#!/usr/bin/env perl
# ex:ts=4
# Copyright © Nicolas BOUTHORS / Smile <nicolas.bouthors@smile.fr>
# 
# Licence GPLv2
#
# Based on a script distributed on munin-exchange.

use strict;
use warnings;

use Cache::Memcached;

my %instances = (); 

# Will look into /etc for memcached config files and extract TCP listening port
# from the config file. 
sub fetch_instances() {
        my @files = glob("/etc/memcached_*.conf");
        undef $/;
        for my $f (@files) {
                $f =~ m/.*memcached_(.*)\.conf/;
                my $instance_name = $1;

                open(CONF, $f);
                my $confdata = <CONF>;
                close(CONF);

                if ($confdata =~ m/-p ([0-9]+)/m) {
                    $instances{$instance_name}{'port'} = $1;
                }
        }
}

fetch_instances();

my $cmd = shift || '';

if ($cmd eq 'config') {
        print "graph_title Memcached bytes used for all instances\n";
        print "graph_args --base 1024 -l 0\n";
        print "graph_vlabel bytes\n";
        print "graph_category memory\n";
        print "graph_info This graph monitors the size of the memcached cache for every instance.\n";

        foreach my $instance_name (keys(%instances)) {
            my $pretty_name = $instance_name;
            $pretty_name =~ s/[^a-zA-Z0-9]/_/g;

            print "${pretty_name}_bytes.label $instance_name used\n";
            print "${pretty_name}_bytes.info Number of bytes currently used\n";
            print "${pretty_name}_bytes.min 0\n";
            print "${pretty_name}_bytes.draw LINE2\n";
            print "${pretty_name}_maxbytes.label $instance_name maximum\n";
            print "${pretty_name}_maxbytes.info The configured cache size\n";
            print "${pretty_name}_maxbytes.min 0\n";
        }

        exit 0;
}

foreach my $instance_name (keys(%instances)) {
    my $ip = "127.0.0.1";
    my $port = $instances{$instance_name}{'port'};
    my $pretty_name = $instance_name;
    $pretty_name =~ s/[^a-zA-Z0-9]/_/g;

    my $address = "$ip:$port";

    my $memd = new Cache::Memcached { 'servers' => [$address] };
    my $memstats = $memd->stats(['misc']);

    print "${pretty_name}_bytes.value " . $memstats->{hosts}->{$address}->{misc}->{bytes} . "\n";
    print "${pretty_name}_maxbytes.value " .
            $memstats->{hosts}->{$address}->{misc}->{limit_maxbytes} . "\n";
}