NewBook credentials from central Settings service

Stack-wide NewBook config lives in the Settings app (LXC 116) and is
fetched live via SETTINGS_URL/SETTINGS_SECRET — same pattern as cashup,
room-planner and maintenance. App-local system_config credentials remain
as a fallback for standalone/dev use. The app's Settings → Newbook page
no longer edits credentials; it points to the central app and keeps
Test Connection.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

backend/services/central_settings.py

@@ -0,0 +1,100 @@
+"""
+Client for the stack's central Settings service.
+
+NewBook credentials are managed once in the Settings app (LXC 116) and
+fetched live by every app — the same pattern as cashup / room-planner /
+maintenance (see their lib/newbook.js). Falls back to None if the service
+is unreachable so callers can fall back to app-local config.
+"""
+import logging
+import os
+import time
+from typing import Optional
+
+import httpx
+
+logger = logging.getLogger(__name__)
+
+SETTINGS_URL = os.getenv("SETTINGS_URL", "")
+SETTINGS_SECRET = os.getenv("SETTINGS_SECRET", "")
+
+_CACHE_TTL = 60  # seconds — credentials change rarely; avoid hammering the service
+_cache: dict = {}
+
+
+async def get_integration(name: str) -> Optional[dict]:
+    """
+    Fetch integration config (e.g. 'newbook') from the central Settings
+    service. Returns the config dict, or None if unavailable/unconfigured.
+    """
+    if not SETTINGS_URL or not SETTINGS_SECRET:
+        return None
+
+    cached = _cache.get(name)
+    if cached and (time.monotonic() - cached[0]) < _CACHE_TTL:
+        return cached[1]
+
+    url = f"{SETTINGS_URL}/settings/api/internal/integration/{name}"
+    try:
+        async with httpx.AsyncClient(timeout=5.0) as client:
+            resp = await client.get(
+                url, headers={"Authorization": f"Bearer {SETTINGS_SECRET}"}
+            )
+            resp.raise_for_status()
+            data = resp.json()
+            _cache[name] = (time.monotonic(), data)
+            return data
+    except Exception as e:
+        logger.warning(f"Central settings fetch failed for '{name}': {e}")
+        return None
+
+
+def _extract_newbook(s: Optional[dict]) -> Optional[dict]:
+    if not s:
+        return None
+    creds = {
+        "api_key": s.get("api_key") or "",
+        "username": s.get("username") or "",
+        "password": s.get("password") or "",
+        "region": s.get("region") or "eu",
+    }
+    # Only usable if the essential fields are present
+    if not (creds["api_key"] and creds["username"] and creds["password"]):
+        return None
+    return creds
+
+
+async def get_newbook_credentials() -> Optional[dict]:
+    """
+    Returns {'api_key', 'username', 'password', 'region'} from central
+    settings, or None if not available (caller should fall back).
+    """
+    return _extract_newbook(await get_integration("newbook"))
+
+
+def get_integration_sync(name: str) -> Optional[dict]:
+    """Blocking variant of get_integration for sync job contexts."""
+    if not SETTINGS_URL or not SETTINGS_SECRET:
+        return None
+
+    cached = _cache.get(name)
+    if cached and (time.monotonic() - cached[0]) < _CACHE_TTL:
+        return cached[1]
+
+    url = f"{SETTINGS_URL}/settings/api/internal/integration/{name}"
+    try:
+        resp = httpx.get(
+            url, headers={"Authorization": f"Bearer {SETTINGS_SECRET}"}, timeout=5.0
+        )
+        resp.raise_for_status()
+        data = resp.json()
+        _cache[name] = (time.monotonic(), data)
+        return data
+    except Exception as e:
+        logger.warning(f"Central settings fetch failed for '{name}': {e}")
+        return None
+
+
+def get_newbook_credentials_sync() -> Optional[dict]:
+    """Blocking variant of get_newbook_credentials for sync job contexts."""
+    return _extract_newbook(get_integration_sync("newbook"))

backend/services/newbook_client.py

@@ -48,7 +48,17 @@ class NewbookClient:
 
     @classmethod
     async def from_db(cls, db):
-        """Create client with credentials from database"""
+        """
+        Create client with credentials from the central Settings service
+        (stack-wide NewBook config), falling back to the app-local
+        system_config table for standalone/dev use.
+        """
+        from services.central_settings import get_newbook_credentials
+
+        central = await get_newbook_credentials()
+        if central:
+            return cls(**central)
+
         from api.config import _get_config_value
 
         api_key = await _get_config_value(db, "newbook_api_key")

backend/services/newbook_rates_client.py

@@ -51,10 +51,14 @@ class NewbookRatesClient:
 
     @classmethod
     async def from_db(cls, db):
-        """Create client with credentials and VAT rate from database"""
+        """
+        Create client with credentials from the central Settings service
+        (stack-wide NewBook config), falling back to the app-local
+        system_config table. VAT rate stays app-local either way.
+        """
         from sqlalchemy import text
+        from services.central_settings import get_newbook_credentials
 
-        # Get credentials from config
         result = await db.execute(
             text("SELECT config_key, config_value FROM system_config WHERE config_key IN ('newbook_api_key', 'newbook_username', 'newbook_password', 'newbook_region', 'accommodation_vat_rate')")
         )
@@ -63,6 +67,10 @@ class NewbookRatesClient:
 
         vat_rate = Decimal(config.get('accommodation_vat_rate', '0.20'))
 
+        central = await get_newbook_credentials()
+        if central:
+            return cls(**central, vat_rate=vat_rate)
+
         return cls(
             api_key=config.get('newbook_api_key'),
             username=config.get('newbook_username'),