🚧 WIP

listener/main.py

@@ -20,7 +20,7 @@ import paho.mqtt.client as mqtt
 from paho.mqtt.enums import CallbackAPIVersion
 
 from listener.db import Inserter
-from listener.process import DEFAULT_TIME_KEYS, normalize_imei, process_message
+from listener.process import DEFAULT_TIME_KEYS, normalize_imei, process_message, validate_imei_map
 
 logger = logging.getLogger("listener")
 
@@ -28,23 +28,12 @@ _stop_event = threading.Event()
 _shutdown_complete = threading.Event()
 
 
-def load_imei_map(path: str) -> dict[str, str]:
-    """Load the IMEI -> device name map from a JSON file.
-
-    Keys must be 15 digit IMEIs; values must be non-empty strings.
-    """
+def load_imei_map(path: str, log: bool = True) -> dict[str, str]:
+    """Load and validate the IMEI -> device name map from a JSON file."""
     data = json.loads(Path(path).read_text(encoding="utf-8"))
-    if not isinstance(data, dict):
-        raise ValueError(f"{path}: expected a JSON object mapping IMEI to device name")
-    result: dict[str, str] = {}
-    for key, value in data.items():
-        if not isinstance(value, str) or not value:
-            raise ValueError(f"{path}: values must be non-empty strings (key {key!r})")
-        normalized = key.strip()
-        if normalize_imei(normalized) is None:
-            raise ValueError(f"{path}: key {key!r} is not a 15-digit IMEI")
-        result[normalized] = value
-    logger.info("loaded %d IMEI mappings from %s", len(result), path)
+    result = validate_imei_map(data, path)
+    if log:
+        logger.info("loaded %d IMEI mappings from %s", len(result), path)
     return result
 
 
@@ -74,6 +63,7 @@ def main() -> None:
 
     map_file = _env("IMEI_MAP_FILE")
     imei_map = load_imei_map(map_file)
+    imei_lock = threading.Lock()  # guards imei_map against the reload thread
     imei_key = _env("INJECT_IMEI_KEY", "imei")
     device_key = _env("INJECT_DEVICE_KEY", "device")
     time_keys = tuple(
@@ -88,6 +78,25 @@ def main() -> None:
     Path("/tmp/listener.pid").write_text(str(os.getpid()), encoding="utf-8")
     logger.info("listener starting, pid %d", os.getpid())
 
+    def reload_imei_map() -> None:
+        """Periodically reload the IMEI map so edits via the API take effect
+        without a container restart. A broken file is logged and skipped; the
+        previously loaded mapping stays in effect."""
+        while not _stop_event.wait(timeout=5.0):
+            try:
+                fresh = load_imei_map(map_file, log=False)
+            except (OSError, ValueError, json.JSONDecodeError):
+                logger.exception("IMEI map reload failed; keeping previous mapping")
+                continue
+            nonlocal imei_map
+            with imei_lock:
+                if fresh != imei_map:
+                    imei_map = fresh
+                    logger.info("IMEI map reloaded: %d mappings", len(fresh))
+
+    reload_thread = threading.Thread(target=reload_imei_map, name="imei-map-reload", daemon=True)
+    reload_thread.start()
+
     def on_connect(client, userdata, flags, reason_code, properties):  # noqa: ANN001
         if reason_code.is_failure:
             logger.error("broker refused connection: %s", reason_code)
@@ -98,10 +107,12 @@ def main() -> None:
     def on_message(client, userdata, message):  # noqa: ANN001
         try:
             topic = message.topic
+            with imei_lock:
+                current_map = imei_map
             result = process_message(
                 topic,
                 bytes(message.payload),
-                imei_map,
+                current_map,
                 imei_key=imei_key,
                 device_key=device_key,
                 time_keys=time_keys,

listener/process.py

@@ -27,6 +27,27 @@ def normalize_imei(value: str) -> str | None:
     return value
 
 
+def validate_imei_map(data: object, source: str) -> dict[str, str]:
+    """Validate an IMEI -> device name mapping.
+
+    Must be a JSON object with 15-digit IMEI keys and non-empty string
+    values. Raises ValueError with a descriptive message otherwise. Shared
+    by the listener (file load) and the API (config write endpoint) so both
+    enforce identical rules.
+    """
+    if not isinstance(data, dict):
+        raise ValueError(f"{source}: expected a JSON object mapping IMEI to device name")
+    result: dict[str, str] = {}
+    for key, value in data.items():
+        if not isinstance(value, str) or not value:
+            raise ValueError(f"{source}: values must be non-empty strings (key {key!r})")
+        normalized = key.strip()
+        if normalize_imei(normalized) is None:
+            raise ValueError(f"{source}: key {key!r} is not a 15-digit IMEI")
+        result[normalized] = value
+    return result
+
+
 def _as_utc(value: datetime) -> datetime:
     """Interpret naive timestamps as UTC."""
     return value if value.tzinfo is not None else value.replace(tzinfo=timezone.utc)