Linux - Stats over MQTT

Proven on:

	11 (bullseye)
	20.04.3

A handy script for keeping track of machines remotely. Maybe even feed it's messages to InfluxDB & Grafana to make pretty charts.

Requirements:

• sudo apt install mosquitto-clients
• sudo apt install lm-sensors
• sudo sensors-detect

The Script

• vi /usr/local/bin/MQTTstats.sh

# Get uptime
if [ -f "/proc/uptime" ]; then
uptime=`cat /proc/uptime`
uptime=${uptime%%.*}
seconds=$(( uptime%60 ))
minutes=$(( uptime/60%60 ))
hours=$(( uptime/60/60%24 ))
days=$(( uptime/60/60/24 ))
fi

# Get loadavg
if [ -f "/proc/loadavg" ]; then
OneMin=`cat /proc/loadavg | cut -b 1-4`
FiveMin=`cat /proc/loadavg | cut -b 6-9`
FifteenMin=`cat /proc/loadavg | cut -b 11-14`
fi

# Get % Memory usage
MemUsed=`/usr/bin/free -t | grep "Mem:" | awk '{print (1-($7/$2))*100}'`

printf '{\t"uptime":"%s:%s:%s:%s",\n' "$days" "$hours" "$minutes" "$seconds"
printf '\t"loadavg1min":%.2f,\n' "$OneMin"
printf '\t"loadavg5min":%.2f,\n' "$FiveMin"
printf '\t"loadavg15min":%.2f,\n' "$FifteenMin"
printf '\t"loadavg":"%s %s %s",\n' "$OneMin" "$FiveMin" "$FifteenMin"
printf '\t"memused":%.2f,\n' "$MemUsed"
printf '"SENSORS":'
printf '%s' `/usr/bin/sensors -j`
printf '}\n'

Don't forget to make it executable...

• sudo chmod +x /usr/local/bin/MQTTstats.sh

The cron job

Add this line by editing roots crontab

• sudo crontab -e

& add this line at the end:

• * * * * * /usr/bin/mosquitto_pub -h broker.domain.tld -t `hostname` -m "`/usr/local/bin/MQTTstats.sh`"

replace broker.domain.tld with the address of your broker