# REPORT — controller v0.106.0: offsite provisioning SLICE 2 (apply-bridge)

**Date:** 2026-07-09 · **Class:** implementation (controller) + risky. **Baseline:** `main` @ `fa9362f`
(v0.105.0) → v0.106.0. Pairs with **hub v0.38.0** (adds `HostFingerprint` to the offsite descriptor).

## What shipped
On startup the controller reconciles the hub-served `offsite:` descriptor into a working key-only offbox
target — the controller half of hub-driven offsite provisioning.
- `internal/config.OffsiteConfig` — the `offsite:` section (mirrors the hub descriptor incl. `host_fingerprint`).
- `internal/offsiteapply.Bridge.Reconcile` — **verify-pin (no blind TOFU)** → generate keypair → **consume
  the one-time password** (single-use, never logged) → install pubkey (`sshpass -e ssh-copy-id -p 23 -s -f`,
  **pinning the scanner-verified `known_hosts` via `StrictHostKeyChecking=yes` — the install/verify sessions
  refuse any key but the one the bridge already matched, closing the scan→install MITM gap**)
  + verify → configure offbox → `EscrowState="pending"` → persist the descriptor-hash marker LAST.
  **Idempotent** (marker prevents re-consuming a spent password) and **fail-safe** (any step fails → nothing
  persisted, retried next cycle; consumed-but-failed install logs a loud "password is spent — reset on the hub").
- `internal/backup.Manager.ApplyOffsiteTarget` — reuses the fork-4 enable primitives (best-effort escrow stage).
- `cmd/controller` — wires the real seams + runs `Reconcile` async at startup. `Dockerfile` + `sshpass`.

## Files changed
`internal/config/config.go`, `internal/offsiteapply/{offsiteapply.go,seams.go,offsiteapply_test.go}` (new),
`internal/backup/offbox.go`, `cmd/controller/main.go`, `Dockerfile`, `CHANGELOG.md`.

## Tests + companion red-proofs
Green gate `go build ./... && go vet ./... && go test ./...` — **ALL-GREEN** (both repos).
- `TestBridge_AppliesEndToEnd` — consume→verify-pin→install→configure→marker; asserts **the installer AND
  the enabler both receive the scanner-verified known_hosts** + the private key, and **the one-time password
  never appears in a log line**. **Red-proof run:** passed an empty known_hosts to the installer (the pre-fix
  TOFU shape) → test FAILED ("installer must receive the scanner-verified known_hosts to pin (no TOFU), got \"\""). Reverted.
  Pinning-the-install-connection (not just the scan) is load-bearing — addresses the security-review TOFU-after-verify finding.
- `TestBridge_HostKeyMismatchRefuses` — a scanned FP ≠ descriptor FP → refuse (no consume/install/configure/marker).
  **Red-proof run:** dropped the verify (`if false`) → the mismatch proceeded to install a wrong key → test
  FAILED ("mismatch must refuse, got <nil>"). Reverted. No-TOFU is load-bearing.
- `TestBridge_IdempotentNoReconsume` — marker matches → `Consume` panics if called → clean no-op.
- `TestBridge_InstallFailIsFailSafe` — install errors → marker NOT persisted, offbox NOT configured, loud
  "password is spent" log. **Red-proof run:** persisted the marker before the install → a failed apply looked
  done → test FAILED ("marker must NOT be persisted on a failed apply"). Reverted. Marker-after-success is load-bearing.
- Hub `internal/offsite`: descriptor carries `HostFingerprint` from a faked scanner; a scan failure fails-closed.

## Deploy verification
(To be filled by the deploy step: controller `:0.106.0 Up (healthy)` on guest 9201 + clean startup logs;
offsite is disabled in the demo config, so the bridge no-ops — the deploy proves the image ships sshpass +
the bridge wiring, not a live apply.)

## NOT yet live-applied
The supervised end-to-end (hub provisions on the new pool box `u629488`/project `15282031` → controller
consumes + installs its key + configures the offbox → `EscrowState="pending"`) is the **next runbook**, gated
on the hub being wired with the new scoped `HETZNER_TOKEN` + `HETZNER_POOL_BOX_ID`. Unit tests (faked seams)
are this slice's proof. Untested-live: the real `sshpass`/`ssh-copy-id -s -f` install + the x/crypto/ssh
host-key scan against a live box (both proven in the API spike; re-confirmed in the supervised run).

## Observations
- The bridge runs once at startup; the config-refresh self-restart re-runs it after a descriptor change (no
  separate post-refresh hook needed — the restart is the trigger).
- The escrow stage-push is best-effort (agent-down leaves the offbox configured+pending, re-stage later) —
  the offbox run-gate still holds until the operator confirms escrow (fork-4).
