Custom plugin output (null)

[sebastiaopburnay]

Hi,

I developed my first Nagios plugin from scratch and I'm getting some issues regarding the way nagios interprets its output.

Execution from CLI returns good output (even $? is as 0), but nagios interface recognizes it as CRITICAL witn an output of '(null)'.

From command line:

nagios@my_Server:/usr/local/nagios/libexec#./my_get_consumo_ups.pl <my_UPS_IP> <my_Community>
CONSUMO OK - Consumo: 10.252kW; | 'Consumo[kW]'=10.252kW;11;14;

The command definition:

define command{
command_name ups_consumos
command_line /usr/local/nagios/libexec/my_get_consumo_ups.pl <my_UPS_IP> <my_Community>
}

The plugin code

Code: Select all

#!/usr/bin/perl -w

use Net::SNMP;
use Getopt::Long;
use warnings;
use strict;
use utils qw(%ERRORS $TIMEOUT);
use lib "/usr/local/nagios/libexec";

my $session = undef;
my $error = undef;
my $ups_current_I = undef;
my $ups_current_II = undef;
my $ups_current_III = undef;
my $ups_consumption_I = undef;
my $ups_consumption_II = undef;
my $ups_consumption_III = undef;
my $total_consumption = undef;
my $status = undef;

# requires a hostname and a community string as its arguments
($session,$error) = Net::SNMP->session(Hostname => $ARGV[0],
                                       Community => $ARGV[1]);

die "SNMP - Erro de Sessao: $error" unless ($session);

$ups_current_I = $session->get_request("1.3.6.1.2.1.33.1.4.4.1.3.1");
$ups_current_II = $session->get_request("1.3.6.1.2.1.33.1.4.4.1.3.2");
$ups_current_III = $session->get_request("1.3.6.1.2.1.33.1.4.4.1.3.3");

die "request error: ".$session->error unless (defined $ups_current_I);

$ups_consumption_I = $ups_current_I->{"1.3.6.1.2.1.33.1.4.4.1.3.1"} * 22 * 0.001;
$ups_consumption_II = $ups_current_II->{"1.3.6.1.2.1.33.1.4.4.1.3.2"} * 22 * 0.001;
$ups_consumption_III = $ups_current_III->{"1.3.6.1.2.1.33.1.4.4.1.3.3"} * 22 * 0.001;

$total_consumption = $ups_consumption_I + $ups_consumption_II + $ups_consumption_III;
$total_consumption=sprintf("%.0f" , $total_consumption);
$status="OK";
#check if output is critical
if($total_consumption > 14){
  $status="CRITICAL";
  print $status . ": Consumo " . $total_consumption . "kW\n";
  exit $ERRORS{"CRITICAL"};
  } else {
     if($total_consumption > 11) {
	$status="WARNING";
	print $status . ": Consumo " . $total_consumption . "kW\n";
        exit $ERRORS{"WARNING"};
        }
    } 
#close SNMP session
$session->close;
#print output and return exit code
print "CONSUMO " . $status . " -  Consumo: " . $total_consumption . "kW; | 'Consumo[kW]'=" .$total_consumption . "kW;11;14;\n";
exit $ERRORS{"OK"};

Well, I'm hoping this is a very simple issue.

All similar issues I've seen either end up related to perl 'use' clause (libraries or paths) or with permissions.

Best regards,
sebastiaopburnay

[jsmurphy]

Interestingly enough there was another user a month back with the same issue, but I don't think we ever actually managed to work out what was causing it. As you already mentioned usually this is caused by a permissions issue or an execution failure related to the libs.

Two things you can try:
1. su - nagios and run the script... ensure that even as the Nagios user it is able to execute from the command line.
2. Disable the Nagios embedded perl handler in nagios/etc/nagios.cfg and try again.

If nothing else it might give us something we can work with to try and further debug the issue.

[sebastiaopburnay]

1. su - nagios and run the script... ensure that even as the Nagios user it is able to execute from the command line.

Yes, I have done that and still returns OK

2. Disable the Nagios embedded perl handler in nagios/etc/nagios.cfg and try again.

I've set the 'enable_embedded_perl=0' and restarted nagios, still dame rresult.

PS. I have already checked the '$?' system variable after execution and it correctly returns 0 (zero), so I'm guessing return code is not the problem.

[agriffin]

Try changing

Code: Select all

use utils qw(%ERRORS $TIMEOUT);
use lib "/usr/local/nagios/libexec";

to

Code: Select all

use lib "/usr/local/nagios/libexec";
use utils qw(%ERRORS $TIMEOUT);

[sebastiaopburnay]

Thank you very much,

That change did the trick,

I will pass that information to the linuxforums where I posted the same doubt.

[agriffin]

Glad I could help!