# REPORT — TASK G1: management-plane break-glass (felhom-agent half) — v0.71.0

**Baseline:** felhom-agent `main` @ `1c75a45` (v0.70.0) → **v0.71.0** (commit `fd4e177`). felhom.eu @
`2f97ce3`. Trunk-based, direct to `main`.

## What shipped (this repo)

The **prevent + auto-heal + observe** thirds of the break-glass system (the hub vault + surfacing are
the felhom.eu half, hub v0.34.1). Closes the lockout from
`felhom.eu/documentation/audits/SPIKE-felhom-sshd-2026-07-05.md` §8: a second sshd's
`RuntimeDirectory=sshd` removed the SHARED `/run/sshd` privsep dir → the stock sshd on :22 reset every
session after `SSH2_MSG_KEXINIT`.

- **Host artifacts** (`configs/`, installed by felhom-host-install):
  - `felhom-privsep.tmpfiles` — `d /run/sshd 0755 root root -` (layer 1: boot-persistent, owned by no
    unit's lifecycle).
  - `felhom-mgmt-watchdog.sh` — the heal action: stat-first recreate `/run/sshd`, `reset-failed` the
    stock sshd ONLY when `failed`, write an RFC3339 heal-marker; never restarts the stock sshd, never
    touches a healthy dir. shellcheck-clean.
  - `felhom-mgmt-watchdog.service` (oneshot) + `.timer` (OnUnitActiveSec=60s, Persistent). **No unit
    declares `RuntimeDirectory=`** (the incident cause).
- **Go** (`internal/mgmtplane/`): a read-only `Reporter` (os.Stat `/run/sshd`, read the heal-marker,
  TCP-dial sshd:22) → the additive `omitempty` `mgmt_plane` heartbeat stanza
  (`privsep_dir_ok, sshd_reachable, healed_recently, privsep_healed_at`). Wired always-on via
  `Collector.SetMgmtPlaneReporter` (report.go additive fields, the SelfUpdatePending precedent — no
  hub-schema change; the golden contract test uses a nil reporter so the golden stays byte-identical).

## Tests + red-proofs

`go build ./... && go vet ./... && go test ./...` on the build server — **all green**.
- `internal/mgmtplane`: healthy (dir ok, no marker → healed_recently=false); missing dir detected
  while sshd_reachable stays true (the "TCP up, sessions broken" trap); marker present → healed_recently
  + timestamp; empty/whitespace marker treated as absent (red-proof for a hub warning with no
  timestamp); sshd-unreachable reported.
- `internal/hub` collector: nil reporter → `mgmt_plane` omitted; wired → carried through.

## Live validation (felhom-pve) — the acceptance

Deployed **manually** (agent self-update needs an operator-signed op + a pinned signer; the box has
**no signer pinned**, so D1's self-update path was not usable — stated honestly). Build on 180
(`-X main.version=0.71.0`, sha `b3b616fe…`) → scp via local → `install -m0755` (backup `.bak-0.70.0`)
→ restart. Host artifacts installed + timer enabled; `systemd-analyze verify` + `systemd-tmpfiles
--create` + shellcheck all clean; RuntimeDirectory guard verified (no directive, only the warning
comment).

**Auto-heal drill (agent STOPPED — the load-bearing proof):** `systemctl stop felhom-agent` →
`rm -rf /run/sshd` → a new `:22` session reproduced the incident (`Connection reset` right after the
banner) → the agent-independent watchdog **recreated `/run/sshd` and a new `:22` session succeeded
again in 30.0 s (measured), with the agent still `inactive`.** Marker written. This proves the heal is
login-free AND agent-independent.

**End-to-end visibility chain (hub v0.34.1):** the v0.71.0 report carried
`mgmt_plane:{privsep_dir_ok:true, sshd_reachable:true, healed_recently:true,
privsep_healed_at:"2026-07-05T17:15:32Z"}`; the prior healthy report had `healed_recently:false`; the
old v0.70.0 report had no stanza (correctly absent). The hub monitor raised the
**`mgmt_plane_healed` warning** at 17:16:21 ("privsep dir … was missing and was AUTO-HEALED …").

**KEXINIT-reset reproduction:** confirmed live in the drill (`Connection reset by 127.0.0.1 port 22`
immediately after the banner exchange, `/run/sshd` absent).

## Cross-repo state

- Agent **v0.71.0** live on felhom-pve; three break-glass layers active + enabled (they STAY — this
  is the shipped feature). Rollback: `.bak-0.70.0`.
- Hub **v0.34.1** live; break-glass vault + `mgmt_plane_healed` monitor. felhom.eu commits `05d8181`
  (hub+installer), `28ac5f5` (runbook), `012e5f3` (monitor fix + v0.34.1).
- **H1 (felhom-sshd) can now assume `/run/sshd` is guaranteed present** (tmpfiles + watchdog) and must
  never declare `RuntimeDirectory=` — the installer refuses any unit that does.

## Notes / observations

- **Secret discipline verified:** the root@pam recovery password appears in NO log/commit (the vault
  handler logs username + length only; red-proofed hub-side).
- **Least-privilege console user** (vs root@pam): not probed live (PVE gates the node Shell to
  root@pam historically); G1 ships the proven root@pam path — a non-blocking future item.
- **Auto-rotation** of the recovery credential is a noted future item; `--rotate-recovery` re-vaults on
  demand.
- Heal cadence: OnUnitActiveSec=60s (measured 30 s this run, mid-cycle); worst case ~60 s.