Files
home-network-k3s-impl/decisions
jakman85andClaude Opus 5 fa4765bb3e feat(schema): declare a host hardware capability, hardware.gpu: intel-quicksync
A ServiceDefinition could not say it needs the host's Intel QuickSync render
device. The schema is `additionalProperties: false`, so there was no authorable
form for it at all, and `apps/` is generated — a hand-edit would be reverted by
the next render.

Adds optional top-level `hardware`, with one optional member `gpu`, an enum
whose only current value is `intel-quicksync` (schema 1.7.0 -> 1.8.0).

The enum is the point. The SD declares WHAT CLASS of device it needs; the
hostPath and the mount live only in catalog/render.py. Migrating to the Intel
GPU device plugin (`gpu.intel.com/i915` resource requests, no hostPath) is then
a renderer change with zero catalog edits. Letting an SD name `/dev/dri`
directly would look simpler and make that migration a catalog-wide edit, so
both the schema description and the renderer contract say so explicitly.

When `hardware.gpu == intel-quicksync`, r_deployment emits exactly two things,
on the app container only:

  - a hostPath volume `dri` -> /dev/dri, type DirectoryOrCreate;
  - a read-write volumeMount of it at /dev/dri (VA-API opens the render node
    read-write, so deliberately not readOnly).

Mounting the device is sufficient. In particular NO
podSecurityContext.supplementalGroups is emitted, and adding one would be a
regression rather than a hardening. Measured in the running container on
prod-2, 2026-09-30:

  PID 1   s6-svscan            Uid: 0     Gid: 0     Groups: 0
  pid 246 Plex Media Server    Uid: 1000  Gid: 1000  Groups: 100 1000

The service is started with `exec s6-setuidgid plex ...`, and the child's group
list is exactly the /etc/group account-database list — root's gid 0, which
PID 1 holds, is gone. That is a setgroups() that REPLACES rather than appends,
so anything Kubernetes supplies is discarded before the app starts. What works
is the image's own /etc/cont-init.d/45-plex-hw-transcode-and-connected-tuner,
which stats each /dev/dri char device, groupadds a matching group inside the
container and usermods the app user into it, every start, nothing hardcoded.
An inert supplementalGroups would have read as the mechanism to whoever
debugged this next, so the absence is documented at the emission site and
asserted by --selftest. Corollary: the hook re-stats on every start, so host
GID drift is self-healing and no GID is pinned anywhere in this repo.

`DirectoryOrCreate` is load-bearing. A node that comes back without the render
device (rebuild, BIOS change, driver regression, hardware swap) must degrade
the workload to software transcoding, not fail the mount: apps-wave-0 is
`wait: true` and apps-wave-1 dependsOn it, so a failed hostPath mount stalls
the whole app tier for a feature that is not load-bearing. /dev is tmpfs, so
the empty directory the kubelet creates leaves nothing durable behind. Its cost
— a missing device is silent, and no metric exists to alert on — is recorded in
the contract rather than papered over with an alert that could not fire.

Also deliberately NOT emitted: no `privileged: true` (Kyverno restrict-host-
namespaces is Enforce and it is not needed), no nodeSelector (placement is a
separate concern with its own justification), no resource requests (there is no
app-container resource render path).

No catalog entry uses the field. Re-rendering `--all catalog -o apps` is a zero
diff, which is the proof the change is inert until opted into.

Self-tests in the existing check(...) style: the positive (volume + mount, and
no securityContext / privileged / nodeSelector), the negative (an SD without
`hardware` gains no volume, no mount, no securityContext — mirroring the
podSecurityContext negative) and a pass-through case (an SD's own
podSecurityContext survives byte-for-byte). Note that NO gate stage runs
`render.py --selftest`; they were run by hand and the gap is recorded in the
handoff.

Co-Authored-By: Claude Opus 5 (1M context) <[email protected]>
2026-10-01 20:54:35 -05:00
..

decisions/ — the handoff log, one file per entry

This directory is the decision log. ../DECISIONS-LOG.md is the frozen archive of everything written before 2026-09-29 and is never edited again (see "The archive is frozen" below).

Why this exists

DECISIONS-LOG.md was append-only in a single file, and every agent appended to its tail. Two branches that both append hit the same last hunk, so git cannot auto-merge them: the second one to be reviewed conflicts, and so does the third, and the fourth. Measured on 2026-09-29: four of the five open PRs were unmergeable, and DECISIONS-LOG.md was the only conflicting file in all four:

#22 fix/crafty-oauth2-proxy-signin      CONFLICT (content): DECISIONS-LOG.md
#20 feat/conformance-job-template       CONFLICT (content): DECISIONS-LOG.md
#19 feat/conformance-trigger-kubeconfig CONFLICT (content): DECISIONS-LOG.md
#18 feat/conformance-runner-image       CONFLICT (content): DECISIONS-LOG.md
#17 feat/ci-is-the-approver             clean  (it touched no log entry)

Nothing was wrong with any of those changes. The log's storage format serialised work that was otherwise parallel, and it got worse with every concurrent branch: N branches produce N-1 rebases, each of which invalidates any gate run that preceded it.

The fix is the obvious one for concurrent appenders: stop sharing a file. Each handoff is its own file. Two agents writing handoffs touch disjoint paths, so there is nothing for git to merge and nothing to conflict. This scales to any number of parallel branches with zero coordination — which is the point, since the agents are deliberately isolated from each other in separate worktrees and cannot coordinate.

There is deliberately no index file and no counter. An index would be a shared mutable file — exactly the thing that just failed — and a sequence number would have two agents racing for 0043. The directory listing is the index.

Writing an entry

One file per handoff, named:

decisions/YYYY-MM-DD-<slug>.md

<slug> is lowercase [a-z0-9-]. Use your branch name's last segment — it is already unique per unit of work, which is precisely the property the filename needs. A branch fix/crafty-oauth2-proxy-signin handed off on 2026-09-29 writes:

decisions/2026-09-29-crafty-oauth2-proxy-signin.md

The file is YAML frontmatter followed by three required sections:

---
date: 2026-09-29
branch: fix/crafty-oauth2-proxy-signin
title: The Keycloak gate works — Crafty's own login was the wall
---

## What changed

Prose. What you actually did, and why.

## What I verified

The measurements, with their numbers. Quote the field you read, not the prose you
believed. Name the gate result and its exit code.

## What I did NOT verify

Everything else. An honest "UNVERIFIED" is worth more than an optimistic "green" —
this repo has been burned by the difference more than once.

All three headings are required and enforced (ci/decisions-log.sh). They are CLAUDE.md §7's contract; making them a checked structure is what stops an entry degrading into "done ✅".

Reading the log

The whole log, oldest first:

ls decisions/[0-9]*.md | sort

The current PM handoff — the newest entry. Ties within a day are broken by what landed on main last, which is the honest answer, so ask git rather than the filename:

git log --diff-filter=A --format='%H' --name-only -- 'decisions/[0-9]*.md' \
  | grep '^decisions/' | head -1

For a quick skim of who said what:

grep -H '^title:' decisions/[0-9]*.md | sort

The archive is frozen

DECISIONS-LOG.md is read-only history. Its SHA-256 is pinned in decisions/ARCHIVE.sha256 and ci/decisions-log.sh fails the merge gate if the file changes. That is not ceremony: without it, the next agent to read runbooks/ or an old CLAUDE.md habit appends to the tail again and re-creates the conflict for everybody else, silently, one PR at a time.

If the archive genuinely must change (a leaked credential to redact, say), that is a deliberate, reviewed act: change it, run sha256sum DECISIONS-LOG.md > decisions/ARCHIVE.sha256, and say in your handoff entry why. Re-pinning is visible in the diff. Appending is not.