无法通过 websockets 发布到 aws mqtt 代理

Posted 2023-02-16

【中文标题】无法通过 websockets 发布到 aws mqtt 代理

【英文标题】：Cant publish to aws mqtt broker over websockets

【发布时间】：2021-10-08 18:23:36

【问题描述】：

我正在关注aws api 通过 websockets 连接到 mqtt。以下是我的代码：

credentials_provider = AwsCredentialsProvider.new_static(
            access_key_id = auth_response_dictionary['user']['accessKeyId'],
            secret_access_key = auth_response_dictionary['user']['secretKey'],
            session_token = auth_response_dictionary['user']['sessionToken']
            )
       
    
    event_loop_group = io.EventLoopGroup(1)
    host_resolver = io.DefaultHostResolver(event_loop_group)
    client_bootstrap = io.ClientBootstrap(event_loop_group, host_resolver)    
    
    mqtt_connection = mqtt_connection_builder.websockets_with_default_aws_signing(
            endpoint=auth_response_dictionary['user']['iotEndpoint'],
            region=auth_response_dictionary['user']['region'],
            credentials_provider=credentials_provider,
            client_bootstrap=client_bootstrap,
            client_id=clientId
            )

    print("Connecting to aws")
    # Make the connect() call
    connect_future = mqtt_connection.connect()
    # Future.result() waits until a result is available
    print('connect_future ' + str(connect_future))
    x= connect_future.result()
    print('connect_future ' + str(x))
    print("Connected!")
    
    future, packet_id = mqtt_connection.publish(topic=TOPIC, payload=json.dumps(message), qos=mqtt.QoS.AT_LEAST_ONCE)
    future, packet_id = mqtt_connection.publish(topic='test/po', payload=json.dumps(message), qos=mqtt.QoS.AT_LEAST_ONCE)
    print('future ' + str(future))
    print('future ' + str(packet_id))
    print('Publish End')

我在连接和发布时没有收到任何错误，但是当我在“测试”部分订阅该主题时，我没有在我的 aws mqtt 代理上收到任何消息。 我认为我在 credentials_provider 或 client_bootstrap 或两者中都配置了错误，但不知道是什么。

这是打印出来的日志

Connecting to aws
connect_future<Future at 0x7f605f942af0 state=pending>
connect_future'session_present': False
Connected!
future <Future at 0x7f605f8e54f0 state=pending>
future 3
Publish End

有人可以帮忙吗？

【参考方案1】：

mqtt_connection.subscribe(...) 用于订阅 AWS IoT 消息的 MQTT 主题，我在您的代码中的任何地方都看不到。

mqtt_connection.subscribe 如下调用，包含主题名称、服务质量级别和回调。

received_count = 0
received_all_event = threading.Event()
...
topic='test/po'
print("Subscribing to topic ''...".format(topic))
subscribe_future, packet_id = mqtt_connection.subscribe(
        topic=topic,
        qos=mqtt.QoS.AT_LEAST_ONCE,
        callback=on_message_received)
subscribe_result = subscribe_future.result()
print("Subscribed with ".format(str(subscribe_result['qos'])))

on_message_received 可以是这样的：

def on_message_received(topic, payload, dup, qos, retain, **kwargs):
    print("Received message from topic '': ".format(topic, payload))
    global received_count
    received_count += 1
    # Number of messages to wait for
    if received_count = 10:
        received_all_event.set()

然后在你的 main 方法中，你可以等到收到 10 条消息：

# Wait for all messages to be received.
# This waits forever if count was set to 0.
if not received_all_event.is_set():
    print("Waiting for all messages to be received...")

received_all_event.wait()
print(" message(s) received.".format(received_count))

sample code provided by AWS 真的很不错，我建议你看看。

【讨论】：

我已在 aws iot 控制台的“测试”部分订阅了我发布的主题。问题是我在那里没有收到任何东西

在哪里？您需要订阅该主题 - 无论test 在哪里，都不是您的问题