Add paho.mqtt API v2.0+ support. Retains V1.x compatibility

callattendant/config.py

@@ -20,7 +20,7 @@
 # and screened callers through to the home phone.
 #
 default_config = {
-    "VERSION": '1.7.3',
+    "VERSION": '1.7.4',
 
     "DEBUG": False,
     "TESTING": False,

callattendant/hardware/mqttindicators.py

@@ -40,6 +40,8 @@ def __init__(self, host, port=1883, topic_prefix='callattendant', username=None,
         if mqtt_client is None:
             # No need to re-init
             mqtt_client = self
+            # Check for callback API version (new in v2)
+            self.has_callback_version = hasattr(mqtt, 'CallbackAPIVersion')
 
             self.server = host
             self.port = port
@@ -52,7 +54,14 @@ def publish(self, topic, message):
         """
         Publish a message to a topic.
         """
-        client = mqtt.Client()
+        # Changes to the Paho MQTT client API in version 2.0
+        # Even if we don't use callbacks, we need to specify the version
+        if (self.has_callback_version):
+            client = mqtt.Client(mqtt.CallbackAPIVersion.VERSION1)
+        else:
+            # Version 1.x compatibility
+            client = mqtt.Client()
+
         if self.username is not None:
             client.username_pw_set(self.username, self.password)
         client.connect(self.server, self.port)

setup.py

@@ -14,7 +14,7 @@
 
 setuptools.setup(
     name="callattendant",   # Add username when uploading to TestPyPI
-    version="1.7.3",        # Ensure this is in-sync with VERSION in config.py
+    version="1.7.4",        # Ensure this is in-sync with VERSION in config.py
     author="Ted Hess",
     author_email="[email protected]",
     description="An automated call attendant and call blocker using a USR5637 or CX930xx modem",