Configuration for collectd to tail a log file and trigger an OpenNMS UEI whenever a certain pattern occurs. http://unicolet.blogspot.it/2013/01/triggering-opennms-notifications-when.html

collectd.conf

Interval 10

LoadPlugin logfile
#LoadPlugin write_graphite
LoadPlugin csv
LoadPlugin threshold
LoadPlugin exec
LoadPlugin tail

<Plugin "logfile">
  LogLevel "debug"
  File "stdout"
  Timestamp true
</Plugin>

<Plugin exec>
  NotificationExec "me" "/opt/collectd/bin/notif.pl"
</Plugin>

<Plugin "csv">
  DataDir "/tmp"
  StoreRates true
</Plugin>

<Plugin "tail">
  <File "/tmp/scp.log">
    Instance "scp"
    <Match>
      Regex "ERROR"
      DSType "CounterInc"
      Type "counter"
      Instance "hi_error"
    </Match>
  </File>
</Plugin>

# Load required matches:
#LoadPlugin match_empty_counter
#LoadPlugin match_hashed
LoadPlugin match_regex
LoadPlugin match_value
#LoadPlugin match_timediff

# Load required targets:
LoadPlugin target_notification
#LoadPlugin target_replace
#LoadPlugin target_scale
#LoadPlugin target_set
#LoadPlugin target_v5upgrade

PostCacheChain "SelectHiErrors"
<Chain "SelectHiErrors">
   <Rule "selecthi">
     <Match "regex">
       TypeInstance "^hi_error$"
     </Match>
     <Target "jump">
        Chain "CheckHiErrors"
     </Target>
   </Rule>
   <Target "write">
   </Target>
</Chain>

<Chain "CheckHiErrors">
   <Rule "checkhivalue">
     <Match "value">
        Min 0
        Max 0
        Invert true
     </Match>
     <Target "notification">
        Message "%{type_instance}"
        Severity "WARNING"
     </Target>
   </Rule>
</Chain>

notif.pl

#!/usr/bin/perl
use Sys::Syslog;
use Sys::Syslog qw(:standard :macros);

openlog('collectd_notif', "ndelay,pid", LOG_USER);

while(<>) {
        chomp;
        ($key, $val) = split("\:", $_);

        if ($key =~ /TypeInstance/ && $val =~ /hi_error/) {
                my @args = ("/opt/collectd/bin/send-event.pl", "uei.my.org/collectd/scp/HiError", "-i", "192.168.123.123", "opennms.my.org");
                system(@args) == 0 or syslog(LOG_ERROR|LOG_USER, "Error sending UEI uei.my.org/collectd/scp/HiError");
        }
}