jnovack / nut-to-mqtt

Network UPS Tools to MQTT exporter.

nut-to-mqtt

nut-to-mqtt is a transmogrifier for exporting data from Network UPS Tools (nut), and streaming to an MQTT broker.

Quick Start

$ nut-to-mqtt \
    -nut_hostname=192.168.9.10 -nut_username=monitor -nut_password=hunter2 \
    -mqtt_hostname=172.23.4.5 -mqtt_username=user24601 -mqtt_password=hunter2

Features

Currently tracks the following metrics from NUT:

• battery.charge - Battery charge (percent of full)
• battery.runtime - Battery runtime (seconds)
• battery.voltage - Battery voltage (V)
• input.voltage - Input voltage (V)
• ups.load - Load on UPS (percent of full)
• ups.status - UPS status

And publishes them to the MQTT broker under the following topic:

• v1/ups/UPSNAME/METRIC

Currently, there are some conversions to published data.

• battery.runtime - Read as seconds, published as minutes (with 1 decimal place)
• ups.status - Read as two-char code, published as full word

Example:

• battery.runtime is read as 2725 (seconds) and published to MQTT as 45.4 (minutes)
• ups.status is read as OL (code) and published to MQTT as Online (text).

Docker Secret Support

nut_password and mqtt_password permit a _FILE suffix (for nut_password_file and mqtt_password_file) to not expose password via environment variables.

You must point to a file called nut_password or mqtt_password which should contain the password only.

Example:

$ nut-to-mqtt \
    -nut_hostname=192.168.9.10 -nut_username=monitor \
    -nut_password_file=/run/secrets/nut_password \
    -mqtt_hostname=172.23.4.5 -mqtt_username=user24601 \
    -mqtt_password_file=/run/secrets/mqtt_password

Caveats

If connecting multiple nut-to-mqtt transmogrifiers to a single broker, each UPS should have a different name within their ups.conf. UPSes are identified by their name only, and not by their host.

Having a UPS called myups on two different hosts will result in metrics being overwritten.

nut-to-mqtt's Issues

Security error on [email protected]

Hello,

jeo ~/d/nut-to-mqtt master* λ go mod download
go: github.com/jnovack/[email protected]: verifying go.mod: checksum mismatch
	downloaded: h1:s8DZ+9C9fQ7sK2KO8KDvuAIJgX+nzHGfXxgZyV/aGrY=
	sum.golang.org: h1:+wCtyeQ6/Ttm8Ih/g+48icj4NyFTvKqCC3v61ZV1CLs=

SECURITY ERROR
This download does NOT match the one reported by the checksum server.
The bits may have been replaced on the origin server, or an attacker may
have intercepted the download attempt.

For more information, see 'go help module-auth'.

Permit run-time setting of loop delay

Loop is hardcoded for 12 (15 - delay(3)) seconds.

• Allow users to set via flag
• Auto subtract disconnected delay??

Restart or error on broken pipe

write tcp 172.18.0.9:43290->192.168.1.101:3493: write: broken pipe

ClientID not sufficiently random

Had two containers on swarm with the same client id (which MQTT does not like).

nut-to-mqtt/pkg/mqtt_publisher/mqtt_publisher.go

Line 46 in f9b9a37

opts.SetClientID(fmt.Sprintf("%s_%v", goVersion.Application, time.Now().Unix()))

References:

• https://www.calhoun.io/creating-random-strings-in-go/
• https://blog.kowalczyk.info/article/JyRZ/generating-good-unique-ids-in-go.html

Permit run-time setting of topic prefix

Topic prefix is currently hardcoded as v1/ups/.

• Permit users setting via flag
• warn for improper slashing

Permit run-time setting of LogLevel

Set log-level from command-line options

• Use numbers 0 (Debug) - 6 (Panic)
• Default 1
• will have to be done post flag.Parse()