#!/usr/bin/env bash

declare -i count_warn
declare -i count_warn_default=100

notification_addresses="ckubu-adm@oopen.de"

host_name=`hostname -f`
from_address="postfix@$host_name"
content_type='Content-Type: text/plain;\n charset="utf-8"'

postfix_queue_dir=/var/spool/postfix


if [[ $1 =~ ^-?[0-9]+$ ]];then
   count_warn=$1
else
   count_warn=$count_warn_default
fi


## - Get number of "deferred" mails in postfix queue
## -
## - Notice: Don't use mailq or postqueue command to examin
## -         the number of mails. Both will open every mail in
## -         the queue and this may take a (very) long time if
## -         many mails are there (and it will cost much resources).
## -
## -         I used a little perl script but its also posible to get
## -         the numbers of mail with:
## -            find ${postfix_queue_dir}/deferred -type f | wc -l
## -
declare -i count=$(

   perl -e '

   use strict;
   use warnings;
   use Symbol;
   sub count {
      my ($dir) = @_;
      my $dh = gensym();
      my $c = 0;
      opendir($dh, $dir) or die "$0: opendir: $dir: $!\n";
      while (my $f = readdir($dh)) {
         if ($f =~ m{^[A-F0-9]{5,}$}) {
               ++$c;
         } elsif ($f =~ m{^[A-F0-9]$}) {
               $c += count("$dir/$f");
         }
      }
      closedir($dh) or die "closedir: $dir: $!\n";
      return $c;
   }
   my $qdir = shift(@ARGV) or die "Usage: $0 queue-directory\n";
   chdir($qdir) or die "$0: chdir: $qdir: $!\n";
   printf count("deferred");
      ' $postfix_queue_dir 
)


if [[ $count -gt $count_warn ]]; then

   subject="[ WARN ] postfix deferred queue exceeds $count_warn Messages"

   msg="\n*${host_name}* - `date +\"%d.%m.%Y %H:%M h\"`\n\n[ Warning ]: $count messages in postfix deferred queue\n"
   msg+="\n\nRecipient domain and time (age in minutes):\n`qshape deferred`\n"
   msg+="\n\nSender domain and time (age in minutes):\n`qshape -s deferred`\n"
   msg+="\n\n\n** Output from script \"`basename $0`\" - Don't reply to this e-mail **"

   for email_to in $notification_addresses ; do

      echo -e "To:${email_to}\n${content_type}\nSubject:$subject\n\n${msg}" | \
         /usr/sbin/sendmail -F $from_address $email_to
      
  done
   
fi

exit 0