Munin contributed plugins

#!/usr/bin/perl -w

#

# Copyright (C) 2006 Lars Strand

#

# Munin plugin to monitor swap usage by use of SNMP.

# Based on the snmp__df plugin

#

# 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; version 2 dated June,

# 1991.

#

# 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; if not, write to the Free Software

# Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.

#

# $Log$

#

#%# family=snmpauto

#%# capabilities=snmpconf

use strict;

use Net::SNMP;

my $DEBUG = 0;

my $MAXLABEL = 20;

my $host      = $ENV{host}      || undef;

my $port      = $ENV{port}      || 161;

my $community = $ENV{community} || "public";

my $iface     = $ENV{interface} || undef;

my $response;

if (defined $ARGV[0] and $ARGV[0] eq "snmpconf")

{

    # HOST-RESOURCES-MIB::hrStorage

    # HOST-RESOURCES-TYPES::hrStorageVirtualMemory

    print "require 1.3.6.1.2.1.25.2. 1.3.6.1.2.1.25.2.1.3\n"; 

    exit 0;

}

if ($0 =~ /^(?:|.*\/)snmp_([^_]+)_swap$/)

{

    $host  = $1;

    if ($host =~ /^([^:]+):(\d+)$/)

    {

	$host = $1;

	$port = $2;

    }

}

elsif (!defined($host))

{

    print "# Debug: $0 -- $1\n" if $DEBUG;

    die "# Error: couldn't understand what I'm supposed to monitor.";

}

my ($session, $error) = Net::SNMP->session(

     -hostname  => $host,

     -community => $community,

     -port      => $port

    );

if (!defined ($session))

{

    die "Croaking: $error";

}

my $hrStorage = "1.3.6.1.2.1.25.2.";

my $hrStorageVirtualMemory = "1.3.6.1.2.1.25.2.1.3";

my $hrStorageSize = "1.3.6.1.2.1.25.2.3.1.5.";

my $hrStorageUsed = "1.3.6.1.2.1.25.2.3.1.6.";

my $swap_d = get_by_regex($session, $hrStorage, $hrStorageVirtualMemory);

my $swapsize = 0; my $swapused = 0;

foreach my $swap (keys %$swap_d) 

{

    $swapsize += get_single($session, $hrStorageSize . $swap);

    $swapused += get_single($session, $hrStorageUsed . $swap);

}

if (defined $ARGV[0] and $ARGV[0] eq "config")

{

    print "host_name $host\n";

    print "graph_title Virtual memory usage\n";

    if ($swapsize > 0) 

    {

	print "graph_args -l 0 --base 1000 --upper-limit $swapsize\n";

    } 

    else 

    {

	print "graph_args -l 0 --base 1000\n";

    }

    print "graph_vlabel Bytes\n";

    print "graph_category disk\n";

    print "graph_info This graph shows swap usage in bytes.\n";

    print "swap.label swap\n";

    print "swap.type DERIVE\n";

    print "swap.min 0\n";

    exit 0;

}

print "swap.value $swapused\n";

sub get_single

{

    my $handle = shift;

    my $oid    = shift;

    print "# Getting single $oid..." if $DEBUG;

    $response = $handle->get_request ($oid);

    if (!defined $response->{$oid})

    {

	print "undef\n" if $DEBUG;

	return undef;

    }

    else

    {

	print "\"$response->{$oid}\"\n" if $DEBUG;

	return $response->{$oid};

    }

}

sub get_by_regex

{

    my $handle = shift;

    my $oid    = shift;

    my $regex  = shift;

    my $result = {};

    my $num    = 0;

    my $ret    = $oid . "0";

    my $response;

    print "# Starting browse of $oid...\n" if $DEBUG;

    while (1)

    {

	if ($num == 0)

	{

	    print "# Checking for $ret...\n" if $DEBUG;

	    $response = $handle->get_request ($ret);

	}

	if ($num or !defined $response)

	{

	    print "# Checking for sibling of $ret...\n" if $DEBUG;

	    $response = $handle->get_next_request ($ret);

	}

	if (!$response)

	{

	    return undef;

	}

	my @keys = keys %$response;

	$ret = $keys[0];

	print "# Analyzing $ret (compared to $oid)...\n" if $DEBUG;

	last unless ($ret =~ /^$oid/);

	$num++;

	next unless ($response->{$ret} =~ /$regex/);

	@keys = split (/\./, $ret);

	$result->{$keys[-1]} = $response->{$ret};;

	print "# Index $num: ", $keys[-1], " (", $response->{$ret}, ")\n" if $DEBUG;

    };

    return $result;

}