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Custom Python plugin returns NULL

Hi all,

I have written a Python plugin to check our NetApp devices using SNMP. If I run it on the command line on my linux Nagios server it runs fine:

[[email protected] netapp-snmp]# /opt/nagios/libexec/check_netapp_disks.py -H netapp1 -o /vol/test1/ -w 80 -c 90
OK - /vol/test1/ - total: 250 Gb - used 6 Gb (2%) - free: 243 Gb|NetApp /vol/gate/ Used Space=6GB;160;180;0;250

But when I add it in to Nagios commands.cfg it returns “null” in the Nagios GUI:

define command{
command_name check-swe-test
command_line $USER1$/check_netapp_disks.py -H netapp1 -o /vol/test1/ -w 80 -c 90
}

For the return codes I use sys.exit in Python (0 for OK, 1 for Warning, 2 for Critical). I have written custom plugins before in shell scripts but this is my first Python one. Not sure where the issue would be exactly.

Here is the if-else where i specify the return code:

if state == 'OK': print '%s - %s - total: %s Gb - used %s Gb (%s%%) - free: %s Gb|NetApp %s Used Space=%sGB;%s;%s;0;%s' % (state, volume, total, used, used_p, avail, volume, used, warn_p, crit_p, total) sys.exit(0) elif state == 'WARNING': print '%s - %s - total: %s Gb - used %s Gb (%s%%) - free: %s Gb|NetApp %s Used Space=%sGB;%s;%s;0;%s' % (state, volume, total, used, used_p, avail, volume, used, warn_p, crit_p, total) sys.exit(1) elif state == 'CRITICAL': print '%s - %s - total: %s Gb - used %s Gb (%s%%) - free: %s Gb|NetApp %s Used Space=%sGB;%s;%s;0;%s' % (state, volume, total, used, used_p, avail, volume, used, warn_p, crit_p, total) sys.exit(2) else: sys.exit(3)

Thanks!

try running the plugin from command line and then run
echo $?
to see what exit code it’s using…

if it returs NULL you probably had no output from the script?

Hi Luca,

It looks like the script returns the error code:

[[email protected] objects]# /opt/nagios/libexec/check_netapp_disks.py -H netapp -o /vol/test/ -w 80 -c 90 [[email protected] objects]# echo $? 0

If I change the warning threshold:

[[email protected] objects]# /opt/nagios/libexec/check_netapp_disks.py -H netapp -o /vol/test/ -w 1 -c 90 [[email protected] objects]# echo $? 1

And if I change the critical threshold it returns 2:

[[email protected] objects]# /opt/nagios/libexec/check_netapp_disks.py -H netapp -o /vol/test/ -w 1 -c 1 [[email protected] objects]# echo $? 2

These are the correct return codes right?

it looks like the plugin works correctly.

are you sure it is being run correctly from nagios? try running it as user nagios from command line.

Here I am logged in as Nagios user and with the output enabled:

[[email protected] ~]$ /opt/nagios/libexec/check_netapp_disks.py -H netapp -o /vol/test/ -w 50 -c 90 OK - /vol/test/ - total: 250 Gb - used 6 Gb (2%) - free: 243 Gb|NetApp /vol/test/ Used Space=6GB;100;180;0;250 [[email protected] ~]$ echo $? 0 [[email protected] ~]$ /opt/nagios/libexec/check_netapp_disks.py -H netapp -o /vol/test/ -w 1 -c 90 WARNING - /vol/test/ - total: 250 Gb - used 6 Gb (2%) - free: 243 Gb|NetApp /vol/test/ Used Space=6GB;2;180;0;250 [[email protected] ~]$ echo $? 1 [[email protected] ~]$ /opt/nagios/libexec/check_netapp_disks.py -H netapp -o /vol/test/ -w 1 -c 1 CRITICAL - /vol/test/ - total: 250 Gb - used 6 Gb (2%) - free: 243 Gb|NetApp /vol/test/ Used Space=6GB;2;2;0;250 [[email protected] ~]$ echo $? 2

This is the entry in nagios.log:

I think I’ve covered all bases with this. Can’t think of anything else that I may have missed which why this wont work.

last thing which comes to mind:

$USER1$ is /opt/nagios/libexec?

Yep it is indeed:

$USER1$=/opt/nagios/libexec

To be honest it’s not critical as there is a Perl script I am using which works. It’s just that I decided to create a Python script as I am learning Python just for the hell of it. I might create something more simple and see if that works. Could be a Nagios + Python thing? Although I can’t see why. Thanks for your help luca :slight_smile:

i used shell scripts the only time i created a “plugin” so i really can’t help you there… :slight_smile:

It’s still worth a couple of extra tries maybe reducing it to something basic and seeing what happens…

Have fun testing :slight_smile:

Luca