#!/usr/bin/perl -w
#
# Plugin to monitor the number of mails delivered and rejected by postfix.
#
# Usage: copy or link into /etc/munin/plugins/
#
# Parameters:
#
# 	config   (required)
# 	autoconf (optional - used by munin-config)
#
# Config variables:
#
# 	logdir       - Which logfile to use
#	logfile      - What file to read in logdir
#
# Magic markers (optional - used by munin-config and some installation
# scripts):
#
#%# family=manual
#%# capabilities=autoconf

my $statefile = "/var/db/munin-pluginstate/munin-plugin-postfix_mailstats.state";
my $pos   = undef;
my $delivered = 0;
my $rejects = {};
my $LOGDIR  = $ENV{'logdir'}  || '/var/log';
my $LOGFILE = $ENV{'logfile'} || 'maillog';


if ( $ARGV[0] and $ARGV[0] eq "autoconf" )
{
    my $logfile;
    if (-d $LOGDIR)
    {
	$logfile = "$LOGDIR/$LOGFILE";

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

    exit 1;
}

my $logfile = "$LOGDIR/$LOGFILE";
my $prevdate = get_prev_date();

if (-f "$logfile.$prevdate")
{
    $rotlogfile = "$logfile.$prevdate";
}
elsif (-f "$logfile.0")
{
    $rotlogfile = $logfile . ".0";
}
elsif (-f "$logfile.1")
{
    $rotlogfile = $logfile . ".1";
}
elsif (-f "$logfile.01")
{
    $rotlogfile = $logfile . ".01";
}
else
{
    $rotlogfile = $logfile . ".0";
}

if (-f "$statefile")
{
    open (IN, "$statefile") or exit 4;
    if (<IN> =~ /^(\d+):(\d+)/)
    {
	($pos, $delivered) = ($1, $2);
    }
    while (<IN>)
    {
    	if (/^(\d+):(\d+)$/)
	{
		$rejects->{$1} = $2;
	}
        elsif (/^OTHER:(\d+)$/)
        {
		$rejects->{OTHER} = $1;
        }
    }
    close IN;
}

if (! -f $logfile and ! -f $rotlogfile)
{
    print "delivered.value U\n";
    foreach my $i (sort keys %{$rejects})
    {
    	print "r$i.value U\n";
    }
    exit 0;
}


$startsize = (stat $logfile)[7];

if (!defined $pos)
{
    # Initial run.
    $pos = $startsize;
}

if ($startsize < $pos)
{
    # Log rotated
    parseLogfile ($rotlogfile, $pos, (stat $rotlogfile)[7]);
    $pos = 0;
}

parseLogfile ($logfile, $pos, $startsize);
$pos = $startsize;

if ( $ARGV[0] and $ARGV[0] eq "config" )
{
    print "graph_title Postfix message throughput\n";
    print "graph_args --base 1000 -l 0\n";
    print "graph_vlabel mails / \${graph_period}\n";
    print "graph_scale  no\n";
    print "graph_total  Total\n";
    print "graph_category postfix\n";
    print "delivered.label delivered\n";
    print "delivered.type DERIVE\n";
    print "delivered.draw AREA\n";
    print "delivered.min 0\n";
    foreach my $i (sort keys %{$rejects})
    {
	    print "r$i.label reject $i\n";
	    print "r$i.type DERIVE\n";
	    print "r$i.draw STACK\n";
	    print "r$i.min 0\n";
    }
    exit 0;
}

print "delivered.value $delivered\n";
foreach my $i (sort keys %{$rejects})
{
	print "r$i.value ", $rejects->{$i}, "\n";
}

if(-l $statefile) {
	die("$statefile is a symbolic link, refusing to touch it.");
}				
open (OUT, ">$statefile") or exit 4;
print OUT "$pos:$delivered\n";
foreach my $i (sort keys %{$rejects})
{
	print OUT "$i:", $rejects->{$i}, "\n";
}
close OUT;

sub parseLogfile 
{    
    my ($fname, $start, $stop) = @_;
    open (LOGFILE, $fname) or exit 3;
    seek (LOGFILE, $start, 0) or exit 2;

    while (tell (LOGFILE) < $stop) 
    {
	my $line =<LOGFILE>;
	chomp ($line);

	if ($line =~ /qmgr.*from=.*size=[0-9]*/) 
	{
	    $delivered++;
	} 
	elsif ($line =~ /postfix\/smtpd.*reject: \S+ \S+ \S+ (\S+)/)
	{
            my $cause = $1;
            $cause = 'OTHER' unless $1 =~ /^\d+$/;
	    $rejects->{$cause} ++;
	}
    }
    close(LOGFILE);    
}

sub get_prev_date
{
	my @date = localtime (time - 86400);
	my $prevdate = $date[5]+1900 . $date[4]+1 . $date[3];
	return $prevdate;
}

# vim:syntax=perl
