sh0rez/promqtt

Generic Prometheus ⟷ MQTT Bridge

promqtt's Issues

Series closing

Currently, when an actor stops sending messages to MQTT, promqtt will export the last received value forever.

How shall we deal with this?

1. Not. Leave as is. This appears to be what the Pushgateway does as well.
2. Add a timeout (e.g. 5m, etc).
3. Use special topics to "close" series, which makes promqtt remove them from its output. This could play well with LWT (Last will & testament), so that devices that disconnect from the broker are automatically removed.

I personally like (3), because it could leverage the quite unique MQTT property of LWT.

Thoughts? @RichiH?

Project name

As per last dev summit, we are trying to come up with new terminology for this use case. "push exporter" is least bad atm.

https://docs.google.com/document/d/11LC3wJcVk00l8w5P3oLQ-m3Y37iom6INAMEu2ZAGIIE/edit?ts=60d93074#

JSON mode?

JSON can already parsed using the regex support, but only if the actors emit JSON in a strict way (same ordering, etc).

We could possibly add a native JSON mode that turns all fields into series

/mqtt target doesn't start

./promqtt 10.8.0.2:1883 
2021/12/17 10:10:39 listening at :9337
2021/12/17 10:10:39 subscribed to '#'

mosquitto_pub -h localhost -t diox/06FE2A3/co2 -m "42.0"

mosquitto_sub -t '#' --host 10.8.0.2
42.0

wget http://localhost:9337/mqtt
--2021-12-17 10:13:25--  http://localhost:9337/mqtt
Resolving localhost (localhost)... ::1, 127.0.0.1
Connecting to localhost (localhost)|::1|:9337... connected.
HTTP request sent, awaiting response... 400 Bad Request
2021-12-17 10:13:25 ERROR 400: Bad Request.

/mqtt target doesn't start

why? How to check it?