作为 MQTT-Publisher 调用 Serverless 函数

Question

我正在尝试调用我的无服务器函数，我正在使用 Open-FaaS 无服务器框架的子集 FaasD。我正在使用 Raspbian OS Lite x64 的树莓派 4b 型号上运行它。

我的无服务器函数将“Hello World”作为 MQTT 消息发布，并且我有一个本地订阅者来接收该消息。

这是我的 handler.py 函数：

import paho.mqtt.client as mqtt

# MQTT broker configuration.
BROKER = 'localhost'
PORT = 1883
TOPIC = 'topic'

def handle(req):
    """handle a request to the function
    Args:
        req (str): request body
    """
    
    # Create the MQTT client.
    client = mqtt.Client()

    # Connect to the broker and publish the request body to the topic.
    client.connect(BROKER, PORT, 60)
    client.publish(TOPIC, req)

    return f'Message published to topic {TOPIC}'

这是我的本地订阅者：

import paho.mqtt.client as mqtt

BROKER = 'localhost'
PORT = 1883
TOPIC = 'topic'

def on_connect(client, userdata, flags, rc):
    print(f'Connected: {rc}')
    client.subscribe(TOPIC)

def on_message(client, userdata, msg):
    print(f'Topic: {msg.topic} - Message: {msg.payload.decode()}')

client = mqtt.Client()

client.on_connect = on_connect
client.on_message = on_message

client.connect(BROKER, PORT, 60)

client.loop_forever()

我尝试设置本地发布者和订阅者，效果很好。每次我尝试调用我们的无服务器函数时，我们都会得到：

ConnectionRefusedError：[Errno 111] 连接被拒绝