#!/usr/bin/perl -w # $Id #------------------------------------------------------------------------------# # Check_multiaddr # # # # Copyright Florent Vuillemin 2005 - lafumah@users.sourceforge.net # # Nagios and the Nagios logo are trademarks of Ethan Galsta # # # # This 'metaplugin' for Nagios will execute a given program several times # # using different addresses (given as an argument) and send back a unique # # result based on the information gathered # # # #------------------------------------------------------------------------------# # # # 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; if not, write to the Free Software # # Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA # #------------------------------------------------------------------------------# use strict; my $TIMEOUT = 9; # You might need to edit this parameter my %STATE = ('OK' => 0, 'WARNING' => 1, 'CRITICAL' => 2, 'UNKNOWN' => 3); my %PRIO = (0=>3, 1=>2, 2=>0, 3=>1); # See comments 'PRIORITY' below #------------------------------------------------------------------------------# # Main Program # #------------------------------------------------------------------------------# # Let's start with several checks : # At least 1 argument provided ? if (scalar @ARGV == 0) { short_usage(); exit $STATE{'UNKNOWN'}; } # Do you need help ? if ($ARGV[0] eq "--help") { long_usage(); exit $STATE{'OK'}; } if ($ARGV[0] eq "-h") { short_usage(); exit $STATE{'OK'}; } # First argument can be executed ? if (! -x $ARGV[0]) { print "$0: ".$ARGV[0]." cannot be executed.\n"; exit $STATE{'UNKNOWN'}; } # Now we look for an argument which would be a set of adresses my @addresses; my $addr_pos = 0; foreach (@ARGV) { if ($_ =~ /((\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3}.?)+)/) { @addresses = split(/,/, $1); last; } $addr_pos++; # Position of this argument } # No address set could be found if (scalar @addresses == 0) { print "$0: Unable to find an address set, such as: 192.168.0.1,192.168.0.2\n"; exit $STATE{'UNKNOWN'}; } # Set up the communication pipe (used by the children processes to send the # plugin outputs and states pipe(READ,WRITE); # Set up an timeout local $SIG{ALRM} = sub { print "Timeout detected (".$TIMEOUT."s - you can edit its duration in $0).\n"; exit $STATE{'UNKNOWN'} }; alarm($TIMEOUT); # Now we fork() as many children as we need spawnchildren(); #------------------------------------------------------------------------------# # This part will be executed by the father process only. # # It receives all the results returned by the plugins and processes them to # # send back Nagios the service state # #------------------------------------------------------------------------------# # Pipe in read-only close WRITE; my ($data, $addr, $state, $output); # $best_* are the default variables to return if no result is better my ($best_addr, $best_state, $best_output) = ("No Address", 3, "No result returned by the plugin !"); # # PRIORITY: # In this part I consider that each state has a priority defined as follows : # OK (0) > WARNING (1) > UNKNOWN (3) > CRITICAL (2) # # As a consequence, if at least one plugin return 'OK', the state returne to # Nagios will necessarily be OK. On the contrary, if this metaplugin returns # 'CRITICAL' to Nagios, then it means every plugin executed (ie on each # address of the checked host) has returned 'CRITICAL'. # # The loop ends when no child process remains connected to the pipe any longer while (defined($data = )) { if ($data =~ /^.+<>.+<>.+$/) { ($addr, $state, $output) = split(/<>/, $data); } else { ($addr, $state, $output) = ("?", $STATE{'UNKNOWN'}, "$0 did not receive valid data from ".$ARGV[0]); } ($best_addr, $best_state, $best_output) = ($addr, $state, $output) if ($state <= $best_state); } # We have all the results, it would be a waste to timeout now... alarm(0); chomp($best_output); # Returned to Nagios : print "$best_addr: $best_output\n"; exit $best_state; #------------------------------------------------------------------------------# # SpawnChildren # # Forks as many children as needed and gives them an address to use # #------------------------------------------------------------------------------# sub spawnchildren { my ($addr, $pid); foreach $addr (@addresses) { $pid = fork(); if ($pid == -1) { print "$0: Unable to fork ! Please check your process count."; exit $STATE{'UNKNOWN'}; } elsif ($pid == 0) { execcmd($addr); exit 0; # should never be executed } } } #------------------------------------------------------------------------------# # ExecCmd # # Modifies the command line provided in @ARGV to target only one address # # Send the results to the father process using a pipe # #------------------------------------------------------------------------------# sub execcmd { my $addr = shift; my @cmd; close READ; # Stop reading input pipe select WRITE; # Use WRITE instead of STDOUT $| = 1; # Replaces the address set by $addr in the command line for (my $i = 0; $i < scalar @ARGV; $i++){ push(@cmd, (($i == $addr_pos) ? $addr : $ARGV[$i])); } my $result = `@cmd;echo \$?`; # I expect the plugin's return value (\d+) at the end of the string if (!($result =~ /^((.*\n*)+)\n(\d+)\n*$/)) { chomp($result); $result =~ s/\n+/;/g; # Removes the line feeds print "$addr<>".$STATE{'UNKNOWN'}."<>$result\n"; exit 1; } else { $result = $1; my $state = $3; chomp($result); $result =~ s/\n+/;/g; # Removes the line feeds print "$addr<>$state<>$result\n"; exit 0; } } #------------------------------------------------------------------------------# # # # Usage # # Short version & long version # # This is really a verbose part # # # #------------------------------------------------------------------------------# sub short_usage { print <> Try '$0 --help | more' for a much verbose help ! END } sub long_usage { print < WARNING > UNKNOWN > CRITICAL Now, to test our DNS service using multiple IP addresses: ---- 1. We define a new check command Add the following section in your 'check commands' definition file (in my case, checkcommands.cfg): define command{ command_name check_multiple_dns command_line \$USER1\$/check_multiaddr.pl \$USER1\$/check_dns -H \$ARG1\$ -s \$HOSTADDRESS\$ } ---- 2. We define our host with several addresses ... ie instead of typing : address 192.168.0.1 ... in our host definition (typically in hosts.cfg), we will use : address 192.168.0.1,192.168.0.11 ---- 3. Then we create a service 'DNS' This service will use 'check_multiple_dns' as check command : define service{ service_description DNS host_name Server4 check_command check_multiple_dns!www.google.com ... } ---- 4. Other services Please note that Nagios will ALWAYS replace \$HOSTADDRESS\$ by THE TWO IP addresses in check commands (including other services and host check). If you also want to monitor each network interface, you can redefine a command like this (it does not use \$HOSTADDRESS\$ but \$ARG1\$): define command{ command_name check_if_alive command_line \$USER1\$/check_ping -H \$ARG1\$ -w 3000.0,80% -c 5000.0,100% } And then define two more services on the host: define service{ service_description eth0 host_name Server4 check_command check_if_alive!192.168.0.1 # 1st IP address ... } define service{ service_description eth1 host_name Server4 check_command check_if_alive!192.168.0.11 # 2nd IP address ... } ---- Hope this plugin will be useful Florent Vuillemin - lafumah\@users.sourceforge.net END }