#!/usr/bin/perl -w
########################################################
# Disk Monitor by Larry Long - larry@djslyde.com       #
# checkdisk - 1/7 programs in checksuite v2.4          #
#                                                      #
# This greps from the 'df' command for the disk        #
# utilization and if it goes over a certain threshold, #
# it can log and/or e-mail a notification.             #
########################################################
use strict;
use Getopt::Std;
use Net::SMTP;

# Options: -h (help) -l (log) -o (output to screen) -t (threshold) -e (email)
my %opt;getopts('hlot:e:', \%opt);
usage_info() unless defined @ARGV;
usage_info() if exists $opt{h};

# Localize variables throughout the rest of the program
my($email,$host,$threshold,$util,@disk_fields,@note,$notify,$logdate,$logfile,$logsnip,@df,$du,$script,$total,$subject);

# Define variables
$threshold = $opt{t};$threshold = '85' unless defined $opt{t};
$email = $opt{e};$email = 'root' unless defined $opt{e};
$host = `hostname`;
$logfile = "/var/log/checksuite";
$logdate = `date '+%m/%d/%Y %H:%M:%S' `;
$script = " - [checksuite] checkdisk\n";
$logsnip = "----\n";
$notify = 0;
$subject = "[checksuite] advisory - disk utilization is high on $host";
chomp $host;chomp $logdate;chomp $subject;

# Pull the disk utilization
open(DISK, "df -hP -x none -x tmpfs -x iso9660|grep dev|");
while()
   {
   @disk_fields = split(/\s+/, $_);
   $util = $disk_fields[4];
   $util =~ s/\%//g;
   if($util >= $threshold)
      {
      push(@note, "Current disk utilization for $disk_fields[5] is above $threshold: $disk_fields[4]\n\n");
      if($disk_fields[5] eq "/")
         {
         $du = `cd / && ls -I *proc* /|xargs du -hs`;
         push(@note, "Disk Usage for $disk_fields[5] by Content:\n$du\n");
         $notify++;
         }
      else
         {
         $du = `du -hs $disk_fields[5]\*`;
         push(@note, "Disk Usage for $disk_fields[5] by Content:\n$du\n");
         $notify++;
         }
      }
   }
close(DISK);

# Define where the output goes
if($notify > 0)
   {
   $total = `df -hP -x none -x tmpfs -x iso9660`;
   push(@note, "Disk Usage Summary:\n$total");
   log_data() if exists $opt{l};
   email_data() if exists $opt{e};
   screen_data() if exists $opt{o};
   }

# Subroutines
sub usage_info
   {
   my $usage = "
Usage: $0 [-h | -lo] [-t ] [-e ]
Options:
-h              display this help
-l              log the output to /var/log/checksuite
-o              force output to screen
-t              sets the threshold for notification
-e              e-mail the output to a specified e-mail address
Where:
(threshold)     threshold value - default is 85 percent
(email)         e-mail address of the recipient of the notification
\n";
   die $usage;
   }

sub log_data
   {
   open(LOG, ">>$logfile") or die "Can't open logfile!\n";
   print LOG $logdate,$script,@note,$logsnip;
   close(LOG);
   }

sub screen_data
   {
   print STDERR @note;
   }

sub email_data
   {
   my $smtp = Net::SMTP->new($host);
   if(! ref($smtp))
      {
      log_die("Cannot connect to SMTP\n");
      }
   $smtp->mail($email);
   $smtp->to($email);
   $smtp->data();
   $smtp->datasend("To: " . $email . "\n");
   $smtp->datasend("From: Checksuite Notification \n");
   $smtp->datasend("Return-Path: " . $email. "\n");
   $smtp->datasend("Subject: " . $subject . "\n");
   $smtp->datasend("\n");
   $smtp->datasend(@note);
   $smtp->datasend();
   $smtp->quit();
   }