Telegraf Debug with MQTT

The following are my notes for working with MQTT and Telegraf.

MQTT

I use the following configuration file:

listener 1883
allow_anonymous true
persistence true
persistence_location /mosquitto/data/
log_type all

Mount the configuration file in docker and run:

docker run --rm -it -p 1883:1883 -p 9001:9001 \
    -v $PWD/mosquitto.conf:/mosquitto/config/mosquitto.conf \
    eclipse-mosquitto

Data

I can use curl to send messages:

curl -d 'metric value=42' mqtt://127.0.0.1:1883/telegraf/test
curl -d 'metric value=43' mqtt://127.0.0.1:1883/telegraf/test

However, this does not let me set the QOS of the message. For that I have used the mosquitto_pub command, with the -q flag:

mosquitto_pub -h localhost -p 1883 -t telegraf -q 2 -m "metric value=43"

Telegraf

The following config would allow for a persistent session and QOS level of 2:

[[inputs.mqtt_consumer]]
  servers = ["tcp://127.0.0.1:1883"]
  topics = ["telegraf/#"]

  qos = 2
  client_id = "telegraf"
  persistent_session = true

  data_format = "influx"