From 95102e68c5198f1421c36e73b0b688ae34a01739 Mon Sep 17 00:00:00 2001
From: Richard Siddall <richard.siddall@elirion.net>
Date: Thu, 13 Feb 2014 21:42:56 -0500
Subject: [PATCH] Added Peter Eisch's load checking plugin, see:
 http://www.nntp.perl.org/group/perl.qpsmtpd/2006/01/msg4422.html, and Steve
 Kemp's alternative at:
 http://www.nntp.perl.org/group/perl.qpsmtpd/2008/03/msg7814.html

---
 plugins/loadcheck | 74 +++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 74 insertions(+)
 create mode 100644 plugins/loadcheck

diff --git a/plugins/loadcheck b/plugins/loadcheck
new file mode 100644
index 0000000..dd0493f
--- /dev/null
+++ b/plugins/loadcheck
@@ -0,0 +1,74 @@
+#!/usr/bin/perl
+
+=head1 NAME
+
+loadcheck
+
+=head1 DESCRIPTION
+
+Only takes email transactions if the system load is at or below a
+specified level.  
+
+=head1 CONFIG
+
+max_load
+
+  This is the 1 minute system load where we won't take transactions
+if our load is higher than this value.  (Default: 7)
+
+uptime
+
+  The path to the command 'uptime' if different than the default.
+(Default: /usr/bin/uptime)
+
+Example:
+
+loadcheck max_load 7 uptime /usr/bin/uptime
+
+=over 4
+
+=head1 AUTHOR
+
+Written by Peter Eisch <peter@boku.net>.
+
+=cut
+
+my $VERSION = 0.01;
+
+sub register {
+  my ($self, $qp, @args) = @_;
+
+  %{$self->{_args}} = @args;
+
+  $self->{_args}->{max_load} = 7
+      if (! defined $self->{_args}->{max_load});
+
+  $self->{_args}->{uptime} = '/usr/bin/uptime'
+      if (! defined $self->{_args}->{uptime});
+  
+  $self->register_hook("connect", "loadcheck");
+}
+
+sub loadcheck {
+  my ($self, $transaction) = @_;
+
+  my $hiload = 0;
+
+  my $cmd = $self->{_args}->{uptime};
+  #10:33AM  up  2:06, 1 user, load averages: 6.55, 3.76, 2.48
+  # 12:29am  2 users,  load average: 0.05, 0.05, 0.06
+  # 12:30am  up 5 days, 12:43,  1 user,  load average: 0.00, 0.00, 0.00
+
+  my $res = `$self->{_args}->{uptime}`;
+  if ($res =~ /aver\S+: (\d+\.\d+)/) {
+      $hiload = $1;
+  }
+
+  if ($hiload > $self->{_args}->{max_load}) {
+      $self->log(LOGERROR, "local load too high: $hiload");
+      return DENYSOFT;
+  }
+
+  return (DECLINED, "continuing with load: $hiload");
+}
+