#!/usr/bin/perl
# Guy Edwards
# Oliver Gorwits
#
# Copyright (c) The University of Oxford 2007.

# This is a Nagios2 check script which takes a single argument, the IP address
# of a device. It then contacts a memcached server and checks the latest state
# of all ports on that device. Only ports which are polled are reported, and
# only ports which are administratively up, but down, are flagged for error.

use strict;
use warnings;

use Cache::Memcached;
use Regexp::Common 'net';
use Readonly;

Readonly my $memcached_conf => {
    servers   => ['my.storage-server.example.com:11211'],
    namespace => 'yatg:',
#    debug     => 1,
};

my $do_quit = sub {
    my ($msg, $status) = @_;
    $status = 1 if !defined $status;

    print "$msg\n";
    exit $status;
};

my $combined_error = q{}; # combine the error messages to fit in nagios report 
my $combined_ok    = q{}; # combine the ok messages to fit in nagios report 

my $target_host = $ARGV[0]
    or $do_quit->( 'ERROR: No target host specified' );

$target_host =~ m/^$RE{net}{IPv4}$/
    or $do_quit->( 'ERROR: Target host must be an IPv4 address' );

my $m = Cache::Memcached->new($memcached_conf)
    or $do_quit->( 'ERROR: Failed to connect to memcached server' );

my @devices = eval { @{ $m->get('yatg_devices') } }
    or $do_quit->( 'ERROR: Failed to get list of devices from memcached' );

((scalar grep m/^$target_host$/, @devices) != 0)
    or $do_quit->( "ERROR: YATG did not poll $target_host ports" );

my @ports = eval { @{ $m->get("ports_for:$target_host") } }
    or $do_quit->( "ERROR: Failed to get ports list for $target_host" );


# look for ports on this host which are administratively up, but not connected
#
# NB: memcached will only contain ports which are administratively up, and are
# not excluded for being uninteresting (e.g. stack ports)

foreach my $port (@ports) {
    (my $O_key = join ':', $target_host, 'ifOperStatus', $port) =~ s/\s/_/g;
    my $ifOperStatus = eval { $m->get($O_key) }
        or $combined_error .= " ERR: Failed to get ifOperStatus for '$O_key';";

    (my $A_key = join ':', $target_host, 'ifAlias', $port) =~ s/\s/_/g;
    my $ifAlias = eval { $m->get($A_key) } || ''; # not a problem to fail

    if ($ifOperStatus eq 'up') {
        $combined_ok .= " i/f $port ($ifAlias) up;";
    }
    else {
        $combined_error .= " WARN: $port ($ifAlias) is $ifOperStatus;";
    }
}

$do_quit->( "ERROR: $target_host$combined_error", 2 ) if $combined_error ne '';
$do_quit->( "OK: $target_host$combined_ok", 0 ) if $combined_ok ne '';
$do_quit->( 'UNKNOWN: Please check the Nagios configuration', 1 );

__END__

Copyright (c) The University of Oxford 2007.

This library is free software; you can redistribute it and/or modify it under
the same terms as Perl itself.