Start receiving mqtt messages

3 files changed, 58 insertions, 1 deletions

diff --git a/kerbana/__init__.py b/kerbana/__init__.py
index ea7f5cf..8d47d35 100644
--- a/kerbana/__init__.py
+++ b/kerbana/__init__.py
@@ -4,7 +4,7 @@ from typing import Optional
 import flask
 import toml
 
-from . import config
+from . import config, mqtt
 
 
 def create_app(test_config: Optional[config.Config] = None):
@@ -45,6 +45,9 @@ def create_app(test_config: Optional[config.Config] = None):
     else:
         app.config.from_object(test_config)
 
+    mqtt_client = mqtt.MQTTClient(app)
+    mqtt_client.connect()
+
     @app.route('/')
     def root():
         return "Hello World!"
diff --git a/kerbana/config.py b/kerbana/config.py
index 2ccaabc..93b0e54 100644
--- a/kerbana/config.py
+++ b/kerbana/config.py
@@ -3,6 +3,12 @@
 class Config:
     SECRET_KEY = "dev"
 
+    MQTT_SERVER = "test.mosquitto.org"
+    MQTT_PORT = 1883
+    MQTT_USER = None
+    MQTT_PASSWORD = None
+    MQTT_TOPIC = "kerbana/#"
+
 
 class DefaultConfig(Config):
     pass
@@ -10,3 +16,5 @@ class DefaultConfig(Config):
 
 class TestConfig(Config):
     TESTING = True
+
+    MQTT_SERVER = "mqtt.invalid.org"
diff --git a/kerbana/mqtt.py b/kerbana/mqtt.py
new file mode 100644
index 0000000..9747de3
--- /dev/null
+++ b/kerbana/mqtt.py
@@ -0,0 +1,46 @@
+import paho.mqtt.client as mqtt
+from flask import Flask
+
+
+class MQTTClient:
+    def __init__(self, app: Flask):
+        self.app = app
+        self.reconnect = True
+        self.connected = False
+
+        self.client = mqtt.Client()
+        self.client.on_connect = self.on_connect
+        self.client.on_disconnect = self.on_disconnect
+        self.client.on_message = self.on_message
+
+    def connect(self):
+        try:
+            self.client.connect(
+                self.app.config["MQTT_SERVER"],
+                self.app.config["MQTT_PORT"],
+                60,  # TODO: make the keepalive configurable
+            )
+        except OSError as e:
+            self.app.logger.warning("Could not connect to MQTT server")
+            self.app.logger.warning(e)
+        self.client.loop_start()
+
+    def disconnect(self, reconnect: bool = True):
+        self.client.loop_stop()
+        self.client.disconnect()
+        self.reconnect = reconnect
+
+    def on_connect(self, client, userdata, flags, rc):
+        self.app.logger.warning("Connected to MQTT")
+        self.connected = True
+        client.subscribe(self.app.config["MQTT_TOPIC"])
+
+    def on_disconnect(self, client, userdata, flags, rc):
+        self.connected = False
+        if self.reconnect:
+            self.connect()
+
+    def on_message(self, client, userdata, msg):
+        self.app.logger.warning(
+            "Received msg %s %s", msg.topic, msg.payload.decode()
+        )