test: enable mosquitto password auth; add mqttping endpoint; use credentials in subscriber; publish defaults

test/subscribe.py

@@ -6,6 +6,8 @@ import paho.mqtt.client as mqtt
 
 broker = os.getenv('MQTT_BROKER', 'localhost:1883')
 topic = os.getenv('MQTT_TOPIC', 'lambdaiot')
+username = os.getenv('MQTT_USERNAME')
+password = os.getenv('MQTT_PASSWORD')
 
 if broker.startswith('tcp://'):
     broker = broker[len('tcp://'):]
@@ -28,6 +30,8 @@ def on_message(client, userdata, msg):
 client = mqtt.Client()
 client.on_connect = on_connect
 client.on_message = on_message
+if username:
+    client.username_pw_set(username, password)
 
 try:
     client.connect(host, port, 60)