chustom_check_mem script for nrpe

chustom_check_mem script for nrpe

#### See https://support.nagios.com/forum/viewtopic.php?f=7&t=53059
# Save the content of the file into /usr/local/nagios/libexec/custom_check_mem
# - ownership     root:nagios
# - permissions   755

#!/bin/bash
# Script to check real memory usage
# L.Gill 02/05/06 - V.1.0
# ------------------------------------------
# ########  Script Modifications  ##########
# ------------------------------------------
# Who  When    What
# ---    ----      ----
# LGill  17/05/06  "$percent" lt 1% fix - sed edits dc result beggining with "."
# Box293 14/06/16  Updated to work with RHEL/CentOS 7.x and fixed perfdata unit
#                  for shared not being displayed.
# 
#
#!/bin/bash
USAGE="`basename $0` [-w|--warning]<percent free> [-c|--critical]<percent free> [-n|--nocache]"
THRESHOLD_USAGE="WARNING threshold must be greater than CRITICAL: `basename $0` $*"
calc=/tmp/memcalc
percent_free=/tmp/mempercent
critical=""
warning=""
STATE_OK=0
STATE_WARNING=1
STATE_CRITICAL=2
STATE_UNKNOWN=3
nocache=0
# print usage
if [[ $# -lt 4 ]]
then
  echo ""
  echo "Wrong Syntax: `basename $0` $*"
  echo ""
  echo "Usage: $USAGE"
  echo ""
  exit 0
fi
# read input
while [[ $# -gt 0 ]]
  do
        case "$1" in
               -w|--warning)
               shift
               warning=$1
        ;;
               -c|--critical)
               shift
               critical=$1
        ;;
        
               -n|--nocache)
               nocache=1
        ;;
        esac
        shift
  done
# verify input
if [[ $warning -eq $critical || $warning -lt $critical ]]
then
  echo ""
  echo "$THRESHOLD_USAGE"
  echo ""
        echo "Usage: $USAGE"
  echo ""
        exit 0
fi

headertest=`free -m | head -1 | gawk '{print $6}'`
memoutput=`free -m | head -2 | tail -1`
if [ "$headertest" = "available" ]; then
  memoutput=`free -m -w | head -2 | tail -1`
fi
# Total memory available
total=`echo $memoutput | gawk '{print $2}'`
# Total memory used
used=`echo $memoutput | gawk '{print $3}'`
# Calc total minus used
if [ "$nocache" -eq "1" ]; then
    free=`echo $memoutput | gawk '{print $4+$7}'`
else
    free=`echo $memoutput | gawk '{print $4}'`
fi
shared=`echo $memoutput | gawk '{print $5}'`
buffers=`echo $memoutput | gawk '{print $6}'`
cached=`echo $memoutput | gawk '{print $7}'`
bufferscached=`echo $memoutput | gawk '{print $6+$7}'`

# normal values
#echo "$total"MB total
#echo "$used"MB used
#echo "$free"MB free

# make it into % percent free = ((free mem / total mem) * 100)
echo "5" > $calc # decimal accuracy
echo "k" >> $calc # commit
echo "100" >> $calc # multiply
echo "$free" >> $calc # division integer
echo "$total" >> $calc # division integer
echo "/" >> $calc # division sign
echo "*" >> $calc # multiplication sign
echo "p" >> $calc # print
percent=`/usr/bin/dc $calc|/bin/sed 's/^\./0./'|/usr/bin/tr "." " "|/usr/bin/gawk {'print $1'}`
if [[ "$percent" -le  $warning ]]; then
    string="WARNING"
    result=1
fi
if [[ "$percent" -le  $critical ]]; then
    string="CRITICAL"
    result=2
fi
if [[ "$percent" -gt  $warning ]]; then
    string="OK"
    result=0
fi

if [ "$headertest" = "available" ]; then
    echo "$string - $free / $total MB ($percent%) Free Memory, Used: $used MB, Shared: $shared MB, Buffers + Cached: $bufferscached MB | total="$total"MB free="$free"MB used="$used"MB shared="$shared"MB buffers_and_cached="$bufferscached"MB"
else
    echo "$string - $free / $total MB ($percent%) Free Memory, Used: $used MB, Shared: $shared MB, Buffers: $buffers MB, Cached: $cached MB | total="$total"MB free="$free"MB used="$used"MB shared="$shared"MB buffers="$buffers"MB cached="$cached"MB"
fi
exit $result