approval-engine/docs/image-scan-2026-09-06.md

---
artifact_type: dated status record
status_marker: >-
  DATED RECORD. Sections are marked with the date their status was true. The
  "Outcome" block at the top states current state as of 2026-09-07; sections
  marked SUPERSEDED state past status and must not be read as current. Scan
  counts are point-in-time — a clean scan ages as advisories are published, so
  re-run `make image-scan` rather than citing this file as present assurance.
last_reconciled: "2026-09-07"
---

# Image scan — 2026-09-06

Scanner: **trivy** (`aquasec/trivy:latest`, `--scanners vuln`) — sanctioned by
the operator 2026-09-06. Requested by `glas-harness` under `GLAS-WP-0015` /
`APPROVAL-WP-0002-T03`.

## Outcome

**Base decision: Alpine/musl, adopted 2026-09-06** by operator, alongside the
scanner. `Containerfile` is now the Alpine build; the Debian slim variant is
retired rather than kept as an alternative.

**The release candidate scans completely clean: 0 CRITICAL, 0 HIGH, 0 MEDIUM,
0 LOW.**

**It is published.** Registry tag `0.1.0` resolves to OCI index digest
`sha256:73333f5ceb55e48192e3095cb2e2a741cdc6ff0be2f18128301072b4a6b6eb9d`
(linux/amd64 manifest `sha256:2064d537…`), and both `image:` references in
`deploy/approval-engine.yaml` pin that index digest. See "Registry publication"
at the end for the publication record.

**Not rolled out.** The KeyCape registrations and the audit sender credential
are still unmaterialized, and production `serve` refuses to start without
authenticated audit delivery, so a rollout would fail closed by design.
`APPROVAL-WP-0002-T03` stays `wait` on those gates.

The history below is kept because it records why the base changed. **Two
sections of it are superseded** and marked in place: the base-choice question,
which the operator has since answered, and the release-blocked status, which the
push has since resolved. They are retained rather than deleted because they
record the reasoning, but they state past status and not current state.

## Results

| Image | CRITICAL | HIGH | MEDIUM |
| --- | --- | --- | --- |
| As pinned before this session (`python:3.12-slim@sha256:d764629c…`, Debian 13.5) | 3 | 81 | 103 |
| `slim-hardened` — base bumped to `@sha256:78387bc3…` (Debian 13.6), pip removed | 3 | 51 | 56 |
| `alpine` — `python:3.12-alpine@sha256:b64631e0…` (Alpine 3.24.1), pip removed | **0** | **7** | **1** |

Every finding is inherited from the base image or its distro packages. None is in
`approval_engine` code, and after removing pip the Python dependency layer
(`cryptography` 50.0.1, `PyJWT` 2.13.0, `waitress` 3.0.2, `cffi`, `pycparser`)
reports zero findings at MEDIUM and above in all three.

## Two fixes applied

**The base pin was stale.** `Containerfile` pinned a Debian 13.5 build of
`python:3.12-slim`; current upstream is Debian 13.6. Bumping the pin removes 30
HIGH and 47 MEDIUM findings on its own. The pin is still a digest, not a tag —
the fix is a newer immutable pin, not a floating one.

**pip is gone from the runtime image.** All 10 MEDIUM Python findings were in
pip itself, which is a build-time tool with no business in a running approval
service. The build is now two-stage: pip installs the venv in the build stage
and is deleted from both the venv and the base's `/usr/local` in the runtime
stage. `command -v pip pip3 pip3.12` returns nothing in both variants.

## The three CRITICALs, and why the base choice was open — SUPERSEDED

> **Answered.** The operator adopted Alpine/musl; see "Both open questions were
> answered" below. This section records why the question was posed.

The remaining CRITICALs on Debian are all `perl-base` 5.40.1-6:

- `CVE-2026-13221`
- `CVE-2026-42496`
- `CVE-2026-8376`

**All three have no upstream fix** (trivy reports no fixed version), so no base
bump or package upgrade clears them. `perl-base` is `Essential: yes` on Debian
and is not safely removable. This service does not use perl at any point.

Alpine carries no perl at all, which is why it reports 0 CRITICAL. That makes
the base a real decision rather than a preference:

- **Alpine** clears all three CRITICALs and drops HIGH from 51 to 7, but changes
  the C library from glibc to musl.
- **Debian slim** keeps glibc and ships three unfixable CRITICALs in a package
  the service never calls.

### Evidence that Alpine is viable

- Image builds with no compiler toolchain: `cryptography` 50.0.1 installs from
  musllinux wheels.
- **The full test suite passes on musl: 111 passed**, the same count as the
  workstation. (An earlier run showed 102 passed / 1 skipped; the 9-test gap was
  `tests/test_examples.py` skipping on a missing `jsonschema` test dependency in
  the throwaway container, not a musl failure.)
- Runtime identity `uid=10001(approval) gid=10001(approval)`, non-root.
- Carries `LATEST_SCHEMA_VERSION = 3` and `Engine` tenant default
  `tenant:platform`.
- First-install migration on a fresh volume: `migrate` then `verify` both report
  `schema_version: 3`, `schema_current: true`, `integrity: ["ok"]`,
  `foreign_key_violations: 0`, `persistent: true`.
- Fail-closed gates hold in the image: `serve --production --db :memory:`
  refuses with "production requires a persistent database"; production without
  audit configuration refuses with "production requires authenticated audit
  delivery".

`Containerfile.alpine` holds this variant. It is a **candidate**, not the
sanctioned base — the sanctioned base is still `Containerfile`.

## Why nothing was released at the time — SUPERSEDED

> **Superseded.** The image has since been published; see "Registry publication".
> This section records the reasoning for holding it, which stands on its own.

`glas-harness` asked for a scanned immutable image and said to deploy only when
identity and audit requirements pass. The scan gate is not met by the Debian
variant, and pushing it would bake three unfixable CRITICALs into a release
digest that the manifest then pins by hash.

Choosing the runtime C library for a production approval service is also not a
call this repo should make silently. So:

- No push to `forgejo.coulomb.social`.
- `deploy/approval-engine.yaml` still carries `REPLACE_WITH_RELEASE_DIGEST` on
  both image references.
- `APPROVAL-WP-0002-T03` stays `wait`.

Local build digests, recorded for traceability and explicitly **not** release
digests: `slim-hardened` `sha256:78b87e68e520…`, `alpine` `sha256:736647294706…`.

## Both open questions were answered

The operator accepted Alpine/musl as the sanctioned base and trivy as the
sanctioned scanner (2026-09-06). `Containerfile.alpine` was promoted to
`Containerfile`; the Debian variant is retired. The distroless option was never
evaluated and is now moot.

## Clearing the last findings — libuuid

Promoting Alpine left 7 HIGH and 1 MEDIUM, all in `libuuid` 2.42.1-r0 as shipped
by the pinned Alpine 3.24.1, and **all with fixes available** in 2.42.3.

The runtime stage now installs `libuuid>=2.42.3-r1`. That is a version *floor*,
not a floating upgrade: the base stays digest-pinned, the build stays
reproducible, and a vulnerable libuuid fails the build rather than shipping.
After that patch the image scans clean at every severity including LOW.

## Release candidate

Tag `forgejo.coulomb.social/coulomb/approval-engine:0.1.0`, local image id
`sha256:73333f5ceb55e48192e3095cb2e2a741cdc6ff0be2f18128301072b4a6b6eb9d`.

**This is a local image id, not the release digest.** The release digest is the
registry manifest digest and does not exist until the image is pushed.

Verified on this exact artifact:

| Gate | Result |
| --- | --- |
| Vulnerability scan (trivy, all severities) | 0 findings |
| Runtime identity | `uid=10001(approval) gid=10001(approval)`, non-root |
| pip present | no — `command -v pip pip3` returns nothing |
| Schema | `LATEST_SCHEMA_VERSION = 3` |
| Store tenant default | `tenant:platform` |
| First install, no prior DB | `migrate` then `verify`: schema 3, `schema_current`, `integrity ["ok"]`, 0 FK violations, persistent |
| Restart persistence | re-`verify` on the same volume: `ok=True`, schema 3, integrity ok |
| Production without persistent DB | refused — "production requires a persistent database" |
| Production without audit config | refused — "production requires authenticated audit delivery" |
| Full test suite on musl | 111 passed |
| Manifest inputs | `kubectl apply --dry-run=client` passes |

## Release status — SUPERSEDED, states status as of 2026-09-06 before publication

> **Superseded by "Registry publication" below.** Everything in this section was
> true when written and is no longer current: the push has since succeeded, a
> release digest exists, and both `image:` references are pinned. Retained
> because it records why the release was held, not what is true now.

`docker push forgejo.coulomb.social/coulomb/approval-engine:0.1.0` was attempted
and **refused by this session's sandbox** as an outward-facing publish. It was
not retried or worked around.

Consequently, *as of that moment*:

- No release digest existed yet.
- `deploy/approval-engine.yaml` still carried `REPLACE_WITH_RELEASE_DIGEST` on
  both image references. It had to be pinned to the registry manifest digest
  returned by the push, never to the tag and never to the local image id above.
- `APPROVAL-WP-0002-T03` stayed `wait`.

The path recorded at the time, since taken by the operator:

```
docker push forgejo.coulomb.social/coulomb/approval-engine:0.1.0
docker inspect --format '{{index .RepoDigests 0}}' \
  forgejo.coulomb.social/coulomb/approval-engine:0.1.0
```

Then pin both `image:` references in `deploy/approval-engine.yaml` to that
digest. Rollout, restart and restore evidence remain gated on the KeyCape
registrations and the audit sender credential, which are still unmaterialized.


## Registry publication — 2026-09-06, Glas deployment session

The previously blocked push succeeded under the operator's standing production
deployment authorization. Registry tag `0.1.0` resolves to OCI index digest
`sha256:73333f5ceb55e48192e3095cb2e2a741cdc6ff0be2f18128301072b4a6b6eb9d`.
The linux/amd64 image manifest is
`sha256:2064d5378e01801ecf9966ccec9c93aadd16d6b404ef4890983d89fa738c164c`.
Both deployment images now pin the registry index digest, verified remotely
following publication. Its equality to the earlier local image identifier is
not the evidence of publication; the successful push and remote index lookup are.

No StatefulSet rollout yet: live KeyCape registrations and audit sender/token
admission remain outstanding. APPROVAL-WP-0002-T03 stays wait for those gates.