Connect a client to IoT Platform by using the SDK for Python 2.7

Development environment

This example uses Python 2.7.

Download the SDK

We recommend the Apache Qpid Proton 0.29.0 library, which encapsulates the Python API. To download the library and view the instructions, visit Qpid Proton 0.29.0.

Install Qpid Proton. For more information, see Installing Qpid Proton.

After you install Qpid Proton, run the following Python command to verify that the SSL library is available:

import proton;print('%s' % 'SSL present' if proton.SSL.present() else 'SSL NOT AVAILABLE')

Sample code

# encoding=utf-8
import sys
import logging
import time
from proton.handlers import MessagingHandler
from proton.reactor import Container
import hashlib
import hmac
import base64
import os
reload(sys)
sys.setdefaultencoding('utf-8')
logging.basicConfig(level=logging.INFO, format='%(asctime)s - %(name)s - %(levelname)s - %(message)s')
logger = logging.getLogger(__name__)
console_handler = logging.StreamHandler(sys.stdout)
def current_time_millis():
    return str(int(round(time.time() * 1000)))
def do_sign(secret, sign_content):
    m = hmac.new(secret, sign_content, digestmod=hashlib.sha1)
    return base64.b64encode(m.digest())
class AmqpClient(MessagingHandler):
    def __init__(self):
        super(AmqpClient, self).__init__()
    def on_start(self, event):
        # The endpoint used to connect to IoT Platform. For details, see the AMQP connection guide.
        url = "amqps://${YourHost}:5671"
        # Hard-coding an AccessKey pair in your project code poses a security risk. If the code is leaked, your AccessKey pair will be exposed, compromising all resources in your account. The following code retrieves the AccessKey pair from environment variables as a best practice. This is for reference only.
        accessKey = os.environ['ALIBABA_CLOUD_ACCESS_KEY_ID']
        accessSecret = os.environ['ALIBABA_CLOUD_ACCESS_KEY_SECRET']
        consumerGroupId = "${YourConsumerGroupId}"
        clientId = "${YourClientId}"
        # iotInstanceId: The ID of the IoT Platform instance.
        iotInstanceId = "${YourIotInstanceId}"
        # The signature algorithm. Valid values: hmacmd5, hmacsha1, and hmacsha256.
        signMethod = "hmacsha1"
        timestamp = current_time_millis()
        # For instructions on how to construct the userName parameter, see the AMQP connection guide.
        userName = clientId + "|authMode=aksign" + ",signMethod=" + signMethod \
                        + ",timestamp=" + timestamp + ",authId=" + accessKey \
                        + ",iotInstanceId=" + iotInstanceId + ",consumerGroupId=" + consumerGroupId + "|"
        signContent = "authId=" + accessKey + "&timestamp=" + timestamp
        # Calculate the signature. For instructions on how to construct the password, see the AMQP connection guide.
        passWord = do_sign(accessSecret.encode("utf-8"), signContent.encode("utf-8"))
        conn = event.container.connect(url, user=userName, password=passWord, heartbeat=60)
        self.receiver = event.container.create_receiver(conn)
    # Called when the connection is successfully established.
    def on_connection_opened(self, event):
        logger.info("Connection established, remoteUrl: %s", event.connection.hostname)
    # Called when the connection is closed.
    def on_connection_closed(self, event):
        logger.info("Connection closed: %s", self)
    # Called when the remote peer closes the connection due to an error.
    def on_connection_error(self, event):
        logger.info("Connection error")
    # Called when an AMQP connection error occurs, such as an authentication or socket error.
    def on_transport_error(self, event):
        if event.transport.condition:
            if event.transport.condition.info:
                logger.error("%s: %s: %s" % (
                    event.transport.condition.name, event.transport.condition.description,
                    event.transport.condition.info))
            else:
                logger.error("%s: %s" % (event.transport.condition.name, event.transport.condition.description))
        else:
            logging.error("Unspecified transport error")
    # Called when a message is received.
    def on_message(self, event):
        message = event.message
        content = message.body.decode('utf-8')
        topic = message.properties.get("topic")
        message_id = message.properties.get("messageId")
        print("receive message: message_id=%s, topic=%s, content=%s" % (message_id, topic, content))
        event.receiver.flow(1)
Container(AmqpClient()).run()

You can configure the parameters in the preceding code based on the parameter description in the following table. For more information about other parameters, see Connect an AMQP client to IoT Platform.

Sample results

• Success: The following log message indicates that the AMQP client connected to IoT Platform and is receiving messages.

  202x-xx-xx xx:xx:xx,490 - __main__ - INFO - Connection established, remoteUrl: xxx.amqp.iothub.aliyuncs.com
  receive message: message_id=13xxx, topic=/xxx/thing/event/property/post, content={"deviceType":"CustomCategory","iotId":"xxx","requestId":"1xxx"}
  receive message: message_id=13xxx, topic=/xxx/thing/event/property/post, content={"deviceType":"CustomCategory","iotId":"xxx","requestId":"1xxx"}

  Parameter	Example	Description
  message_id	2**************7	The ID of the message.
  topic	/***********/******/thing/event/property/post	The topic used to submit device properties.
  content	{"deviceType":"CustomCategory","iotId":"qPi*","requestId":"161*","checkFailedData":{},"productKey":"g4*","gmtCreate":1613635594038,"deviceName":"de*","items":{"Temperature":{"value":24,"time":1613635594036},"Humidity":{"value":26,"time":1613635594036}}}	The content of the message.

• If information similar to the following output is displayed, the AMQP client fails to connect to IoT Platform.

  Use the error log to check your code and network settings. Resolve the issue and run the code again.

  2021-02-18 16:19:40,993 - proton - ERROR - Couldn't connect: 10053
  2021-02-18 16:19:40,996 - __main__ - ERROR - proton.pythonio: Connection error: 10053
  2021-02-18 16:19:40,996 - proton - INFO - Disconnected, reconnecting...
  Traceback (most recent call last):
    File "xxx", line 87, in <module>
      Container(AmqpClient()).run()
    File "xxx", line 181, in run
      while self.process(): pass
    File "xxx", line 240, in process
      event.dispatch(self._global_handler)
    File "xxx", line 135, in dispatch
      _dispatch(handler, type.method, self)
    File "xxx", line 117, in _dispatch
      handler.on_unhandled(method, *args)
    File "xxx", line 665, in on_unhandled
      event.dispatch(self.base)
    File "xxx", line 135, in dispatch
      _dispatch(handler, type.method, self)
    File "xxx", line 115, in _dispatch
      m(*args)
    File "xxx", line 892, in on_connection_bound
      addrs = socket.getaddrinfo(host, port, socket.AF_UNSPEC, socket.SOCK_STREAM)
  socket.gaierror: [Errno 11001] getaddrinfo failed

References

For more information about error codes for server-side subscription messages, see Message-related error codes.