cc-ci/machine-docs/REVIEW-pxgate.md

# REVIEW — phase pxgate

**Phase:** pxgate — break deploy-proxy ↔ dashboard health-gate circular dependency (D8 fix)
**Adversary:** autonomic-bot (Sonnet 4.6)
**Started:** 2026-06-13T12:41Z

---

## Adversary orientation (cold start — 2026-06-13T12:41Z)

Independent cold read of the root cause and fix spec. NOT a gate claim — recording what I found so
the M1 verdict below is COLD and reproducible.

### Root cause — INDEPENDENTLY CONFIRMED

Reading `nix/modules/proxy.nix` + `runner/warm_reconcile.py` + `nix/modules/dashboard.nix`:

1. `deploy-proxy.service` runs `warm_reconcile.py traefik`.
2. The traefik SPEC in `warm_reconcile.py:117-128` sets:
   ```python
   "health_domain": "ci.commoninternet.net",
   "health_path": "/",
   ```
   So `health_code()` probes `https://ci.commoninternet.net/` — the dashboard.
3. `deploy-dashboard.service` (dashboard.nix:89) has:
   ```
   After=deploy-bridge.service deploy-proxy.service ...
   ```
   systemd will not start deploy-dashboard until deploy-proxy exits.
4. **Deadlock:** proxy waits for dashboard; dashboard waits for proxy.

### Root cause — PROVEN LIVE (not merely theoretical)

The alert file `/var/lib/ci-warm/alerts/20260613T054428Z-traefik-unhealthy-on-latest.json`
confirms the deadlock hit TODAY at boot time:

```
deploy-proxy started: 05:38:21 UTC
  → probed ci.commoninternet.net (60s timeout): unhealthy
  → redeployed traefik
  → probed ci.commoninternet.net (300s timeout): still unhealthy
  → wrote alert "unhealthy-on-latest", exited 05:44:28 UTC (status=0, RemainAfterExit=true)
deploy-dashboard started: 05:44:46 UTC (AFTER proxy exited)
  → deployed dashboard successfully
  → ci.commoninternet.net now returns 200
```

traefik startDate = 2026-06-13T05:38:02Z (was already up before proxy reconciler started at
05:38:21) — so traefik itself was healthy; the probe was blocked on the dashboard.

### Verified fix endpoint

`curl -sk --resolve traefik.ci.commoninternet.net:443:127.0.0.1 https://traefik.ci.commoninternet.net/api/version`
→ `{"Version":"3.6.15","Codename":"ramequin","startDate":"2026-06-13T05:38:02.987423426Z"}` (200)

This endpoint is up the moment traefik is serving, has no backend dependency, requires no auth.

`/ping` → 404 (not configured in the current recipe — avoid).

### Required change (my independent read of the fix)

In `runner/warm_reconcile.py` SPECS["traefik"]:
- Remove `"health_domain": "ci.commoninternet.net"` — so `health_code()` falls back to `spec["domain"]` = `"traefik.ci.commoninternet.net"`
- Change `"health_path": "/"` → `"health_path": "/api/version"`

`health_code()` will then probe `https://traefik.ci.commoninternet.net/api/version` directly
(via `--resolve traefik.ci.commoninternet.net:443:127.0.0.1`), which returns 200 as soon as
traefik is up — no dashboard dependency.

### Pre-M1 break-it probes (before Builder's fix, 2026-06-13T12:50Z)

**P5 — Secret leak in alert files:** PASS. `/var/lib/ci-warm/alerts/20260613T054428Z-traefik-unhealthy-on-latest.json`
contains only `{"app": "traefik", "reason": "unhealthy-on-latest", "ts": "...", "version": "5.1.1+v3.6.15"}`.
No credentials, no secrets.

**P3 — After=deploy-proxy consumers ordering:** PASS (no regression in current ordering):
- deploy-drone: After=deploy-proxy.service
- deploy-bridge: After=deploy-drone.service deploy-proxy.service
- deploy-dashboard: After=deploy-bridge.service deploy-proxy.service
- deploy-backupbot: After=deploy-dashboard.service deploy-proxy.service
- deploy-reports: After=deploy-dashboard.service deploy-proxy.service
- nightly-sweep: After=deploy-proxy.service warm-keycloak.service
- warm-keycloak: After=deploy-proxy.service
These all correctly depend on deploy-proxy; after the fix, proxy completes without
deadlock and the rest of the chain proceeds normally.

**Endpoint stability:** `/api/version` returns 200 reliably (3/3 probes). No backend dependency.

**P1-negative (traefik-down):** PENDING at M1 gate — requires a controlled stop of
traefik (risky on live system); will execute at M1 verification using a short pause
or by examining the reconciler code path (deploy_version raises → upgrade_ok=False → rollback).

---

## M1 — Fix + controlled reproduction

### PASS @2026-06-13T13:00Z — Adversary cold-verified

**Commit:** `0e9fd38` (`claim(pxgate-M1): change traefik health probe to /api/version`)

#### Check 1 — Code change correct ✅

`runner/warm_reconcile.py` SPECS["traefik"] (lines 120–129):
```python
"traefik": {
    "recipe": "traefik",
    "domain": "traefik.ci.commoninternet.net",
    "health_path": "/api/version",   # ← changed from "/"
    "health_ok": (200,),
    "stateful": False,
    "deploy_timeout": 600,
    "health_timeout": 300,
    "setup": _traefik_setup,
},
```
`health_domain` key is **absent** → `health_code()` falls back to `spec["domain"]` =
`"traefik.ci.commoninternet.net"`. Probe is now `https://traefik.ci.commoninternet.net/api/version`
with `--resolve traefik.ci.commoninternet.net:443:127.0.0.1` — traefik's own API, no backend dep.

#### Check 2 — Controlled reproduction ✅

Scaled `ccci-dashboard_app` to 0 replicas (dashboard absent):
- **New probe** (`/api/version` on traefik domain): HTTP **200** ← cycle broken
- **Old probe** (`ci.commoninternet.net/`): HTTP **404** ← confirms old gate was deadlocked

Dashboard restored to 1/1 and returns 200 after scale-up.

#### Check 3 — Consumer ordering unchanged ✅

All `After=deploy-proxy.service` consumers unchanged:
```
deploy-drone:      After=deploy-proxy.service swarm-init.service docker.service network-online.target
deploy-bridge:     After=deploy-drone.service deploy-proxy.service ...
deploy-dashboard:  After=deploy-bridge.service deploy-proxy.service ...
deploy-backupbot:  After=deploy-dashboard.service deploy-proxy.service ...
deploy-reports:    After=deploy-dashboard.service deploy-proxy.service ...
nightly-sweep:     After=deploy-proxy.service warm-keycloak.service docker.service
warm-keycloak:     After=deploy-proxy.service ...
```
`deploy-proxy` itself: `After=swarm-init.service docker.service network-online.target` — no dashboard
dependency in its own ordering (correct). Fix does not change any service ordering.

#### Check 4 — Alert dir empty ✅

`/var/lib/ci-warm/alerts/` is empty — Builder cleared the stale 05:44Z alert (valid false-alarm from
the old gate hitting the deadlock this morning).

#### Check 5 — proxy.nix comment ✅

Comment updated: "health-gate (traefik.ci.commoninternet.net/api/version returns 200 — traefik's own
API, no backend dep)". No functional change to the nix module (same systemd unit).

#### Check 6 — Gate has teeth ✅ (with one documentation note)

**Functional PASS:** `health_code()` line 276 returns `int(r.stdout.strip() or "0")` → on curl
connection failure, stdout = "000" (curl's HTTP-code sentinel) → `int("000") = 0` → 0 ∉ `health_ok=(200,)`
→ `wait_healthy()` returns False → rollback triggered. Gate genuinely fails on a broken traefik.

**Documentation discrepancy (non-blocking):** The STATUS claim says "EXPECTED: error sentinel 999 returned
when curl fails." The actual code returns 0 (not 999) on curl failure. `grep` for "999" returns no matches.
This is a documentation error in the M1 claim only — the functional behavior is correct (0 ≠ 200 → gate
fails → rollback). No code defect; no blocking finding.

#### Check 7 — DEFERRED + DECISIONS updated ✅

`machine-docs/DEFERRED.md`: 2026-06-13 circular-dependency entry marked `[x] CLOSED @2026-06-13` with fix pointer.
`machine-docs/DECISIONS.md`: "deploy-proxy health gate — SETTLED (2026-06-13, phase pxgate)" entry added with rationale.

---

**M1 VERDICT: PASS** — cycle broken, new probe is dashboard-independent, rollback gate has teeth,
ordering unchanged, DEFERRED closed, docs updated. One non-blocking STATUS discrepancy (999 vs 0
sentinel) noted; no code defect.

---

## M2 — Proven on a real from-scratch boot

### PENDING — awaiting orchestrator nixos-rebuild (as of 2026-06-13T13:08Z)

M1 is PASS. The fix is in the repo (`0e9fd38`). The live cc-ci host still has the OLD probe:
- Active reconcile script: `/nix/store/km6173hm5a77wxggd7zba3mfakrz0c94-cc-ci-reconcile-proxy`
- Calls: `/nix/store/ls5d6s7q2892z0n0qv7sfk03zimwx3nd-runner/warm_reconcile.py`
- That file has: `"health_domain": "ci.commoninternet.net"`, `"health_path": "/"` — OLD probe still live

**Orchestrator action required:**
```bash
ssh cc-ci
cd /root/builder-clone
git pull   # to get commit 0e9fd38
nixos-rebuild switch --flake "git+file:///root/builder-clone?submodules=1#cc-ci"
```

After nixos-rebuild, I will verify (per STATUS-pxgate.md M2 checks):
1. `deploy-proxy.service` shows `active (exited)` (not unhealthy alert)
2. New nix store path with `/api/version` in use
3. All services 1/1 unaffected
4. Cold-boot simulation: stop dashboard + restart proxy → proxy completes healthy without dashboard