v1.8.17: Atomarer Config-Write + Backup-Fallback

Verhindert Datenverlust wenn HAOS den Container während eines Saves
stoppt. Schreibt erst config.json.tmp, dann atomares os.replace().
Hält config.json.bak als Fallback für den nächsten Start.

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

haos-addon/src/main.py

@@ -110,25 +110,34 @@ def _defaults() -> Dict[str, Any]:
         "z2m_base": "zigbee2mqtt",
     }
 
+def _load_json_safe(path: str) -> Optional[Dict]:
+    """Lädt eine JSON-Datei; gibt None zurück wenn fehlend oder korrupt."""
+    try:
+        with open(path) as f:
+            return json.load(f)
+    except Exception as e:
+        log.warning("JSON-Ladefehler %s: %s", path, e)
+        return None
+
+
 def load_config() -> Dict[str, Any]:
     cfg = _defaults()
+    # MQTT-Grundeinstellungen aus HAOS-Options (überschreibbar durch config.json)
     if os.path.exists(HA_OPTIONS_PATH):
-        try:
-            with open(HA_OPTIONS_PATH) as f:
-                ha = json.load(f)
-                for k in ("mqtt_broker", "mqtt_port", "mqtt_user", "mqtt_pass"):
-                    if k in ha:
-                        cfg[k] = ha[k]
-        except Exception as e:
-            log.warning("HA options Fehler: %s", e)
-    if os.path.exists(CONFIG_PATH):
-        try:
-            with open(CONFIG_PATH) as f:
-                cfg.update(json.load(f))
-        except Exception as e:
-            log.warning("Config-Datei Fehler: %s", e)
+        ha = _load_json_safe(HA_OPTIONS_PATH) or {}
+        for k in ("mqtt_broker", "mqtt_port", "mqtt_user", "mqtt_pass"):
+            if k in ha:
+                cfg[k] = ha[k]
+    # Eigene persistente Config — Hauptdatei, dann Backup als Fallback
+    loaded = _load_json_safe(CONFIG_PATH)
+    if loaded is None and os.path.exists(CONFIG_PATH + ".bak"):
+        log.warning("config.json korrupt — lade Backup")
+        loaded = _load_json_safe(CONFIG_PATH + ".bak")
+    if loaded:
+        cfg.update(loaded)
     return cfg
 
+
 def save_config():
     data = {
         "mqtt_broker": State.mqtt_cfg.get("mqtt_broker", ""),
@@ -150,8 +159,17 @@ def save_config():
         "surplus_devices": State.surplus_devices_cfg,
         "z2m_base": State.z2m_base,
     }
-    with open(CONFIG_PATH, "w") as f:
+    # Backup der letzten guten Config anlegen
+    if os.path.exists(CONFIG_PATH):
+        try:
+            os.replace(CONFIG_PATH, CONFIG_PATH + ".bak")
+        except OSError:
+            pass
+    # Atomarer Write: erst .tmp schreiben, dann umbenennen
+    tmp = CONFIG_PATH + ".tmp"
+    with open(tmp, "w") as f:
         json.dump(data, f, indent=2)
+    os.replace(tmp, CONFIG_PATH)
 
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