#!/bin/bash

# -------------------------------------------------------------------------- #
# Copyright 2002-2015, OpenNebula Project (OpenNebula.org), C12G Labs        #
#                                                                            #
# Licensed under the Apache License, Version 2.0 (the "License"); you may    #
# not use this file except in compliance with the License. You may obtain    #
# a copy of the License at                                                   #
#                                                                            #
# http://www.apache.org/licenses/LICENSE-2.0                                 #
#                                                                            #
# Unless required by applicable law or agreed to in writing, software        #
# distributed under the License is distributed on an "AS IS" BASIS,          #
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.   #
# See the License for the specific language governing permissions and        #
# limitations under the License.                                             #
#--------------------------------------------------------------------------- #

###############################################################################
# This script is used to monitor the free and used space of a datastore
###############################################################################

# -------- Set up the environment to source common tools & conf ------------

if [ -z "${ONE_LOCATION}" ]; then
    LIB_LOCATION=/usr/lib/one
else
    LIB_LOCATION=$ONE_LOCATION/lib
fi

. $LIB_LOCATION/sh/scripts_common.sh

DRIVER_PATH=$(dirname $0)
source ${DRIVER_PATH}/../libfs.sh
source ${DRIVER_PATH}/lvm.conf

# -------- Get datastore arguments from OpenNebula core ------------

DRV_ACTION=$1
ID=$2

XPATH="${DRIVER_PATH}/../xpath.rb -b $DRV_ACTION"

unset i j XPATH_ELEMENTS

while IFS= read -r -d '' element; do
    XPATH_ELEMENTS[i++]="$element"
done < <($XPATH     /DS_DRIVER_ACTION_DATA/DATASTORE/TEMPLATE/BRIDGE_LIST \
                    /DS_DRIVER_ACTION_DATA/DATASTORE/TEMPLATE/VG_NAME)

BRIDGE_LIST="${XPATH_ELEMENTS[j++]}"
VG_NAME="${XPATH_ELEMENTS[j++]:-$VG_NAME}"

HOST=`get_destination_host`

if [ -z "$HOST" ]; then
    error_message "Datastore template missing 'BRIDGE_LIST' attribute."
    exit -1
fi
# ------------ Compute datastore usage -------------

MONITOR_SCRIPT=$(cat <<EOF
set -e

VG_OPTS="--units M -C --noheadings --nosuffix $VG_NAME"

TOTAL_MB=\$($SUDO $VGDISPLAY -o vg_size \$VG_OPTS | $TR -d ' ')
FREE_MB=\$($SUDO $VGDISPLAY -o vg_free \$VG_OPTS | $TR -d ' ')
USED_MB=\$($AWK "BEGIN {print \$TOTAL_MB - \$FREE_MB}")

echo "USED_MB=\$USED_MB"
echo "TOTAL_MB=\$TOTAL_MB"
echo "FREE_MB=\$FREE_MB"
EOF
)

MONITOR_DATA=$(ssh_monitor_and_log $HOST "$MONITOR_SCRIPT" 2>&1)
MONITOR_STATUS=$?

if [ "$MONITOR_STATUS" = "0" ]; then
    echo "$MONITOR_DATA" | tr ' ' '\n'
else
    echo "$MONITOR_DATA"
    exit $MONITOR_STATUS
fi
