#!/bin/bash
#
# Plugin to monitor Memory usage inspired by cpubyuser
#
# Usage: Place in /etc/munin/plugins/ (or link it there using ln -s)
#	Add this to your /etc/munin/plugin-conf.d/munin-node:
#		[membyuser]
#		user root # required if /proc can't be read from by any user!

## 2012-05-23 Sebastien Campion
# changed on 2019-08-30 by pcy <pcy@ulyssis.org>:
# - change category from 'memory' to 'system' (so it appears next to cpubyuser)
# - use rss instead of vsz
# - more robust username enumeration

USERS="$(ps ax --format uname | tail +2 | sort -u | grep -v -e '^root$')"

if [ "$1" = "autoconf" ]; then
	if [ -n "$USERS" ]; then
		echo "yes"
	else
		echo "\$USERS not defined."
	fi
	exit
fi

if [ "$1" = "config" ]; then
	echo "graph_args --base 1024"
	echo "graph_title Memory usage, by user"
	echo "graph_category memory"
	echo "graph_info This graph shows memory usage, for monitored users."
	echo "graph_vlabel Bytes"
	echo "graph_period second"
	_USERS=${USERS//[-.]/_}
	echo "graph_order $_USERS others"
	FIRSTUSER=1;
	for USER in $USERS "others"; do
		_USER=${USER//[-.]/_}
		echo "${_USER}.label $USER"
		echo "${_USER}.info Memory used by user $USER"
		echo "${_USER}.type GAUGE"
		echo "${_USER}.draw AREASTACK"
	done
	exit
fi

ps -e -o rss,user | \
	awk -v USERS="$USERS" '
		{ if ($2 != "USER") MEM_USER[$2]+=$1 }
		END {
			others_sum = 0
			for (user in MEM_USER) {
				m = match(USERS,user)
				if (m != 0) {
					_user=user
					gsub(/[-.]/,"_", _user);
					print _user".value", (MEM_USER[user] * 1024)
				} else
					others_sum += (MEM_USER[user] * 1024)
			}
		print "others.value", others_sum;
	}'