#!/bin/bash
# -*- sh -*-
: <<=cut

=head1 NAME

quota2percent - Plugin to show disk usage in percent of quota hard limit.

=head1 APPLICABLE SYSTEMS

All systems with "bash", "quota", "repquota" and "munin"

Systems with multiple users and individual storage space limitations administered via 'quota'

=head1 CONFIGURATION

The following is the default configuration

  [quota2percent_*]
  user root

You could define two alert levels, the graph language, min. human UID and dealing with system users

  [quota2percent_*]
  env.warning   [value]        (default: 90)
  env.critical  [value]        (default: 95)
  env.language  [en|de|es]     (default: en)
  env.humanuid  [value]        (default: 1000, only need if there is an other value define for UID_MIN in /etc/login.defs)
  env.low_uid   [never|no|yes] (default: never)
                                set to no for producing rrd files for system user, but don't show those graphs (e.g. for later analyses)
                                if set to yes system user graphs are drawn

=head1 DESCRIPTION

Wild card Plugin for monitoring the utilization of devices with quota rules.
A graph is drawn for each user, which shows the usage as a percentage of his hard limit. System accounts (UID <1000) are suppressed.
In addition, a graph is displayed which indicates the ratio device size to device coverage.
The script repqutoa, usually part of the package quota, is needed.
The plugin itself can be stored in any directory. For example, the device sdb1 shell be monitored, a symbolic link must be created
in the /etc/munin/plugins/ directory as follows:

=over

I<<<  ln -s /<path to file>/quota2percent_  quota2percent_sdb1 >>>

=back

=head1 MAGIC MARKERS

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

=head1 VERSION

17.0214

=head1 HISTORY

V17.0214

  fix    hard reading logic operation for skipping by Low_UID=never
  fix    some slips
  fix    some nitpicking details

  add    env.low_uid
  add    env.humanid
  add    env.language
  add    check if device exist
  add    if no limitations administered via 'quota' for the device the total line is shown only
  add    a few comments
  add    POD documentation
  add    example graph for Munin Plugin Gallery

  remove setting a PATH
  remove German comments

V17.0124

  not published, first version

=head1 AUTHOR

Jo Hartmann

=head1 LICENSE

GPLv2 (L<http://www.gnu.org/licenses/gpl-2.0.html>)

=cut

###################################################
# Autoconf section                                #
###################################################

  if [ "$1" = "autoconf" ]; then
     if ! repquota -V &> /dev/null ; then
        echo "no ('requota' executable is missing)"
        exit 0
     fi

     if ! df "/dev/${0##*_}" &> /dev/null; then
        echo "no (device /dev/${0##*_} does not exist!)"
        exit 0
     fi

     echo yes
     exit 0
  fi

###################################################
# Preparation section                             #
###################################################

# Load munin's shell library
  . "$MUNIN_LIBDIR/plugins/plugin.sh"

# if any fetch from munin-node file
     Warning=${warning:-90}
     Critical=${critical:-95}
     Language=${language:-en}
     Min_UID=${humanuid:-1000}
     Low_UID=${low_uid:-never}

# Checking if repquota installed and on the path
  if ! repquota -V &> /dev/null ; then
     echo "The script 'repquota' is not installed or on the path" >&2
     # Send the exit code FATAL ERROR happens
     exit 127
  fi

# get tehe wild card text
  Id=${0##*_}

# Check if device exist
  if ! df "/dev/$Id" &> /dev/null; then
     echo "The device /dev/$Id does not exist!" >&2
     exit 128
  fi

###################################################
# Data reading sections                           #
###################################################

# Reading the quotes for the selected device, using repquota
  if repquota "/dev/$Id" &> /dev/null; then
     readarray Quotas < <( repquota "/dev/$Id" | grep " -- " )
  else
     echo "No limitations administered via 'quota' for $Id" >&2

   # If no limitatitons administered: create a dummy for regarding
   # the avoidance of a divide-by-zero error
     Quotas[0]="root -- 1 1 1 1 1 1"

   # no rrd file need
     Low_UID="never"
  fi

  readarray Totals < <( df "/dev/$Id" )

# Get the count of Users
   Users=${#Quotas[@]}


###################################################
# Munin Configuration Section                     #
###################################################

  if [ "$1" = "config" ]; then

     # Localisation of the graphic texts
     case $Language in
          de)
            echo "graph_title    Quota-Hard-Limit von $Id"
            echo "graph_vlabel   Nutzung in % Hardlimit"
            echo "graph_info     Die Grafik zeigt die Belegung des durch Quota reglementierten Speicherplatzes für all regulären Nutzer (UID >= $Min_UID) in Prozent des Hardlimits."
            Total_txt="Su. aller Nutzer"
            Total_info="Inklusive Systemnutzer (UID < $Min_UID)"
            ;;
          es)
            echo "graph_title    Cuota de límite absoluto de $Id"
            echo "graph_vlabel   el % de uso del límite duro"
            echo "graph_info     El gráfico muestra la disponibilidad de espacio regulado por cuotas para todos los usuarios regulares (UID >= $Min_UID) como porcentaje de límites duros."
            Total_txt="Suma de todos los usuarios "
            Total_info="La inclusión de usuario del sistema (UID < $Min_UID) "
            ;;
           *)
            echo "graph_title    quota hard limit of $Id"
            echo "graph_vlabel   Usage in %"
            echo "graph_info     The graphic shows the allocation of the quota-regulated storage space for all regular users (UID >= $Min_UID) as a percentage of the hard limit ."
            Total_txt="all users"
            Total_info="system users (UID < $Min_UID) included"
            ;;
     esac

     # Defaults configuration
       echo "graph_category disk"
       echo "graph_args     --lower-limit 0 --upper-limit 100"
       echo "graph_printf   %5.2lf %%"
       echo "graph_scale    no"

     # Processing the individual user
       for((i=0; i<"$Users"; i++));do
         Quota=( ${Quotas[$i]} )
         User=${Quota[0]}
       # solve the root problem
         Fieldname="$(clean_fieldname "$User")"

       # Determine the currently processing UID
         Cur_UID="$(id -u "$User")"

       # skip if actual user a system user und low_uid is set to never
         [ "$Cur_UID" -lt "$Min_UID" ] && [ "$Low_UID" = "never" ] && continue

       # No graph for none human uid if low_uid is set to no
         [ "$Cur_UID" -lt "$Min_UID" ] && echo "$Fieldname.graph    $Low_UID"

       # configure the user lines
         echo "$Fieldname.label    $User"
         echo "$Fieldname.warning  $Warning"
         echo "$Fieldname.critical $Critical"

       done

     # configure the total line and send exit code NO ERROR happens
       echo "total.label    $Total_txt"
       echo "total.warning  $Warning"
       echo "total.critical $Critical"
       echo "total.info     $Total_info"
       exit 0
  fi

###################################################
# Munin value section                             #
###################################################

# fetch the needed values (used and hard limit) for each user, work around the root problem, calculate the percent value
  for((i=0; i<"$Users"; i++));do
    Quota=( ${Quotas[$i]} )
    Fieldname="$(clean_fieldname "${Quota[0]}")"

  # skip if actual user a system user und low_uid is set to never
    [ "$Cur_UID" -lt "$Min_UID" ] && [ "$Low_UID" = "never" ] && continue

  # write the result zu munin
    echo "${Quota[2]} ${Quota[4]} $Fieldname.value" | awk '{printf "%s %f\n",$3,$1*100/$2}'

  done

# the value for the total line
  Total=( ${Totals[1]} )
  echo "${Total[2]} ${Total[1]} total.value" | awk '{printf "%s %f\n",$3,$1*100/$2}'

# send the exit code NO ERROR happens
  exit 0

###################################################
# Script end                                      #
###################################################