install.sh: enrollment token via header file too — it was on curl argv despite the comment

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

drb-edge-node/app/internal/credentials.py

@@ -3,8 +3,12 @@ Manages the persisted node API key, plus the local-auth signing material used
 by app/internal/auth.py.
 
 The API key is provisioned by the C2 server after an admin approves the node.
-It arrives via MQTT and is saved to /configs/credentials.json so it survives
-container restarts.
+install.sh fetches it over HTTPS (GET /nodes/{id}/credentials + the pickup
+secret it saved to /configs/pickup_secret) and writes /configs/credentials.json;
+the running app can also fetch it itself (app/internal/key_pickup.py) and
+re-read the file at any time (reload_api_key), so a key written after startup
+is picked up without a container restart (node-26#14). The legacy MQTT
+delivery (nodes/{id}/api_key) still saves here too.
 
 The scrypt salt and session-signing secret are generated locally on first boot
 (never provisioned externally) and persisted the same way, so dashboard
@@ -12,12 +16,14 @@ sessions survive a container restart instead of forcing every operator to
 re-login whenever the node restarts.
 """
 import json
+import os
 import secrets
 from pathlib import Path
 from app.config import settings
 from app.internal.logger import logger
 
 _CREDS_FILE = Path(settings.config_path) / "credentials.json"
+_PICKUP_FILE = Path(settings.config_path) / "pickup_secret"
 _api_key: str | None = None
 _auth_salt: bytes | None = None
 _session_secret: bytes | None = None
@@ -74,6 +80,37 @@ def get_api_key() -> str | None:
     return _api_key
 
 
+def reload_api_key() -> str | None:
+    """Re-read the api_key from disk (install.sh, or an operator, may have
+    written it after startup). Returns the key now in effect. Only the api_key
+    is taken from the file — the auth material already in memory stays."""
+    global _api_key
+    try:
+        data = json.loads(_CREDS_FILE.read_text())
+    except FileNotFoundError:
+        return _api_key
+    except Exception as e:
+        logger.warning(f"Could not re-read credentials file: {e}")
+        return _api_key
+    key = data.get("api_key")
+    if key and key != _api_key:
+        _api_key = key
+        logger.info("Node API key re-read from disk (changed since it was last loaded).")
+    return _api_key
+
+
+def get_pickup_secret() -> str | None:
+    """The one-time pickup secret install.sh saved at enrollment, if any."""
+    try:
+        secret = _PICKUP_FILE.read_text().strip()
+    except FileNotFoundError:
+        return None
+    except Exception as e:
+        logger.warning(f"Could not read pickup secret: {e}")
+        return None
+    return secret or None
+
+
 def save_api_key(key: str) -> None:
     global _api_key
     _api_key = key
@@ -88,4 +125,10 @@ def _write() -> None:
         data["auth_salt"] = _auth_salt.hex()
     if _session_secret is not None:
         data["session_secret"] = _session_secret.hex()
-    _CREDS_FILE.write_text(json.dumps(data))
+    # Atomic replace with 0600: install.sh on the host writes this same file,
+    # and a torn half-written JSON would lose the key AND the auth material.
+    tmp = _CREDS_FILE.with_name(_CREDS_FILE.name + ".tmp")
+    fd = os.open(tmp, os.O_WRONLY | os.O_CREAT | os.O_TRUNC, 0o600)
+    with os.fdopen(fd, "w") as f:
+        f.write(json.dumps(data))
+    os.replace(tmp, _CREDS_FILE)

drb-edge-node/app/internal/key_pickup.py

@@ -0,0 +1,73 @@
+"""
+HTTPS api_key pickup — the node's own half of C2's enrollment flow
+(Server/drb-c2-core/app/routers/enrollment.py, GET /nodes/{id}/credentials).
+
+Why this exists (node-26#14): key delivery used to be MQTT-only
+(nodes/{id}/api_key), and a dynsec broker refuses a node that has no key — or
+a stale one — so a locked-out node could never receive the key that would let
+it in. install.sh already did this pickup once at install time; doing it from
+the running app too means a node approved after install, or whose key was
+reissued, recovers on its own with no SSH and no container restart.
+
+Auth is the pickup secret install.sh saved to /configs/pickup_secret at
+enrollment (the same file, bind-mounted). Only ever sent to settings.c2_url,
+over whatever scheme the operator configured (https in production).
+"""
+from typing import Optional
+
+import httpx
+
+from app.config import settings
+from app.internal import credentials
+from app.internal.logger import logger
+
+_TIMEOUT = 15
+
+
+async def fetch_api_key() -> Optional[str]:
+    """Ask C2 for this node's api_key. Returns it, or None when there isn't one
+    to be had yet (not approved, no pickup secret, C2 unreachable, rejected).
+    Never raises — the caller retries on its own backoff."""
+    if not settings.c2_url:
+        logger.warning("Key pickup skipped: C2_URL is not configured.")
+        return None
+    secret = credentials.get_pickup_secret()
+    if not secret:
+        logger.warning(
+            f"Key pickup skipped: no {settings.config_path}/pickup_secret. This node was not enrolled by "
+            "install.sh on this machine — re-run install.sh, or have an admin Reissue key and write it in."
+        )
+        return None
+
+    url = f"{settings.c2_url.rstrip('/')}/nodes/{settings.node_id}/credentials"
+    try:
+        async with httpx.AsyncClient(timeout=_TIMEOUT) as client:
+            r = await client.get(url, headers={"X-Pickup-Secret": secret})
+    except Exception as e:
+        logger.warning(f"Key pickup: could not reach C2 ({e}).")
+        return None
+
+    if r.status_code == 401:
+        logger.error(
+            "Key pickup: C2 rejected the saved pickup secret (401) — it was rotated by a re-enroll elsewhere. "
+            "Re-run install.sh with --token to recover."
+        )
+        return None
+    if r.status_code == 404:
+        logger.error("Key pickup: C2 does not know this node (404) — it was deleted server-side. Re-run install.sh.")
+        return None
+    if r.status_code != 200:
+        logger.warning(f"Key pickup: unexpected HTTP {r.status_code} from C2.")
+        return None
+
+    try:
+        body = r.json()
+    except ValueError:
+        logger.warning("Key pickup: C2 returned a non-JSON body.")
+        return None
+    key = body.get("api_key") if isinstance(body, dict) else None
+    if not key or not isinstance(key, str):
+        status = body.get("approval_status") if isinstance(body, dict) else None
+        logger.info(f"Key pickup: no api_key yet (approval_status={status!r}) — waiting for an admin to approve.")
+        return None
+    return key

drb-edge-node/app/internal/mqtt_manager.py

@@ -6,12 +6,30 @@ from typing import Optional, Callable, Awaitable, Dict, Any
 import paho.mqtt.client as mqtt
 from app.config import settings
 from app.internal.logger import logger
-from app.internal import credentials
+from app.internal import credentials, key_pickup
 
 CommandCallback = Callable[[Dict[str, Any]], Awaitable[None]]
 ConfigCallback = Callable[[Dict[str, Any]], Awaitable[None]]
 ApiKeyCallback = Callable[[Dict[str, Any]], Awaitable[None]]
 
+# CONNACK codes meaning "your credentials are wrong", as paho reports them:
+# MQTT 3.1.1 return codes 4/5, and the MQTT 5 reason codes paho maps them to
+# (134 Bad user name or password, 135 Not authorized).
+_AUTH_FAILURE_CODES = {4, 5, 134, 135}
+
+# Credential-recovery backoff (node-26#14). The pickup endpoint is cheap, but a
+# node that is simply not approved yet must not hammer C2 for days.
+RECOVERY_MIN_DELAY = 30
+RECOVERY_MAX_DELAY = 900
+
+
+def _is_auth_failure(reason_code) -> bool:
+    value = getattr(reason_code, "value", reason_code)
+    if isinstance(value, int) and value in _AUTH_FAILURE_CODES:
+        return True
+    text = str(reason_code).lower()
+    return "not authori" in text or "bad user name or password" in text
+
 
 class MQTTManager:
     def __init__(self):
@@ -19,6 +37,11 @@ class MQTTManager:
         self._loop: Optional[asyncio.AbstractEventLoop] = None
         self._connected = False
         self._connect_task: Optional[asyncio.Task] = None
+        # The api_key the CURRENT paho client was built with — not necessarily
+        # credentials.get_api_key(), which can move ahead of it (MQTT key push,
+        # install.sh writing the file). Recovery compares against this.
+        self._client_key: Optional[str] = None
+        self._recovery_task: Optional[asyncio.Task] = None
 
         self.on_command: Optional[CommandCallback] = None
         self.on_config_push: Optional[ConfigCallback] = None
@@ -53,6 +76,7 @@ class MQTTManager:
         )
 
         api_key = credentials.get_api_key()
+        self._client_key = api_key
         if api_key:
             # Post-cutover auth: broker's dynsec plugin authenticates this
             # exact (username, password) pair as this node's own client — see
@@ -70,18 +94,14 @@ class MQTTManager:
             client.username_pw_set(settings.mqtt_user, settings.mqtt_pass)
         else:
             # No api_key on disk and no legacy shared login configured. A
-            # dynsec broker (allow_anonymous false) refuses this outright —
-            # expected, not a bug to route around here: this node hasn't been
-            # enrolled/approved yet, and the enrollment flow that would fix
-            # that client-side is a later, separate pass (out of scope here;
-            # see MQTT-PUBLIC-AUTH-PLAN.md). paho's reconnect_delay_set()
-            # below bounds the retry rate (2..60s exponential backoff), so
-            # this degrades to a slow, clearly-logged refusal loop via
-            # _on_connect's "MQTT connect refused" line — not a hot spin.
+            # dynsec broker (allow_anonymous false) refuses this outright.
+            # connect() starts _recover_credentials() in this case, which
+            # fetches the key over HTTPS (key_pickup.py) and rebuilds this
+            # client with it — node-26#14. paho's reconnect_delay_set() below
+            # bounds the refusal loop meanwhile (2..60s backoff).
             logger.warning(
                 "No API key on disk and no legacy MQTT_USER configured — "
-                "connecting without credentials; the broker is expected to "
-                "refuse this until the node is enrolled/approved."
+                "connecting without credentials while the key is fetched from C2."
             )
 
         if settings.mqtt_tls:
@@ -120,6 +140,10 @@ class MQTTManager:
             asyncio.run_coroutine_threadsafe(self._flush_offline_buffer(), self._loop)
         else:
             logger.error(f"MQTT connect refused: {reason_code}")
+            if _is_auth_failure(reason_code) and self._loop is not None:
+                # paho thread -> event loop. A refused login never fixes itself
+                # by retrying the same password, so go get the right one.
+                self._loop.call_soon_threadsafe(self._start_recovery, f"broker refused login ({reason_code})")
 
     def _on_disconnect(self, client, userdata, disconnect_flags, reason_code, properties):
         self._connected = False
@@ -144,6 +168,72 @@ class MQTTManager:
         self._loop = asyncio.get_event_loop()
         self._client = self._build_client()
         self._connect_task = asyncio.create_task(self._connect_with_retry())
+        if not self._client_key and not settings.mqtt_user:
+            self._start_recovery("no API key at startup")
+
+    # ------------------------------------------------------------------
+    # Credential self-heal (node-26#14)
+    #
+    # A node with no key, or a stale one, used to sit in an MQTT refusal loop
+    # forever: key delivery was MQTT-only, and credentials were read once at
+    # startup. Now: re-read credentials.json (install.sh may have written it),
+    # else fetch from C2 over HTTPS with the pickup secret; if that yields a
+    # key different from the one the client is using, rebuild the client with
+    # it in place. No container restart.
+    # ------------------------------------------------------------------
+    def _start_recovery(self, why: str) -> None:
+        if self._recovery_task and not self._recovery_task.done():
+            return
+        logger.warning(f"MQTT credential recovery started: {why}")
+        self._recovery_task = asyncio.create_task(self._recover_credentials())
+
+    async def _recover_credentials(self) -> None:
+        delay = RECOVERY_MIN_DELAY
+        while True:
+            tried = self._client_key
+            key = credentials.reload_api_key()
+            if not key or key == tried:
+                fetched = await key_pickup.fetch_api_key()
+                if fetched and fetched != tried:
+                    credentials.save_api_key(fetched)
+                    key = fetched
+            if key and key != tried:
+                logger.info("MQTT credential recovery: new API key in hand — reconnecting with it.")
+                await self._rebuild_client()
+                return
+            if self._connected:
+                return
+            if key and key == tried:
+                logger.error(
+                    "MQTT credential recovery: C2 returns the same key the broker refuses. The broker's login for "
+                    "this node is out of sync with C2 (dynsec) — an admin re-approve re-syncs it without rotating."
+                )
+            logger.info(f"MQTT credential recovery: retrying in {delay}s.")
+            await asyncio.sleep(delay)
+            delay = min(delay * 2, RECOVERY_MAX_DELAY)
+
+    async def _rebuild_client(self) -> None:
+        """Swap the paho client for one built from the current credentials."""
+        old = self._client
+        if self._connect_task and not self._connect_task.done():
+            self._connect_task.cancel()
+        if old is not None:
+            # loop_stop() joins paho's thread, which can be mid-backoff — off the event loop.
+            await asyncio.to_thread(old.loop_stop)
+            try:
+                old.disconnect()
+            except Exception:
+                pass
+        self._connected = False
+        self._client = self._build_client()
+        self._connect_task = asyncio.create_task(self._connect_with_retry())
+
+    def update_api_key(self, key: str) -> None:
+        """A key arrived while connected (legacy MQTT push / reissue): use it on
+        the next reconnect without dropping the current, working session."""
+        if self._client is not None and key != self._client_key:
+            self._client.username_pw_set(settings.node_id, key)
+            self._client_key = key
 
     async def _connect_with_retry(self):
         """Attempt the initial TCP connect, retrying with backoff until it succeeds."""
@@ -161,6 +251,8 @@ class MQTTManager:
                 delay = min(delay * 2, 60)
 
     async def disconnect(self):
+        if self._recovery_task:
+            self._recovery_task.cancel()
         if self._connect_task:
             self._connect_task.cancel()
         if self._client:

drb-edge-node/app/internal/update_request.py

@@ -0,0 +1,41 @@
+"""
+Hand an MQTT `node_update` command to the host-level updater (node-26#15).
+
+The edge-node container has no business updating its own host: it writes a
+sentinel file into /configs (bind-mounted from <install dir>/configs), and the
+host's systemd drb-update.path unit — installed by install.sh — triggers
+drb-update.service, which runs Client/scripts/drb-update.sh. The host treats
+the file as a bare "please update" flag and never reads its content as input,
+so nothing C2 sends can pick the ref, image or command that runs.
+"""
+import json
+import os
+from datetime import datetime, timezone
+from pathlib import Path
+
+from app.config import settings
+from app.internal.logger import logger
+
+SENTINEL_NAME = "update-requested"
+
+
+def sentinel_path() -> Path:
+    return Path(settings.config_path) / SENTINEL_NAME
+
+
+def request_host_update() -> bool:
+    """Drop the sentinel. Returns False if it could not be written."""
+    path = sentinel_path()
+    try:
+        path.parent.mkdir(parents=True, exist_ok=True)
+        tmp = path.with_name(SENTINEL_NAME + ".tmp")
+        tmp.write_text(json.dumps({"requested_at": datetime.now(timezone.utc).isoformat()}))
+        os.replace(tmp, path)
+    except OSError as e:
+        logger.error(f"Node update requested but the sentinel could not be written ({e}).")
+        return False
+    logger.info(
+        f"Node update requested — handed to the host updater via {path}. If nothing happens within a minute, "
+        "this node predates the updater: re-run install.sh on it once."
+    )
+    return True

drb-edge-node/app/main.py

@@ -170,17 +170,15 @@ async def on_command(payload: dict):
         await asyncio.sleep(2)
         await op25_client.start()
     elif action == "node_update":
-        # TODO: Full OTA update — register a host-level systemd service (e.g. drb-update.service)
-        # that stops all DRB containers, runs `docker compose pull`, then `docker compose up -d`.
-        # The C2 server triggers it by sending this MQTT command; the host service watches for the
-        # restart signal (e.g. via a Unix socket, a sentinel file, or a lightweight webhook).
-        # Not implemented yet — for now, just restart the container so any pre-pulled image
-        # is picked up (requires a prior `docker compose pull` on the host).
-        logger.info("Node update requested — restarting container to pick up latest image.")
-        await mqtt_manager.publish_status("offline")
-        await asyncio.sleep(1)
-        import os
-        os._exit(0)  # Docker restart=unless-stopped will bring the container back up
+        # node-26#15: the container cannot (and must not) update itself. It
+        # drops a sentinel in /configs; the host's drb-update.path unit
+        # (installed by install.sh) sees it and runs drb-update.service, which
+        # pulls the node's own pinned repo ref + images and recreates the
+        # stack. The sentinel's content is ignored by the host — C2 cannot
+        # choose what gets installed. Offline/locked-out nodes get the same
+        # request over HTTPS via the updater's timer instead.
+        from app.internal.update_request import request_host_update
+        request_host_update()
     else:
         logger.warning(f"Unknown command: {action}")
 
@@ -189,6 +187,7 @@ async def on_api_key(payload: dict):
     key = payload.get("api_key")
     if key:
         credentials.save_api_key(key)
+        mqtt_manager.update_api_key(key)
         logger.info("Node API key received and saved.")
 
 

drb-edge-node/tests/test_credential_recovery.py

@@ -0,0 +1,205 @@
+"""
+node-26#14 — a node with no key, or a stale key, recovers on its own:
+re-read credentials.json, else fetch over HTTPS with the pickup secret, then
+rebuild the MQTT client in place. node-26#15 — node_update hands off to the
+host updater via a sentinel file.
+"""
+import asyncio
+import json
+from unittest.mock import AsyncMock
+
+import httpx
+import pytest
+
+from app.config import settings
+from app.internal import credentials, key_pickup, mqtt_manager as mm_mod, update_request
+from app.internal.mqtt_manager import MQTTManager, _is_auth_failure
+
+
+@pytest.fixture(autouse=True)
+def isolated(tmp_path, monkeypatch):
+    monkeypatch.setattr(credentials, "_CREDS_FILE", tmp_path / "credentials.json")
+    monkeypatch.setattr(credentials, "_PICKUP_FILE", tmp_path / "pickup_secret")
+    monkeypatch.setattr(credentials, "_api_key", None)
+    monkeypatch.setattr(settings, "config_path", str(tmp_path))
+    monkeypatch.setattr(settings, "c2_url", "https://c2.example")
+    monkeypatch.setattr(settings, "mqtt_user", None)
+    monkeypatch.setattr(mm_mod, "RECOVERY_MIN_DELAY", 0)
+    yield tmp_path
+
+
+def _manager(client_key=None):
+    m = MQTTManager()
+    m._client_key = client_key
+    m._rebuild_client = AsyncMock()
+    return m
+
+
+# --- credentials.py -----------------------------------------------------------
+
+def test_reload_picks_up_a_key_written_after_startup(isolated):
+    credentials.load()
+    assert credentials.get_api_key() is None
+    data = json.loads((isolated / "credentials.json").read_text())
+    data["api_key"] = "written-by-install-sh"
+    (isolated / "credentials.json").write_text(json.dumps(data))
+    assert credentials.reload_api_key() == "written-by-install-sh"
+
+
+def test_write_is_atomic_and_private(isolated):
+    credentials.save_api_key("k1")
+    f = isolated / "credentials.json"
+    assert json.loads(f.read_text())["api_key"] == "k1"
+    assert (f.stat().st_mode & 0o777) == 0o600
+    assert not (isolated / "credentials.json.tmp").exists()
+
+
+def test_pickup_secret_read_and_absent(isolated):
+    assert credentials.get_pickup_secret() is None
+    (isolated / "pickup_secret").write_text("abc123\n")
+    assert credentials.get_pickup_secret() == "abc123"
+
+
+# --- auth-failure classification -------------------------------------------------
+
+@pytest.mark.parametrize("code", [4, 5, 134, 135])
+def test_auth_failure_codes(code):
+    assert _is_auth_failure(code)
+
+
+def test_non_auth_failures_do_not_trigger_recovery():
+    assert not _is_auth_failure(3)  # server unavailable
+    assert not _is_auth_failure(136)
+
+
+def test_paho_reason_code_objects_classified():
+    from paho.mqtt.reasoncodes import ReasonCode
+    from paho.mqtt.packettypes import PacketTypes
+    assert _is_auth_failure(ReasonCode(PacketTypes.CONNACK, "Not authorized"))
+    assert _is_auth_failure(ReasonCode(PacketTypes.CONNACK, "Bad user name or password"))
+    assert not _is_auth_failure(ReasonCode(PacketTypes.CONNACK, "Server unavailable"))
+
+
+# --- recovery loop ----------------------------------------------------------------
+
+async def test_recovery_uses_key_already_on_disk_without_calling_c2(isolated, monkeypatch):
+    credentials.save_api_key("disk-key")
+    monkeypatch.setattr(credentials, "_api_key", None)  # process started before the write
+    fetch = AsyncMock()
+    monkeypatch.setattr(key_pickup, "fetch_api_key", fetch)
+    m = _manager(client_key=None)
+    await m._recover_credentials()
+    m._rebuild_client.assert_awaited_once()
+    fetch.assert_not_awaited()
+
+
+async def test_recovery_fetches_over_https_and_persists(isolated, monkeypatch):
+    monkeypatch.setattr(key_pickup, "fetch_api_key", AsyncMock(return_value="fresh-key"))
+    m = _manager(client_key="stale-key")
+    monkeypatch.setattr(credentials, "_api_key", "stale-key")
+    await m._recover_credentials()
+    m._rebuild_client.assert_awaited_once()
+    assert credentials.get_api_key() == "fresh-key"
+    assert json.loads((isolated / "credentials.json").read_text())["api_key"] == "fresh-key"
+
+
+async def test_recovery_backs_off_until_approved(isolated, monkeypatch):
+    fetch = AsyncMock(side_effect=[None, None, "approved-key"])
+    monkeypatch.setattr(key_pickup, "fetch_api_key", fetch)
+    m = _manager()
+    await asyncio.wait_for(m._recover_credentials(), timeout=5)
+    assert fetch.await_count == 3
+    m._rebuild_client.assert_awaited_once()
+
+
+async def test_recovery_stops_if_connection_recovers_meanwhile(isolated, monkeypatch):
+    monkeypatch.setattr(key_pickup, "fetch_api_key", AsyncMock(return_value=None))
+    m = _manager()
+    m._connected = True
+    await asyncio.wait_for(m._recover_credentials(), timeout=5)
+    m._rebuild_client.assert_not_awaited()
+
+
+async def test_start_recovery_is_single_flight(isolated, monkeypatch):
+    gate = asyncio.Event()
+
+    async def slow_fetch():
+        await gate.wait()
+        return "k"
+    monkeypatch.setattr(key_pickup, "fetch_api_key", slow_fetch)
+    m = _manager()
+    m._start_recovery("a")
+    first = m._recovery_task
+    m._start_recovery("b")
+    assert m._recovery_task is first
+    gate.set()
+    await first
+
+
+async def test_connect_without_key_starts_recovery(isolated, monkeypatch):
+    m = MQTTManager()
+    started = []
+    monkeypatch.setattr(m, "_connect_with_retry", AsyncMock())
+    monkeypatch.setattr(m, "_start_recovery", lambda why: started.append(why))
+    await m.connect()
+    assert started == ["no API key at startup"]
+
+
+def test_update_api_key_changes_creds_for_next_reconnect(isolated):
+    m = MQTTManager()
+    m._client = m._build_client()
+    m.update_api_key("rotated")
+    assert m._client._password == b"rotated"
+    assert m._client_key == "rotated"
+
+
+# --- key_pickup.fetch_api_key -----------------------------------------------------
+
+def _mock_http(monkeypatch, handler):
+    real = httpx.AsyncClient
+
+    def factory(*a, **kw):
+        kw["transport"] = httpx.MockTransport(handler)
+        return real(*a, **kw)
+    monkeypatch.setattr(key_pickup.httpx, "AsyncClient", factory)
+
+
+async def test_fetch_sends_pickup_secret_and_returns_key(isolated, monkeypatch):
+    (isolated / "pickup_secret").write_text("the-secret")
+    seen = {}
+
+    def handler(request):
+        seen["url"] = str(request.url)
+        seen["secret"] = request.headers.get("X-Pickup-Secret")
+        return httpx.Response(200, json={"approval_status": "approved", "api_key": "K"})
+    _mock_http(monkeypatch, handler)
+    assert await key_pickup.fetch_api_key() == "K"
+    assert seen == {"url": f"https://c2.example/nodes/{settings.node_id}/credentials", "secret": "the-secret"}
+
+
+@pytest.mark.parametrize("resp", [
+    httpx.Response(200, json={"approval_status": "pending", "api_key": None}),
+    httpx.Response(401, json={"detail": "Invalid pickup secret"}),
+    httpx.Response(404),
+    httpx.Response(500),
+    httpx.Response(200, text="not json"),
+])
+async def test_fetch_returns_none_when_no_key(isolated, monkeypatch, resp):
+    (isolated / "pickup_secret").write_text("s")
+    _mock_http(monkeypatch, lambda request: resp)
+    assert await key_pickup.fetch_api_key() is None
+
+
+async def test_fetch_without_pickup_secret_does_not_call_c2(isolated, monkeypatch):
+    def handler(request):
+        raise AssertionError("must not call C2 without a pickup secret")
+    _mock_http(monkeypatch, handler)
+    assert await key_pickup.fetch_api_key() is None
+
+
+# --- node_update -> host sentinel ---------------------------------------------------
+
+def test_node_update_writes_sentinel(isolated):
+    assert update_request.request_host_update() is True
+    data = json.loads((isolated / "update-requested").read_text())
+    assert "requested_at" in data

drb-edge-node/tests/test_host_updater.py

@@ -0,0 +1,179 @@
+"""
+node-26#15 — Client/scripts/drb-update.sh, the host-level updater.
+
+Runs the real script with stub git/docker/curl on PATH, so what is checked is
+the script's decision logic and its security guards: it only updates when
+asked (MQTT sentinel or a new C2 request), never takes anything but "update
+now" from C2, refuses a mismatched git origin or registry, and keeps node
+credentials off curl's argv.
+"""
+import json
+import os
+import shutil
+import stat
+import subprocess
+from pathlib import Path
+
+import pytest
+
+SCRIPT = Path(__file__).resolve().parents[2] / "scripts" / "drb-update.sh"
+
+pytestmark = pytest.mark.skipif(
+    not (SCRIPT.exists() and shutil.which("bash") and shutil.which("jq") and shutil.which("flock")),
+    reason="needs the repo's scripts/ (absent inside the image) plus bash, jq and flock",
+)
+
+REPO = "https://git.example.net/logan/node-26.git"
+OLD, NEW = "a" * 40, "b" * 40
+
+STUB_GIT = r'''#!/usr/bin/env bash
+echo "git $*" >> "$STUB/calls"
+while [ "$1" = -c ]; do shift 2; done
+case "$1" in
+  rev-parse) if [ "$2" = HEAD ]; then cat "$STUB/head"; else echo "$STUB_NEW"; fi ;;
+  remote) echo "$STUB_ORIGIN" ;;
+  fetch) exit 0 ;;
+  show-ref) [ "$4" = "refs/tags/v1" ] ;;
+  checkout) echo "${@: -1}" > "$STUB/head" ;;
+  *) exit 0 ;;
+esac
+'''
+STUB_DOCKER = '#!/usr/bin/env bash\necho "docker $*" >> "$STUB/calls"\n'
+STUB_CURL = r'''#!/usr/bin/env bash
+echo "curl $*" >> "$STUB/calls"
+for a in "$@"; do case "$a" in @*) cat "${a#@}" >> "$STUB/headers" ;; esac; done
+cat "$STUB/response"
+'''
+
+
+def _exe(path: Path, body: str):
+    path.write_text(body)
+    path.chmod(path.stat().st_mode | stat.S_IEXEC)
+
+
+@pytest.fixture
+def env(tmp_path):
+    stub = tmp_path / "stub"
+    bindir = stub / "bin"
+    bindir.mkdir(parents=True)
+    _exe(bindir / "git", STUB_GIT)
+    _exe(bindir / "docker", STUB_DOCKER)
+    _exe(bindir / "curl", STUB_CURL)
+    (stub / "head").write_text(OLD + "\n")
+    (stub / "calls").write_text("")
+    (stub / "response").write_text(json.dumps({"update_requested_at": None}))
+
+    inst = tmp_path / "node"
+    (inst / ".git").mkdir(parents=True)
+    (inst / "configs").mkdir()
+    (inst / ".env").write_text(
+        "NODE_ID=node-7\nC2_URL=https://api.example.net\nIMAGE_REGISTRY=git.example.net\n"
+    )
+    (inst / "configs" / "credentials.json").write_text(json.dumps({"api_key": "k" * 64}))
+    (inst / "configs" / "pickup_secret").write_text("p" * 48)
+
+    conf = tmp_path / "updater.conf"
+    conf.write_text(f"INSTALL_DIR={inst}\nREPO_URL={REPO}\nREF=v1\nREGISTRY=git.example.net\nBUILD=0\n")
+
+    e = dict(os.environ)
+    e.update({
+        "PATH": f"{bindir}:{os.environ['PATH']}",
+        "STUB": str(stub), "STUB_NEW": NEW, "STUB_ORIGIN": REPO,
+        "DRB_UPDATER_CONF": str(conf),
+        "DRB_UPDATER_STATE": str(tmp_path / "state"),
+        "DRB_UPDATER_LOCK": str(tmp_path / "lock"),
+    })
+    return {"env": e, "stub": stub, "inst": inst, "conf": conf, "state": tmp_path / "state"}
+
+
+def _run(env):
+    return subprocess.run(["bash", str(SCRIPT)], env=env["env"], capture_output=True, text=True, timeout=30)
+
+
+def _calls(env):
+    return (env["stub"] / "calls").read_text()
+
+
+def test_no_request_means_checkin_only(env):
+    r = _run(env)
+    assert r.returncode == 0, r.stderr
+    calls = _calls(env)
+    assert "update-check" in calls
+    assert "docker" not in calls
+    assert "fetch" not in calls
+
+
+def test_c2_request_updates_once_and_reports(env):
+    (env["stub"] / "response").write_text(json.dumps({"update_requested_at": "2026-10-04T12:00:00+00:00"}))
+    r = _run(env)
+    assert r.returncode == 0, r.stderr + r.stdout
+    calls = _calls(env)
+    assert "docker compose pull" in calls
+    assert "docker compose up -d --no-build --force-recreate --remove-orphans" in calls
+    assert (env["stub"] / "head").read_text().strip() == NEW
+    assert '"applied_request_at":"2026-10-04T12:00:00+00:00"' in calls
+    assert '"result":"ok"' in calls
+    # Same request again: nothing to do.
+    (env["stub"] / "calls").write_text("")
+    assert _run(env).returncode == 0
+    assert "docker" not in _calls(env)
+
+
+def test_mqtt_sentinel_triggers_update_and_is_consumed(env):
+    sentinel = env["inst"] / "configs" / "update-requested"
+    sentinel.write_text('{"ref": "evil", "cmd": "rm -rf /"}')
+    r = _run(env)
+    assert r.returncode == 0, r.stderr
+    assert not sentinel.exists()
+    calls = _calls(env)
+    assert "docker compose pull" in calls
+    assert "evil" not in calls and "rm -rf" not in calls
+
+
+def test_c2_response_is_never_used_as_a_ref_or_command(env):
+    (env["stub"] / "response").write_text(json.dumps({"update_requested_at": "$(touch /tmp/pwned); main"}))
+    r = _run(env)
+    assert r.returncode == 0
+    assert "docker" not in _calls(env)  # malformed request is ignored, not executed
+
+
+def test_refuses_when_git_origin_differs(env):
+    env["env"]["STUB_ORIGIN"] = "https://attacker.example/node-26.git"
+    (env["inst"] / "configs" / "update-requested").write_text("")
+    r = _run(env)
+    assert r.returncode != 0
+    assert "refusing" in r.stderr
+    assert "docker" not in _calls(env)
+
+
+def test_refuses_when_env_registry_differs(env):
+    (env["inst"] / ".env").write_text(
+        "NODE_ID=node-7\nC2_URL=https://api.example.net\nIMAGE_REGISTRY=evil.example\n"
+    )
+    (env["inst"] / "configs" / "update-requested").write_text("")
+    r = _run(env)
+    assert r.returncode != 0
+    assert "docker compose pull" not in _calls(env)
+
+
+def test_non_https_repo_in_conf_is_rejected(env):
+    env["conf"].write_text(env["conf"].read_text().replace("https://", "http://"))
+    r = _run(env)
+    assert r.returncode != 0
+    assert "git" not in _calls(env)
+
+
+def test_credentials_go_in_a_header_file_never_argv(env):
+    _run(env)
+    calls = _calls(env)
+    assert "k" * 64 not in calls and "p" * 48 not in calls
+    headers = (env["stub"] / "headers").read_text()
+    assert f"Authorization: Bearer {'k' * 64}" in headers
+    assert f"X-Pickup-Secret: {'p' * 48}" in headers
+
+
+def test_plain_http_c2_skips_checkin(env):
+    (env["inst"] / ".env").write_text("NODE_ID=node-7\nC2_URL=http://api.example.net\nIMAGE_REGISTRY=git.example.net\n")
+    r = _run(env)
+    assert r.returncode == 0
+    assert "curl" not in _calls(env)

install.sh

@@ -17,9 +17,13 @@
 #   2. Install Docker + compose plugin + git + curl + jq
 #   3. Clone logan/node-26 at a PINNED ref into $INSTALL_DIR
 #   4. Write .env (non-interactive from flags/env, interactive fallback)
-#   5. Enroll with C2 (POST /nodes/enroll) and poll for the api_key
-#   6. docker compose pull && up -d   (prebuilt; --build opts into the ~1h build)
-#   7. Print the approval step
+#   5. Enroll with C2 (POST /nodes/enroll), then BLOCK until an admin approves
+#      and the api_key is written (node-26#14). Ctrl-C safe: re-run resumes
+#      from configs/pickup_secret. A re-run also refreshes a stale key.
+#   6. docker compose pull && up -d, ALWAYS recreating edge-node so it loads
+#      the key on disk  (prebuilt; --build opts into the ~1h build)
+#   7. Install the host updater (systemd timer + path unit, node-26#15)
+#   8. Print a summary
 #
 # It does NOT set up WireGuard. WireGuard-per-node was evaluated and rejected
 # (Server/MQTT-PUBLIC-AUTH-PLAN.md, Server/infra/main.tf:67-73). A field node
@@ -85,7 +89,14 @@ REGISTRY_PASS="${DRB_REGISTRY_PASS:-}"
 DO_BUILD=0        # 0 = pull prebuilt images (default), 1 = build on the Pi (~1h for op25)
 DO_START=1
 ASSUME_YES=0
-ENROLL_WAIT="${DRB_ENROLL_WAIT:-0}"   # seconds to block waiting for admin approval; 0 = don't block
+# How long to block waiting for admin approval. Default: forever (node-26#14 —
+# the old default of 0 started a keyless stack that never came online).
+# N>0 = give up after N seconds and start anyway; 0 = don't wait at all. Either
+# way the edge-node app keeps fetching the key itself and comes online on its
+# own once approved.
+ENROLL_WAIT="${DRB_ENROLL_WAIT:-forever}"
+APP_URL="${DRB_APP_URL:-}"
+INSTALL_UPDATER=1
 
 C='\033[0;36m'; G='\033[0;32m'; Y='\033[1;33m'; R='\033[0;31m'; N='\033[0m'
 say()  { printf "${C}==>${N} %s\n" "$*"; }
@@ -111,7 +122,12 @@ Usage: install.sh [options]
   --dir PATH           install location (default /opt/drb/node-26)
   --build              build images locally instead of pulling (~1h for op25)
   --no-start           configure and enroll, but do not start containers
-  --wait-approval SEC  block up to SEC seconds polling for admin approval
+  --wait-approval SEC  stop waiting for admin approval after SEC seconds
+                       (default: wait forever; 0 = don't wait). The node
+                       still fetches its key by itself once approved.
+  --app-url URL        admin UI base for the approval message
+                       (default: C2 URL without its "api." prefix)
+  --no-updater         don't install the host updater (no remote updates)
   -y, --yes            never prompt; fail instead of asking
 
 Every option also has an env var: DRB_NODE_ID, DRB_C2_URL, DRB_ENROLLMENT_TOKEN,
@@ -138,12 +154,17 @@ while [ $# -gt 0 ]; do
     --build)          DO_BUILD=1; shift ;;
     --no-start)       DO_START=0; shift ;;
     --wait-approval)  ENROLL_WAIT="$2"; shift 2 ;;
+    --app-url)        APP_URL="$2"; shift 2 ;;
+    --no-updater)     INSTALL_UPDATER=0; shift ;;
     -y|--yes)         ASSUME_YES=1; shift ;;
     -h|--help)        usage; exit 0 ;;
     *)                die "unknown option: $1 (try --help)" ;;
   esac
 done
 
+[ "$ENROLL_WAIT" = forever ] || [[ "$ENROLL_WAIT" =~ ^[0-9]+$ ]] \
+  || die "--wait-approval takes a number of seconds (or omit it to wait until approved)"
+
 # Prompts must come from the terminal, not from the `curl |` pipe on stdin.
 ask() {  # ask VAR "prompt" "default"
   local __v="$1" __p="$2" __d="${3:-}" __r=""
@@ -226,7 +247,9 @@ mkdir -p "$(dirname "$INSTALL_DIR")"
 if [ -d "$INSTALL_DIR/.git" ]; then
   ok "existing install at $INSTALL_DIR — updating in place (.env is preserved)"
   git -C "$INSTALL_DIR" remote set-url origin "$REPO_URL"
-  git -C "$INSTALL_DIR" fetch --tags --prune origin
+  # --force: a moved release tag (v1 re-cut) must replace the local copy,
+  # otherwise fetch refuses with "would clobber existing tag" and set -e dies.
+  git -C "$INSTALL_DIR" fetch --force --tags --prune origin
 else
   git clone --no-checkout "$REPO_URL" "$INSTALL_DIR"
 fi
@@ -345,39 +368,68 @@ PICKUP_FILE="$INSTALL_DIR/configs/pickup_secret"
 # GET /nodes/{id}/credentials. Sets CRED_HTTP + CRED_BODY (no -f: we need the
 # body and status on a 4xx). One implementation so first-run and re-run agree.
 creds_pickup() {  # creds_pickup PICKUP_SECRET
-  local _tmp; _tmp="$(mktemp)"
+  local _tmp _hdr; _tmp="$(mktemp)"; _hdr="$(mktemp)"; chmod 600 "$_hdr"
+  # Secret via a 0600 header file, never curl's argv (visible in `ps`).
+  printf 'X-Pickup-Secret: %s\n' "$1" > "$_hdr"
   CRED_HTTP="$(curl -sS -o "$_tmp" -w '%{http_code}' \
-      "$C2_URL/nodes/$NODE_ID/credentials" -H "X-Pickup-Secret: $1" 2>/dev/null || echo 000)"
+      "$C2_URL/nodes/$NODE_ID/credentials" -H "@$_hdr" 2>/dev/null || echo 000)"
   CRED_BODY="$(cat "$_tmp" 2>/dev/null || true)"
-  rm -f "$_tmp"
+  rm -f "$_tmp" "$_hdr"
 }
 cred_field() { printf '%s' "${CRED_BODY:-}" | jq -r "$1 // empty" 2>/dev/null || true; }
 
+KEY_WRITTEN=0
+# Merge into the existing file: the edge-node app keeps its dashboard auth
+# salt + session secret in the same JSON, and clobbering them logs everyone
+# out. Atomic (tmp + mv) so a Ctrl-C can never leave half a file.
 write_creds() {  # write_creds API_KEY
-  umask 077; jq -n --arg k "$1" '{api_key:$k}' > "$CREDS"; umask 022
-  ok "api_key received and written to configs/credentials.json"
+  local _tmp="$CREDS.tmp"
+  umask 077
+  if [ -s "$CREDS" ] && jq -e . "$CREDS" >/dev/null 2>&1; then
+    jq --arg k "$1" '.api_key = $k' "$CREDS" > "$_tmp"
+  else
+    jq -n --arg k "$1" '{api_key:$k}' > "$_tmp"
+  fi
+  umask 022
+  mv -f "$_tmp" "$CREDS"
+  KEY_WRITTEN=1
+  ok "api_key written to configs/credentials.json"
 }
 
+[ -n "$APP_URL" ] || { APP_URL="${C2_URL/:\/\/api./://}"; }
+APP_URL="${APP_URL%/}"
+
 say_pending() {  # say_pending APPROVAL_STATUS  — not an error: node is enrolled, key not minted yet
   warn "not approved yet — C2 reports approval_status=${1:-pending}, no api_key minted."
-  warn "an admin must, at  <app-url>/settings/nodes :  Approve '$NODE_ID'  (assigning a system is separate)."
-  warn "then re-run this installer — it reuses configs/pickup_secret — or fetch it directly:"
-  warn "  curl -fsS $C2_URL/nodes/$NODE_ID/credentials -H \"X-Pickup-Secret: \$(cat $PICKUP_FILE)\" | jq -r .api_key"
+  warn "an admin must approve '$NODE_ID' at ${APP_URL}/settings/nodes. The node keeps fetching"
+  warn "its key by itself and comes online once approved; re-running this installer also works."
 }
 
-# Poll creds_pickup for up to ENROLL_WAIT seconds while still pending. Result
-# left in CRED_HTTP/CRED_BODY. --wait-approval is what would have avoided the
-# original prod bug; the default (0) does not block, so the re-run path below
-# must stand on its own.
+# Block until the node is approved and C2 hands back an api_key (node-26#14).
+# Result left in CRED_HTTP/CRED_BODY. Returns 0 with a key, 1 on timeout/0-wait,
+# dies on a credential error (401/404) that waiting cannot fix.
 wait_for_key() {  # wait_for_key PICKUP_SECRET
-  [ "${ENROLL_WAIT:-0}" -gt 0 ] || return 0
-  local _end; _end=$(( $(date +%s) + ENROLL_WAIT ))
-  say "Waiting up to ${ENROLL_WAIT}s for an admin to approve '$NODE_ID'"
-  while [ "$(date +%s)" -lt "$_end" ]; do
-    sleep 10
+  [ "$ENROLL_WAIT" = 0 ] && return 1
+  local _end=0 _shown=0 _delay=5
+  [ "$ENROLL_WAIT" = forever ] || _end=$(( $(date +%s) + ENROLL_WAIT ))
+  trap 'printf "\n"; warn "interrupted — nothing is lost: re-run the same command to resume waiting (configs/pickup_secret is saved)."; exit 130' INT TERM
+  while :; do
+    case "$CRED_HTTP" in
+      200) [ -n "$(cred_field '.api_key')" ] && { trap - INT TERM; return 0; } ;;
+      401) die "C2 rejected the saved pickup secret (401) while waiting — re-run with --token DRB-… to re-enroll." ;;
+      404) die "C2 no longer knows node '$NODE_ID' (404) — it was deleted. Re-run with --token DRB-… to enroll again." ;;
+      *)   : ;;  # 000/5xx: transient, keep waiting
+    esac
+    if [ "$_shown" = 0 ]; then
+      printf "\n${Y}Please have an admin approve node '%s' at %s/settings/nodes to continue.${N}\n" \
+        "$NODE_ID" "$APP_URL"
+      printf "Waiting for approval%s… (Ctrl-C is safe — re-run the same command to resume)\n\n" \
+        "$([ "$_end" = 0 ] && echo "" || echo " for up to ${ENROLL_WAIT}s")"
+      _shown=1
+    fi
+    if [ "$_end" != 0 ] && [ "$(date +%s)" -ge "$_end" ]; then trap - INT TERM; return 1; fi
+    sleep "$_delay"; [ "$_delay" -lt 30 ] && _delay=$(( _delay + 5 ))
     creds_pickup "$1"
-    [ "$CRED_HTTP" = 200 ] || return 0
-    [ -z "$(cred_field '.api_key')" ] || return 0
   done
 }
 
@@ -390,12 +442,15 @@ do_fresh_enroll() {
   BODY="$(jq -nc --arg id "$NODE_ID" --arg n "${NODE_NAME:-$NODE_ID}" \
             --argjson lat "${NODE_LAT:-0}" --argjson lon "${NODE_LON:-0}" \
             '{node_id:$id,name:$n,lat:$lat,lon:$lon}')"
-  # Token goes in a header from a shell variable — never on a process command
-  # line, never echoed.
+  # Token goes in a 0600 header file — never on a process command line (curl's
+  # argv is visible in `ps`; CISO condition, server-26#61), never echoed.
+  local _ehdr; _ehdr="$(mktemp)"; chmod 600 "$_ehdr"
+  printf 'X-Enrollment-Token: %s\n' "$ENROLLMENT_TOKEN" > "$_ehdr"
   if ! RESP="$(curl -fsS -X POST "$C2_URL/nodes/enroll" \
             -H "Content-Type: application/json" \
-            -H "X-Enrollment-Token: $ENROLLMENT_TOKEN" \
+            -H "@$_ehdr" \
             --data "$BODY" 2>&1)"; then
+    rm -f "$_ehdr"
     case "$RESP" in
       *403*) die "enroll refused (403): node '$NODE_ID' is already approved on C2, and
   this machine has no configs/pickup_secret to collect its key with. A token
@@ -409,6 +464,7 @@ do_fresh_enroll() {
       *)     die "enroll failed: $RESP" ;;
     esac
   fi
+  rm -f "$_ehdr"
   PICKUP="$(printf '%s' "$RESP" | jq -r '.pickup_secret')"
   STATUS="$(printf '%s' "$RESP" | jq -r '.approval_status')"
   [ -n "$PICKUP" ] && [ "$PICKUP" != null ] || die "enroll returned no pickup_secret: $RESP"
@@ -418,21 +474,32 @@ do_fresh_enroll() {
 
   creds_pickup "$PICKUP"
   [ "$CRED_HTTP" = 200 ] || die "post-enroll credential fetch failed (HTTP $CRED_HTTP): ${CRED_BODY:-<no body>}"
-  KEY="$(cred_field '.api_key')"
-  if [ -z "$KEY" ]; then
-    wait_for_key "$PICKUP" || true
-    KEY="$(cred_field '.api_key')"
-  fi
-  if [ -n "$KEY" ]; then
-    write_creds "$KEY"
+  if wait_for_key "$PICKUP"; then
+    write_creds "$(cred_field '.api_key')"
   else
     say_pending "$(cred_field '.approval_status')"
   fi
 }
 
-if [ -s "$CREDS" ] && jq -e '.api_key // empty' "$CREDS" >/dev/null 2>&1; then
+DISK_KEY="$(jq -r '.api_key // empty' "$CREDS" 2>/dev/null || true)"
+if [ -n "$DISK_KEY" ] && [ -s "$PICKUP_FILE" ] && [ -n "${C2_URL:-}" ]; then
+  # Key on disk, but it may be STALE (an admin Reissue, or the old approve
+  # that rotated on every click). Ask C2 for the current one and replace it if
+  # different. Best-effort: on any error keep the key we have.
+  say "Enrollment — key on disk; checking it is still current"
+  creds_pickup "$(cat "$PICKUP_FILE")"
+  SERVER_KEY="$(cred_field '.api_key')"
+  if [ "$CRED_HTTP" = 200 ] && [ -n "$SERVER_KEY" ] && [ "$SERVER_KEY" != "$DISK_KEY" ]; then
+    warn "the key on disk is not the one C2 has on file (reissued?) — replacing it"
+    write_creds "$SERVER_KEY"
+  elif [ "$CRED_HTTP" = 200 ] && [ -n "$SERVER_KEY" ]; then
+    ok "api_key on disk matches C2"
+  else
+    warn "could not confirm the key with C2 (HTTP $CRED_HTTP) — keeping the key on disk"
+  fi
+elif [ -n "$DISK_KEY" ]; then
   say "Enrollment"
-  ok "api_key already on disk — skipping enrollment"
+  ok "api_key already on disk (no pickup secret to re-check it with) — skipping enrollment"
 elif [ -z "${C2_URL:-}" ]; then
   say "Enrollment"
   warn "no C2_URL — skipping enrollment"
@@ -446,16 +513,11 @@ elif [ -s "$PICKUP_FILE" ]; then
   creds_pickup "$PICKUP"
   case "$CRED_HTTP" in
     200)
-      API_KEY="$(cred_field '.api_key')"
-      if [ -z "$API_KEY" ]; then
-        wait_for_key "$PICKUP" || true
-        API_KEY="$(cred_field '.api_key')"
-      fi
-      if [ -n "$API_KEY" ]; then
-        write_creds "$API_KEY"
+      if wait_for_key "$PICKUP"; then
+        write_creds "$(cred_field '.api_key')"
       else
-        # Still pending. Enrolled and idempotent — next run collects the key.
-        # Clean exit, fall through to start the stack. NOT a failure.
+        # Only with --wait-approval N/0. Enrolled and idempotent; the app
+        # fetches the key itself once approved. NOT a failure.
         say_pending "$(cred_field '.approval_status')"
       fi
       ;;
@@ -510,12 +572,30 @@ if [ "$DO_START" = 1 ]; then
     fi
     docker compose up --no-build -d
   fi
-  ok "stack started"
+  # ALWAYS recreate edge-node (node-26#14): `up -d` leaves an already-running
+  # container alone, and a process started before the key was written would
+  # otherwise keep running keyless. Cheap, and makes every re-run a fix.
+  docker compose up -d --no-build --force-recreate --no-deps edge-node
+  ok "stack started (edge-node recreated so it loads configs/credentials.json)"
 else
   say "Skipping start (--no-start). Run: cd $INSTALL_DIR && make up-prebuilt"
 fi
 
-# ── 7. What the operator does next ──────────────────────────────────────────
+# ── 7. Host updater (node-26#15) ───────────────────────────────────────────
+UPDATER_STATE="not installed (--no-updater)"
+if [ "$INSTALL_UPDATER" = 1 ]; then
+  say "Installing the host updater"
+  UPD_ARGS=(--dir "$INSTALL_DIR" --repo-url "$REPO_URL" --ref "$REF" --registry "$REGISTRY")
+  [ "$DO_BUILD" = 1 ] && UPD_ARGS+=(--build)
+  if bash "$INSTALL_DIR/scripts/install-updater.sh" "${UPD_ARGS[@]}"; then
+    UPDATER_STATE="enabled — checks C2 every ~15 min; 'Update Node Software' in the admin UI"
+  else
+    warn "host updater NOT installed — this node cannot be updated remotely"
+    UPDATER_STATE="FAILED to install (see above)"
+  fi
+fi
+
+# ── 8. Summary ──────────────────────────────────────────────────────────────
 IP="$(hostname -I 2>/dev/null | awk '{print $1}')"
 cat <<EOF
 
@@ -525,20 +605,18 @@ $(printf "${G}Node '%s' installed at %s${N}" "$NODE_ID" "$INSTALL_DIR")
   images         $([ "$DO_BUILD" = 1 ] && echo "built locally" || echo "pulled from $REGISTRY")
   dashboard      http://${IP:-<node-ip>}/    (user: ${DASHBOARD_USER})
   logs           cd $INSTALL_DIR && docker compose logs -f edge-node
+  updater        ${UPDATER_STATE}
+  api key        $([ -n "$(jq -r '.api_key // empty' "$CREDS" 2>/dev/null)" ] && echo "present" || echo "NOT YET — node fetches it once approved")
 
-NEXT — an admin must approve this node before it can do anything:
-
-  1. Open  <app-url>/settings/nodes
-  2. Approve  "$NODE_ID"
-  3. Assign it a radio system
+NEXT — assign this node a radio system at ${APP_URL}/nodes/${NODE_ID}
 
 EOF
 if [ "${GENERATED_DASH:-0}" = 1 ]; then
   printf "${Y}Generated dashboard password (shown once): %s${N}\n\n" "$DASHBOARD_PASS"
 fi
-if [ ! -s "$CREDS" ]; then
+if [ -z "$(jq -r '.api_key // empty' "$CREDS" 2>/dev/null)" ]; then
   if [ -s "$PICKUP_FILE" ]; then
-    printf "${Y}This node has no api_key yet. After an admin approves it, re-run the same\ninstall command — it reuses configs/pickup_secret and will collect the key\n(no --token needed for the re-run).${N}\n\n"
+    printf "${Y}This node has no api_key yet. Once an admin approves it at %s/settings/nodes\nthe node fetches the key and comes online by itself (no re-run needed).${N}\n\n" "$APP_URL"
   else
     printf "${Y}This node has no api_key and no saved pickup secret, so a plain re-run cannot\nfix it. Re-run with --token DRB-… to enroll; or, if the node is already\napproved, have an admin Reissue key and write it into\n%s by hand.${N}\n\n" "$CREDS"
   fi

scripts/drb-update.sh

@@ -0,0 +1,172 @@
+#!/usr/bin/env bash
+#
+# DRB node host updater (node-26#15). Runs as root from systemd:
+#   drb-update.timer  -> every ~15 min: HTTPS check-in with C2; update if asked
+#   drb-update.path   -> fires when the edge-node container drops
+#                        <install>/configs/update-requested (MQTT node_update)
+# Both start drb-update.service, which runs this script. install-updater.sh
+# writes the units and /etc/drb/updater.conf; install.sh calls it.
+#
+# SECURITY MODEL — this is a remote-update path onto devices in the field:
+#   * What gets installed comes ONLY from /etc/drb/updater.conf (root-owned,
+#     written by install.sh): the repo URL, the ref, the image registry. C2's
+#     answer is a single timestamp meaning "update now"; it is never used as a
+#     ref, URL, path or command. The MQTT sentinel's content is never read.
+#   * git origin must equal the configured REPO_URL (https only) and the .env
+#     IMAGE_REGISTRY must equal the configured REGISTRY, or nothing runs.
+#   * Node credentials go to curl via a 0600 header file, never argv.
+#   * C2 must be https.
+# What this does NOT defend against: a compromised git host or registry —
+# refs and images are not signed (see the issue filed with node-26#15).
+#
+# The whole body is inside main(), called on the last line: bash parses the
+# function completely before running it, so `git checkout` replacing this
+# very file mid-run cannot change what is executing.
+set -euo pipefail
+
+main() {
+  local CONF="${DRB_UPDATER_CONF:-/etc/drb/updater.conf}"
+  local STATE_DIR="${DRB_UPDATER_STATE:-/var/lib/drb-update}"
+  local LOCK="${DRB_UPDATER_LOCK:-/run/drb-update.lock}"
+
+  log()  { printf 'drb-update: %s\n' "$*"; }
+  err()  { printf 'drb-update: ERROR: %s\n' "$*" >&2; }
+  conf() { grep -E "^$1=" "$CONF" 2>/dev/null | head -1 | cut -d= -f2- || true; }
+
+  [ -r "$CONF" ] || { err "$CONF missing — re-run install.sh"; return 1; }
+  local INSTALL_DIR REPO_URL REF REGISTRY BUILD
+  INSTALL_DIR="$(conf INSTALL_DIR)"; REPO_URL="$(conf REPO_URL)"; REF="$(conf REF)"
+  REGISTRY="$(conf REGISTRY)"; BUILD="$(conf BUILD)"
+
+  [[ "$INSTALL_DIR" =~ ^/[A-Za-z0-9._/-]+$ ]] && [ -d "$INSTALL_DIR/.git" ] \
+    || { err "bad INSTALL_DIR '$INSTALL_DIR' in $CONF"; return 1; }
+  [[ "$REPO_URL" =~ ^https://[A-Za-z0-9._/:-]+$ ]] || { err "REPO_URL must be https: '$REPO_URL'"; return 1; }
+  [[ "$REF" =~ ^[A-Za-z0-9._][A-Za-z0-9._/-]*$ ]] || { err "bad REF '$REF'"; return 1; }
+  [[ "$REGISTRY" =~ ^[A-Za-z0-9.-]+(:[0-9]+)?$ ]] || { err "bad REGISTRY '$REGISTRY'"; return 1; }
+
+  mkdir -p "$STATE_DIR"; chmod 700 "$STATE_DIR"
+  exec 9>"$LOCK"
+  flock -n 9 || { log "another update is already running"; return 0; }
+
+  cd "$INSTALL_DIR"
+  envget() { grep -E "^$1=" .env 2>/dev/null | head -1 | cut -d= -f2- | tr -d '"' || true; }
+  local NODE_ID C2_URL
+  NODE_ID="$(envget NODE_ID)"; C2_URL="$(envget C2_URL)"; C2_URL="${C2_URL%/}"
+  [[ "$NODE_ID" =~ ^[A-Za-z0-9_-]+$ ]] || { err "no valid NODE_ID in $INSTALL_DIR/.env"; return 1; }
+
+  local reason=""
+  local SENTINEL="$INSTALL_DIR/configs/update-requested"
+  if [ -e "$SENTINEL" ] || [ -L "$SENTINEL" ]; then
+    rm -f "$SENTINEL"          # content deliberately ignored
+    reason="mqtt node_update"
+  fi
+
+  # ── HTTPS check-in ──────────────────────────────────────────────────────
+  local tmpd; tmpd="$(mktemp -d)"; chmod 700 "$tmpd"
+  # shellcheck disable=SC2064
+  trap "rm -rf '$tmpd'" RETURN
+
+  local sha; sha="$(git rev-parse HEAD 2>/dev/null || echo '')"
+  local requested=""
+
+  checkin() {  # checkin APPLIED_AT RESULT -> stdout: response body
+    [[ "$C2_URL" == https://* ]] || return 1
+    local key="" pickup=""
+    key="$(jq -r '.api_key // empty' configs/credentials.json 2>/dev/null || true)"
+    pickup="$(cat configs/pickup_secret 2>/dev/null || true)"
+    : > "$tmpd/h"; chmod 600 "$tmpd/h"
+    if [[ "$key" =~ ^[A-Za-z0-9]+$ ]]; then
+      printf 'Authorization: Bearer %s\n' "$key" >> "$tmpd/h"
+    fi
+    if [[ "$pickup" =~ ^[A-Za-z0-9]+$ ]]; then
+      printf 'X-Pickup-Secret: %s\n' "$pickup" >> "$tmpd/h"
+    fi
+    [ -s "$tmpd/h" ] || return 1
+    local body
+    body="$(jq -nc --arg sha "$sha" --arg a "$1" --arg r "$2" \
+      '{sha:$sha} + (if $a != "" then {applied_request_at:$a} else {} end)
+                  + (if $r != "" then {result:$r} else {} end)')"
+    curl -fsS --proto '=https' --max-time 20 -X POST \
+      "$C2_URL/nodes/$NODE_ID/update-check" \
+      -H "Content-Type: application/json" -H "@$tmpd/h" --data "$body"
+  }
+
+  local resp
+  if [[ "$C2_URL" != https://* ]]; then
+    log "C2_URL is not https — skipping the HTTPS check-in"
+  elif resp="$(checkin "" "" 2>"$tmpd/err")"; then
+    requested="$(printf '%s' "$resp" | jq -r '.update_requested_at // empty' 2>/dev/null || true)"
+    if [ -n "$requested" ] && ! [[ "$requested" =~ ^[0-9T:.+Z-]{10,40}$ ]]; then
+      log "ignoring malformed update_requested_at from C2"
+      requested=""
+    fi
+  else
+    log "HTTPS check-in failed: $(tr -d '\n' < "$tmpd/err" | head -c 200)"
+  fi
+
+  local last=""; last="$(cat "$STATE_DIR/last_request" 2>/dev/null || true)"
+  local new_request=""
+  if [ -n "$requested" ] && [ "$requested" != "$last" ]; then
+    new_request="$requested"
+    reason="${reason:-C2 request $requested}"
+  fi
+  [ -n "$reason" ] || { log "no update requested"; return 0; }
+
+  # ── Update ─────────────────────────────────────────────────────────────
+  log "updating ($reason) — repo $REPO_URL @ $REF"
+  local result=ok
+  if do_update; then
+    log "update complete: $(git rev-parse --short HEAD)"
+  else
+    result=failed
+    log "update FAILED — will retry on the next timer run"
+  fi
+  if [ -n "$new_request" ]; then
+    [ "$result" = ok ] && printf '%s' "$new_request" > "$STATE_DIR/last_request"
+    sha="$(git rev-parse HEAD 2>/dev/null || echo '')"
+    checkin "$new_request" "$result" >/dev/null 2>&1 || log "could not report the result to C2"
+  fi
+  [ "$result" = ok ]
+}
+
+do_update() {
+  local origin; origin="$(git remote get-url origin)"
+  [ "$origin" = "$REPO_URL" ] || { err "git origin '$origin' != configured '$REPO_URL' — refusing"; return 1; }
+
+  # --force: a moved release tag (v1) must replace the local copy.
+  git -c protocol.allow=never -c protocol.https.allow=always fetch --force --tags --prune origin || return 1
+
+  local target
+  if git show-ref --verify -q "refs/remotes/origin/$REF"; then
+    target="refs/remotes/origin/$REF"
+  elif git show-ref --verify -q "refs/tags/$REF"; then
+    target="refs/tags/$REF"
+  else
+    err "ref '$REF' not found on origin"; return 1
+  fi
+  local old new
+  old="$(git rev-parse HEAD)"; new="$(git rev-parse "$target^{commit}")"
+  if [ "$old" != "$new" ]; then
+    git -c advice.detachedHead=false checkout --force --detach "$new" || return 1
+    log "checked out $REF: ${old:0:12} -> ${new:0:12}"
+    # Units/conf may have changed with the new scripts.
+    bash scripts/install-updater.sh --refresh || log "unit refresh failed (continuing with the old units)"
+  fi
+
+  local env_registry
+  env_registry="$(grep -E '^IMAGE_REGISTRY=' .env | head -1 | cut -d= -f2- | tr -d '"' || true)"
+  [ "${env_registry:-git.vpn.cusano.net}" = "$REGISTRY" ] \
+    || { err ".env IMAGE_REGISTRY '$env_registry' != configured '$REGISTRY' — refusing"; return 1; }
+
+  if [ "$BUILD" = 1 ]; then
+    docker compose build || return 1
+  else
+    docker compose pull || return 1
+  fi
+  # --force-recreate: app code is bind-mounted from the checkout (install.sh
+  # D3), so a code-only change also needs every container restarted.
+  docker compose up -d --no-build --force-recreate --remove-orphans || return 1
+  docker image prune -f >/dev/null 2>&1 || true
+}
+
+main "$@"

scripts/install-updater.sh

@@ -0,0 +1,107 @@
+#!/usr/bin/env bash
+#
+# Install (or refresh) the DRB host updater units (node-26#15). Run as root.
+#
+#   install-updater.sh --dir /opt/drb/node-26 --repo-url URL --ref v1 \
+#                      --registry git.vpn.cusano.net [--build]
+#   install-updater.sh --refresh      # re-render units from /etc/drb/updater.conf
+#
+# Writes /etc/drb/updater.conf (root:root 0644 — the ONLY source of what the
+# updater may install), drb-update.{service,timer,path}, and enables the timer
+# and the path watcher. install.sh calls this; drb-update.sh calls --refresh
+# after a checkout so unit changes ship with the repo.
+set -euo pipefail
+
+CONF=/etc/drb/updater.conf
+UNIT_DIR="${DRB_UNIT_DIR:-/etc/systemd/system}"
+conf() { grep -E "^$1=" "$CONF" 2>/dev/null | head -1 | cut -d= -f2- || true; }
+die()  { printf 'install-updater: %s\n' "$*" >&2; exit 1; }
+
+INSTALL_DIR="" REPO_URL="" REF="" REGISTRY="" BUILD=0 REFRESH=0
+while [ $# -gt 0 ]; do
+  case "$1" in
+    --dir)       INSTALL_DIR="$2"; shift 2 ;;
+    --repo-url)  REPO_URL="$2"; shift 2 ;;
+    --ref)       REF="$2"; shift 2 ;;
+    --registry)  REGISTRY="$2"; shift 2 ;;
+    --build)     BUILD=1; shift ;;
+    --refresh)   REFRESH=1; shift ;;
+    *)           die "unknown option: $1" ;;
+  esac
+done
+
+[ "$(id -u)" -eq 0 ] || die "must run as root"
+if [ "$REFRESH" = 1 ]; then
+  [ -r "$CONF" ] || die "$CONF missing — run install.sh"
+  INSTALL_DIR="$(conf INSTALL_DIR)"; REPO_URL="$(conf REPO_URL)"; REF="$(conf REF)"
+  REGISTRY="$(conf REGISTRY)"; BUILD="$(conf BUILD)"
+fi
+
+[[ "$INSTALL_DIR" =~ ^/[A-Za-z0-9._/-]+$ ]] || die "bad --dir '$INSTALL_DIR' (absolute, no spaces)"
+[[ "$REPO_URL" =~ ^https://[A-Za-z0-9._/:-]+$ ]] || die "--repo-url must be https: '$REPO_URL'"
+[[ "$REF" =~ ^[A-Za-z0-9._][A-Za-z0-9._/-]*$ ]] || die "bad --ref '$REF'"
+[[ "$REGISTRY" =~ ^[A-Za-z0-9.-]+(:[0-9]+)?$ ]] || die "bad --registry '$REGISTRY'"
+[ "$BUILD" = 1 ] || BUILD=0
+
+if ! command -v systemctl >/dev/null 2>&1 || [ ! -d /run/systemd/system ]; then
+  die "systemd not running — the host updater needs systemd (remote updates disabled on this node)"
+fi
+
+install -d -m 755 /etc/drb
+umask 022
+cat > "$CONF.tmp" <<EOF
+# DRB host updater — written by install-updater.sh. The updater installs ONLY
+# from these values; nothing C2 sends can change them. Edit = root only.
+INSTALL_DIR=$INSTALL_DIR
+REPO_URL=$REPO_URL
+REF=$REF
+REGISTRY=$REGISTRY
+BUILD=$BUILD
+EOF
+chown root:root "$CONF.tmp"; chmod 644 "$CONF.tmp"; mv -f "$CONF.tmp" "$CONF"
+
+cat > "$UNIT_DIR/drb-update.service" <<EOF
+[Unit]
+Description=DRB node updater (node-26#15)
+After=network-online.target docker.service
+Wants=network-online.target
+Requires=docker.service
+
+[Service]
+Type=oneshot
+ExecStart=/bin/bash $INSTALL_DIR/scripts/drb-update.sh
+TimeoutStartSec=$([ "$BUILD" = 1 ] && echo 3h || echo 45min)
+Nice=10
+EOF
+
+cat > "$UNIT_DIR/drb-update.timer" <<'EOF'
+[Unit]
+Description=DRB node updater — periodic HTTPS check-in with C2
+
+[Timer]
+OnBootSec=3min
+OnUnitActiveSec=15min
+RandomizedDelaySec=2min
+Persistent=true
+
+[Install]
+WantedBy=timers.target
+EOF
+
+cat > "$UNIT_DIR/drb-update.path" <<EOF
+[Unit]
+Description=DRB node updater — MQTT node_update sentinel
+
+[Path]
+PathExists=$INSTALL_DIR/configs/update-requested
+Unit=drb-update.service
+
+[Install]
+WantedBy=multi-user.target
+EOF
+
+systemctl daemon-reload
+systemctl enable --now drb-update.timer drb-update.path >/dev/null 2>&1 \
+  || die "could not enable drb-update.timer/path"
+printf 'install-updater: host updater enabled (timer every ~15 min + MQTT sentinel), tracking %s @ %s\n' \
+  "$REPO_URL" "$REF"