问题描述
我有一个 Python 脚本，它实现了 Paho 库以订阅和重新发布来自 Mosquitto 服务器的 MQTT 主题。当我从终端调用它时，我的脚本工作正常。什么让我绊倒是试图守护脚本运行无人看管。我正在使用 daemonize 库，虽然我可以让脚本作为守护程序启动，但它实际上没有做任何事情。当我运行非守护程序脚本时，我看到在我指定的端点收到了 MQTT 消息，但是当相同的脚本作为守护程序运行时，我的接收端点没有显示任何消息。我包括了非守护程序和守护程序脚本以供参考。
关于为什么非守护脚本有效而守护脚本不起作用的任何想法？
非守护进程
import paho.mqtt.client as mqtt
import random
import json
import time
#replace [device-id] with your device you created in IoT Hub.
iothubmqtttopic = "devices/MoxieSensorsBHM/messages/events/"
#define on_connect function
def on_connect(client,userdata,flags,rc):
print("Connected with result code " + str(rc))
client.subscribe("MW/oneal/Tag/#")
#define on_message function - this function translates the incoming topic
#and publishes to the specified topic for IoT Hub
def on_message(client,message):
global iothubmqtttopic
topic = message.topic
if(topic != iothubmqtttopic):
#extract the sensor ID from the topic
splitTopic = topic.split("/") #split the topic into a list
sensorID = splitTopic[3] #the 3rd item in the list is the sensor ID
msgType = splitTopic[4] #the 4th item in the list is the type (e.g. status,UWB)
#convert the json response to a python dictionary object
m_decode = str(message.payload.decode("utf-8"))
m_in = json.loads(m_decode)
#get current time for timestamp
ts = time.gmtime()
tsFormatted = time.strftime("%Y-%m-%d %H:%M:%s",ts)
#add new elements to the dictionary for topic and sensor ID
m_in["topic"] = topic
m_in["sensorID"] = sensorID
m_in["messageType"] = msgType
m_in["timestamp"] = tsFormatted
#set the propertybag for IoT Hub
propertybag = "topic=" + topic + "&sensorID=" + sensorID + "&messageType=" + msgType
print(propertybag)
#convert back to JSON
m_encode = json.dumps(m_in)
#create an array of all the possible sensor IDs
#print to screen and publish to IoT Hub
print("Topic: ",topic)
print("Message received: ",m_encode)
print("IoT Hub Topic: ",iothubmqtttopic)
client.publish(iothubmqtttopic,m_encode)
# replace <broker address> with the FQDN or IP address of your MQTT broker
broker_address="localhost"
#create the client and connect to the broker
print("creating new instance")
client = mqtt.Client("iottopicxlate" + str(random.randrange(1,1000000))) #create new instance
client.on_message=on_message #attach function to callback
print("connecting to broker")
client.connect(broker_address) #connect to broker
client.on_connect = on_connect #attach function to callback
client.loop_forever() #stop the loop
守护进程
import paho.mqtt.client as mqtt
import random
import json
import time
import os,sys
from daemonize import Daemonize
def main():
#replace [device-id] with your device you created in IoT Hub.
iothubmqtttopic = "devices/MoxieSensorsBHM/messages/events/"
#define on_connect function
def on_connect(client,rc):
#print("Connected with result code " + str(rc))
client.subscribe("MW/oneal/Tag/#")
#define on_message function - this function translates the incoming topic
#and publishes to the specified topic for IoT Hub
def on_message(client,message):
global iothubmqtttopic
topic = message.topic
if(topic != iothubmqtttopic):
#extract the sensor ID from the topic
splitTopic = topic.split("/") #split the topic into a list
sensorID = splitTopic[3] #the 3rd item in the list is the sensor ID
msgType = splitTopic[4] #the 4th item in the list is the type (e.g. status,UWB)
#convert the json response to a python dictionary object
m_decode = str(message.payload.decode("utf-8"))
m_in = json.loads(m_decode)
#get current time for timestamp
ts = time.gmtime()
tsFormatted = time.strftime("%Y-%m-%d %H:%M:%s",ts)
#add new elements to the dictionary for topic and sensor ID
m_in["topic"] = topic
m_in["sensorID"] = sensorID
m_in["messageType"] = msgType
m_in["timestamp"] = tsFormatted
#set the propertybag for IoT Hub
propertybag = "topic="+topic+"&sensorID="+sensorID+"&messageType="+msgType
#print(propertybag)
#convert back to JSON
m_encode = json.dumps(m_in)
#print to screen and publish to IoT Hub
print("Topic: ",topic + propertybag)
print("Message received: ",m_encode)
client.publish(iothubmqtttopic,m_encode)
# replace <broker address> with the FQDN or IP address of your MQTT broker
broker_address="localhost"
#create the client and connect to the broker
#print("creating new instance")
client = mqtt.Client("iottopicxlate" + str(random.randrange(1,1000000))) #create new instance
client.on_message=on_message #attach function to callback
#print("connecting to broker")
client.connect(broker_address) #connect to broker
client.on_connect = on_connect #attach function to callback
client.loop_forever() #stop the loop
#start the daemon
topictransdpid = os.path.basename(sys.argv[0])
pidfile = "topictransd.pid"
daemon = Daemonize(app = "topictransd",pid = pidfile,action = main)
daemon.start()
更新 文森特，我正在尝试执行您的建议以写入文件进行调试。请耐心等待，因为我正在快速学习 Python。我已将以下代码片段添加到脚本的非守护程序（即工作）版本中的 on_message 函数中，并且我看到了写入“调试”目录中文本文件的消息。当我在守护程序版本中实现相同的片段时，没有写入任何文件。所以当我的守护进程运行时，它实际上并没有做任何事情。
f = open("debug/" + sensorID+tsFormatted + ".txt","x")
f.write(m_encode)
f.close
对我遗漏的东西有什么想法吗？
更新 2 我实现了一个简单的记录器，用于在脚本启动时编写调试消息，并在 daemonize 调用 main() 函数时编写另一个记录器。我的日志文件有一个启动脚本的条目，但是没有一个条目用于调用 main() 时 - 好像 daemonize 没有执行 main() 函数？这是我启用了记录器的更新后的守护程序脚本：
import paho.mqtt.client as mqtt
import random
import json
import time
import logging
import os,sys
from daemonize import Daemonize
def main():
logger.warning("main has been started") # write a log file entry to indicate main has been called by daemonize
#replace [device-id] with your device you created in IoT Hub.
iothubmqtttopic = "devices/MoxieSensorsBHM/messages/events/"
#define on_connect function
def on_connect(client,ts)
#add new elements to the dictionary for topic and sensor ID
m_in["topic"] = topic
m_in["sensorID"] = sensorID
m_in["messageType"] = msgType
m_in["timestamp"] = tsFormatted
#set the propertybag for IoT Hub
propertybag = "topic="+topic+"&sensorID="+sensorID+"&messageType="+msgType
#print(propertybag)
#convert back to JSON
m_encode = json.dumps(m_in)
#print to screen and publish to IoT Hub
#print("Topic: ",topic + propertybag)
#print("Message received: ",m_encode)
#write the message to a debug file
f = open("debug/" + sensorID+tsFormatted + ".txt","w")
f.write(m_encode)
f.close
# replace <broker address> with the FQDN or IP address of your MQTT broker
broker_address="localhost"
#create the client and connect to the broker
#print("creating new instance")
client = mqtt.Client("iottopicxlate" + str(random.randrange(1,1000000))) #create new instance
#create a logger
#logging.basicConfig(level=logging.DEBUG,filename="topictransd.log",format="%(asctime)s %(message)s",filemode="w")
#logger = logging.getLogger()
#client.enable_logger(logger)
client.on_message=on_message #attach function to callback
#print("connecting to broker")
client.connect(broker_address) #connect to broker
client.on_connect = on_connect #attach function to callback
#start the loop
client.loop_forever()
#start the daemon
logging.basicConfig(level=logging.DEBUG,filemode="w")
logger = logging.getLogger()
pidfile = "topictransd.pid"
logger.warning("successfully started the script") # write a log file entry to indicate the script has successfully started
daemon = Daemonize(app = "topictransd",action = main)
daemon.start()
解决方法
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