That would be cool. It would require users to learn about the RRD definition options, but at least they wouldn't have to code and compile their own C module. Would it also create a default entry for them in hobbitgraph.cfg, or would they have to learn those options as well?
The plugin system sounds cool...any chance it will make it into an RC before 4.0 final?
-Charles
Henrik Stoerner wrote:
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 ?