Re: [Nagiosplug-help] How to verify if nagios was built with embperl?

From: Tal Cohen <nagios(at)cohen123.com>
Date: Mon Sep 24 2007 - 09:32:45 EDT

Hi Ralph,

While I am no expert, here are some thoughts that I hope will be helpful:

Are you getting any additional output when running this as a Nagios check?
>From my experience working with the EPN, you will normally get a perl
message about P1.PL when you encounter an unknown state (usually this happens to me when I modify a check, but did not restart Nagios).

Also, I notice that you are using "exit 3" instead of importing %ERRORS from utils.pm and using "exit $ERRORS{'UNKNOWN')". If I remember how EPN work right, by using exit 3, you actually exit the EPN environment (which is not what you want). By using the %ERRORS hash instead, you remain within EPN.

Last, can you post the entire check to the group? We may be able to identify the problem that way too.

Tal      

-----Original Message-----
From: nagiosplug-help-bounces@lists.sourceforge.net [mailto:nagiosplug-help-bounces@lists.sourceforge.net] On Behalf Of Ralph.Grothe@itdz-berlin.de
Sent: Monday, September 24, 2007 9:22 AM To: nagiosplug-help@lists.sourceforge.net Subject: [Nagiosplug-help] How to verify if nagios was built with embperl?

Hello,

this is a follow-on to my posting to this list about inexplicable UNKNOWN state determination
by nagios of a custom plugin.

Unfortunately, no one seemed interested enough to reply.

However, meanwhile I think to have traced down the culprit.

It seems to be my convenience definition of a __DIE__ signal handler in my plugin.

I defined this vileness in my code

$SIG{__DIE__} = sub { chomp(my $out = shift);

                      printf "%s - %s\n",
$NAGIOS_SERVICESTATE{3}, $out;
                      exit 3
                    };

as a sort of catch all abnomalies which I could catch as usual by an or-ed die.

As shown in my last posting (see below)
my plugin's output and exit code behaved absolutely as expected when run as nagios from the shell.

As soon as I comment the above sigdie handler out the plugin shows
the green OK also in the web interface when run by nagios.

Since the %SIG hash is a package global I suspect that my nagios binary was built with some embperl support
which I wasn't aware of.
(btw, no difference when I declare my sig handler as local which should mask
SIG's symbol table entry)

I haven't built nagios from the sources but for ease of installation
resorted to prebuilt RPMs.
Unfortunately, in these RPMs I couldn't find any hint about the build options,
nor some spec file.

So, how can I verify that my nagios binary indeed is precaching Perl plugins
and executing them via embperl?

When I look at the shared libs there is a reference to some libperl
which to me looks like I do run an embperl enabled nagios.

# rpm -q nagios
nagios-2.9-1.el5

# uname -r
2.6.18-8.el5  

# cat /etc/redhat-release
Red Hat Enterprise Linux Server release 5 (Tikanga)

# ldd /usr/sbin/nagios

        linux-gate.so.1 =>  (0x00631000)
        libperl.so =>

/usr/lib/perl5/5.8.8/i386-linux-thread-multi/CORE/libperl.so (0x00110000)

        libresolv.so.2 => /lib/libresolv.so.2 (0x008a7000)
        libnsl.so.1 => /lib/libnsl.so.1 (0x00708000)
        libdl.so.2 => /lib/libdl.so.2 (0x004ac000)
        libm.so.6 => /lib/libm.so.6 (0x00483000)
        libcrypt.so.1 => /lib/libcrypt.so.1 (0x046f2000)
        libutil.so.1 => /lib/libutil.so.1 (0x00df8000)
        libpthread.so.0 => /lib/libpthread.so.0 (0x004b2000)
        libc.so.6 => /lib/libc.so.6 (0x00344000)
        /lib/ld-linux.so.2 (0x00327000)

Regards

Ralph

> -----Original Message-----
> From: nagiosplug-help-bounces@lists.sourceforge.net
> [mailto:nagiosplug-help-bounces@lists.sourceforge.net]On Behalf
Of
> Ralph.Grothe@itdz-berlin.de
> Sent: Friday, September 21, 2007 7:30 PM
> To: nagiosplug-help@lists.sourceforge.net
> Subject: [Nagiosplug-help] Inexplicable UNKNOWN state of custom
> plugindisplayed in web interface
>
>
> Hello,
>
> I have a nasty bug that I cannot resolve.
>
> I have written a Perl plugin that runs snmp checks against
> environmental sensor devices
> to poll the temprature at various spots in the data centre.
>
> As far as I can see I have obeyed the prerequisites a plugin
must
> meet.
> It outputs a single line with status and values
> as well as the correct return code.
>
> When I execute it from the shell as nagios user it behaves as
> expected.
> e.g.
>
> $ /usr/lib/nagios/plugins/check_sensor_temp.pl -H sensor_r06 -C
> public -w 17:27 -c 10:30
> SENSOR OK - temp: T0=21.40 degC T1=24.50 degC
> $ echo $?
> 0
>
> The plugin's output is also correctly displayed as above in the
> web interface's status information field.
> However, this is not true for the bg coloring (which is orange)
> and
> the text in the table field that displays the status of the
last
> check,
> where it reads UNKNOWN,
> just as if nagios had received an exit code of 3
>
> In the nagios log in the filesystem I can only see appearances
of
> my nothing changing forced
> external commands from reschedule check clicks via the web
> interface,
> like this (but nothing else):
>
> [1190389354] EXTERNAL COMMAND:
> SCHEDULE_FORCED_SVC_CHECK;sensor_r06;SRZ_Temp;1190389352
>
> Trying to look at the event log from within the web interface
> stalls my browser
> because the log file is obviously too long as I get a lot of
> check results for passive checks
> from distributed servers.
> Maybe a quicker log rotation scheme could alliviate, but I find
> event log CGI broken
> if it hangs my browser.
>
> Can anyone give me some hint why I get UNKNOWN states
displayed,
> and how I could try to debug this (maybe some strace on the
> nagios scheduler?)
>
> Regards
>
> Ralph
>
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https://lists.sourceforge.net/lists/listinfo/nagiosplug-help ::: Please include plugins version (-v) and OS when reporting any issue. ::: Messages without supporting info will risk being sent to /dev/null Received on Mon Sep 24 09:32:59 2007