#!/usr/bin/perl -w
#
# xmlrpc based munin plugin for monitoring rtorrent's memory usage
# prerequisites:
#  - rtorrent 0.7.5 or newer compiled with --with-xmlrpc-c
# check http://libtorrent.rakshasa.no/wiki/RTorrentXMLRPCGuide for further information
#
# written by Gabor Hudiczius
# web: http://projects.cyla.homeip.net/rtwi/wiki/rTorrentOMeter
# email: ghudiczius@gmail.com
#
# 0.2.0 - 080619
#  support for scgi_port and scgi_local
#  configurable via munin env variables
#  initial release
#
#
# Parameters:
#
#	config		required
#
#
# Configurable variables
#
#	src		"socket" when using scgi_socket, or anything else when using scgi_port
#	socket		rTorrent's rpc socket (scgi_local)	- using scgi_local	- needed, when "src" is set to "socket"
#	ip		rTorrent's ip address			- using scgi_port	- needed, when "src" is NOT set to "socket"
#	port		rTorrent's scgi port (scgi_port)	- using scgi_port	- needed, when "src" is NOT set to "socket"
#	category        Change graph category
#
# Configuration example
#
#	[rtom_mem]
#	user username
#	env.src socket
#	env.socket /home/user/torrent/.socket/rpc.socket
#	env.category Category	
#
#	[rtom_mem]
#	env.ip 127.0.0.1
#	env.port 5000
#
#
#%# family=auto


if ( $ARGV[0] and $ARGV[0] eq "autoconf" ) {
	exit 1;
}

if ( $ARGV[0] and $ARGV[0] eq "config" ) {
	my $category = $ENV{"category"} || "";
	print "graph_title rTorrent memory usage\n";
	print "graph_args --base 1024 --lower-limit 0\n";
	print "graph_vlabel Bytes\n";
	print "graph_category filetransfer".${category}."\n";
	print "mem.label Memory usage\n";
	print "mem.info Memory osage of rTorrent\n";
	print "mem.type GAUGE\n";
	print "mem.draw LINE2\n";
	exit 0;
}

use IO::Socket;

my $src 	= $ENV{"src"} || "";
my $ip		= $ENV{"ip"} || "127.0.0.1";
my $port	= $ENV{"port"} || "5000";
my $socket	= $ENV{"socket"} || "";

my $pattern	= qr/<value><(int|i4|i8|ex\.i8)>(\d+)<\/(int|i4|i8|ex\.i8)><\/value>/;

my $line	= "<?xml version=\"1.0\" encoding=\"utf-8\"?><methodCall><methodName>get_memory_usage</methodName></methodCall>";
my $llen	= length $line;
my $header	= "CONTENT_LENGTH\000${llen}\000SCGI\001\000";
my $hlen	= length $header;
$line		= "${hlen}:${header},${line}";

if ( ( defined $src ) && ( $src eq "socket" ) ) {
	socket( SOCK, PF_UNIX, SOCK_STREAM, 0 ) or die;
	connect( SOCK, sockaddr_un( $socket ) ) or die $!;
} else {
	socket( SOCK, PF_INET, SOCK_STREAM, getprotobyname( "tcp" ) );
	connect( SOCK, sockaddr_in( $port, inet_aton( $ip ) ) );
}

print SOCK $line;
flush SOCK;

my $mem = 0;
while ( $line = <SOCK> ) {
	if ( $line =~ /$pattern/ ) {
		$mem = $2;
	}
}
close (SOCK);

print "mem.value ${mem}\n";

exit;