tliu93
ef48032adb
- mqtt.py: subscription registry, on_message dispatch (swallows handler errors), re-subscribe on (re)connect; publish/connect/disconnect/reconnect unchanged. - app/services/dsmr_ingest.py: handle_message stores the full telegram frame (no allowlist; gas/phases/null preserved), 10s downsample by timestamp.second, source_id idempotency (select + IntegrityError rollback). Net-thread safe. - main.py registers the DSMR subscription only when dsmr_ingest_enabled.
321 lines
12 KiB
Python
321 lines
12 KiB
Python
"""MQTT client integration (paho-mqtt 2.x).
|
|
|
|
Provides :class:`MqttManager`: a long-lived MQTT client that runs paho's
|
|
loop in a background thread. Designed to be started in FastAPI's lifespan
|
|
and shared across the application as a module-level singleton (``mqtt_manager``).
|
|
|
|
Key design decisions
|
|
--------------------
|
|
- **paho 2.x API**: ``Client`` requires ``CallbackAPIVersion.VERSION2`` as the
|
|
first positional argument. VERSION2 on_connect callback receives
|
|
``(client, userdata, connect_flags, reason_code, properties)`` — not the
|
|
older RC int.
|
|
- **Background thread**: ``loop_start()`` spawns a daemon thread; ``loop_stop()``
|
|
joins it cleanly on shutdown.
|
|
- **Never crash the process**: all paho operations are wrapped in try/except;
|
|
connection failure is logged but does not propagate to the caller.
|
|
- **Password safety**: the MQTT password is never passed to ``logger`` calls.
|
|
- **Reconnect**: ``reconnect(settings)`` tears down the old client and
|
|
establishes a fresh connection with the new settings. Callers (e.g. PUT
|
|
/api/config) call this after saving MQTT-related config values.
|
|
- **Subscribe**: ``subscribe(topic, handler)`` registers a topic → handler
|
|
mapping. Subscriptions are re-established automatically on reconnect.
|
|
The ``on_message`` callback dispatches incoming payloads to the registered
|
|
handler; handler exceptions are caught and logged so they never crash the
|
|
paho loop thread or the network connection.
|
|
"""
|
|
|
|
from __future__ import annotations
|
|
|
|
import logging
|
|
import threading
|
|
from collections.abc import Callable
|
|
from typing import TYPE_CHECKING
|
|
|
|
import paho.mqtt.client as mqtt
|
|
|
|
if TYPE_CHECKING:
|
|
from app.config import Settings
|
|
|
|
logger = logging.getLogger(__name__)
|
|
|
|
# MQTT settings keys that, when changed, should trigger a reconnect.
|
|
MQTT_SETTINGS_KEYS = {
|
|
"mqtt_enabled",
|
|
"mqtt_broker_host",
|
|
"mqtt_broker_port",
|
|
"mqtt_username",
|
|
"mqtt_password",
|
|
"mqtt_tls_enabled",
|
|
}
|
|
|
|
|
|
def _is_configured(settings: Settings) -> bool:
|
|
"""Return True if MQTT is enabled *and* the broker host is set."""
|
|
return bool(settings.mqtt_enabled and settings.mqtt_broker_host)
|
|
|
|
|
|
class MqttManager:
|
|
"""Long-lived MQTT client wrapper.
|
|
|
|
Lifecycle
|
|
---------
|
|
1. ``connect(settings)`` — start background loop + connect to broker.
|
|
2. ``publish(...)`` — publish messages while connected.
|
|
3. ``disconnect()`` — graceful teardown (called on app shutdown).
|
|
4. ``reconnect(settings)`` — disconnect then re-connect with new settings
|
|
(called after saving updated MQTT configuration).
|
|
|
|
When MQTT is not enabled or not configured, all methods are no-ops.
|
|
Connection failures are caught and logged; they do not raise.
|
|
"""
|
|
|
|
def __init__(self) -> None:
|
|
self._client: mqtt.Client | None = None
|
|
self._lock = threading.Lock()
|
|
self._connected = False
|
|
# topic → handler registry; persists across reconnects so subscriptions
|
|
# are automatically re-established when the client reconnects.
|
|
self._subscriptions: dict[str, Callable[[bytes], None]] = {}
|
|
|
|
# ------------------------------------------------------------------
|
|
# Public properties
|
|
# ------------------------------------------------------------------
|
|
|
|
@property
|
|
def is_connected(self) -> bool:
|
|
"""True if the underlying paho client is currently connected."""
|
|
return self._connected
|
|
|
|
# ------------------------------------------------------------------
|
|
# Public interface
|
|
# ------------------------------------------------------------------
|
|
|
|
def is_configured(self, settings: Settings) -> bool:
|
|
"""Return True if MQTT is enabled and broker host is configured."""
|
|
return _is_configured(settings)
|
|
|
|
def connect(self, settings: Settings) -> None:
|
|
"""Connect to the MQTT broker and start the background loop thread.
|
|
|
|
No-op if MQTT is not enabled or broker host is not set.
|
|
Connection errors are logged but do not raise.
|
|
"""
|
|
if not _is_configured(settings):
|
|
logger.debug("MQTT not configured or not enabled — skipping connect.")
|
|
return
|
|
|
|
with self._lock:
|
|
self._start_client(settings)
|
|
|
|
def disconnect(self) -> None:
|
|
"""Disconnect from the broker and stop the background loop thread.
|
|
|
|
No-op if no client is active.
|
|
"""
|
|
with self._lock:
|
|
self._stop_client()
|
|
|
|
def reconnect(self, settings: Settings) -> None:
|
|
"""Disconnect the current client (if any) and reconnect with *settings*.
|
|
|
|
Call this after saving updated MQTT configuration values.
|
|
No-op if MQTT is not enabled or broker host is not set.
|
|
"""
|
|
with self._lock:
|
|
self._stop_client()
|
|
self.connect(settings)
|
|
|
|
def publish(
|
|
self,
|
|
topic: str,
|
|
payload: str | bytes | None,
|
|
*,
|
|
retain: bool = False,
|
|
qos: int = 0,
|
|
) -> None:
|
|
"""Publish a message to *topic*.
|
|
|
|
If the client is not connected the call is silently skipped.
|
|
Errors are logged but do not raise.
|
|
"""
|
|
with self._lock:
|
|
client = self._client
|
|
|
|
if client is None or not self._connected:
|
|
logger.debug("MQTT publish skipped — not connected (topic=%s).", topic)
|
|
return
|
|
|
|
try:
|
|
client.publish(topic, payload=payload, qos=qos, retain=retain)
|
|
except Exception:
|
|
logger.exception("MQTT publish error (topic=%s).", topic)
|
|
|
|
def subscribe(self, topic: str, handler: Callable[[bytes], None]) -> None:
|
|
"""Register *handler* to be called when a message arrives on *topic*.
|
|
|
|
If the client is already connected, the subscription is sent to the
|
|
broker immediately. Otherwise it is queued and will be established
|
|
the next time ``_on_connect`` fires (including after a reconnect).
|
|
|
|
Handler exceptions are swallowed by the ``on_message`` dispatcher so
|
|
that a buggy handler can never crash the paho loop thread.
|
|
"""
|
|
self._subscriptions[topic] = handler
|
|
# Grab the client reference outside the lock to avoid holding the lock
|
|
# while calling back into paho (which may itself acquire internal locks).
|
|
with self._lock:
|
|
client = self._client
|
|
connected = self._connected
|
|
|
|
if client is not None and connected:
|
|
try:
|
|
client.subscribe(topic)
|
|
logger.debug("MQTT subscribed to topic=%s (immediate).", topic)
|
|
except Exception:
|
|
logger.exception("MQTT subscribe error (topic=%s).", topic)
|
|
|
|
# ------------------------------------------------------------------
|
|
# Internal helpers — must be called with self._lock held
|
|
# ------------------------------------------------------------------
|
|
|
|
def _start_client(self, settings: Settings) -> None:
|
|
"""Build a fresh paho Client, configure it, and call loop_start + connect."""
|
|
client = mqtt.Client(
|
|
callback_api_version=mqtt.CallbackAPIVersion.VERSION2,
|
|
client_id="home-automation",
|
|
)
|
|
|
|
# Callbacks — VERSION2 on_connect signature:
|
|
# (client, userdata, connect_flags, reason_code, properties)
|
|
def _on_connect(
|
|
_client: mqtt.Client,
|
|
_userdata: object,
|
|
_flags: mqtt.ConnectFlags,
|
|
reason_code: mqtt.ReasonCode,
|
|
_properties: mqtt.Properties | None,
|
|
) -> None:
|
|
if reason_code.is_failure:
|
|
logger.warning("MQTT connection refused: %s", reason_code)
|
|
self._connected = False
|
|
else:
|
|
logger.info("MQTT connected (reason_code=%s).", reason_code)
|
|
self._connected = True
|
|
# Re-establish all registered subscriptions after (re-)connect.
|
|
for sub_topic in self._subscriptions:
|
|
try:
|
|
_client.subscribe(sub_topic)
|
|
logger.debug("MQTT re-subscribed to topic=%s.", sub_topic)
|
|
except Exception:
|
|
logger.exception(
|
|
"MQTT re-subscribe failed (topic=%s).", sub_topic
|
|
)
|
|
|
|
# VERSION2 on_disconnect signature:
|
|
# (client, userdata, disconnect_flags, reason_code, properties)
|
|
def _on_disconnect(
|
|
_client: mqtt.Client,
|
|
_userdata: object,
|
|
_disconnect_flags: mqtt.DisconnectFlags,
|
|
reason_code: mqtt.ReasonCode,
|
|
_properties: mqtt.Properties | None,
|
|
) -> None:
|
|
self._connected = False
|
|
if reason_code.is_failure:
|
|
logger.warning("MQTT disconnected unexpectedly (reason_code=%s).", reason_code)
|
|
else:
|
|
logger.info("MQTT disconnected cleanly.")
|
|
|
|
# VERSION2 on_message signature: (client, userdata, message)
|
|
def _on_message(
|
|
_client: mqtt.Client,
|
|
_userdata: object,
|
|
message: mqtt.MQTTMessage,
|
|
) -> None:
|
|
handler = self._subscriptions.get(message.topic)
|
|
if handler is None:
|
|
logger.debug(
|
|
"MQTT on_message: no handler for topic=%s.", message.topic
|
|
)
|
|
return
|
|
try:
|
|
handler(message.payload)
|
|
except Exception:
|
|
logger.exception(
|
|
"MQTT message handler raised for topic=%s (swallowed).",
|
|
message.topic,
|
|
)
|
|
|
|
client.on_connect = _on_connect
|
|
client.on_disconnect = _on_disconnect
|
|
client.on_message = _on_message
|
|
|
|
# TLS
|
|
if settings.mqtt_tls_enabled:
|
|
try:
|
|
client.tls_set()
|
|
except Exception:
|
|
logger.exception("MQTT TLS setup failed.")
|
|
return
|
|
|
|
# Credentials — never log the password
|
|
if settings.mqtt_username:
|
|
client.username_pw_set(
|
|
username=settings.mqtt_username,
|
|
password=settings.mqtt_password or None,
|
|
)
|
|
|
|
# Start background loop thread *before* connect so paho can handle
|
|
# the connection handshake asynchronously.
|
|
client.loop_start()
|
|
|
|
try:
|
|
client.connect(
|
|
host=settings.mqtt_broker_host,
|
|
port=settings.mqtt_broker_port,
|
|
keepalive=60,
|
|
)
|
|
except Exception:
|
|
# Log without leaking the password
|
|
logger.exception(
|
|
"MQTT connect failed (host=%s, port=%s). Stopping loop.",
|
|
settings.mqtt_broker_host,
|
|
settings.mqtt_broker_port,
|
|
)
|
|
try:
|
|
client.loop_stop()
|
|
except Exception:
|
|
pass
|
|
return
|
|
|
|
self._client = client
|
|
logger.info(
|
|
"MQTT client started (host=%s, port=%s).",
|
|
settings.mqtt_broker_host,
|
|
settings.mqtt_broker_port,
|
|
)
|
|
|
|
def _stop_client(self) -> None:
|
|
"""Disconnect and stop the background loop. Idempotent."""
|
|
client = self._client
|
|
if client is None:
|
|
return
|
|
self._client = None
|
|
self._connected = False
|
|
try:
|
|
client.disconnect()
|
|
except Exception:
|
|
logger.debug("MQTT disconnect raised (ignoring).", exc_info=True)
|
|
try:
|
|
client.loop_stop()
|
|
except Exception:
|
|
logger.debug("MQTT loop_stop raised (ignoring).", exc_info=True)
|
|
logger.info("MQTT client stopped.")
|
|
|
|
|
|
# ---------------------------------------------------------------------------
|
|
# Module-level singleton — shared across lifespan and route handlers
|
|
# ---------------------------------------------------------------------------
|
|
|
|
mqtt_manager = MqttManager()
|