#!/usr/bin/perl
#
# Copyright 2012 Chris Wilson
# Copyright 2006 Holger Levsen
#
# This plugin monitors ALL processes on a system. No exceptions. It can
# produce very big graphs! But if you want to know where your CPU time
# is going without knowing what to monitor in advance, this can help;
# or in addition to one of the more specific CPU plugins to monitor
# just Apache or MySQL, for example.
#
# It's not obvious what the graph heights actually mean, even to me.
# Each counter is a DERIVE (difference since the last counter reading)
# of the CPU time usage (in seconds) accounted to each process, summed
# by the process name, so all Apache and all MySQL processes are grouped
# together. Processes with no CPU usage at all are ignored. Processes
# that die may not appear on the graph, and anyway their last chunk of
# CPU usage before they died is lost. You could modify this plugin to
# read SAR/psacct records if you care about that.
#
# This program is free software; you can redistribute it and/or
# modify it under the terms of the GNU General Public License
# as published by the Free Software Foundation; version 2 dated June,
# 1991.

#scriptname=`basename $0`
#vsname=`echo $scriptname | perl -ne '/^vserver_proc_VM_(.*)/ and print $1'`

#if [ "$1" = "suggest" ]; then
#	ls -1 /etc/vservers
#	exit 0
#elif [ -z "$vsname" ]; then
#	echo "Must be used with a vserver name; try '$0 suggest'" >&2
#	exit 2
#fi

use strict;
use warnings;

my $cmd = "ps -eo time,comm h";
open PS, "$cmd|" or die "Failed to run ps command: $cmd: $!";

# my $header_line = <PS>;
my %total_cpu_by_process;

while (<PS>)
{
	my @fields = split;
	my $cputime = $fields[0];
	my $process = $fields[1];

	# remove any / and everything after it from the process name,
	# e.g. kworker/0:2 -> kworker
	$process =~ s|/.*||;

	# remove any . at the end of the name (why does this appear?)
	# $process =~ s|\.$||;

	# change any symbol that's not allowed in a munin variable name to _
	$process =~ tr|a-zA-Z0-9|_|c;

	my @times = split /:/, $cputime;
	my @days = split /-/, $times[0];
	if ($days[1]) {
		$cputime = ((($days[0] * 24) + $days[1]) * 60 + $times[1]) * 60 + $times[2];
	} else {
		$cputime = (($times[0] * 60) + $times[1]) * 60 + $times[2];
	}
	$total_cpu_by_process{$process} += $cputime;
}

foreach my $process (keys %total_cpu_by_process)
{
	# remove all processes with 0 cpu time
	if (not $total_cpu_by_process{$process})
	{
		delete $total_cpu_by_process{$process};
	}
}

close(PS);

if (@ARGV and $ARGV[0] eq "config")
{
	print <<END;
graph_title CPU time by Process
graph_args --base 1000
graph_vlabel seconds
graph_category processes
graph_info Shows CPU time used by each process name
END

	my $stack = 0;
	sub draw() { return $stack++ ? "STACK" : "AREA" }
	print map
	{
		"$_.label $_\n" .
		"$_.min 0\n" .
		"$_.type DERIVE\n" .
		"$_.draw " . draw() . "\n"
	} sort keys %total_cpu_by_process;
}
else
{
	print map
	{
		"$_.value $total_cpu_by_process{$_}\n"
	} sort keys %total_cpu_by_process;
}

exit(0);