#!/usr/bin/perl -w
#
# byprojects_bandwidth
#
# Perl script to monitor total bandwidth *byprojects* (e.g. vhost) from multiple files and/or regex.
#
# Danny Fullerton <northox@mantor.org> 
# Mantor Organization <www.mantor.org>
#
# You need logtail (https://www.fourmilab.ch/webtools/logtail/) and
#
# Your nginx configuration should look like this (i.e. $request_length $body_bytes_sent at the end):
#   log_format main  '$remote_addr - $remote_user $time_local "$request" '
#                    '$status $body_bytes_sent "$http_referer" '
#                    '"$http_user_agent" $request_length $body_bytes_sent';
#
# Log can be gather from multiple sources by simply specifying multiple log filename and/or an array with two
# elements: log filename and a regex.
#   - 'prod' => array('/home/prod/log/access.log'),
#     Prod graph will be using everything in /home/prod/log/access.log
#   - 'test' => array(array('/var/log/httpd/access.log', '"[A-Z]+ /test/'), '/home/test/log/access.log')
#     Test graph will be using eveything in /home/test/log/access.log and stuff that match '"[A-Z] /test/' in 
#     /var/log/httpd/access.log such as '"GET /test/'

$statepath = '/usr/local/var/munin/plugin-state'; # directory where logtail will save the state
$logtail = '/usr/local/bin/logtail';

$server = 'Nginx';

%logs = (
'prod' => ('/home/prod/log/access.log'),
'test' => (
            ('/var/log/httpd/access.log', '"[A-Z]+ /test/'),
            '/home/test/log/access.log'
          )
);

###########

if(defined($ARGV[0])) {
  if ($ARGV[0] eq 'autoconf') {
    print "yes\n";
    exit(0);
  } elsif ($ARGV[0] eq 'config') {
    $order = '';
    while (($client, $files) = each(%logs)) { $order .= $client.' ' }
    print "graph_order $order\n";
    print "graph_title $server total bandwidth byprojects\n";
    print "graph_total Total\n";
    print "graph_vlabel Bits\n";
    print "graph_category $server\n";
    print "graph_info This graph show $server total bandwidth used by various projects.\n";
    while (($client, $files) = each(%logs)) {
      print $client.".label $client\n";
      print $client.".type GAUGE\n";
    }
    exit(0);
  }
}

while (($client, $files) = each(%logs)) {
  $i = $o = $x = 0;
  foreach $file ($files) {
    $regex = '';
    $state = $statepath.'/'.$client.$x.'_totalbandwidth.state';
    if(ref($file) eq 'ARRAY') { ($file, $regex) = @file }
    open(my $lt, "$logtail -f $file -o $state |") or die "Can't open $logtail : $!";
    while (<$lt>) {
      $buf = $_;
      if($buf eq '') { next }
      if(!defined($regex) || $buf =~ m/$regex/) {
        if($buf =~ m/(\d+) (\d+)$/) {
          $i += $1;
          $o += $2;
        }
      }
    }
    close($lt);
    $x++;
  }
  $x = $i + $o;
  print $client.".value $x\n";
}