike: can the off-site copy be restore-tested without a person? (2026-08-31)

Written as REPORT-r87-spike.md, not REPORT.md: this repo's CLAUDE.md says the shared report is overwritten and two sessions clobber each other.

Findings document (the deliverable): documentation/audits/SPIKE-restic-restore-test-2026-08-31.md Evidence: documentation/audits/evidence-spike-restic-restore-2026-08-31/ — 31 files.

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1. Baselines, re-checked at the start

repo	main @	version	matched the task's stated baseline?
felhom-controller	2d802d75e88616d86cbade8a0e16965c2b85771c	v0.230.0	yes
felhom.eu	dddcc808be95d1c89b276b4d791491bad3c96bba	—	yes; clean tree, HEAD == origin/main
felhom-agent	058b945	v0.130.0	yes

2. Part 1 — the register correction

• The mis-filing commit: ef6ac6f, 2026-08-22, "One register, enforced by a gate; closed work compressed into siblings (R-376..R-378)". Established by git log -S '**R-87**' on both register files — it is the only commit that added the row to CLOSED-ITEMS.md and the only one that removed it from OPEN-ITEMS.md. The history settled it; no guess was needed.
• It is a survivor of R-378, not a separate incident. R-378 records six rows moved wrongly by that same sweep and restored in the same session. R-87 is a seventh it missed, and it escaped because its state cell led with READY and carried the word closed later, describing a different row.
• My own count, reproduced: 1 mis-filed row under the leading-verdict predicate. The same scan convicts 3 if it reads the whole state cell (R-224 and R-260 are false positives — long prose verdicts containing "open"/"OPEN") and 144 if it reads the whole row. The task author's count of one is confirmed, and only under the predicate R-378 argues for.
• The gate: scripts/closed_register_gate.py. Two rules. Red-proof rule 1: a planted READY row convicts by name, rc=1; removing it leaves the file byte-identical. Red-proof rule 2: a planted duplicate id convicts, rc=1. Negative control: run against the files as pushed (HEAD:), it convicts R-87 at L72 and R-398 at L139, rc=1. Registered LAST, as the 12th gate in repo_gates.py, after it was green.
• Also corrected: R-398 had a row in both registers (a deliberate cross-reference stub). Now prose beneath the table.

3. Q1–Q7, one paragraph each

Q1 — restic 0.14.0, go1.19.8, Debian bookworm 12.15, from the running container. The four source comments asserting 0.14.0 are confirmed. Method: docker exec felhom-controller restic version.

Q2 — --verify exists and is NOT a content check. restic restore --help lists --verify verify restored files content; positive control --target = 1 hit, negative controls --delete/--dry-run/--overwrite/--sparse and a nonsense string = 0 hits each. Neither --verify nor --no-lock appears anywhere in the controller source (grep -rn rc=1, with --json/--target as the positive control). Red-proof: one byte changed in a restored 160 MB tar with size and mtime preserved — restore --verify passed clean, rc=0. Verify took 131 ms on a 213 MB / 7-file tree, which cannot be hashing. A size or mtime mismatch causes a silent re-download, not a failure. So restic cannot tell us a restore produced correct files.

Q3 — no reference for "correct" exists today. restic ls --json file nodes in 0.14.0 carry no content hash. The recovery unit's manifest.json hashes three config files — 4 918 B of a 213 231 242 B unit, 0.0023 % — and not the DB dump or the volume tars. A planted sentinel is a drill technique and does not transfer; the live data drifts. What the manifest CAN answer is completeness, through the existing unitCarriesData (r403_hollow.go:40), with no new metadata. Filed as R-409.

Q4 — ~4 s per app, 25 s for all eight, cheaper than the weekly check. Through the product's own path: docmost unit 9 s, kimai full 11 s. Raw restic, all 8 snapshots / 774 378 123 B logical back to back: 25 s, individual times 2 253–3 978 ms regardless of size (185 KB → 2.25 s, 213 MB → 3.20 s). The cost is per-snapshot round-trip plus ≈ 1 s per 200 MB. Peak scratch = the app's full logical size, 213 272 202 B for the largest. The restic cache is 1.1 MB (index only) and does not hide the cost: --no-cache 5 423 ms vs cached 3 198 ms, trees byte-identical. Against R-359's 35.0 s / 39.2 s: the same 100 % check re-measured today is 40 257 ms — so restore-testing the whole box costs LESS than one weekly check. Extrapolation to 10×/100× is in the findings doc, labelled as extrapolation, with scratch space named as the constraint that binds before time does; the single-store hole is R-401's.

Q5 — skip-if-busy stays right, and a bigger thing is wrong. Scheduler registrations read off the box (CEST): db-dump 02:30, tier2 03:30, offbox-backup 04:15 (2m52s measured), abandon-sweep 05:10, offsite-integrity 06:00 (40.3 s). A 25 s hold is seconds, not minutes, and there is an empty gap 04:18–06:00. But RestoreOffboxScratch takes no acquireRunning at all — nine non-test callers, it is not one — while offbox_integrity.go:28 asserts "Every off-site operation takes acquireRunning". restore_wizard.go:174 records the same fact independently. Filed as R-408.

Q6 — the restore itself writes nothing; the product writes anyway; and check writes a lock. Observed with a lock sampler and an argv sampler, both inside the container, the repo URL redacted at source. Positive control: across the product's integrity run the repo went locks=0 → locks=1 id=81fd4d42… for nine consecutive samples → locks=0. The same instrument saw zero locks across two restores, so restic restore in 0.14.0 does not lock. Observed argv for one restore: snapshots latest --tag <app> --json, then unlock, then restore <id> --target …. The middle one is unlockStale (offbox_restore.go:289), unconditional, a delete verb. §5's lead was right in direction and wrong in mechanism — the write is unlockStale, not resticStep's escalation. The constraint IS satisfiable: --no-lock + skipping unlockStale writes nothing, and both mechanisms exist in 0.14.0 unused. offbox_integrity.go:255's "It NEVER writes to the repository" is filed as R-407. Neither was fixed — §7 forbids it.

Q7 — one of five. R-353 (a local restore path) no; R-354 (no volume-replay leg, after the scratch) no; R-356 (refused every driveless app) YES — five of eight apps on this box would have fired it on the first night; R-358 (needs a part-way failure) no; R-403 (destroyed a local copy) no as filed, yes for the shape. The honest verdict is "few", and it points elsewhere: check proves the stored bytes are the stored bytes, never that we stored the right thing. A hollow unit backs up, checks at 100 % and restores cleanly, and recovers nothing — R-403, measured in bytes nine days ago. Nothing asks that question on any tier.

4. Recommendation

Three options with costs and a do-nothing outcome are in the findings document. I would pick option C — the narrow test: one app a night, restored to scratch, checked against its own manifest.json, scratch deleted, the snapshot recorded as the proof. ~4 s and ≤ 213 MB per night; catches R-356 and the R-403 class; needs no new metadata. It must use --no-lock, skip unlockStale, and take acquireRunning — all three established by this spike. Options A (do not build) and B (scheduled attended drill) were considered explicitly and are argued in the document; B is the weakest, because it is what already happens. R-87 should be RE-SCOPED, not built as written — and that is Viktor's call, so the row stays open carrying the verdict, and STATUS.md item 4 asks it in plain words.

5. Evidence

documentation/audits/evidence-spike-restic-restore-2026-08-31/, 31 files, numbered by question. Every file was pulled off the box before any teardown (R-320) — including the two in-container sampler logs, which were cated to DooPlex before the container /tmp was cleared.

6. Probes removed — all three layers, and none of them is "nothing was created"

layer	created	after teardown
PVE host /root	6 scripts + one 0600 password file	ls | grep → nothing
guest 9201 /root, /tmp	9 files	grep → nothing
container /tmp	5 files + 2 run-flags	/tmp lists empty; no restic process left

Scratch directories: the four created by this session's restores (docmost, kimai, privatebin, opengist) were removed. Three (bookstack, calibre-web, paperless-ngx) pre-date this session and were left alone. The local password copy was shred -u'd.

Two state changes recorded rather than hidden: the integrity check run as the lock positive control recorded its verdict (last_integrity_check → 2026-08-31T13:41:28Z, depth structure → 100%, due-ness advanced 7 days), and four restores plus two logins appear in the controller log. Nothing was written to the off-site repository by hand.

7. Register

id	action
R-87	moved back to OPEN-ITEMS.md (verbatim from ef6ac6f^, beside R-95), then updated with the spike verdict and a re-scope proposal
R-398	de-tabled in CLOSED-ITEMS.md; the open row is the record
R-404	bypass count corrected six → seven (this session's Part 1 push)
R-405	filed + CLOSED — the mis-file, the reproduced count, the gate
R-406	filed — two findings share the id R-133
R-407	filed — restic check takes a lock; the comment says it never writes
R-408	filed — RestoreOffboxScratch takes no acquireRunning
R-409	filed — the unit manifest hashes 0.002 % of the unit

Register size: OPEN-ITEMS.md 165 → 171 rows (+R-87 restored, +R-405..R-409); CLOSED-ITEMS.md 153 → 151 (−R-87, −R-398). Ceiling R-404 → R-409.

python3 scripts/unproven.py --summary: 55 claims, walked 20 / partial 17 / built 14 / missing 4, NOT WALKED 35 of 55 — unchanged by this session, which shipped no product claim.

7b. Golden 0.230.0 — baked, vouched, delivered (second half of the session, on request)

This was NOT part of the spike and is reported separately so the two are not confused. Asked for after the spike closed; the spike itself still changed no product code.

GOLDEN_SHA256	9287f7cef5f13166276e8406005e3f28004004510c5184f1c1c7377f7aafad2e, 657 873 700 B
markers	docker OK (overlay2 1 · including mount point rootfs 1 + mp0 1 · upload OK (HTTP 201) 1 · excluding 0 · FATAL 0 — counted on the committed log
three readers agreed	the bake's own print, the round trip of the published bytes, and the hub's Day-0 dropdown reading Gitea on a different code path
the artifact names its own controller	tar --zstd -xOf golden.tar.zst ./etc/felhom-controller-image → felhom-controller:0.230.0, with 19 382 entries under var/lib/felhom/docker/
vouch	golden_version 0.229.0 → 0.230.0; agent_version 0.130.0 and min_agent 0.129.0 unchanged — v0.230.0's MinAgent is 0.129.0, and 0.129.0 ≤ 0.130.0 so this is not the R-216 shape. Re-read from the page; golden_behind_fleet confirmed absent
floor	min_controller_version 0.229.0 → 0.230.0, a separate setting, done on the operator's explicit answer
the unattended proof	demo-felhom was on 0.229.0 — the R-403 build — and moved itself: controller-swap: image file written 16:21:30 → controller-swap: new controller healthy 16:21:40 CEST. Both boxes now 0.230.0, healthy
pre-gates	404 pre-gate passed; token-leak grep 0 on the committed log and 1 on a seeded throwaway copy, so the zero is earned. Unit properties grepped for the token: 0, positive control 1
teardown	pct destroy 9100 --purge, shred -u after the log was copied out, poweroff, qemu confirmed exited with ps -eo comm (not pgrep -f, which self-matches), disk back to virgin

Full record: documentation/tests/golden-0.230.0-2026-08-31/README.md.

One honest gap vs. the 0.229.0 precedent: the bake script's sha256 was not compared across the hop, only recorded on DooPlex (7b0fb5cf…73b6a1). A corrupted scp would have failed the bake rather than produced a wrong golden — but that is an argument, not a measurement.

And the gate that flagged all this has a hole, found while it went green: golden_currency_gate.py matches a directory name (scripts/golden_currency_gate.py:89,123). I created documentation/tests/golden-0.230.0-2026-08-31/ before the bake finished, and the gate would have passed at that moment. Filed as R-410.

8. Controller code, and the golden debt as it now stands

The spike changed no controller code, and that remains true — the golden bake ships the image that was already released as v0.230.0, unchanged.

8. No controller code changed and no golden is owed

felhom-controller and felhom-agent were read only for the spike. No version bump, no build, no deploy. The golden debt — v0.230.0 released with the newest bake at 0.229.0 — was already red at dddcc80 before this session started and belonged to that release, not to the spike; golden_currency_gate.py was the only failing gate throughout the spike. It was then PAID on request (§7b): the gate now exits 0, and the two register-only pushes below were the last that needed a bypass.

git push --no-verify was used, twice, for exactly that reason — records-only pushes meeting the golden gate. That is R-404's subject and the count is updated in its row.

CI is RED for both of this session's pushes, and I checked rather than assumed. Pulled by run id from gitea.dooplex.hu/api/v1/repos/admin/felhom.eu/actions/tasks:

run id	run_number	head_sha	status
451	280	66156c619f	success
456	281	dddcc808be	failure — the commit this session STARTED from
458	282	6e550aedd3	failure — this session's Part 1
459	283	130f7a6eba	failure — this session's spike commit
460	284	32a4c35c9c	failure — the CI-verdict amendment
461	285	2263245cf2	SUCCESS — the golden bake commit

CI runs the same repo_gates.py entry point, so it fails on golden_currency_gate.py exactly as the pre-push hook did. Run 281 is the proof that it is not mine: it is the previous session's commit, pushed before this session began, and it is already red. Nothing else in the suite fails at any of the three commits. It resolved exactly there: run 285, the golden-bake commit, is GREEN — the first green run since 66156c619f, and the first push this session that the pre-push hook let through unbypassed (pre-push [felhom.eu]: gates OK - push proceeding). All 13 gates pass.

9. Observations — noticed, not acted on

• paperless-ngx has an off-site snapshot under that tag and none under paperless; filebrowser has none at all (it is infrastructure, so that may be correct). Not chased.
• CLOSED-ITEMS.md rows R-399 and R-400 supply two columns where the table declares four — they render with no Shipped and no Evidence. The new gate warns rather than convicts, because an empty state cell is not an open state word.
• Two rows (R-309, R-351) carry a | inside their body, shifting their own cells. Named as the gate's first residual hole.
• The controller image has no ps and no python3. /proc/*/cmdline is the substitute that works, and it is worth knowing before writing any probe that runs in there.
• The guest scheduler logs in CEST, not UTC — offbox-backup scheduled for 2026-09-01 04:15 CEST against a last_run of 02:17:57Z. Consistent, and the opposite of what the project memory says about guest time.