#!/usr/bin/perl


# ipvs.monitor - Linux Virtual Server monitor for mon
#   Check  whether  the  specified virtual  service   is defined, and,
#   optionally, whether it has any realservers defined.
#
# Invocation:
#   ipvs.monitor [options] -V <virtual_server:port> -P <protocol>
#
# Options:
#   -V virtual server
#   -P protocol (tcp|udp)
#   -z allows a virtual service to have zero realservers defined
#
# Notes:
#   - Since  it uses  ipvsadm, this  script  (and therefore  mon) must
#   unfortunately run as root :(
#   - ipvs.monitor returns 0 on success and 1 on failure


use Getopt::Std;

getopts ("zV:P:");

%proto = (
	"tcp" => "-t",
	"udp" => "-u",
);

$virtual_service = "$opt_V";

@ipvs = `/sbin/ipvsadm -l $proto{$opt_P} $virtual_service 2>&1`;

# allow a service with no realservers?
defined $opt_z ?
	($n = 2)
	:
	($n = 3);

# Check the output:
# ...two lines of headers
# ...one line of virtual service
# ...one line for each realserver
$#ipvs < $n ?
	exit 1
	:
	exit 0;


# # ## ### ##### ######## ############# #####################
# CHANGELOG
# Tue Jul 27 11:17:39 MYT 2004
#   Initial version
#   Christopher DeMarco <cdemarco@md.com.my>
# Tue Jul 27 14:14:08 MYT 2004
#   added -z switch
#   Christopher DeMarco <cdemarco@md.com.my>
# Wed Oct  1 18:34:27 CEST 2008
#   fixed inline documentation
#   fixed whitespace/tab
#   Richard Hartmann <richih@net.in.tun.de>


# # ## ### ##### ######## ############# #####################
#   Copyright (C) 2004, Christopher DeMarco
#   Copyright (C) 2008, Richard Hartmann
#
#   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.,  59  Temple   Place,   Suite 330,  Boston,   MA
#   02111-1307 USA