I am trying to publish single message to MQTT and disconnect with following code. But it works sometime, sometime doesn't work as expected. I want to listen for a topic for if the switch1 os on then turn off, of its of then turn on based on the received data and disconnect.
#!/usr/bin/env python2.7
import json
import time
import os
import paho.mqtt.client as mqtt
mqtt_host = os.getenv('HOST', 'xxxx')
mqtt_port = os.getenv('PORT', 1883)
mqtt_username = os.getenv('USERNAME', 'xxxx')
mqtt_password = os.getenv('PASSWORD', 'xxxx')
mqtt_subacribe_topic = os.getenv('SUBSCRIBE_TOPIC', 'xxxx')
mqtt_publish_topic = os.getenv('PUBLISH_TOPIC', 'xxxx')
sleep_time = os.getenv('SLEEP_TIME', 15)
CLIENT_ID = "lambda"
SWITCH1_ON = { "SWITCH1": "on" }
SWITCH1_OFF = { "SWITCH1": "off" }
def on_publish(client, userdata, mid):
print ("Message Published...")
client.disconnect()
def on_subscribe(client, userdata, mid, granted_qos):
print("Subscribed: " + str(message.topic) + " " + str(mid) + " " + str(granted_qos))
def on_connect(client, userdata, flags, rc):
if rc == 0:
print("Connected to broker")
client.subscribe(mqtt_subacribe_topic)
else:
print("Connection failed")
def on_message(client, userdata, msg):
payload = json.loads(msg.payload)
if payload.get('switch1') == 1:
client.publish(mqtt_publish_topic,json.dumps(SWITCH1_ON))
elif payload.get('switch1') == 0:
client.publish(mqtt_publish_topic,json.dumps(SWITCH1_OFF))
def main():
client = mqtt.Client(CLIENT_ID)
client.username_pw_set(mqtt_username, password=mqtt_password)
# Register publish callback function
client.on_publish = on_publish
client.on_connect = on_connect
client.on_message = on_message
# Connect with MQTT Broker
client.connect(mqtt_host, port=mqtt_port)
# Loop forever
client.loop_start()
time.sleep(sleep_time)
client.loop_stop()
client.disconnect()
if __name__ == "__main__":
main()
Based on hardillb's answer I tried :
#!/usr/bin/env python2.7
import json
import time
import os
import paho.mqtt.subscribe as subscribe
import paho.mqtt.publish as publish
mqtt_host = os.getenv('HOST', 'xxx.cloudmqtt.com')
mqtt_port = os.getenv('PORT', 1883)
mqtt_username = os.getenv('USERNAME', 'xxx')
mqtt_password = os.getenv('PASSWORD', 'xxx')
mqtt_subacribe_topic = os.getenv('SUBSCRIBE_TOPIC', 'xxx')
mqtt_publish_topic = os.getenv('PUBLISH_TOPIC', 'xxx')
sleep_time = os.getenv('SLEEP_TIME', 14)
CLIENT_ID = "lambda"
SWITCH1_ON = { "SWITCH1": "on" }
SWITCH1_OFF = { "SWITCH1": "off" }
auth = {'username':mqtt_username, 'password':mqtt_password}
def on_message(client, userdata, msg):
payload = json.loads(msg.payload)
print(payload)
if payload.get('switch1') == 1:
publish.single(mqtt_publish_topic,json.dumps(SWITCH1_ON),hostname=mqtt_host,auth=auth)
print "Turning switch1 ON"
elif payload.get('switch1') == 0:
publish.single(mqtt_publish_topic,json.dumps(SWITCH1_OFF),hostname=mqtt_host,auth=auth)
print "Turning switch1 OFF"
def main():
subscribe.callback(on_message, mqtt_subacribe_topic,hostname=mqtt_host,auth=auth)
if __name__ == "__main__":
main()
But script is keep running, I have to kill it to stop. Is it possible to just subscribed to a topic and once first message is received, process it, publish to another topic and end the execution.
If you just want to publish a single message then the Paho client has a built in method to do this. You can find the doc here
import paho.mqtt.publish as publish
publish.single("paho/test/single", "payload", hostname="iot.eclipse.org")
There is an equivalent method for also subscribing to a topic and receiving a single message.
Related
I use paho.mqtt. And I send messange to topic test/data/user1
My Subscribe Client:
from paho.mqtt import client as mqtt_client
host = 'myhost.com'
port = 1883
topic = 'test/data/#'
auth = {
'username': 'myuser',
'password': 'mypass'
}
client_id = 'python-mqtt-1'
def connect_mqtt() -> mqtt_client:
def on_connect(client, userdata, flags, rc):
if rc == 0:
print("Connected to MQTT Broker!")
else:
print("Failed to connect, return code %d\n", rc)
client = mqtt_client.Client(client_id)
client.username_pw_set(**auth)
client.on_connect = on_connect
client.connect(host, port)
return client
def subscribe(client: mqtt_client):
def on_message(client, userdata, msg):
print(f"Received `{msg.payload.decode()}` from `{msg.topic}` topic")
client.subscribe(topic)
client.on_message = on_message
def run():
client = connect_mqtt()
subscribe(client)
client.loop_forever()
if __name__ == '__main__':
run()
But I don't get my messange with topic='test/data/#'. If I use topic='test/data/user1', I get my messange. Why is the wildcard theme not working?
My broker is RabbitMQ.
So apparently RabbitMQ itself doesn't support this feature.
https://github.com/rabbitmq/rabbitmq-server/issues/2556
I'm usuing paho.mqtt.client to forward a local mqtt broker to another public mqtt broker,
so what I did is, have two client, and subscribe on both, and on receive mqtt message, forward to another borker, the issue I have is it will always has a additional forward slash in the forwarded mqtt message topic.
the original message topic:
elevator/11112901/cabin/load/actual-load
the forward message topic:
elevator/11112901/cabin/load/actual-load/
Appreciate if you could share your comments,thanks!
The code
#!/usr/bin/env python
#coding=utf-8
import hmac
import queue
import base64
from hashlib import sha1
import time
from paho.mqtt.client import MQTT_LOG_INFO, MQTT_LOG_NOTICE, MQTT_LOG_WARNING, MQTT_LOG_ERR, MQTT_LOG_DEBUG
from paho.mqtt import client as mqtt
import random
import string
dev_key = ''.join(random.sample(string.ascii_letters + string.digits, 12))
# 实例 ID，购买后从产品控制台获取
instanceId ='xxx'
#账号AccessKey 从阿里云账号控制台获取
accessKey = 'xxx'
#账号secretKey 从阿里云账号控制台获取
secretKey = 'xxx'
#MQTT GroupID,创建实例后从 MQTT 控制台创建
groupId = 'xxx'
#MQTT ClientID，由 GroupID 和后缀组成，需要保证全局唯一
client_id=groupId+'###'+ dev_key
#MQTT 接入点域名，实例初始化之后从控制台获取
brokerUrl='xxx'
topic_elevator_command = 'commands/#'
topic_elevator_status = 'elevator/#'
q = queue.Queue()
def on_log_aliyun(client, userdata, level, buf):
if level == MQTT_LOG_INFO:
head = 'INFO'
elif level == MQTT_LOG_NOTICE:
head = 'NOTICE'
elif level == MQTT_LOG_WARNING:
head = 'WARN'
elif level == MQTT_LOG_ERR:
head = 'ERR'
elif level == MQTT_LOG_DEBUG:
head = 'DEBUG'
else:
head = level
print('%s: %s' % (head, buf))
def on_connect_cube(client, userdata, flags, rc):
print('Connected with result code ' + str(rc))
client.subscribe(topic_elevator_status, 1)
client.publish("elevator/test", "32q14324")
def on_message_cube(client, userdata, msg):
print(msg.topic + ' ' + str(msg.payload))
if msg.topic.startswith(topic_elevator_status[:len(topic_elevator_status)-2]):
q.put(("Cube", msg))
def on_disconnect_cube(client, userdata, rc):
if rc != 0:
print('Unexpected disconnection %s' % rc)
def on_connect_aliyun(client, userdata, flags, rc):
print('Connected with result code ' + str(rc))
client.subscribe(topic_elevator_command, 0)
client.publish("elevator/test", "32q14324")
def on_message_aliyun(client, userdata, msg):
print(msg.topic + ' ' + str(msg.payload))
if msg.topic.startswith(topic_elevator_command[:len(topic_elevator_command)-2]):
q.put(("Aliyun", msg))
def on_disconnect_aliyun(client, userdata, rc):
if rc != 0:
print('Unexpected disconnection %s' % rc)
client_aliyun = mqtt.Client(client_id, protocol=mqtt.MQTTv311, clean_session=True)
#client_aliyun.on_log = on_log_aliyun
client_aliyun.on_connect = on_connect_aliyun
client_aliyun.on_message = on_message_aliyun
client_aliyun.on_disconnect = on_disconnect_aliyun
## username和 Password 签名模式下的设置方法，参考文档 https://help.aliyun.com/document_detail/48271.html?spm=a2c4g.11186623.6.553.217831c3BSFry7
userName ='Signature'+'|'+accessKey+'|'+instanceId
password = base64.b64encode(hmac.new(secretKey.encode(), client_id.encode(), sha1).digest()).decode()
client_aliyun.username_pw_set(userName, password)
# ssl设置，并且port=8883
#client.tls_set(ca_certs=None, certfile=None, keyfile=None, cert_reqs=ssl.CERT_REQUIRED, tls_version=ssl.PROTOCOL_TLS, ciphers=None)
client_aliyun.connect(brokerUrl, 1883, 60)
client_aliyun.loop_start()
client_cube = mqtt.Client(dev_key, clean_session=True)
#client_cube.on_log = on_log_aliyun
client_cube.on_connect = on_connect_cube
client_cube.on_message = on_message_cube
client_cube.on_disconnect = on_disconnect_cube
client_cube.connect("xxx",1883)
client_cube.loop_start()
while 1:
qmsg = q.get()
dir, msg = qmsg
print(dir, msg.topic)
if dir == "Cube":
client_aliyun.publish(msg.topic, msg.payload)
if dir == "Aliyun":
client_cube.publish(msg.topic, msg.payload)
I need to build a network with multiple publishers, one broker, and one subscriber.
Issue:
I have a working code with one to one option (one pub - one sub). However, when I run more publishers the subscriber receives messages only from the last connected publisher and I have no idea why it is happening.
More information: Broker (mosquitto) is working in a docker container, each publisher is a separate script and the target is to run multiple docker containers with one publisher in each container, but now I need to work around the communication issue.
Does anyone have any clues or ideas on how to debug or solved this?
This is the publisher script:
import time
import paho.mqtt.client as mqtt
import datetime
import random
import json
import logging
from multiprocessing import Process
CLEAN_SESSION = False
def on_connect(client, userdata, flags, rc):
logging.info(f"New connection {client}, {rc}")
def sensor(client_id):
localhost = '172.17.0.2'
port = 1883
timeout = 60
topic = "/mia/sensor"
client_id = f"sensor_{client_id}"
def check_sensor():
time.sleep(1)
rand = random.randint(0, 10)
if rand > 5:
current_time = datetime.datetime.now()
current_time = current_time.strftime('%Y-%m-%d %H:%M:%S')
return {"time": current_time, "signal": 1, "id": client_id}
else:
return 0
client = mqtt.Client(client_id, clean_session=CLEAN_SESSION)
client.on_connect = on_connect
client.connect(localhost, port, timeout)
while True:
check_info = check_sensor()
if check_info:
message_payload = json.dumps(check_info)
logging.info(message_payload)
client.publish(topic, message_payload, qos=2)
client.loop()
client.disconnect()
if __name__ == "__main__":
p = Process(target=sensor, args=(1,))
p.start()
print("new publisher created!")
This is the subscriber script:
import paho.mqtt.client as mqtt
import paho.mqtt.subscribe as sub
import json
import logging
localhost = '172.17.0.2'
port = 1883
timeout = 60
topic = "/mia/sensor"
def on_connect(client, userdata, flags, rc):
logging.info(f"New connection {client}, {rc}")
client.subscribe(topic, qos=2)
def on_message(client, userdata, msg):
data = json.loads(msg.payload.decode('utf-8'))
logging.debug(f"new message from {client} - {data}")
print(data)
client = mqtt.Client("python", clean_session=False)
client.on_connect = on_connect
client.on_message = on_message
client.connect_async(localhost, port, timeout)
client.loop_forever()
Thanks in advance
Your client_id needs to be unique. Check that.
I managed to publish on several topics and read one of them. What I need to do is to listen and read to all published topics and get messages. This is the code I use:
Publish messages to 3 topics :
#!/usr/bin/env python3
import paho.mqtt.client as mqtt
client = mqtt.Client()
client.connect("localhost",1883,60)
client.publish("topic/1", "400 | 350 | 320 | 410");
client.publish("topic/2", "200 | 350 | 420 | 110");
client.publish("topic/3", "200 | 350 | 420 | 110");
client.disconnect();
Subscribe and read messages for 1 topic
#!/usr/bin/env python3
import paho.mqtt.client as mqttClient
import time
def on_connect(client, userdata, flags, rc):
if rc == 0:
print("Connected to broker")
global Connected #Use global variable
Connected = True #Signal connection
else:
print("Connection failed")
def on_message(client, userdata, message):
print "Message received : " + message.payload
Connected = False
broker_address= "localhost"
port = 1883
client = mqttClient.Client("Python")
client.on_connect= on_connect
client.on_message= on_message
client.connect(broker_address, port=port)
client.loop_start()
while Connected != True:
time.sleep(0.1)
client.subscribe("topic/2")
try:
while True:
time.sleep(1)
except KeyboardInterrupt:
print "exiting"
client.disconnect()
client.loop_stop()
You can call the client.subscribe() function multiple times to subscribe to multiple topics.
Also you should move the calls to subscribe to the on_connect callback to remove the need for the first loop.
#!/usr/bin/env python3
import paho.mqtt.client as mqttClient
import time
def on_connect(client, userdata, flags, rc):
if rc == 0:
print("Connected to broker")
client.subscribe("topic/1")
client.subscribe("topic/2")
client.subscribe("topic/3")
client.subscribe("topic/4")
else:
print("Connection failed")
def on_message(client, userdata, message):
print("Message received : " + str(message.payload) + " on " + message.topic)
broker_address= "localhost"
port = 1883
client = mqttClient.Client("Python")
client.on_connect= on_connect
client.on_message= on_message
client.connect(broker_address, port=port)
client.loop_start()
try:
while True:
time.sleep(1)
except KeyboardInterrupt:
print("exiting")
client.disconnect()
client.loop_stop()
EDIT:
You can also subscribe to multiple topics in one go with the following syntax
client.subscribe([("topic/1", 0), ("topic/2", 0), ("topic/3", 0),("topic/4", 0)])
I'm using MQTT since a while to monitor some channels I subscribed. Now I want to implement to send a message as reaction to a state. I got it running with the code below, where I just react in the on_message callback (code 1 at the end). But this code uses
loop_forever()
in the main code which is blocking.
What I would like to do is to just send a single message to MQTT. When I try the following (with all different loop-functions), nothing is received by the MQTT server:
import paho.mqtt.client as mqtt
if __name__ == "__main__":
mqtt_client = mqtt.Client()
mqtt_client.connect("192.168.178.204", 1883, 60)
mqtt_client.username_pw_set(username="test", password="test")
mqtt_client.publish(topic='TEST', payload='CCCCCCCCC', retain=False)
mqtt_client.loop_write()
# mqtt_client.loop()
# mqtt_client.loop_start()
mqtt_client.disconnect()
How can I send a message to MQTT which does not block the process?
Code 1:
import paho.mqtt.client as mqtt
def on_connect(client, userdata, rc):
topic_list = [("TEST_MS", 1)]
if rc == 0:
print("Successful connected and subscribed to: {}".format(topic_list))
client.subscribe(topic_list)
def on_message(client, userdata, msg):
print(msg.payload)
client.publish(topic='TEST_MS2', payload=msg.payload, retain=False)
def on_publish(client, userdata, mid):
print("message published")
def on_subscribe(mosq, obj, mid, granted_qos):
print("Subscribed: " + str(mid) + " " + str(granted_qos))
if __name__ == "__main__":
mqtt_client = mqtt.Client()
mqtt_client.on_connect = on_connect
mqtt_client.on_message = on_message
mqtt_client.on_publish = on_publish
mqtt_client.on_subscribe = on_subscribe
mqtt_client.connect("192.168.178.204", 1883, 60)
mqtt_client.username_pw_set(username="test", password="test")
# mqtt_client.publish(topic='TEST_MS', payload='CCCCCCCCC', retain=False)
mqtt_client.loop_forever()
mqtt_client.disconnect()
If you want to send just a single message and then exit use the API specifically for that. Docs here
import paho.mqtt.publish as publish
publish.single("paho/test/single", "payload", hostname="iot.eclipse.org")