#!@@PERL@@ -w
#
# Plugin to monitor the volume of mails delivered by postfix.
#
# Usage: copy or link into /etc/munin/node.d/
#
# 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=auto
#%# capabilities=autoconf

my $statefile = "@@PLUGSTATE@@/munin-plugin-postfix_mailvolume.state";
my $pos   = undef;
my $volume = 0;
my $LOGDIR  = $ENV{'logdir'}  || '/var/log';
my $LOGFILE = $ENV{'logfile'} || 'syslog';


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, $volume) = ($1, $2);
    }
    close IN;
}

if (! -f $logfile and ! -f $rotlogfile)
{
    print "delivered.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 bytes throughput\n";
    print "graph_args --base 1000 -l 0\n";
    print "graph_vlabel bytes / \${graph_period}\n";
    print "graph_scale  yes\n";
    print "graph_category  postfix\n";
    print "volume.label throughput\n";
    print "volume.type DERIVE\n";
    print "volume.min 0\n";
    exit 0;
}

print "volume.value $volume\n";

if(-l $statefile) {
	die("$statefile is a symbolic link, refusing to touch it.");
}				
open (OUT, ">$statefile") or exit 4;
print OUT "$pos:$volume\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]+)/) 
	{
	    $volume += $1;
	} 
    }
    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
