home-network-k3s-impl/CLAUDE.md

# CLAUDE.md — how work lands in this repo

Read this before doing anything durable. It is the delivery contract for AI coding
sessions and agents. The newest entry in `decisions/` is the current PM handoff and
takes precedence on *what* to work on; this file governs *how* it lands.

## 1. Never push to `main`. Ever.

Every durable change reaches `main` exactly one way:

    branch  ->  push the branch  ->  open a PR  ->  CI gate green  ->  human approval  ->  merge

There is no other path. Specifically:

- **Do not `git push origin main`.**
- **Do not `git push origin HEAD:main`.** Same thing wearing a hat.
- **Do not merge your own PR.** See the approval model below — and either way, the merge is
  someone else's action, never yours.

### Who approves

**The CI/CD pipeline is the approver.** A green gate is sufficient for an ordinary change; the
branch requires no human approval for one. That is a deliberate transfer of authority, on the
operator's stated principle: *if the pipeline is not good enough to be trusted for this, it is not
good enough to do its job and needs improving* — so a weak gate is a bug to fix, not a reason to
add a human.

**One exception, enforced by `ci/approval-policy.sh`:** a change to the pipeline itself, the
admission policies, the Flux wiring, the SOPS recipients, the RBAC, or this file needs an
approving review from someone who is not its author. The reason is narrow and structural — **a
change to the gate cannot be gated by the gate.** A PR that weakens a check would be approved by
the weakened check. Everything else merges on green.

The path list is data, with a reason per entry: `infra/gitea/approval-policy.json`. It is itself a
sensitive path, so the policy cannot be widened or narrowed without a human.

That stage is **fail-closed** — if it cannot evaluate, it blocks. Unlike `gitea-settings`, where a
missing credential is a lock-out, here a skip would be a bypass.
- **Do not `kubectl apply` / `edit` / `patch` a durable change.** Flux reconciles `main`;
  anything applied by hand is drift that the next reconcile reverts or, worse, adopts.

> **Many runbooks under `runbooks/` still say `git push origin main` IS the deploy.**
> That wording is **stale** — it predates the PR flow. It describes what Flux does
> (main is what the cluster follows), not what you are permitted to do. Honour this
> file, not that line. Fixing those runbooks is tracked work.

## 2. Enforcement (as of 2026-09-29: the rule is now MACHINE-ENFORCED)

Verified against the live Gitea on 2026-09-29:

| Expected | Actual |
|---|---|
| `main` protected, direct push rejected | ✅ `protected: true`, `user_can_push: false` — **verified by a real rejected push**, not by the API's word |
| PR blocked until the gate passes | ✅ `enable_status_check: true`, context `gate / gate (pull_request)` |
| Gate runs on every PR | ✅ runner `incluster-dind` online; ~1m35s |
| Approval required before merge | ✅ `required_approvals: 1` |

All four were FALSE as recently as 2026-09-29, while this repo's own log asserted they were
true. They are true now because each was measured, and the push rejection was provoked rather
than assumed. **Re-measure before relying on any of them** — see §2b.

Still not covered: `vars.CLUSTER_AVAILABLE` is unset, so **L2/L3 conformance does not run in
CI**. A green PR therefore proves the L0/L1 offline subset, not runtime behaviour.

**Consequence for you:** CI now runs, but it does not yet *block* anything. Always run
the toolbox gate yourself and quote its numbers. Never describe a PR as "green" on the
strength of a check you have not seen report — and note that a **skipped** Gitea job
reports as `success`, so a green tick is not by itself evidence that anything ran.

## 2b. Never infer platform state from this repository

**This repo is not evidence about the live platform.** Neither is the handoff log
(`decisions/`, and the frozen `DECISIONS-LOG.md` archive). Both describe what someone
believed at the time of writing, and both have been confidently wrong for a month at a
stretch.

On 2026-09-29 the log stated the merge gate was a required status check with a runner
online. The API said `branch_protections: []` and **zero** runners. Everything downstream
of that belief — "the gate enforces this", "your push would be rejected", "CI covers it" —
was wrong, and nothing in the tree could have revealed it, because the tree was the source
of the error.

**So, before asserting that any gate, protection, runner, secret, or workload is in a
given state: query the thing itself.**

| Claim about... | Check |
|---|---|
| branch protection / required checks | `GET /api/v1/repos/{owner}/{repo}/branches/main` |
| a runner exists | `GET /api/v1/admin/actions/runners` |
| CI actually ran | the commit's `/statuses` — and read the **description**; a *skipped* Gitea job reports `success` with "Has been skipped" |
| a workload / Secret / env | `kubectl --context k3s-prod ...` (read-only is fine for agents) |
| Flux applied your commit | compare `.status.lastAppliedRevision` against the GitRepository's artifact revision |

Quote the measured field, not the prose. If you cannot measure it, say so explicitly —
"unverified" is a legitimate report, and a far better one than a confident guess that
matches the docs.

**A green tick is not proof anything ran.** Read what actually executed.

## 3. Gate before you push

    ./infra/devcontainer/dev.sh run bash -c './ci/gate.sh'

Exit codes are a contract — do not flatten them:

| rc | Meaning |
|---|---|
| 0 | PASS |
| 1 | BLOCKED — something failed |
| 3 | UNDETERMINED — a stage did not run. **Never report this as green.** |

`spec-immutability` reaches rc 3 whenever the sibling spec repo is not checked out
beside this one; that single skip is expected and tolerated. Any *other* skip is a
real gap in your run.

**Never gate on the host.** `promtool` and `kustomize` are not on the host `$PATH`,
so checks SKIP and you get a false rc 3. Only the pinned toolbox result counts.

### Running the gate from a git worktree

Two unrelated failures, both with known workarounds — put both in any agent brief:

1. **`dev.sh` refuses to start:** `infra/ansible/.cache/prod.kubeconfig` is untracked
   and exists only in the main checkout. Do **not** copy it (it is a credential).
   Use `DEV_KUBECONFIG=/dev/null` — the gate contacts no cluster, so L2/L3 scaffold-skip
   normally.
2. **Every `git` call inside the container fails:** a worktree's `.git` is a pointer to a
   gitdir outside the mounted root. `dev.sh` takes no extra-mount flag, so inject one via
   the `ENGINE` hook — a shim that intercepts `run` and re-execs
   `podman run -v /path/to/main/.git:/path/to/main/.git:ro "$@"`. A traceback in
   `tracked_files()` is this bug, not a broken tree.

## 4. Branch naming

Use `feat/`, `fix/`, `docs/`, `chore/`. Note that `.gitea/workflows/gate.yml`'s **push**
trigger lists `feature/**` — not `feat/**` — so branch pushes get no fast-feedback run.
The `pull_request` trigger fires regardless of branch name, so the PR gate is unaffected.

## 5. Cluster access

`kubectl` does not work on the operator workstation; the toolchain lives only in the
pinned container. Always name the context explicitly:

    ./infra/devcontainer/dev.sh run bash -c 'kubectl --context k3s-prod get nodes'

`dev.sh` merges both clusters and picks a current-context **per invocation**; that
default has already changed once. Never rely on it. Do not run two `dev.sh`
invocations concurrently.

**Mutating `kubectl` and `flux reconcile` are operator actions, not agent actions.**

## 6. Secrets

- **Never `sops -d` a file into a terminal, a log, or a transcript.**
- **Never print a Secret's `.data`/`.stringData`** when checking whether it exists —
  list key names or object names only. A password has been leaked into a transcript
  this way before.
- Encrypted files are `*.sops.yaml` or live under `secrets/`. The root `.sops.yaml` is
  the single creation-rules file; do not add a second one in a subtree.
- A short-lived credential (e.g. a plex.tv claim token, ~minutes) cannot survive the PR
  flow. Do not design around committing one — read the expiry from the issuing page and
  treat a burnt token as free to retry.

## 7. Before you finish — write a handoff entry, in its OWN file

Add **one new file**:

    decisions/YYYY-MM-DD-<slug>.md          <slug> = your branch's last segment

with frontmatter (`date`, `branch`, `title`) and exactly these three sections:

    ## What changed
    ## What I verified
    ## What I did NOT verify

State gaps plainly — an honest "UNVERIFIED" is worth more than an optimistic "green",
and this repo has already been burned by the difference. All three headings are
**enforced** by `ci/decisions-log.sh`, because the third is the one that gets dropped.
Template and full rationale: `decisions/README.md`.

**Do NOT append to `DECISIONS-LOG.md`.** It is a frozen archive (pre-2026-09-29), its
SHA-256 is pinned in `decisions/ARCHIVE.sha256`, and the merge gate rejects any change
to it. Appending to its tail is what every agent used to do, and because every branch
appended to the *same last hunk*, no two concurrent branches could auto-merge. Measured
on 2026-09-29: **four of the five open PRs were `mergeable: false`, with
`DECISIONS-LOG.md` the only conflicting path in all four** — none of those changes had
anything to do with each other. Separate files have nothing to merge, which is the
entire fix. Note that the damage from getting this wrong lands on *other people's*
branches, later, which is why it is a gate stage and not a request.

Many older handoff entries and runbooks say "append to `DECISIONS-LOG.md`". That
wording is **stale**, in the same way §1's `git push origin main` wording is stale.