#! /bin/bash
#
# Wrapper arround check_by_ssh to avoid returning CRITICAL when the plugin timeout.
#
# @AUTHOR: Patrik Dufresne (http://patrikdufresne.com)
# Copyright 2012 Patrik Dufresne
# Last modified 2012-11-02
# Please send all comments, suggestions, bugs and patches to (info AT patrikdufresne DOT com)
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, version 2 of the License.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program.  If not, see <http://www.gnu.org/licenses/>.
###

# You should provide a meaningful VERSION
VERSION=0.2
# Who can be contacted about this?
AUTHOR="Patrik Dufresne"

declare -rx PROGNAME=${0##*/}
declare -rx PROGPATH=${0%/*}/

# Replacement for the exit function, will cleanup any tempfiles or such
# before exiting.
function cleanup {
    exit $1
}

if [ -r "${PROGPATH}utils.sh" ] ; then
    source "${PROGPATH}utils.sh"
else
    printf "Can't find utils.sh. This plugin needs to be run from the same directory as utils.sh which is most likely something like /usr/lib/nagios/plugins or /usr/lib64/nagios/plugins"
    printf "Currently being run from %s\n" "$PROGPATH"
    # Since we couldn't define STATE_UNKNOWN since reading utils.sh
    # failed, we use 3 here but everywhere else after this use cleanup $STATE
    cleanup 3
fi

SSH="ssh"

# use getopt, trust me on this one. It's the easiest way
getopt -T
if [ $? -ne 4 ] ; then
  printf "%s: getopt is in compatibility mode.\n" "$PROGNAME"
  cleanup $STATE_UNKNOWN
fi

# provide a quick one liner of how to use the program
function usage {
	printf " %s %s for Nagios - Usage %s -H <hostname> -C <command> [-t timeout] [-v [-v [-v]]]\n" "$PROGNAME" "$VERSION" "$PROGNAME"
	cleanup $STATE_UNKNOWN
}

# provide detailed explanations of the command line syntax
function longhelp {
	# put your long help here
	printf "%s plugin version %s for Nagios by %s
  -C, --command       Command to execute on the remote machine.
  -h, --help          Display this message.
  -H, --hostname      Host name, IP Address.
  -t, --timeout=sec   Set script timeout in seconds.
  -v, --verbose       Up the verbosity level by one.
  --verbosity=val     Set the verbosity level to val.
  -V, --version       Print version information.
" "$PROGNAME" "$VERSION" "$AUTHOR"
	cleanup $STATE_UNKNOWN
}

if [ $# -eq 0 ] ; then
    usage
fi

# Tell it which switches and longswitches you'll take and place a trailing
# colon (:) on the ones take arguments. Nagios guidelines require you to
# use all the ones specified below with the exception of --verbosity which I've
# added to circumvent the awkward -v -v -v syntax. Getopt takes care of
# positional parameters and errors for missing expected arguments so we can
# shift later without checking
RESULT=`getopt --name "$PROGNAME" --options "-h,-V,-v,-t:,-H:,-C" \
--longoptions "help,version,verbose,verbosity:,timeout:,hostname:,command:" -- "$@"`

# make the result of getopt your new argument list ($@)
eval set -- "$RESULT"

declare -i TIMELIMIT=10
declare -i VERBOSITY=0
declare HOST
declare COMMAND

while [ $# -gt 0 ] ; do
  case "$1" in
    -h | --help)
      longhelp;;
    -V | --version)
      print_revision "$PROGNAME" "$VERSION"
      cleanup $STATE;;
    -v | --verbose)
      VERBOSITY=$(($VERBOSITY + 1));;
    --verbosity)
      shift
      VERBOSITY=$1;;
    -t | --timeout)
      shift
      TIMELIMIT=$1;;
    -H | --hostname)
      shift
      HOST=$1;;
    -C | --command)
      shift
      COMMAND=$1;;
    --)
      shift
      break;;
    *)
      echo "Option $1 not supported. Ignored." >&2;;
  esac
  shift
done

#Verbosity level  Type of output
#0      Single line, minimal output. Summary
#1      Single line, additional information (eg list processes that fail)
#2      Multi line, configuration debug output (eg ps command used)
#3      Lots of detail for plugin problem diagnosis
if [ $VERBOSITY -gt 2 ] ; then
  shopt -o -s xtrace
fi

if [ -z "$HOST" ]; then
  printf "%s: You must provide a host name\n" "$PROGNAME"
  cleanup $STATE_UNKNOWN
fi

if [ -z "$COMMAND" ]; then
  printf "%s: No remotecmd\n" "$PROGNAME"
  cleanup $STATE_UNKNOWN
fi

# what needs to happen in the event of a timeout
function timeout {
  echo "UNKNOWN - script timed out after $TIMELIMIT seconds."
  cleanup $STATE_UNKNOWN
}

# since we've processed the options which potentially set the timeout limit,
# we can setup a timeout trap now
trap timeout USR1
    (
        ((t = $TIMELIMIT))
        while ((t > 0)); do
            sleep 1
            kill -0 $$ || exit 0
            ((t -= 1))
        done
        kill -s USR1 $$ || exit 0
        sleep 2
        kill -- -$$
    ) 2>/dev/null >/dev/null &

    OUT=`$SSH "$HOST" "$COMMAND" 2>&1`
    STATE=$?

trap - USR1

printf "$OUT"
cleanup $STATE