Can not take jstat metrics using bash as Sensu plugin

Question

I have created bash scirpt that takes jstat metrics of my jvm instances!

Here is the output example :

demo.server1.sms.jstat.eden 24.34   0
demo.server1.lcms.jstat.eden    54.92   0
demo.server1.lms.jstat.eden 89.49   0
demo.server1.tms.jstat.eden 86.05   0

But when the Sensu-client runs this script it returns

Could not attach to 8584
Could not attach to 8588
Could not attach to 17141
Could not attach to 8628
demo.server1.sms.jstat.eden     0
demo.server1.lcms.jstat.eden    0
demo.server1.lms.jstat.eden     0
demo.server1.tms.jstat.eden     0

Here is the example of check_cron.json

{
  "checks": {
    "jstat_metrics": {
      "type": "metric",
      "handlers": ["graphite"],
      "command": "/etc/sensu/plugins/jstat-metrics.sh",
      "interval": 5,
          "subscribers": [ "webservers" ]
    }
  }
}

And piece of my bash script

jvm_list=("sms:$sms" "lcms:$lcms" "lms:$lms" "tms:$tms" "ums:$ums")
for jvm_instance in ${jvm_list[@]}; do
    project=${jvm_instance%%:*}
    pid=${jvm_instance#*:}
        if [ "$pid" ]; then
          metric=`jstat -gc $pid|tail -n 1`
          output=$output$'\n'"demo.server1.$project.jstat.eden"$'\t'`echo $metric |awk '{ print $3}'`$'\t0'
        fi
done
echo "$output"

I find out that problem is with jstat and i tried to write full jstat path like /usr/lib/jvm/java-1.7.0-openjdk.x86_64/bin/jstat -gc $pid|tail -n 1 but it didn't help!

By the way if i will comment this row the output like "Could not attach to 8584" disappears!

Answer 1

Yes you're right sensu runs all script as sensu user. To use jstat you have to add sensu to a sudoers.

just add file /etc/sudoers.d/sensu

Example:

Defaults:sensu !requiretty

Defaults:sensu secure_path = /usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin

sensu ALL = NOPASSWD: /etc/sensu/plugins/jsat-metrics.rb