#!/bin/sh
#
# Plugin to monitor CPU usage, for a selected set of users
#
# Usage: Place in /etc/munin/node.d/ (or link it there using ln -s)
#       Add this to your /etc/munin/plugin-conf.d/munin-node:
#               [cpubyuser]
#               env.USERS root yann
#
#       If env.USERS is set to ALL, count all logged in users.
#
#        root and yann being a list of the users to monitor.
#        You need to also make sure that awk is installed
#
# 2008-12-08 v 1.3.1 Hanisch Elián:
#                               - support for dots in user names.
#                               - fix labels
#
# 2008-12-01 v 1.3 Hanisch Elián:
#                               - fixes, refactoring and code cleanup
#                               - Users that use cpu but aren't in the USERS env var
#                               are plotted as "others", set others.graph to 'no' if
#                               you     don't want this.
#
# 2008-03-20 v 1.2 fireball:    fixed minor screwup, works now ^^
#
# 2008-01-09 v 1.1 fireball:    fixed "-" in usernames, those get replaced by "_" now.
#                               set usernames in config accordingly (that is with _)
#
#
# Parameters understood:
#
#       config          (required)
#       autoconf        (optional - used by munin-config)
#

#%# family=auto
#%# capabilities=autoconf

. "$MUNIN_LIBDIR/plugins/plugin.sh"

OTHER_FIELD="others"
[ "$USERS" = "ALL" ] && USERS=$(w --no-header | awk '{ print $1 }' | sort | uniq)


if [ "$1" = "autoconf" ]; then
        if [ -n "$USERS" ]; then
                echo "yes"
        else
                echo "no (USERS setting is missing)"
        fi
        exit
fi

if [ "$1" = "config" ]; then
        echo "graph_args --base 1000 -r --lower-limit 0"
        echo "graph_title CPU usage, by user"
        echo "graph_category cpu"
        echo "graph_info This graph shows CPU usage, for monitored users."
        echo "graph_vlabel %"
        echo "graph_scale no"
        echo "graph_period second"
        user_fields="$(for user in $USERS; do clean_fieldname "$user" | tr '\n' ' '; done)"
        echo "graph_order $user_fields $OTHER_FIELD"
        for user in $USERS "$OTHER_FIELD"; do
                user_field="$(clean_fieldname "$user")"
                echo "${user_field}.label $user"
                echo "${user_field}.info CPU used by user $user"
                echo "${user_field}.type GAUGE"
                echo "${user_field}.draw AREASTACK"
        done
        exit
fi

top -b -n 1 | sed '1,/^ *PID /d' | \
        awk -v USERS="$USERS" '
                # Store the CPU usage of each process - the mapping to the
                # user happens later. We cannot use the second column
                # (username) directly, since it may be abbreviated (ending
                # with "+").
                { CPU_PER_PID[$1]=$9 }
                END {
                        split(USERS, user_array)
                        for (user_index in user_array) {
                                user = user_array[user_index]
                                # retrieve all process IDs belonging to the user
                                "ps -u "user" -o pid --no-headers 2>/dev/null | tr \"\n\" \" \"" | getline pids
                                user_cpu = 0
                                split(pids, pid_array)
                                # summarize the cpu usage of this usage
                                for (pid_index in pid_array) {
                                        pid = pid_array[pid_index]
                                        user_cpu += CPU_PER_PID[pid]
                                        delete CPU_PER_PID[pid]
                                }
                                print user, user_cpu
                        }
                        # add all remaining cpu usages into "others"
                        others_sum = 0
                        for (other_usage in CPU_PER_PID) others_sum+=CPU_PER_PID[other_usage]
                        print "'"$OTHER_FIELD"'", others_sum;
                }' | while read -r user count; do
                        # apply fieldname cleanup
                        echo "$(clean_fieldname "$user").value $count"
                done