[Nagiosplug-devel] new plugin check_cpu.pl

[Ken Menzel]

OK - my first plugin submission.   Check CPU usage on Linux, FreeBSD
and AIX.

Output looks like this
janeway# ./check_cpu.pl -c5 -w30
CPU usage OK - 5% used 95% idle
janeway# ./check_cpu.pl -c80 -w97
CPU usage WARNING - 9% used 91% idle

It will can check IDLE% USER% or SYSTEM% CPU usage.  So if I want be
warned as I have  LESS idle cpu (IE usages approaches %100) I use the
default mode (-i) and with -c5 -w30 I will be warned if I have less
then 30% CPU available and go critical when I have less then 5%
available.

Is this confusing?

Also if anyone wants to email me more systems to add I am OK with
that, also I can easily add SCO Openserver 5.
Hope you like my plugin,
Ken


check_cpu.pl
---------------------------------------------------------
#!/usr/bin/perl -w

# check_cpu.pl Copyright (C) 2003 Ken Menzel <kenm at icarz.com>
#
# This program is free software; you can redistribute it and/or
# modify it under the terms of the GNU General Public License
# as published by the Free Software Foundation; either version 2
# of the License, or (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty
# of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# you should have received a copy of the GNU General Public License
# along with this program (or with Netsaint);  if not, write to the
# Free Software Foundation, Inc., 59 Temple Place - Suite 330,
# Boston, MA 02111-1307, USA

# Tell Perl what we need to use
use strict;
use Getopt::Std;

use vars qw($opt_c $opt_s $opt_u $opt_w $opt_i $opt_v
            $cpu_system $cpu_user $cpu_idle
            $crit_level $warn_level
            %exit_codes @memlist
            $percent $fmt_pct
            $command_line $uname);

# Predefined exit codes for NetSaint
%exit_codes   = ('UNKNOWN' ,-1,
                 'OK'      , 0,
                 'WARNING' , 1,
                 'CRITICAL', 2,);

# Get the options
if ($#ARGV le 0)
{
  &usage;
}
else
{
  getopts('c:isuw:v');
}

# Shortcircuit the switches
if (!$opt_w or $opt_w == 0 or !$opt_c or $opt_c == 0)
{
  print "*** You must define WARN and CRITICAL levels! ****\n";
  &usage;
}
elsif (!$opt_s and !$opt_u)
{
   $opt_i=1;
#  print "*** You must select to monitor either USED or FREE cpu!";
#  &usage;
}

# Check if levels are sane
if ($opt_w <= $opt_c and $opt_i)
{
  print "*** WARN level must not be less than CRITICAL when checking
IDLE CPU! ****\n";
  &usage;
}
elsif ($opt_w >= $opt_c and ($opt_u or $opt_s) )
{
  print "*** WARN level must not be greater than CRITICAL when
checking USER or SYSTEM CPU! ***\n";
  &usage;
}

$warn_level   = $opt_w;
$crit_level   = $opt_c;

# This the unix command string that brings Perl the data
$uname= `uname`;
chomp($uname);
if ($opt_v) { print "Sytem Type $uname,\n"; }

if (($uname eq 'Linux') or ($uname eq 'AIX') )
  {$command_line = `vmstat 1 2 | tail -1 | awk '{print \$14,\$15,
\$16}'`; }
else
  {$command_line = `vmstat -c 2 -w 1 | tail -1 | awk '{print
\$17,\$18, \$19}'`; }

if ($opt_v) { print "$command_line\n"; }

chomp $command_line;
@memlist      = split(/ /, $command_line);

# Define the calculating scalars
$cpu_user  = $memlist[0];
$cpu_system  = $memlist[1];
$cpu_idle = $memlist[2];

if ($opt_i)
{
  $fmt_pct= 100 - $cpu_idle;
  if ($cpu_idle <= $crit_level)
  {
    print "CPU usage CRITICAL - $fmt_pct% used $cpu_idle% idle \n";
    exit $exit_codes{'CRITICAL'};
  }
  elsif ($cpu_idle <= $warn_level)
  {
    print "CPU usage WARNING - $fmt_pct% used $cpu_idle% idle\n";
    exit $exit_codes{'WARNING'};
  }
  else
  {
    print "CPU usage OK - $fmt_pct% used $cpu_idle% idle\n";
    exit $exit_codes{'OK'};
  }
}
elsif ($opt_u)
{
  if ($cpu_user >= $crit_level)
  {
    print "CPU usage CRITICAL - $cpu_user% user\n";
    exit $exit_codes{'CRITICAL'};
  }
  elsif ($percent >= $warn_level)
  {
    print "CPU usage WARNING - $cpu_user% user\n";
    exit $exit_codes{'WARNING'};
  }
  else
  {
    print "CPU usage OK - $cpu_user% user\n";
    exit $exit_codes{'OK'};
  }
}
elsif ($opt_s)
{
  if ($cpu_system >= $crit_level)
  {
    print "CPU usage CRITICAL - $cpu_system% system\n";
    exit $exit_codes{'CRITICAL'};
  }
  elsif ($percent >= $warn_level)
  {
    print "CPU usage WARNING - $cpu_system% system\n";
    exit $exit_codes{'WARNING'};
  }
  else
  {
    print "CPU usage OK - $cpu_system% system\n";
    exit $exit_codes{'OK'};
  }
}


# Show usage
sub usage()
{
my $mymsg=<<MYMSG
check_cpu.pl v1.0 - Nagios/NetSaint Plugin\n
usage:
 check_cpu.pl -<i|s|u> -w <warnlevel> -c <critlevel>\n
options:\n
 -i           Check IDLE cpu (default)
 -s           Check SYSTEM cpu
 -u           Check USER cpu
 -w PERCENT   Percent free/used when to warn
 -c PERCENT   Percent free/used when critical
 -v           Verbose output for debug
\nCopyright (C) 2003 Ken Menzel (kenm\@icarz.com)
check_cpu.pl comes with absolutely NO WARRANTY either implied or
explicit
This program is licensed under the terms of the
GNU General Public License (check source code for details)

MYMSG
;
  print "$mymsg";

  exit $exit_codes{'UNKNOWN'};
}
-----------------------------------------------------
Ken Menzel  ICQ# 9325188
www.icarz.com  kenm at icarz.com