Question

作为 this 问题的扩展并根据答案，我使用 websockets 连接到 MQTT 代理，使用 dash_mqtt 以 this app script 作为参考。但我无法使用以下 app.py 中的配置发送或接收数据。

import dash_mqtt
import dash
from dash.dependencies import Input, Output, State
import dash_html_components as html
import dash_core_components as dcc
import flask
import json
import paho.mqtt.client as mqtt



TEST_SERVER = '172.17.0.2'
TEST_SERVER_PORT = 1883
TEST_SERVER_PATH = 'mqtt'
MESSAGE_OUT_TOPIC = 'testtopic'
MESSAGE_IN_TOPIC = 'testtopic'

external_stylesheets = ['https://codepen.io/chriddyp/pen/bWLwgP.css']

server = flask.Flask(__name__)
app = dash.Dash(__name__, external_stylesheets=external_stylesheets)
app.config.suppress_callback_exceptions = True



app.layout = html.Div([
    dash_mqtt.DashMqtt(
        id='mqtt',
        broker_url=TEST_SERVER,
        broker_port = TEST_SERVER_PORT,
        broker_path = TEST_SERVER_PATH,
        topics=[MESSAGE_IN_TOPIC]
    ),
    html.H1('MQTT echo'),
    html.P('MQTT echo server to ' + TEST_SERVER + ' on port ' + str(TEST_SERVER_PORT)),
    dcc.Input(
        id='message_to_send',
        placeholder='message to send',
        debounce = True),
    html.Button('Send',id='send'),
    html.Div(id='return_message')
])


@app.callback(
        Output('mqtt', 'message'),
        Input('send', 'n_clicks'),
        State('message_to_send', 'value')
    )
def display_output(n_clicks, message_payload):
    if n_clicks:
        return {
            'topic': MESSAGE_OUT_TOPIC,
            'payload' : message_payload
        }
    return dash.no_update

if __name__ == '__main__':
    app.run_server(host='0.0.0.0',port=8050,debug=True)

简而言之，

我正在尝试连接到正在运行的 eclipse mqtt 代理在与 IP 地址关联的 docker 容器中 172.17.0.2 监听端口 1883。
Dash 应用正在另一个 docker 容器中运行，端口为 8050。

mosquitto.config 文件的所有基本配置都已完成，以便它侦听和响应外部通信。此外，此应用程序运行成功，日志中没有错误，但无法与 MQTT 代理进行通信。

我应该进行哪些配置更改才能连接到代理？

谢谢

编辑：浏览器控制台显示WebSocket connection to 'ws://172.17.0.2:1883/mqtt' failed:

mosquitto.conf

# Config file for mosquitto

# =================================================================
# Listeners
# =================================================================

# listener port-number [ip address/host name/unix socket path]
listener 1883

# =================================================================
# Persistence
# =================================================================

persistence True

# =================================================================
# Security
# =================================================================

# Defaults to false, unless there are no listeners defined in the configuration
# file, in which case it is set to true, but connections are only allowed from
# the local machine.
allow_anonymous True

Answer 1

如评论中所述，

对于 TCP 上的原生 MQTT 和 Websocket 上的 MQTT，您不能使用相同的端口，因此您需要向 mosquitto.conf 添加第二个侦听器

例如

listener 1884
protocol websockets

并将应用中的端口更改为 1884

无法通过 dash_mqtt 连接

1 个答案: