#!/bin/bash
#
# Copyright (c) 2013, Haukur Kristinsson
# All rights reserved.
# 
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions are met:
#     * Redistributions of source code must retain the above copyright
#       notice, this list of conditions and the following disclaimer.
#     * Redistributions in binary form must reproduce the above copyright
#       notice, this list of conditions and the following disclaimer in the
#       documentation and/or other materials provided with the distribution.
#     * Neither the name of Haukur Kristinsson nor the
#       names of its contributors may be used to endorse or promote products
#       derived from this software without specific prior written permission.

# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
# ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
# WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
# DISCLAIMED. IN NO EVENT SHALL Haukur Kristinsson BE LIABLE FOR ANY
# DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
# (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
# LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
# ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
# SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

#######################################################################################
# NAGIOS CHECK PLUGIN FOR check_fs_aix.
# Author: Haukur Kristinsson 2013
#
# Example on a remote AIX server:
# NRPE COMMAND LINE = 
#  command[check_fs_verbose]=/usr/nagios/libexec/check_fs_aix -w 90 -c 95 -p jfs -v 
# Nagios Server side (this script) =
#  ./check_nrpe19_aix_disks -r serverhostname -x check_fs_verbose -f "/dmsrfr:97:99"
#######################################################################################

### SECTION - Configuration Variables
NRPEBIN="/usr/lib64/nagios/plugins/check_nrpe19"
### EOF SECTION

### SECTION - DO NOT TOUCH THESE VARIABLES!
RHOSTNAME=
RCOMMAND=
FORCELIST=""
VERBOSE=0
STATE_OK=0
STATE_WARNING=1
STATE_CRITICAL=2
STATE_UNKNOWN=3
STATE_DEPENDENT=4
EXITSTATUS=$STATE_UNKNOWN # Default Exit Code as UNKNOWN.
EXITSTATUS=0
EXITOUTPUT=""
ENTRYCOUNT=0
CHECKSTATUS="UNKNOWN"
DEFAULTWARNINGTHRESHOLD=90
DEFAULTCRITICALTHRESHOLD=97
### EOF SECTION

### FUNCTION SECTION

### <summary>
###  Print out usage help.
### </summary>
usage()
{
cat << EOF
usage: $0 options

Nagios check plugin for check_fs_aix.

Tested with NRPE 1.9, on AIX 5.3, 6.1 and 7.1

OPTIONS:
   -h      Show this message
   -r      Remote hostname
   -x      Remote command of check_fs_aix (with -v flag)
   -w      Default warning level in percentage (without %).
   -c      Default critical level in percentage (without %).
   -f      Define forced threshold for filesystems. Ex. "/var:95:99 /tmp:96:99".
   -v      verbose output (all filesystem status OK;WARNING;CRITICAL)
EOF
}


### <summary>
###  Generate the thresholds based on the list of forced filesystems.
### </summary>
### <returns>
###  prints out a threshold string of the format "/filesystem:WARNING:CRITICAL".
### </returns>
generatethresholds() {
       FILESYSTEM=$(echo $1)
       MATCHED=0
       FUNCTIONOUTPUT=""
       for f in $FORCELIST; do
            FORCEDFILESYSTEM=$(echo $f | cut -d: -f1)
            FORCEDWARNING=$(echo $f | cut -d: -f2)
            FORCEDCRITICAL=$(echo $f | cut -d: -f3)
            if [ $FILESYSTEM = $FORCEDFILESYSTEM ]
            then
              FUNCTIONOUTPUT="$FORCEDFILESYSTEM:$FORCEDWARNING:$FORCEDCRITICAL"
              MATCHED=1
            fi
       done
       if [ $MATCHED -eq 1 ]
       then
            echo $FUNCTIONOUTPUT
       else
            echo "$FILESYSTEM:$DEFAULTWARNINGTHRESHOLD:$DEFAULTCRITICALTHRESHOLD"
       fi
}


### <summary>
###  Filters each check for forced threshold or exclusions.
###  Updated EXITOUTPUT accordingly.
### </summary>
### <returns>
###  None. 
### </returns>
buildoutput() {
       ARGFILESYSTEM=$(echo $1 | cut -d: -f1)
       ARGPRC=$(echo $2| tr -d "%") 
       THRESHOLDS=`generatethresholds $ARGFILESYSTEM`
       CALCULATEDCRITICAL=$(echo $THRESHOLDS | cut -d: -f3)
       CALCULATEDWARNING=$(echo $THRESHOLDS | cut -d: -f2)
       CALCULATEDFS=$(echo $THRESHOLDS | cut -d: -f1)
       #echo $THRESHOLDS 
       if [ $ARGPRC -gt $CALCULATEDCRITICAL ]
       then
          EXITOUTPUT=`echo $EXITOUTPUT "CRITICAL:$CALCULATEDFS:$ARGPRC% "`
          ENTRYCOUNT=`expr $ENTRYCOUNT + 1`
          if [ $EXITSTATUS -ne $STATE_CRITICAL ]
          then
             EXITSTATUS=$STATE_CRITICAL
          fi
       elif [ $ARGPRC -gt $CALCULATEDWARNING ]
       then
          EXITOUTPUT=`echo $EXITOUTPUT "WARNING:$CALCULATEDFS:$ARGPRC% "`
          EXITCOUNT=`expr $EXITCOUNT + 1`
          if [ $EXITSTATUS -eq $STATE_CRITICAL ]
          then
             EXITSTATUS=$STATE_CRITICAL
          else
             EXITSTATUS=$STATE_WARNING
          fi
       elif [ $VERBOSE -eq 1 ]
       then
          EXITOUTPUT=`echo $EXITOUTPUT "OK:$CALCULATEDFS:$ARGPRC% "`
       fi
}

### EOF SECTION

### SECTION - GETOPTS

while getopts "h:r:x:f:c:w:v" OPTION
do
     case $OPTION in
         h)
             usage
             exit 1
             ;;
         r)
             RHOSTNAME=$OPTARG
             ;;
         x)
             RCOMMAND=$OPTARG
             ;;
         f)
             FORCELIST=$OPTARG
             ;;
         c)
             DEFCRITICAL=$OPTARG
             ;;
         w)
             DEFWARNING=$OPTARG
             ;;
         v)
             VERBOSE=1
             ;;
         ?)
             usage
             exit
             ;;
     esac
done

if [[ -z $RHOSTNAME ]] || [[ -z $RCOMMAND ]] 
then
     usage
     exit 1
fi

### EOF SECTION

### SECTION - SANITY CHECK

if ! [ -f $NRPEBIN ];
then
   echo "NRPE binary at $NRPEBIN does not exist."
   exit -1
fi
### EOF SECTION

### SECTION - PLUGIN RUN

NRPERESULT=`$NRPEBIN -H $RHOSTNAME -c $RCOMMAND`

### SUBSECTION - HACKY ERROR HANDLING
if grep -q "not defined" <<< "$NRPERESULT" ; then
   echo "Remote server replied: $NRPERESULT"
   exit $STATE_UNKNOWN
elif grep -q "Invalid host name" <<< "$NRPERESULT"; then
   echo "Remote server replied: $NRPERESULT"
   exit $STATE_UNKNOWN
elif grep -q "not found" <<< "$NRPERESULT"; then
   echo "Remote server replied: $NRPERESULT"
   exit $STATE_UNKNOWN
elif ! grep -qE "OK:0|WARNING:1|CRITICAL:2" <<< "$NRPERESULT"; then
   echo "Are you sure you are using check_fs on the remote server? Remember to use the v flag."
   exit $STATE_UNKNOWN 
fi
### EOF SUBSECTION

for entry in $NRPERESULT; do
   MOUNTPOINT=`echo $entry | cut -d: -f3`
   MOUNTPRC=`echo $entry | cut -d: -f5`
   buildoutput $MOUNTPOINT $MOUNTPRC
done
if [ "$EXITOUTPUT" = "" ] 
then
   EXITOUTPUT="FILESYSTEMS OK!"
   EXITSTATUS=$STATE_O
fi

### EOF SECTION

echo $EXITOUTPUT
exit $EXITSTATUS