Possibility for multiple topics, keys, data and commands implemented

example_config/config.py

 MQTT_PASS = "pass"
 MQTT_SERVER = "host"
 
-TOPIC = 'topic'
-PAYLOAD_KEY = 'key'             # Give a key or None to compare plain DATA
-PAYLOAD_DATA = 'data'           # Give data to compare or None if no comparison is needed
-
-COMMAND = "aplay %s/ring.wav -D plughw:UACDemoV10,0" % __BASEPATH__
+EXEC_LIST = {
+    'topic_1': {
+        'key': 'key',                   # Give a key or None to compare plain DATA
+        'data': 'data',                 # Give data to compare or None if no comparison is needed
+        'command': 'echo 123'
+    },
+    'topic_2': {
+        'key': None,                    # Give a key or None to compare plain DATA
+        'data': 'data',                 # Give data to compare or None if no comparison is needed
+        'command': 'echo 321'
+    }
+}
 
 #
 # Logging

exec_command.py

     def __init__(self):
         self.__block_execution__ = False
         mqtt.mqtt_client.__init__(self, config.APP_NAME, config.MQTT_SERVER, 1883, config.MQTT_USER, config.MQTT_PASS)
-        self.add_callback(config.TOPIC, self.mqtt_rx)
+        for topic in config.EXEC_LIST:
+            self.add_callback(topic, self.mqtt_rx)
         # Start a pseudo process
         self.process = subprocess.Popen(["sleep", "0"])
 
-    def exec_command(self):
-        self.process = subprocess.Popen(config.COMMAND.split(" "))
+    def exec_command(self, cmd):
+        self.process = subprocess.Popen(cmd.split(" "))
 
     def mqtt_rx(self, client, userdate, message):
-        data = None
-        if config.PAYLOAD_KEY is None:
+        payload = None
+        key = config.EXEC_LIST[message.topic].get('key')
+        data = config.EXEC_LIST[message.topic].get('data')
+        if key is None:
             try:
-                data = message.payload.decode('utf-8')
+                payload = message.payload.decode('utf-8')
             except:
                 logger.exception("Error decoding mqtt message")
         else:
             except:
                 logger.exception("Error decoding json mqtt message")
             else:
-                data = payload.get(config.PAYLOAD_KEY)
-        if config.PAYLOAD_DATA is None or data == config.PAYLOAD_DATA:
+                try:
+                    payload = payload.get(key)
+                except AttributeError:
+                    logger.exception("payload seems to be no dictionary")
+        if data is None or payload == data:
             if self.process.poll() is None:
                 self.process.kill()
             logger.debug("Starting execution in background...")
-            self.exec_command()
+            self.exec_command(config.EXEC_LIST[message.topic]['command'])
 
 
 if __name__ == '__main__': 

ring.wav

-sounds/door-bell.wav