#!/usr/bin/perl
#
=head1 NAME

A Plugin to monitor OpenTracker Servers and their Performance

=head1 MUNIN CONFIGURATION

 [opentracker*]
 env.host 127.0.0.1      *default*
 env.port 6969           *default*
 env.uri /stats          *default*

=head2 MUNIN ENVIRONMENT CONFIGURATION EXPLANATION

 host = opentracker host to connect to
 port = opentracker http port to connect to
 uri = stats uri for appending requests for data

 I need this information so I can later build the full url which normally
 looks like the following example when put together:
    http://127.0.0.1:6969/stats?mode=conn

=head1 AUTHOR

Matt West < https://github.com/mhwest13/OpenTracker-Munin-Plugin >

=head1 LICENSE

GPLv2

=head1 MAGIC MARKERS

 #%# family=auto
 #%# capabilities=autoconf suggest

=cut

use strict;
use warnings;

use File::Basename;
use LWP::UserAgent;

if (basename($0) !~ /^opentracker_/) {
    print "This script needs to be named opentracker_ and have symlinks which start the same.\n";
    exit 1;
}

my $host = $ENV{host} || '127.0.0.1';
my $port = $ENV{port} || 6969;
my $uri = $ENV{uri} || '/stats';

=head1 Graph Declarations

    This block of code builds up all of the graph info for all root / sub graphs.

    %graphs   is a container for all of the graph definition information. In here is where you'll
           find the configuration information for munin's graphing procedure.
    Format:

    $graph{graph_name} => {
        config => {
            { key => value }, You'll find the main graph config stored here.
            { ... },
        },
        keys => [ 'Name', 'Name', 'Name', ... ], Used for building results set.
        datasrc => [
            # Name: name given to data value
            # Attr: Attribute for given value, attribute must be valid plugin argument
            { name => 'Name', info => 'info about graph' },
            { ... },
        ],
        results => {
            { key => value }, You'll find the results info from fetch_stats call stored here.
            { ... },
        },
    }

=cut

my %graphs;

# graph for connections
$graphs{conn} = {
    config => {
        args => '--lower-limit 0',
        vlabel => 'Connections',
        category => 'filetransfer',
        title => 'Current Connections',
        info => 'Current Connections to OpenTracker',
    },
    keys => [ 'Requests', 'Announces' ],
    datasrc => [
        { name => 'Requests', label => 'Requests', min => '0', type => 'COUNTER', info => 'number of Requests', draw => 'AREA' },
        { name => 'Announces', label => 'Announces', min => '0', type => 'COUNTER', info => 'number of Announces', draw => 'LINE2' },
    ],
};
# graph for peers
$graphs{peer} = {
    config => {
        args => '--lower-limit 0',
        vlabel => 'Peers',
        category => 'opentracker',
        title => 'Peers and Seeders',
        info => 'Current Peer and Seeder Connections',
    },
    keys => [ 'Peers', 'Seeders' ],
    datasrc => [
        { name => 'Peers', label => 'Peers', min => '0', type => 'GAUGE', info => 'current number of leechers & seeders (peers)', draw => 'AREA' },
        { name => 'Seeders', label => 'Seeders', min => '0', type => 'GAUGE', info => 'current number of seeders', draw => 'LINE2' },
    ],
};
# graph for scrapes
$graphs{scrp} = {
    config => {
        args => '--lower-limit 0',
        vlabel => 'Scrapes',
        category => 'opentracker',
        title => 'Scrapes',
        info => 'Number of Scrapes (TCP/UDP)',
    },
    keys => [ 'TCP', 'UDP' ],
    datasrc => [
        { name => 'TCP', label => 'TCP Requests', min => '0', type => 'COUNTER', info => 'number of scrapes requested via tcp', draw => 'AREASTACK' },
        { name => 'UDP', label => 'UDP Requests', min => '0', type => 'COUNTER', info => 'number of scrapes requested via udp', draw => 'AREA' },
    ],
};
# graph for livesyncs
$graphs{syncs} = {
    config => {
        args => '--lower-limit 0',
        vlabel => 'Syncs',
        category => 'opentracker',
        title => 'LiveSyncs',
        info => 'OpenTracker LiveSync Requests',
    },
    keys => [ 'Incoming', 'Outgoing' ],
    datasrc => [
        { name => 'Incoming', label => 'Incoming Syncs', min => '0', type => 'COUNTER', info => 'number of Incoming Syncs', draw => 'AREA' },
        { name => 'Outgoing', label => 'Outgoing Syncs', min => '0', type => 'COUNTER', info => 'number of Outgoing Syncs', draw => 'LINE2' },
    ],
};
# graph for tcp4 connections
$graphs{tcp4} = {
    config => {
        args => '--lower-limit 0',
        vlabel => 'TCP4 Requests',
        category => 'opentracker',
        title => 'TCP4 Requests',
        info => 'Current TCP4 Requests / Announces',
    },
    keys => [ 'Requests', 'Announces' ],
    datasrc => [
        { name => 'Requests', label => 'Requests', min => '0', type => 'COUNTER', info => 'number of tcp4 Requests', draw => 'AREA' },
        { name => 'Announces', label => 'Announces', min => '0', type => 'COUNTER', info => 'number of tcp4 Announces', draw => 'LINE2' },
    ],
};
# graph for torrents
$graphs{torr} = {
    config => {
        args => '--lower-limit 0',
        vlabel => '# of Torrents',
        category => 'opentracker',
        title => 'Torrents',
        info => 'Current number of Torrents',
    },
    keys => [ 'Torrents' ],
    datasrc => [
        { name => 'Torrents', label => 'Torrents', min => '0', type => 'GAUGE', info => 'number of torrents', draw => 'AREA' },
    ],
};
# graph for udp4 connections
$graphs{udp4} = {
    config => {
        args => '--lower-limit 0',
        vlabel => 'UDP4 Requests',
        category => 'opentracker',
        title => 'UDP4 Requests',
        info => 'Current UDP4 Requests / Announces',
    },
    keys => [ 'Requests', 'Announces' ],
    datasrc => [
        { name => 'Requests', label => 'Requests', min => '0', type => 'COUNTER', info => 'number of udp4 Requests', draw => 'AREA' },
        { name => 'Announces', label => 'Announces', min => '0', type => 'COUNTER', info => 'number of udp4 Announces', draw => 'LINE2' },
    ],
};

=head1 Munin Checks

    These checks look for config / autoconf / suggest params

=head2 Config Check

    This block of code looks at the argument that is possibly supplied,
    should it be config, it then checks to make sure the plugin
    specified exists, assuming it does, it will run the do_config
    subroutine for the plugin specified, otherwise it dies complaining
    about an unknown plugin.

=cut

if (defined $ARGV[0] && $ARGV[0] eq 'config') {
    # Lets take the plugin from the execution name.
    $0 =~ /opentracker_(.+)*/;
    my $plugin = $1;
    # And lets make sure we have a plugin called that.
    die 'Unknown Plugin Specified: ' . ($plugin ? $plugin : '') unless $graphs{$plugin};
    # Now lets go ahead and print out our config.
    print_config($plugin);
	exit 0;
}

=head2 Autoconf Check

    This block of code looks at the argument that is possibly supplied,
    should it be autoconf, we are going to print yes at this point since
    we've already tested for our binary to exist and be executable, the
    process will then exit.

=cut

if (defined $ARGV[0] && $ARGV[0] eq 'autoconf') {
    # well we can execute the binary, so lets make sure we can curl opentracker
    my $url = "http://".$host.":".$port.$uri."\?mode=version";
    my $ua = LWP::UserAgent->new;
    $ua->timeout(15);
    my $response = $ua->get($url);
    if ($response->is_success) {
        print "yes\n";
    } else {
        print "no: unable to connect to url: $url\n";
    }
    exit 0;
}

=head2 Suggest Check

    This block of code looks at the argument that is possibly supplied,
    should it be suggest, we are going to print the possible plugins
    which can be specified.

=cut

if (defined $ARGV[0] && $ARGV[0] eq 'suggest') {
    # well we can execute the binary, so print possible plugin names
    my @rootplugins = ('conn','peer','scrp','syncs','tcp4','torr','udp4');
    foreach my $plugin (@rootplugins) {
        print "$plugin\n";
    }
    exit 0;
}

=head1 Subroutines

    Begin Subroutine calls to output data / config information

=head2 fetch_output

    This subroutine is the main call for printing data for the plugin.
    No parameters are taken as this is the default call if no arguments
    are supplied from the command line.

=cut

fetch_output();

sub fetch_output {
    # Lets figure out what plugin they want to run, and check that it exists
    $0 =~ /opentracker_(.+)*/;
    my $plugin = $1;
    die 'Unknown Plugin Specified: ' . ($plugin ? $plugin : '') unless $graphs{$plugin};
    # Lets print out the data for our plugin
    print_output($plugin);
    return;
}

=head2 print_output

    This block of code prints out the return values for our graphs. It takes
    one parameter $plugin. Returns when completed

        $plugin;    graph we are calling up to print data values for

    Example: print_output($plugin);

=cut

sub print_output {
    # Lets get our plugin, set our graph information, and print for Munin to process
    my ($plugin) = (@_);
    my $graph = $graphs{$plugin};
    print "graph opentracker_$plugin\n";
    # Getting keys to pass to fetch_stats for data retrieval
    # call up fetch_stats with the keys we just got.
    my @keys = @{$graph->{keys}};
    fetch_stats($plugin,@keys);
    # print the results for the keys with the name for Munin to process
    foreach my $dsrc (@{$graph->{datasrc}}) {
        my $output = 0;
        my %datasrc = %$dsrc;
        while ( my ($key, $value) = each(%datasrc)) {
            next if ($key ne 'name');
            print "$dsrc->{name}.value $graph->{results}->{$value}\n";
        }
    }
    return;
}

=head2 print_config

    This subroutine prints out the main config information for all of the graphs.
    It takes one parameters, $plugin

        $plugin;    graph being called up to print config for

    Example:  print_config($plugin);

=cut

sub print_config {
    # Lets get our plugin and graph, after that print for Munin to process it.
    my ($plugin) = (@_);
    my $graph = $graphs{$plugin};
    print "graph opentracker_$plugin\n";
    # Lets print out graph's main config info.
    my %graphconf = %{$graph->{config}};
    while ( my ($key, $value) = each(%graphconf)) {
        print "graph_$key $value\n";
    }
    # Lets print our graphs per graph config info.
    foreach my $dsrc (@{$graph->{datasrc}}) {
        my %datasrc = %$dsrc;
        while ( my ($key, $value) = each(%datasrc)) {
            next if ($key eq 'name');
            print "$dsrc->{name}.$key $value\n";
        }
    }
    return;
}

=head2 fetch_stats

    This subroutine actually fetches data from opentracker with the plugin specified
    It will then parse the data using the keys assigned in an array.
    Two parameters are passed, $plugin and @keys, and it will return when complete.

        $plugin;    graph we are calling up, we use this to store the results in the hash
                    for easy recall later.
        @keys;      keys we want the values for from opentracker stats url.

    Example: fetch_stats($plugin,@keys);

=cut

sub fetch_stats {
    # Lets get our current plugin and list of keys we want info for, as well as reference our graph
    my ($plugin,@keys) = (@_);
    my $graph = $graphs{$plugin};
    # Lets create our url to fetch
    my $url = "http://".$host.":".$port.$uri."\?mode=".$plugin;
    my $ua = LWP::UserAgent->new;
    $ua->timeout(15);
    my $response = $ua->get($url);
    # Lets print some info since we got back some info
    if ($response->is_success) {
        my @tmparray = split("\n",$response->content);
        foreach my $key (@keys) {
            my $value = shift(@tmparray);
            $graph->{results}->{$key} = $value;
        }
    } else {
        print "Unable to Fetch data from URL: $url\n";
        exit 1;
    }
    return;
}