I recently purchased a new UPS which has a USB interface, the APC BX1500M to be precise. After piecing together a few blog posts I had a working Grafana dashboard giving me information about the power consumption of the devices connected to the UPS. Nice.

If you followed Part 1 of this series you'll already have Grafana and InfluxDB setup and working. I will assume that you have this for the rest of this guide.

A big thanks in particular goes to @MariusGilberg for the awesome Grafana dashboard used in this article via this post on his blog. Also to Viaduct (unraid forums) for writing the PHP script used.

Debian Linux Host Setup

As you know by now I use Debian to run the 'Perfect Media Server' and therefore this guide will be applicable to Debian hosts but easily adapted for other Linux OSs.

I assume you have connected the UPS to a free USB port on your motherboard and it shows up using lsusb thus:

Bus 002 Device 003: ID 051d:0002 American Power Conversion Uninterruptible Power Supply

On Debian install the required APC UPS daemon and PHP packages with:

apt install apcupsd php -y

Once installed stop the apcupsd service if it started automatically with

systemctl stop apcupsd

You'll next need to edit the configuration file for the service which lives at /etc/apcupsd/apcupsd.conf. If you'd like enter a UPSNAME that makes sense (mine looked like UPSNAME awesomo). Then the default version of this file on my system had a line that looked like DEV /tty/xxx0, delete this line and restart the service with:

systemctl start apcupsd
systemctl status apcupsd

If everything looks good in status you should now be able to run

root@awesomo:~# apcaccess
APC      : 001,036,0874
DATE     : 2018-11-14 20:53:55 -0500  
HOSTNAME : awesomo
VERSION  : 3.14.14 (31 May 2016) debian
UPSNAME  : awesomo
CABLE    : USB Cable
DRIVER   : USB UPS Driver
UPSMODE  : Stand Alone
STARTTIME: 2018-11-14 20:53:54 -0500  
MODEL    : Back-UPS XS 1500M 
STATUS   : ONLINE 
LINEV    : 119.0 Volts
LOADPCT  : 34.0 Percent
BCHARGE  : 100.0 Percent
TIMELEFT : 17.2 Minutes
MBATTCHG : 5 Percent
MINTIMEL : 3 Minutes
MAXTIME  : 0 Seconds
SENSE    : Medium
LOTRANS  : 88.0 Volts
HITRANS  : 139.0 Volts
ALARMDEL : 30 Seconds
BATTV    : 27.3 Volts
LASTXFER : Unacceptable line voltage changes
NUMXFERS : 0
TONBATT  : 0 Seconds
CUMONBATT: 0 Seconds
XOFFBATT : N/A
SELFTEST : NO
STATFLAG : 0x05000008
SERIALNO : 3B1828X67626  
BATTDATE : 2018-07-13
NOMINV   : 120 Volts
NOMBATTV : 24.0 Volts
NOMPOWER : 900 Watts
FIRMWARE : 947.d7 .D USB FW:d7
END APC  : 2018-11-14 20:54:04 -0500 

If you see this output, you've completed the UPS / host setup.

InfluxDB Setup

Whether you're creating an InfluxDB setup just for this purpose or you're tacking onto an existing instance I'd suggest putting all the data from your UPS into a separate database.

First, we'll need to create it and can do so using curl:

curl -i -XPOST  "http://localhost:8086/query?q=CREATE+DATABASE+ups"

We can verify successful DB creation again using curl:

alex@cartman:~$ curl -i -XPOST  "http://localhost:8086/query?q=SHOW+DATABASES"
HTTP/1.1 200 OK
Content-Type: application/json
Request-Id: 2fd65ad1-e87a-11e8-8009-0242ac120008
X-Influxdb-Build: OSS
X-Influxdb-Version: 1.7.0
X-Request-Id: 2fd65ad1-e87a-11e8-8009-0242ac120008
Date: Thu, 15 Nov 2018 02:00:12 GMT
Transfer-Encoding: chunked

{"results":[{"statement_id":0,"series":[{"name":"databases","columns":["name"],"values":[["_internal"],["ups"]]}]}]}

Note that final entry is ups which is the database we just created. Now we have to move onto scraping the output the UPS generates and write it to the database.

Scraping the UPS output

The following script is PHP based and was written by Viaduct over on the unraid forums.

Note the section near the top tagsArray and compare the items in the array being scraped against the actual output of apcacess as shown above. Pick and choose the items you want and these are what will be written to the database. The name must match exactly else the scraping will fail.

You will also need to modify, near the bottom, your InfluxDB IP. You needed this above for the curl commands.

#!/usr/bin/php
<?php

$command = "apcaccess";
$args = "status";
$tagsArray = array(
"LOADPCT", 
"BATTV", 
"TIMELEFT", 
"BCHARGE"
);

//do system call

$call = $command." ".$args;
$output = shell_exec($call);

//parse output for tag and value

foreach ($tagsArray as $tag) {

preg_match("/".$tag."\s*:\s([\d|\.]+)/si", $output, $match);

//send measurement, tag and value to influx

sendDB($match[1], $tag);

}
//end system call


//send to influxdb

function sendDB($val, $tagname) {

$curl = "curl -i -XPOST 'http://influxDBIP:8086/write?db=ups' --data-binary 'APC,host=awesomo ".$tagname."=".$val."'";
$execsr = exec($curl);

}

?>

Save the script somewhere on your filesystem and make it executable chmod +x /opt/scrape.php. You can do a test run with /opt/scrape.php and then verify your InfluxDB logs and look for some successful writes via curl (code 204 = good).

2018-11-15T02:11:16.965547498Z [httpd] 192.168.1.250 - - [15/Nov/2018:02:11:16 +0000] "POST /write?db=ups HTTP/1.1" 204 0 "-" "curl/7.52.1" bc1826d1-e87b-11e8-800a-0242ac120008 53295
2018-11-15T02:11:16.990611179Z [httpd] 192.168.1.250 - - [15/Nov/2018:02:11:16 +0000] "POST /write?db=ups HTTP/1.1" 204 0 "-" "curl/7.52.1" bc2193c2-e87b-11e8-800b-0242ac120008 16600
2018-11-15T02:11:17.014354572Z [httpd] 192.168.1.250 - - [15/Nov/2018:02:11:16 +0000] "POST /write?db=ups HTTP/1.1" 204 0 "-" "curl/7.52.1" bc253e9c-e87b-11e8-800c-0242ac120008 16297
2018-11-15T02:11:17.042864060Z [httpd] 192.168.1.250 - - [15/Nov/2018:02:11:17 +0000] "POST /write?db=ups HTTP/1.1" 204 0 "-" "curl/7.52.1" bc28ca91-e87b-11e8-800d-0242ac120008 215

Automating the scraping

We'll use cron for automating the running of the scraping script. Do not edit the crontab with crontab -e instead you must edit /etc/crontab and specify a user in order for this work.

Add the following line to /etc/crontab - this will run the scraping script every minute. Modify to suit your needs.

* * * * * root /usr/bin/php /opt/scrape.php >/dev/null 2>&1

Again verify the InfluxDB logs for 204 response codes to check everything went OK.

Grafana Dashboard

The next step is to add a data source in Grafana. Under the configuration menu in Grafana click "Add data source".

Modify the Name, Type = InfluxDB, URL = http://influxdb:8086, Database = ups, User = root, Pass = root. If you modified these values obviously modify to suit.

Then hit save & test.

Next in Grafana click the + icon on the left and select 'import'. We'll be importing this awesome dashboard by Marius Gilberg. The ID you need is 7197.

Select your Influx UPS data source as the new data source we just created above and hit import.

BOOM! That's it.

Note in the top left you can dynamically configure this dashboard based on your currency, UPS capacity and kWh price. Fantastic stuff by Marius, thanks a lot!!

That's it. We're done here. Thanks for reading.