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.

Start with §0. It is first because it is the rule you can break before you have read anything else: the very first git checkout -b in the wrong directory has already done the damage.

0. Work in your OWN workspace. Never in the shared checkout.

Before you create a branch, edit a file, or run git anything: make yourself a git worktree outside the repository root, and do all of your work there. One workspace per agent run, no exceptions.

# from the shared checkout, ONCE, at the start of your run
git fetch origin main
git worktree add -b <type>/<slug> /path/outside/the/repo/wt-<slug> origin/main
cd /path/outside/the/repo/wt-<slug>        # everything after this happens HERE

/path/outside/the/repo means outside this repository's tree — your session scratchpad, or a sibling like /var/home/keith/source/wt-<slug>. Branch from origin/main, never from main and never from HEAD; see "stale base" below.

The shared checkout is /var/home/keith/source/home-network-k3s-impl — the operator's working copy, the one you are probably started in. In it, do not:

• git checkout / git switch / git checkout -b. Its HEAD is shared state; moving it moves the tree out from under whoever else is using it.
• edit, create or delete a file. Including "just one doc", including a file you intend to move later.
• git add / git commit / git stash / git restore. git add -A there stages whatever another agent left lying around; git stash removes their uncommitted work into a place they will not look.
• git worktree remove anything you did not create.

Read-only commands there are fine, and the one write you do need is creating your own worktree.

Why — measured in the shared checkout, 2026-10-05

What was measured	Value
checkout: moving entries in its reflog	107 — the tree has been yanked between branches 107 times
the branch it was sitting on	feat/pm-agent-issue-to-pr — not main
uncommitted trees left in it by other runs	2 (infra/agent/, platform/pm-agent/), mtimes five minutes apart the same evening
its local main vs origin/main	two commits behind (4386d14 vs 22c94ef)
registered worktrees	42, of which 31 are on branches already merged to main
gate scripts carrying an explicit .claude/ exclusion	9

Each row is a distinct way the shared checkout damages work:

• Dirty tree, foreign files. Two other runs' uncommitted directories were sitting in it. An agent that edits there and runs git add -A ships someone else's half-finished work inside its own PR, and the PR's author has no idea what those files are. This is not hypothetical and it is not historical: eleven minutes after those two directories were measured, while this very section was being written, another run committed them — 5334abe feat(pm-agent): ..., 1,000+ lines across infra/agent/, clusters/, catalog/ and apps/ — onto the shared checkout's checked-out branch, moving its HEAD under anyone reading it. Had this rule's author been working in that tree rather than in a worktree, that commit and this one would have collided.
• Stale base. Its main was two commits behind origin/main, so git checkout -b x main there branches off a tree that is already not what CI will merge into — the gate you run locally proves a base nobody else has. Worse, it was not even on main: a bare git checkout -b x would have branched off feat/pm-agent-issue-to-pr and silently inherited that work into your PR. git fetch first, and name origin/main explicitly as the start point.
• Shared HEAD. 107 branch switches in one tree is 107 chances to switch it while another agent is mid-edit. The loser's changes are either carried onto the wrong branch or lost to a checkout conflict — and the symptom surfaces in their session, not yours.

Put the workspace OUTSIDE the repo root

A worktree inside the tree (.claude/worktrees/agent-*/ — which is where Claude Code's own default puts it) is a full second copy of the repo that every tree-walking check then finds. Measured 2026-09-12: find-based discovery reported the same manifest under test once per worktree, up to 18 times, and the L0 check comparing that listing against the tree failed on paths that are not authored surface at all (platform/monitoring/tests/run.sh:115-123). Nine gate scripts now carry an explicit .claude/ prune for this reason — which means the hazard is worked around, not fixed, and the next check that walks the tree will hit it again. Keep the copy out of the tree and none of that applies.

Clean up — and expect not to be able to

31 of the 42 registered worktrees are on branches already merged to main. A registered worktree pins its branch: while it exists, that branch cannot be deleted or checked out anywhere else. So a left-behind workspace is a lock on a branch name, and the cost lands on whoever next needs it.

Remove yours when you are done:

git worktree remove /path/outside/the/repo/wt-<slug>

Measured 2026-10-05: on a worktree you created yourself, in the session scratchpad, that command succeeds — rc 0, no prompt, with or without a branch checked out. The "worktree removal is sandbox-blocked" note in circulation is about the .claude/worktrees/agent-* ones belonging to other sessions, some of which are additionally locked on git's own terms. So: remove yours, and only yours. If removal is refused, say so in your handoff and leave the worktree registered — do not rm -rf the directory, which leaves a registered worktree pointing at nothing and still holding the branch.

If someone else's stale worktree is holding the branch you need, do not try to reclaim the branch name. Push a rework/<pr-number> branch to the PR's refspec instead.

If you are already standing in the shared checkout with edits

Stop. Do not git stash (that moves other agents' work too). Create your worktree as above, redo the edits there, and leave the shared checkout's HEAD and working tree exactly as you found them.

Gating from a worktree

Three known breakages, all with workarounds, all required every run: see §3, "Running the gate from a worktree".

If you are writing a brief for another agent

The brief must name its own explicit branch and tell it to create its own worktree from origin/main. "Work on the current branch" and "continue in the checkout" are how branch sprawl and cross-contamination got here: an agent given no workspace uses the one it is started in, which is the shared one. Also carry §3's three gate workarounds into the brief — an agent that cannot gate will report rc 3 as green.

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.

The administrator override (2026-10-01). The rule above was unsatisfiable for the one human who runs this repo: Gitea refuses to let an author approve their own PR, and jakman85 is the only collaborator — so a sensitive-path PR the operator opened could never be merged, including the PR that would fix that. An administrator may therefore waive the review by posting this on the PR:

/approve-override <reason>

Post it as a PR review of type "Comment", not in the plain comment box. CI's SETTINGS_API_TOKEN is minted [read:repository, read:admin], and /issues/{n}/comments sits behind Gitea's issue scope — so an override typed into the comment box is invisible to CI, and the stage reports it as a missing approval rather than as a permission problem (measured on PR #38, 2026-10-02). /pulls/{n}/reviews is readable, so a review body works today. Both sources are accepted and the gate names which it used; the comment box starts working once infra/gitea/set-ci-token.sh is re-run to pick up read:issue.

The directive must start a line, the reason is mandatory, the poster's admin/owner permission is re-checked live when the gate runs, and it must be newer than the head commit — push again and you must override again. The overrider, the timestamp and the reason are printed in the gate log and the job summary. For an administrator, "a change to the gate cannot be gated by the gate" is therefore advisory, not structural; what is kept is an attributed record of each waiver. Note that the agent account gitea-admin also holds owner here, so an agent can clear this on its own PR — do not: posting that directive to unblock your own agent work is exactly the self-approval the stage exists to prevent. Get the operator to post it, or move the change out of the sensitive paths.

required_approvals on main is 0, not 1 — the gate is the approver. That drops the approval count only: block_admin_merge_override and enable_status_check both remain true, so a red gate is unmergeable by everyone, administrators included.

• 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
Gate cannot be overridden, by anyone	✅ block_admin_merge_override: true
Human approval required before merge	⬜ No — required_approvals: 0 since 2026-10-01. The gate is the approver; sensitive paths are gated by ci/approval-policy.sh instead. See §1

The first three 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.

The fourth row deliberately changed on 2026-10-01. required_approvals: 1 was a lock-out, not a protection: with a single collaborator and Gitea refusing author self-approval, nothing could satisfy it (measured on PR #35 — green gate, zero reviews, unmergeable). It also contradicted the model already written into ci/approval-policy.sh and ci/gate.sh. Rationale and the live-change script: infra/gitea/allow-admin-self-merge.sh.

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 — and from a worktree it is avoidable outright (§3's worktree list, item 3). gitea-settings is the other expected skip: it needs SETTINGS_API_TOKEN, which exists only in CI, so a local run cannot return 0 — the honest best local result is rc 3 with gitea-settings as the only stage that did not run. Any further skip is a real gap in your run. Report the rc and name the skipped stages; never round rc 3 up.

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 worktree

This is the normal path, not an edge case — §0 requires you to be in a worktree, so every gate run you do hits all of these. Three known breakages, all with workarounds, all of them yours to apply every run — put them 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.
3. spec-immutability skips — the skip called tolerated above is also avoidable. dev.sh derives the sibling spec path from its own REPO_ROOT, which in a worktree is your workspace, so ../home-network-k3s does not resolve and it adds no mount. Mount the spec repo read-only in the same ENGINE shim and pass -e SPEC_REPO=/home-network-k3s: with both mounts the stage reports pass, not SKIPPED, and R-TEST-06 is actually covered (measured — decisions/2026-10-01-render-selftest-runs-in-gate.md).

4. Branch naming

Use feat/, fix/, docs/, chore/. One branch, one workspace, one PR — if you need a second branch, make a second worktree (§0); do not re-point an existing one. 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.