RE: [hobbit] Custom graphs (was: temperature-larrd.pl)

[Kevin Hanrahan <Kevin (at) ewormhole.com>]

I could use this for a great number of data sets! 

-----Original Message-----
From: Henrik Stoerner [mailto:henrik (at) hswn.dk] 
Sent: Friday, February 04, 2005 5:51 PM
To: hobbit (at) hswn.dk
Subject: [hobbit] Custom graphs (was: temperature-larrd.pl)
Importance: Low

On Fri, Jan 28, 2005 at 04:47:27AM -0700, Charles Jones wrote:
> Speaking of this, it sure would be nice to have some sort of plugin 
> system, or something for easily creating custom graphs. I can think of 
> many uses for simple one-element graphs (temperature, emails sent per 
> day, etc).

Sounds reasonable. I've found a way of doing this that keeps as much as
possible of the RRD handling in Hobbit, and makes it easy to use custom
scripts (written in your favourite scripting language) to process a message
and pick out the interesting data you want to put into a graph.

Basically, you tell hobbitd_larrd which status- or data-messages are handled
by an external script, and what the script is. Your script is then called
when such a message arrives, and is fed the status message in a file. In
return, the script must output the RRD definitions for the data you want to
store, a filename for the RRD file, and the values.

E.g. if you have a message like

   green Weather in Copenhagen is FAIR

   Temperature: 6
   Wind: 4
   Humidity: 72

and you want to track these, then this script would do:

   #!/bin/sh

   # Input parameters: Hostname, testname (column), and messagefile
   HOSTNAME="$1"
   TESTNAME="$2"
   FNAME="$3"

   # Analyze the message we got
   TEMP=`cat $FNAME | grep "^Temperature:" | awk '{print $2}'
   WIND=`cat $FNAME | grep "^Wind:" | awk '{print $2}'
   HMTY=`cat $FNAME | grep "^Humidity:" | awk '{print $2}'

   # The RRD dataset definition
   echo "DS:temperature:GAUGE:600:-30:50"
   echo "DS:wind:GAUGE:600:0:U"
   echo "DS:humidity:GAUGE:600:0:100"

   # The filename
   echo "weather.rrd"

   # The data
   echo "$TEMP:$WIND:$HMTY"

   exit 0


Does that seem like a usable plug-in facility ?


Henrik

To unsubscribe from the hobbit list, send an e-mail to
hobbit-unsubscribe (at) hswn.dk