python - AWS IoT 设备未收到 iOS 应用程序发布的消息

Question

所以我正在构建一个可以通过 AWS IoT 与设备通信的 iOS 应用程序。设备和应用程序都订阅了更新/接受、获取/接受和更新/增量。我可以从任何一方发布更新，并且更新反射(reflect)在 AWS IoT 事物影子上，但不知何故，更新从未从一个设备中继到另一个设备。因此，如果我在应用程序上按下发送，更新将显示在 AWS IoT 上，但应该订阅主题的设备似乎永远不会收到此类更新，反之亦然。 下面是设备端的代码片段。

# For certificate based connection
myShadowClient = AWSIoTMQTTShadowClient("myDevice")
myShadowClient.configureEndpoint("xxxxxxxxx.iot.us-east-1.amazonaws.com", 8883)
myShadowClient.configureCredentials("certs/root-CA.crt", "certs/private.pem.key", "certs/certificate.pem.crt")
myShadowClient.configureConnectDisconnectTimeout(10)  # 10 sec
myShadowClient.configureMQTTOperationTimeout(5)  # 5 sec


# Custom MQTT message callback
def customCallback(client, userdata, message):
    print("Received a new message: ")
    print(message.payload)
    print("from topic: ")
    print(message.topic)
    print("--------------\n\n")

# Custom Shadow callback
def customShadowCallback_Update(payload, responseStatus, token):
    # payload is a JSON string ready to be parsed using json.loads(...)
    # in both Py2.x and Py3.x
    if responseStatus == "timeout":
        print("Update request " + token + " time out!")
    if responseStatus == "accepted":
        payloadDict = json.loads(payload)
        print("~~~~~~~~~~~~~~~~~~~~~~~")
        print("Update request with token: " + token + " accepted!")
        print("property: " + str(payloadDict["state"]["desired"]["property"]))
        print("~~~~~~~~~~~~~~~~~~~~~~~\n\n")
    if responseStatus == "rejected":
        print("Update request " + token + " rejected!")

def customShadowCallback_Delete(payload, responseStatus, token):
    if responseStatus == "timeout":
        print("Delete request " + token + " time out!")
    if responseStatus == "accepted":
        print("~~~~~~~~~~~~~~~~~~~~~~~")
        print("Delete request with token: " + token + " accepted!")
        print("~~~~~~~~~~~~~~~~~~~~~~~\n\n")
    if responseStatus == "rejected":
        print("Delete request " + token + " rejected!")

#MQTT Operations
JSONPayload = '{"state":{"reported":{"property": "published from Device"}}}'


myShadowClient.connect()
myMQTTClient = myShadowClient.getMQTTConnection()

# AWSIoTMQTTClient connection configuration
myMQTTClient.configureAutoReconnectBackoffTime(1, 32, 20)
myMQTTClient.configureOfflinePublishQueueing(-1)  # Infinite offline Publish queueing
myMQTTClient.configureDrainingFrequency(2)  # Draining: 2 Hz
myMQTTClient.configureConnectDisconnectTimeout(10)  # 10 sec
myMQTTClient.configureMQTTOperationTimeout(5)  # 5 sec

myMQTTClient.publish("$aws/things/myDevice/shadow/update", JSONPayload, 1)
myMQTTClient.publish("$aws/things/myDevice/shadow/get", "", 1)
myMQTTClient.subscribe("$aws/things/myDevice/shadow/update/accepted", 1, customCallback)
myMQTTClient.subscribe("$aws/things/myDevice/shadow/update/rejected", 1, customCallback)

myMQTTClient.subscribe("$aws/things/myDevice/shadow/get/accepted", 1, customCallback)
myMQTTClient.subscribe("$aws/things/myDevice/shadow/get/rejected", 1, customCallback)
myMQTTClient.subscribe("$aws/things/myDevice/shadow/update/delta", 1, customCallback)


# Create a device shadow instance using persistent subscription

myDeviceShadow = myShadowClient.createShadowHandlerWithName("Bot", True)
while True:
    time.sleep(10)

Answer 1

这是预期的行为。解释可见here

Delta state is a virtual type of state that contains the difference between the desired and reported states. Fields in the desired section that are not in the reported section are included in the delta. Fields that are in the reported section and not in the desired section are not included in the delta.