add startup arguments

README.md

@@ -257,6 +257,9 @@ NOTE:
 * Change the working directory: `cd edge_iot_simulator`
 * Run:`python3 main.py`
 
+NOTE: If you want disable the `TemperatureService` (not burdening your broker with a lot messages), start the application with the following command: `python3 main.py --services cpu_load_svc`.
+Then, the `TemperatureService` is effectively disabled.
+
 You should see the following output:
 
 ```bash

edge_iot_simulator/core/temperature_svc.py

+from datetime import datetime
 from enum import Enum
 import threading
 import time
@@ -6,6 +7,7 @@ import json
 import copy
 import logging
 import os
+import sys
 
 from messaging.mqtt_client import MqttMessage
 logging.basicConfig(format='%(asctime)s %(module)s %(message)s', datefmt='%m/%d/%Y %I:%M:%S %p', level=logging.DEBUG)
@@ -50,10 +52,11 @@ class TemperatureService(threading.Thread):
 
     def get_temperature(self, unit):
         with self.lock:
-            temperature_measurement = copy.deepcopy(self.last_temperature_measurement)
+            if (self.last_temperature_measurement is not None):
+                temperature_measurement = copy.deepcopy(self.last_temperature_measurement)
 
-        if (temperature_measurement is None):
-            raise TemperatureServiceException("No valid measurement available!")
+        if (self.last_temperature_measurement is None):
+            temperature_measurement = TemperatureMeasurement(time.time(), float('inf'), TemperatureUnits.celsius.name)
 
         return temperature_measurement.convert(unit)
 

edge_iot_simulator/main.py

 #!/usr/bin/env python3
+import argparse
 from core.temperature_svc import TemperatureMeasurement, TemperatureService,TemperatureUnits
 from core.cpu_load_svc import CPULoadJobAllCores, CPULoadService
 from messaging.mqtt_client import MqttException, MqttClient, MqttStatus, MessageBroker
@@ -19,6 +20,15 @@ load_dotenv()
 
 if __name__=="__main__":
 
+
+    parser = argparse.ArgumentParser(description='Edge-IoT Simulator')
+    parser.add_argument('--services', metavar='S', type=str, nargs='+', default='temperature_svc cpu_load_svc', help='add the services you would like to start')
+    args = parser.parse_args()
+
+    services = []
+    for item in [args.services]:
+        services += item
+
     publisher_queue = queue.Queue()
     consumer_queue = queue.Queue()
 
@@ -31,8 +41,10 @@ if __name__=="__main__":
     try:
         logging.info('Start Edge-IoT Simulator...')
         publisher.start()
-        temperature_svc.start()
-        cpu_load_svc.start()
+        if "temperature_svc" in services:
+            temperature_svc.start()
+        if "cpu_load_svc" in services:
+            cpu_load_svc.start()
         web_app.start()
         message_broker.start()
         time.sleep(5) # wait for connection to mqtt broker
@@ -45,16 +57,20 @@ if __name__=="__main__":
         logging.error("Unknown error occurred: " + str(e))
     finally:
         publisher.stop()
-        temperature_svc.stop()
-        cpu_load_svc.stop()
+        if "temperature_svc" in services:
+            temperature_svc.stop()
+        if "cpu_load_svc" in services:
+            cpu_load_svc.stop()
         web_app.stop()
         message_broker.stop()
 
         logging.info('Wait for graceful termination...')
         
         publisher.join()
-        temperature_svc.join()
-        cpu_load_svc.join()
+        if "temperature_svc" in services:
+            temperature_svc.join()
+        if "cpu_load_svc" in services:
+            cpu_load_svc.join()
         web_app.join()
         message_broker.join()