check_nagios_kvm_hosts

#!/bin/bash
# +-----------------------------------------------------------------------------------------+
# |  Dit script checked het aantal draaiende KVM hosts op Ubuntu/Debian                     |
# |                                                                                         |
# | Mei 2012 flip hess flip@lachendemensen.com                                              |
# +-----------------------------------------------------------------------------------------+

# Global variables:

PATH='/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin'
SCRIPT_PATH="${0}"
ARGS="${#}"

VIRSH="/usr/bin/virsh list --all"
STATE="/var/tmp/KVM-stalefile"

STATE_OK="0"
STATE_WARNING="1"
STATE_CRITICAL="2"
STATE_UNKNOWN="3"

# Functions:

  # exit function
  function die()
  {
    # output
    echo -e "Error in ${SCRIPT_PATH}: ${1}"

    # return state unknown
    exit ${STATE_UNKNOWN}
  }

  # Shows usage function.
  function fShowUsage()
  {
    echo -e "Usage: ${SCRIPT_PATH}
    Check KVM state\n - flip@mhasmo.nl\n\nVersie 1.0"

    exit "${STATE_UNKNOWN}"
  }

  # resets
  function fCheckReset()
  {
    # Reset state old file
    if [ ! -f "${STATE}" ] ; then
       touch "${STATE}"
       { ${VIRSH} | grep -Ev '(Id Name                 State|-------------------|^$)' | awk '{ print $2" "$3}'  > ${STATE}; } || die "Failed to get Virsh output"
    else
       echo "State file exist! Please remove state file ${STATE}" ; exit "${STATE_UNKNOWN}"
    fi

    return 0
  }

  # The main function.
  function fMain()
  {
    # check for arguments:
    [ "${ARGS}" = 0 ] || fShowUsage

    # this script depends on virsh
    [  -x /usr/bin/virsh ] || { echo "This scripts depends on virsh, install it by using \"sudo apt-get install virsh\"" ; exit "${STATE_UNKNOWN}"; }

   #check state file
   [ -f "${STATE}" ] || \
        { fCheckReset && { echo "WARNING - check has been reset - a new ${STATE} error state file is created" ; exit "${STATE_WARNING}"; };}

   # get info
   local TEMP="$(mktemp)"
    # get output
    ${VIRSH} | grep -Ev '(Id Name                 State|-------------------|^$)' | awk '{ print $2" "$3}' > ${TEMP} || die "Failed to get Virsh output"

   # diff
   DIFFS="$( diff "${TEMP}" "${STATE}" |grep -E '(<|>)'  |sed -e 's/^>/missing virsh output:/g;s/^</new virsh output:/g' )"

   local DELTA="$( echo "${DIFFS}" | wc -l )"
   local TOTAL="$( cat "${TEMP}" | wc -l )"

   # make results
   if [ -z "${DIFFS}" ] ; then
     rm ${TEMP}
     echo -e "ALL OK: ${TOTAL} KVM images present in config. Virsh KVM output did not change"
     exit ${STATE_OK}
  else
     rm ${TEMP}
     echo -e "CRITICAL: ${DELTA} new Virsh KVM output lines"
     echo "${DIFFS}"
     exit ${STATE_CRITICAL}
   fi
  }



 # Start the program:
  fMain

 # Exit with previous return code:
  exit "${?}"