從 Influxdb 輸出數據到 MQTT 代理/服務器

Question

這是我第一次使用 MQTT，我想將數據從 influxdb 獲取到 Snowflake，但在此之前我必須：

• 從 influxdb 獲取數據到 MQTT，我在網上找不到任何示例。

我嘗試使用以下腳本將數據從 mqtt 保存到 InfluxDB：

"""A MQTT to InfluxDB Bridge
This script receives MQTT data and saves those to InfluxDB.
"""

import re
from typing import NamedTuple

import paho.mqtt.client as mqtt
from influxdb import InfluxDBClient

INFLUXDB_ADDRESS = '10.10.10.247'
INFLUXDB_USER = 'iotuser'
INFLUXDB_PASSWORD = 'iotpassword'
INFLUXDB_DATABASE = 'homeiot_db'

MQTT_ADDRESS = '10.10.10.247'
MQTT_USER = 'iotuser'
MQTT_PASSWORD = 'iotpassword'
MQTT_TOPIC = 'home/+/+'  # [room]/[temperature|humidity|light|status]
MQTT_REGEX = 'home/([^/]+)/([^/]+)'
MQTT_CLIENT_ID = 'MQTTInfluxDBBridge'

influxdb_client = InfluxDBClient(INFLUXDB_ADDRESS, 8086, INFLUXDB_USER, INFLUXDB_PASSWORD, None)


class SensorData(NamedTuple):
    location: str
    measurement: str
    value: float


def on_connect(client, userdata, flags, rc):
    """ The callback for when the client receives a CONNACK response from the server."""
    print('Connected with result code ' + str(rc))
    client.subscribe(MQTT_TOPIC)


def on_message(client, userdata, msg):
    """The callback for when a PUBLISH message is received from the server."""
    print(msg.topic + ' ' + str(msg.payload))
    sensor_data = _parse_mqtt_message(msg.topic, msg.payload.decode('utf-8'))
    if sensor_data is not None:
        _send_sensor_data_to_influxdb(sensor_data)


def _parse_mqtt_message(topic, payload):
    match = re.match(MQTT_REGEX, topic)
    if match:
        location = match.group(1)
        measurement = match.group(2)
        if measurement == 'status':
            return None
        return SensorData(location, measurement, float(payload))
    else:
        return None


def _send_sensor_data_to_influxdb(sensor_data):
    json_body = [
        {
            'measurement': sensor_data.measurement,
            'tags': {
                'location': sensor_data.location
            },
            'fields': {
                'value': sensor_data.value
            }
        }
    ]
    print (json_body)
    influxdb_client.write_points(json_body)


def _init_influxdb_database():
    databases = influxdb_client.get_list_database()
    if len(list(filter(lambda x: x['name'] == INFLUXDB_DATABASE, databases))) == 0:
        influxdb_client.create_database(INFLUXDB_DATABASE)
    influxdb_client.switch_database(INFLUXDB_DATABASE)


def main():
    _init_influxdb_database()

    mqtt_client = mqtt.Client(MQTT_CLIENT_ID)
    mqtt_client.username_pw_set(MQTT_USER, MQTT_PASSWORD)
    mqtt_client.on_connect = on_connect
    mqtt_client.on_message = on_message

    mqtt_client.connect(MQTT_ADDRESS, 1883)
    mqtt_client.loop_forever()


if __name__ == '__main__':
    print('MQTT to InfluxDB bridge')
    main()

如果有人以前這樣做過或知道如何解決這個問題，我將非常感謝任何幫助。

Answer 1

如果您只需要將數據從 InfluxDB 傳輸到 Snowflake，您可以嘗試充分利用以下現有 API：

import "sql"
  
data
    |> sql.to(
        driverName: "snowflake",
        dataSourceName: "user:password@account/db/exampleschema?warehouse=wh",
        table: "example_table",
    )

在此處查看更多詳細信息。

好吧，如果您堅持使用 MQTT，有一種官方且簡單的方法可以通過 Flux（您可以在 InfluxDB 2.0 UI 上配置這些）而不是 Python 來完成此任務：

import "mqtt"
from(bucket: "telegraf")
    |> range(start: -task.every)
    |> filter(fn: (r) =>
        (r._measurement == "cpu"))
    |> filter(fn: (r) =>
        (r._field == "usage_system"))
    |> filter(fn: (r) =>
        (r.cpu == "cpu-total"))
    |> last()
    |> mqtt.to(
        broker: "tcp://davidgs.com:8883",
        topic: "cpu",
        clientid: "cpu-flux",
        valueColumns: ["_value"],
        tagColumns: ["cpu", "host"],
    )