#!/usr/bin/perl -w
# -*- perl -*-

=head1 NAME

postfix_mailflow - Plugin to monitor the number of mails handled
  by postfix.

=head1 APPLICABLE SYSTEMS

Any postfix.

=head1 CONFIGURATION

The following shows the default configuration.

  [postfix*]
    env.logdir /var/log
    env.logfile syslog

=head1 INTERPRETATION

The plugin shows the number of bytes of mail that has passed through
the postfix installation.

=head1 MAGIC MARKERS

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

=head1 BUGS

None known

=head1 AUTHOR

Copyright (C) 2012 M. Broek

=head1 LICENSE

GPLv2

=cut

use strict;
use Munin::Plugin;

my $postpos  = undef;
my $num_rec = 0;         # Received
my $num_sent = 0;        # Sent
my $num_deferred = 0;
my $num_bounced = 0;
my $num_reject = 0;      # Rejected
my $num_banned = 0;
my $LOGDIR   = $ENV{'logdir'}  || '/var/log';
my $LOGFILE  = $ENV{'logfile'} || 'syslog';


sub parseLogfile {
    my ($fname, $start) = @_;
    my ($LOGFILE,$rotated) = tail_open($fname,$start);

    while ( <$LOGFILE> ) {
	if ( /status=sent/ && /relay=local/ ) { $num_rec++; }
	elsif ( /status=sent/ && ! /relay=(mailfilter|procmail|local|127.0.0.1)/ ) { $num_sent++; }
	elsif ( /status=deferred/ ) { $num_deferred++; }
	elsif ( /status=bounced/ ) { $num_bounced++; }
	elsif ( /: NOQUEUE: reject: / ) { $num_reject++; }
	elsif ( /warning: non-SMTP command / ) { $num_reject++; }
	elsif ( / Blocked BANNED/ ) { $num_banned++; }

    }
    return tail_close($LOGFILE);
}

if ( $ARGV[0] and $ARGV[0] eq "autoconf" ) {
    my $logfile;
    `which postconf >/dev/null 2>/dev/null`;
    if (!$?) {
	$logfile = "$LOGDIR/$LOGFILE";

	if (-f $logfile) {
            if (-r "$logfile") {
                print "yes\n";
                exit 0;
            } else {
                print "no (logfile '$logfile' not readable)\n";
            }
	} else {
	    print "no (logfile '$logfile' not found)\n";
	}
    } else {
	print "no (postfix not found)\n";
    }

    exit 0;
}


if ( $ARGV[0] and $ARGV[0] eq "config" ) {
    print "graph_title Postfix Mailflow\n";
    print "graph_args --base 1000 -l 0\n";
    print "graph_vlabel messages / \${graph_period}\n";
    print "graph_scale yes\n";
    print "graph_category postfix\n";
    
    print "received.label Received\n";
    print "received.type DERIVE\n";
    print "received.min 0\n";
    
    print "sent.label Sent\n";
    print "sent.type DERIVE\n";
    print "sent.min 0\n";
    
    print "deferred.label Deferred\n";
    print "deferred.type DERIVE\n";
    print "deferred.min 0\n";
    
    print "bounced.label Bounced\n";
    print "bounced.type DERIVE\n";
    print "bounced.min 0\n";

    print "reject.label Rejected\n";
    print "reject.type DERIVE\n";
    print "reject.min 0\n";

    print "banned.label Banned\n";
    print "banned.type DERIVE\n";
    print "banned.min 0\n";

    exit 0;
}


my $logfile = "$LOGDIR/$LOGFILE";

if (! -f $logfile) {
    print "received.value U\n";
    print "sent.value U\n";
    print "deferred.value U\n";
    print "bounced.value U\n";
    print "reject.value U\n";
    print "banned.value U\n";
    exit 1;
}


($postpos) = restore_state();

if (!defined($num_rec)) {
    
    # No state file present.  Avoid startup spike: Do not read log
    # file up to now, but remember how large it is now, and next
    # time read from there.

    $postpos = (stat $logfile)[7]; # File size

    $num_rec = 0;         # Received
    $num_sent = 0;        # Sent
    $num_deferred = 0;
    $num_bounced = 0;
    $num_reject = 0;      # Rejected
    $num_banned = 0;

} else {
    $postpos = parseLogfile ($logfile, $postpos);
}

print "received.value $num_rec\n";
print "sent.value $num_sent\n";
print "deferred.value $num_deferred\n";
print "bounced.value $num_bounced\n";
print "reject.value $num_reject\n";
print "banned.value $num_banned\n";

save_state($postpos);

# vim:syntax=perl