Initial version

energy_usage/mqtt_client.py

@@ -0,0 +1,46 @@
+import logging
+
+import paho.mqtt.client as mqtt
+
+class MqttClient:
+    def __init__(self, server, port, username, password, topic, ca_certs, msg_q):
+        self.username = username
+        self.password = password
+        self.topic = topic
+        self.ca_certs = ca_certs
+        self.server = server
+        self.port = port
+        self.msg_q = msg_q
+
+        self.logger = logging.getLogger(__name__)
+
+        self.client = mqtt.Client()
+        self.client.on_connect = self.on_connect
+        self.client.on_message = self.on_message
+
+    def __del__(self):
+        self.client.loop_stop()
+
+    def connect(self):
+        self.client.username_pw_set(self.username, password=self.password)
+        self.client.tls_set(ca_certs=self.ca_certs)
+        self.client.connect(self.server, self.port, 60)
+
+    def run(self):
+        # Blocking call that processes network traffic, dispatches callbacks and
+        # handles reconnecting.
+        # Other loop*() functions are available that give a threaded interface and a
+        # manual interface.
+        self.client.loop_start()
+
+    # The callback for when the client receives a CONNACK response from the server.
+    def on_connect(self, client, userdata, flags, rc):
+        self.logger.info("Connected with result code " + str(rc))
+
+        # Subscribing in on_connect() means that if we lose the connection and
+        # reconnect then subscriptions will be renewed.
+        client.subscribe(self.topic)
+
+    # The callback for when a PUBLISH message is received from the server.
+    def on_message(self, client, userdata, msg):
+        self.msg_q.put(msg)