NodeIOPressureCritical has now fired twice on k3s-prod-1 for opposite causes and
said the same thing both times. On 2026-09-14 02:40-02:45Z it fired at PSI(full)
20.98% — twice the threshold, four times the 2026-09-07 level — while every local
device was idle (0.09-0.27 utilisation) and fast (1.4-4.8 ms per write), NFS
retransmissions were zero and no Longhorn volume was degraded. Establishing that
took eight ad-hoc PromQL queries after the event had already recovered.
Adds the group platform-health.node-io-cause: eight rules, one per cause class,
each naming its cause in its own summary.
NodeDiskDeviceSaturated device saturation >0.85 busy, 10m
NodeDiskWriteLatencyHigh device latency >20ms/write, 10m
NodeDiskWriteLatencyCritical device latency >50ms/write, 5m
NodeDiskReadLatencyHigh device latency >250ms/read, 15m
NodeNFSRetransmissionRateHigh NFS transport >1% retransmitted, 10m
NodeIOPressureNotLocalDisk not local disk PSI>10% with all of the above absent
NodeEtcdRequestsSlow etcd >0.5% of etcd requests over 1s
ContainerIOStallHigh which workload per-container PSI >15%
Every threshold is measured on prod over 24-48h, not guessed, and each rule
records its headroom. The PSI thresholds themselves are deliberately unchanged:
the 21% stall was real, it fired twice in 24h for two real events on the one node
that has a problem, and raising the bar would also have raised it above the 11.36%
at which prod-1 was already losing etcd on 2026-09-07.
Context reaches the operator at page time three ways: the summary states the cause
class; every rule carries a diagnostic_query annotation with the exact companion
PromQL; and node-pressure-dashboard.yaml gains a WHY row (seven panels) plotting
saturation, write/read service time, NFS retransmissions, our own NFS op rate,
the etcd slow-request fraction and per-container PSI side by side. runbooks/node-io.md
gains a 10-row triage table with the real healthy / 2026-09-14 / 2026-09-07 columns,
which turns those eight queries into a two-minute read.
etcd and NFS metric availability, verified on prod rather than assumed:
* etcd SERVER disk metrics do NOT exist. etcd_disk_wal_fsync_duration_seconds and
etcd_disk_backend_commit_duration_seconds are absent (kubeEtcd disabled for k3s);
a query for etcd_disk_*/etcd_server_*/etcd_mvcc_* returns nothing at all.
NodeEtcdRequestsSlow uses the apiserver's client-side view of its own local
member instead, and says in its own description that it is a proxy.
* node_nfs_* DOES exist — the nfs collector is on by default, host-wide via
/proc/net/rpc/nfs, confirmed on all three nodes. It gives op counts and
retransmissions and NO latency, so it can see a dropping export but not a slow
one. The mountstats collector is enabled here to close that gap; NO rule
references node_mountstats_* yet, because the series do not exist until the
HelmRelease rolls out and the collector's visibility through the node-exporter
mount namespace must be verified on prod first. The runbook records the check
and says to revert if it comes back empty.
Proof, per the repo's two shipped alerting failure modes:
* platform/monitoring/tests/node-io-cause.test.yaml — 7 fixtures, all from
measured profiles: healthy (all 8 quiet), 2026-09-14 (NotLocalDisk fires and
names sonarr), 2026-09-07 re-queried at offset 164h (write-latency and etcd
fire, NotLocalDisk correctly silent), rebuild storm, NFS transport, read
latency, and the `unless` semantics.
* 10 mutations of the shipped rules, all killed. The mutation run found a real
gap: the etcd threshold could be changed without failing any test, because it
was only pinned by a promql_expr_test that restated the threshold in the test
file. An alert_rule_test now pins it.
* All 11 referenced metrics verified to return series on prod with
`promtool query instant`, and all 8 expressions verified quiet on today's state.
Also extends the alert-metrics-have-scrape-targets owner table for container_*
(the kubelet ServiceMonitor's cAdvisor path, which this entry already claimed in
its title) and for etcd_request_duration_seconds_* by EXACT NAME, deliberately not
by an etcd_ prefix, so a future rule on the unscraped etcd_disk_* names still fails
the gate.
Co-Authored-By: Claude Opus 5 <[email protected]>
conformance/ — the home-k3s conformance harness (WS-TEST)
This subtree is the definition of "done" for the whole platform. Nothing is accepted
on a demo, a screenshot, or "it reconciled": every requirement is proven by an
automated, reproducible, behavior-based test tagged with the requirement ID(s) it
verifies (spec docs/14,
ADR-0010,
ADR-0011).
Tooling is fixed by ADR-0011: Kyverno for L0 (the CI policy gate + in-cluster admission enforcer — owned by task T-0.5) and Chainsaw for L1 rendering / L2 behavioral / L3 fault-injection (this harness).
The single command
./run.sh # full suite (skips L1/L2/L3 if no cluster)
./run.sh --requirements R-NET-01,R-NET-06 # merge-gate subset (tagged)
./run.sh --layer l2 # one layer: l1 | l2 | l3 | meta | all
./run.sh --coverage-only # regenerate the coverage report (no cluster)
./run.sh --status # derived requirement-STATUS report (no cluster)
./run.sh --lint # structural-validate test defs (no cluster)
./run.sh --strict-coverage # hygiene gate: fail on tag/annotation drift
./run.sh --require-all # phase-exit gate: every requirement must be covered
./run.sh --record # run AND capture the evidence (see "Proof of pass")
./run.sh --layer l0 --include-scope whole-repo # union: the tagged subset PLUS every test
# declaring `conformance.home.k3s/scope: whole-repo`
./run.sh --layer l0 --print-selection # print the dirs the selection resolves to; run nothing
Gating is scoped, not "all 51 always" (R-TEST-03). Three distinct checks:
-
--strict-coverage— hygiene (always-on, WS-TEST owns it): fails only on tag/annotation drift or a tag absent from the registry. Uncovered future-phase requirements are visible gaps in the report, not a harness failure. -
--requirements R-…— merge gate: selects the tagged tests to run and asserts those touched requirements are covered (a listed safety-critical one must have an L3 test). -
--require-all— phase-exit gate: every registry requirement must be covered. -
--include-scope whole-repo— the escape hatch scoping needs, because scoping has one blind spot and it is the worst-shaped kind. Some L0 invariants quantify over the WHOLE tracked tree (no plaintext secrets anywhere; no RBAC wildcard anywhere), or over subtrees the coarse path→requirement map keys to nothing (apps/,infra/, most ofplatform/). For those, the change most likely to break the invariant attributes no requirement at all, so requirement-scoped selection filters the check out of exactly that change. Such a test declares its scope:metadata: annotations: conformance.home.k3s/scope: "whole-repo"and
--include-scope whole-repounions every declaring test into the selection. The CI stages (ci/l0.sh,ci/l1.sh,ci/conformance.sh) all pass it, so adding the annotation is the only step — there is nothing to remember and nothing to hand-write. Two consequences, both deliberate: a declaring test always runs, and a SKIP of a declaring test is UNWIRED, not green (the runner exits 3, whichci/l0.shturns into the gate's own rc 3 — never a pass).tests/l0-static/whole-repo-invariants-wiredproves the mechanism end-to-end and falsifiably, so it cannot rot silently. This replaced a hand-written "UNCONDITIONAL" stage per check inci/l0.sh; seelib/common.shfor the full rationale and the incidents behind it. -
Documented out-of-scope gaps (e.g.
R-ENV-02dev→prod promote andR-GITOPS-01state-in-git, owned by WS-INFRA/WS-GITOPS and keyed wholesale by the coarse path map) are exempted from the completeness gates via--allow-gap, wired inrun.shasDOCUMENTED_GAPSso the exemption is explicit and reviewable. (R-STATE-02node-loss used to be here; it now has a real L3 test —tests/l3-fault-injection/node-loss— and is covered, not exempted.)
Coverage vs status — two different questions
coverage.md answers "does a requirement-tagged test EXIST for R-x?" (R-TEST-04).
status.md (./run.sh --status, generator lib/status.py) answers the operator's
question — "what is the real state of each requirement given what is actually in the
repo?" — deriving three orthogonal axes per requirement:
- implementation — is there a tracked artifact naming the requirement?
- reconciliation — is that artifact reachable by walking
resources:fromclusters/<env>/kustomization.yamland expanding every FluxKustomization'sspec.path? This is what separates authored from actually reconciled: a commented-outresources:entry (e.g.platform/image-automation) is correctly reported as in-git-but-not-on-any-cluster. - verification — is the tagged test EXECUTABLE, or a TODO scaffold? Coverage counts
both as "covered"; status does not. TODO markers in a body always outrank an
executable: "true"annotation, so ambiguity never upgrades a test.
It deliberately refuses to derive proof-of-pass. Nothing tracked in git records a test
result — _artifacts/ and results/ are git-ignored and DECISIONS-LOG.md prose is not a
signal — so every requirement's proof state is reported as not-derivable rather than
defaulting to green. A status report that overstates completion is worse than none
(agents/definition-of-done.md). Closing that gap needs a committed, machine-readable
run ledger; until then the strongest claim the report makes is wired and testable.
--strict-coverage also applies status's hygiene gate (registry↔spec drift,
annotation/body conflicts, a safety-critical requirement whose only L3 test is a scaffold).
Exit codes follow ci/lib.sh: 0 pass / 1 fail / 3 skipped — a skip is never green.
run.sh is the only entrypoint. Local runs and the in-cluster CI Chainsaw Job call
the same script with the same config, so results are identical.
Artifacts (always emitted, under _artifacts/, git-ignored)
| Path | What | Consumer |
|---|---|---|
_artifacts/report.junit.xml |
JUnit — Chainsaw results, or a skipped-scaffold shim when no cluster | CI gate |
_artifacts/coverage/coverage.md |
Human requirement-coverage report | PR reviewers / logs |
_artifacts/coverage/coverage.json |
Machine coverage: {requirement: [tests]}, gaps, safety gaps |
CI gate |
_artifacts/status/status.md |
Human requirement-STATUS report derived from repo state | operator / PM |
_artifacts/status/status.json |
Machine status: implementation / reconciliation / verification per requirement | tooling |
Reproducibility contract (R-TEST-02 — what the harness guarantees)
- Single command.
./run.sh(or a tagged/layer subset) runs everything and emits the artifacts above — locally and in CI. - Hermetic. Each Chainsaw test provisions its own namespace + fixtures/probes and tears
them down (
config/chainsaw-config.yamlauto-creates/auto-deletes the namespace; tests addfinallyfor anything out-of-namespace). It never relies on pre-existing state. - Deterministic. Tool versions pinned in
versions.env; eventual consistency handled by bounded polling with explicit timeouts (config), never sleeps or wall-clock/ordering assumptions. - Isolated & parallel-safe. Unique generated namespaces + per-requirement labels; tests run concurrently without cross-talk.
- Machine-readable & requirement-tagged. JUnit + coverage, every result carrying its
R-*tags (convention intests/README.md). - Self-cleaning. Fixtures removed on pass or fail; a leaked namespace/fixture is
itself a failure (
skipDelete: false, enforced delete/cleanup timeouts). - Versioned with the code. Tests live next to what they verify and change only when the human-owned spec they encode changes — never weakened to go green (R-TEST-06).
Layout
run.sh single-command runner (the entrypoint)
versions.env pinned toolchain (Chainsaw/kubectl/Kyverno) — determinism
config/chainsaw-config.yaml shared execution contract (timeouts, ns isolation, JUnit)
requirements/registry.yaml mirror of EVERY spec R-* ID (coverage enumerates from here)
lib/
common.sh tagging convention + test discovery/selection helpers
coverage.py requirement-coverage generator (stdlib only)
status.py requirement-STATUS generator (stdlib only; --selftest)
record_run.py run-ledger writer: PROOF-of-pass (stdlib only; --selftest)
emit_skipped_junit.py Phase-0 skipped-JUnit shim (no cluster)
runs/
ledger.jsonl TRACKED append-only proof-of-pass ledger (one row per
testcase per run) — the only source status.py trusts
<UTC>-<short-sha>/ TRACKED per-run evidence: run.log + report.junit.xml
tests/
l1-rendering/ l2-behavioral/ l3-fault-injection/ meta/ (see tests/README.md)
incluster/
chainsaw-job.yaml rbac.yaml in-cluster L2/L3 Job + scoped test SA (ADR-0011)
Proof of pass — the run ledger (runs/)
--status used to report PROVEN: 0 for all 51 requirements, and said so honestly:
proof-of-pass was not recoverable from repo state. _artifacts/ is gitignored and the
root .gitignore kills *.junit.xml globally, so no run result ever reached git; the
only record of a green run was DECISIONS-LOG.md prose. runs/ is the fix lib/status.py
asked for — a committed, machine-readable run ledger.
./run.sh --record # runs normally, and captures the evidence
# -> conformance/runs/<UTC>-<short-sha>/run.log (tee'd, carries the sentinels)
# -> conformance/runs/<UTC>-<short-sha>/report.junit.xml (that run's JUnit)
# -> conformance/runs/ledger.jsonl (one appended row per testcase)
python3 lib/record_run.py --run-dir runs/<id> [--dry-run] # or record an existing run dir
python3 lib/record_run.py --selftest # deterministic, no cluster
Recording is explicit, never implicit. Plain ./run.sh writes no ledger row: a run
that silently records itself is how a bad run becomes a permanent false proof. Commit
the run dir and the ledger — an uncommitted ledger proves nothing.
Why a committed JUnit alone would be WORSE than nothing
The L2/L3 tests are runnable and self-skipping: when a precondition is missing (no
longhorn StorageClass, no Velero CRDs, fewer than 3 Ready nodes) they echo a skip token
and exit 0, and their check: accepts either outcome —
(contains($stdout, 'DR_RESTORED_FROM_OFF_CLUSTER_BACKUP_OK')
|| contains($stdout, 'DR_RESTORE_SKIPPED_OK')): true
So a self-skip exits 0 and Chainsaw records passed exactly as a real run does, and
Chainsaw's JUnit carries no stdout — its <testcase> elements hold only <properties>.
A committed JUnit on its own would therefore record DR_RESTORE_SKIPPED_OK as proof of
R-STATE-03: fake green, and worse than no ledger because it would look authoritative.
The sentinel token in run.log is the only thing that separates proven from skipped.
record_run.py derives each test's tokens from its own chainsaw-test.yaml (every
contains($stdout, 'TOKEN'); *_SKIP*_OK is a skip token, the last non-skip token is the
verdict token), so the table below is never hand-maintained:
| Test | pass token (proof) | skip token (never proof) |
|---|---|---|
l3/node-loss |
NODE_LOSS_VOLUME_AVAILABLE_OK |
NODE_LOSS_SKIPPED_OK |
l3/dr-restore |
DR_RESTORED_FROM_OFF_CLUSTER_BACKUP_OK (+ OFF_CLUSTER_TARGET_OK, BACKUPS_ARE_SCHEDULED_OK) |
DR_RESTORE_SKIPPED_OK, DR_SCHEDULE_SKIPPED_OK |
l3/data-survival |
DATA_SURVIVED_OK |
DATA_SURVIVAL_SKIPPED_OK |
l3/vm-data-survival |
VM_DATA_SURVIVED_OK |
VM_DATA_SURVIVAL_SKIPPED_OK |
l3/hands-off-update |
HANDS_OFF_UPDATE_OK |
HANDS_OFF_UPDATE_SKIPPED_OK |
l2/vm-lifecycle |
VM_LIFECYCLE_OK |
VM_LIFECYCLE_SKIPPED_OK |
l2/vm-default-deny |
VM_DEFAULT_DENY_OK |
VM_DEFAULT_DENY_SKIPPED_OK |
A row reaches proof: "proven" on one path: JUnit passed, every declared pass
token present in that test's log lines, and no skip token anywhere in them. A skip
token beats a pass token (worst wins). Anything else is skipped, failed,
junit-skipped, unknown-no-sentinel-declared or unknown-sentinel-absent — all
non-green. L0/L1 need no sentinel because lib/run_l1_offline.py already renders their
skips as JUnit <skipped/>, never as a green pass.
Staleness — a proof is a claim about a tree, not a badge
--status honours a proven row only while the run's git_sha is a descendant of the
last commit touching that requirement's implementing manifests or its verifying test.
Otherwise the row degrades to stale-proof, which is not green. A run captured from a
dirty working tree is recorded as <sha>-dirty, which no ancestry check can satisfy — so
it never counts. Re-run with --record to refresh.
A requirement reads proven only when every verifying test does; one skipped, failed
or unrecorded test drags the whole requirement down. With an empty ledger --status
behaves exactly as before: every requirement not-derivable, headline PROVEN 0.
How CI invokes it
CI (Gitea Actions, wired in T-0.2 / migrated in T-6.1b) calls this same run.sh:
- No-cluster stage (every PR, fast):
./run.sh --lintand./run.sh --coverage-only --strict-coverage --requirements <IDs the change touches>. Validates every test parses- is tagged, regenerates coverage, fails the PR on tag/annotation drift (hygiene) and on any touched requirement lacking a test (merge gate). (L0 Kyverno CLI runs alongside — task T-0.5.)
- Cluster stage (L2/L3): CI does not hold a kubeconfig. It triggers the
in-cluster Chainsaw Job (
incluster/), which runs./run.shunder the scopedconformance-runnerServiceAccount and writes JUnit + coverage to a results volume CI collects.- Merge gate: the Job runs
--requirements <IDs the change touches>; that subset runs green and those requirements are covered to merge (R-TEST-03). - Phase-exit gate: the Job runs
--layer all --strict-coverage; add--require-allonly at the milestone where the full requirement set is expected covered. The phase suite must be green before the phase's exit criteria are met.
- Merge gate: the Job runs
Phase 0 status (no cluster yet)
No cluster exists, so L1/L2/L3 cannot execute. The behavior tests are valid
scaffolds (steps + assertions authored, tagged, TODO(T-x.y) where a later phase
delivers the fixture). In this phase run.sh:
- always generates the coverage report (cluster-independent), and
- emits a skipped JUnit listing every scaffold (so the gate is green and the artifact shape is real), and
- the
meta/harness-selfcheckchecks (reproducible output, JUnit+coverage emitted, everything tagged, zero safety-critical gaps) are whatrun.sh --strict-coverageactually enforces today.
As later phases deliver capabilities, each scaffold's TODOs are filled and the test flips
from skipped to executing green — landing coverage without re-architecting the harness.