#!/bin/bash

# -------------------------------------------------------------------------- #
# Copyright 2002-2017, OpenNebula Project, OpenNebula Systems                #
#                                                                            #
# 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.                                             #
#--------------------------------------------------------------------------- #
# snap_revert host:parent_image snap_id vmid ds_id

SRC=$1
SNAP_ID=$2
VMID=$3
DSID=$4

if [ -z "${ONE_LOCATION}" ]; then
    TMCOMMON=/var/lib/one/remotes/tm/tm_common.sh
    DATASTORES=/var/lib/one/datastores
else
    TMCOMMON=$ONE_LOCATION/var/remotes/tm/tm_common.sh
    DATASTORES=$ONE_LOCATION/var/datastores
fi

DRIVER_PATH=$(dirname $0)

. $TMCOMMON

SRC_PATH=$(arg_path $SRC)
SRC_HOST=$(arg_host $SRC)
DS_SYS_ID=$(echo $SRC_PATH | $AWK -F '/' '{print $(NF-2)}')


#-------------------------------------------------------------------------------
# Get Image information
#-------------------------------------------------------------------------------

DISK_ID=$(basename ${SRC} | cut -d. -f2)
SYSTEM_DS_PATH=$(dirname ${SRC_PATH})
SYSTEM_DS_DISK_PATH="${SYSTEM_DS_PATH}/disk.${DISK_ID}"

VG_NAME="vg-one-${DS_SYS_ID}"
ORIG_LV_NAME="lv-one-vm-${VMID}-${DISK_ID}"
NEW_LV_NAME="${ORIG_LV_NAME}-snap${SNAP_ID}"

CMD=$(cat <<EOT
set -ex -o pipefail

hostn=\$(hostname -s)
SNAP_DEV="/dev/${VG_NAME}-\${hostn}/${NEW_LV_NAME}"

ln -sf \$SNAP_DEV $SYSTEM_DS_DISK_PATH
EOT
)

ssh_exec_and_log "${SRC_HOST}" "${CMD}" \
                 "Error reverting snapshot ${NEW_LV_NAME}"

