Adding MQTT automation rule

homeassistant/components/automation/mqtt.py

@@ -0,0 +1,34 @@
+"""
+homeassistant.components.automation.mqtt
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+Offers MQTT listening automation rules.
+"""
+import logging
+
+import homeassistant.components.mqtt as mqtt
+
+DEPENDENCIES = ['mqtt']
+
+CONF_TOPIC = 'mqtt_topic'
+CONF_PAYLOAD = 'mqtt_payload'
+
+
+def register(hass, config, action):
+    """ Listen for state changes based on `config`. """
+    topic = config.get(CONF_TOPIC)
+    payload = config.get(CONF_PAYLOAD)
+
+    if topic is None:
+        logging.getLogger(__name__).error(
+            "Missing configuration key %s", CONF_TOPIC)
+        return False
+
+    def mqtt_automation_listener(msg_topic, msg_payload, qos):
+        """ Listens for MQTT messages. """
+        if payload is None or payload == msg_payload:
+            action()
+
+    mqtt.subscribe(hass, topic, mqtt_automation_listener)
+
+    return True