#!/bin/bash
#
# Copyright 2006 The Apache Software Foundation
#
# 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.
#
# Shell script to install a snapshot into place as the Lucene collection
# for a Solr server

orig_dir=$(pwd)
cd ${0%/*}/..
solr_root=$(pwd)
cd ${orig_dir}

unset master_host master_status_dir data_dir user verbose debug
. ${solr_root}/bin/scripts-util

# set up variables
prog=${0##*/}
log=${solr_root}/logs/${prog}.log

# define usage string
USAGE="\
usage: $prog [-M master] [-S sdir] [-d dir] [-u username] [-v]
       -M master   specify hostname of master server from where to pull index
                   snapshot
       -S          specify directory holding snapshot status on master server
       -d          specify directory holding index data on local machine
       -u          specify user to sudo to before running script
       -v          increase verbosity
       -V          output debugging info
"

# parse args
while getopts M:S:d:u:vV OPTION
do
    case $OPTION in
    M)
        master_host="$OPTARG"
        ;;
    S)
        master_status_dir="$OPTARG"
        ;;
    d)
        data_dir="$OPTARG"
        ;;
    u)
        user="$OPTARG"
        ;;
    v)
        verbose="v"
        ;;
    V)
        debug="V"
        ;;
    *)
        echo "$USAGE"
        exit 1
    esac
done

[[ -n $debug ]] && set -x

if [[ -z ${master_host} ]]
then
    echo "name of master server missing in $confFile or command line."
    echo "$USAGE"
    exit 1
fi

if [[ -z ${master_status_dir} ]]
then
    echo "directory holding snapshot status on master server missing in $confFile or command line."
    echo "$USAGE"
    exit 1
fi

fixUser "$@"

# use default value for data_dir if not specified
# relative path starts at ${solr_root}
if [[ -z ${data_dir} ]]
then
    data_dir=${solr_root}/data
elif [[ "`echo ${data_dir}|cut -c1`" != "/" ]]
then
    data_dir=${solr_root}/${data_dir}
fi

# assume relative path to start at ${solr_root}
if [[ "`echo ${master_status_dir}|cut -c1`" != "/" ]]
then
    master_status_dir=${solr_root}/${master_status_dir}
fi

start=`date +"%s"`

logMessage started by $oldwhoami
logMessage command: $0 $@

# get directory name of latest snapshot
name=`find ${data_dir} -name snapshot.* -print|grep -v wip|sort -r|head -1`

# clean up after INT/TERM
trap 'echo "caught INT/TERM, exiting now but partial installation may have already occured";/bin/rm -rf ${data_dir"/index.tmp$$;logExit aborted 13' INT TERM

# is there a snapshot
if [[ "${name}" == "" ]]
then
    logMessage no shapshot available
    logExit ended 0
fi

# has snapshot already been installed
if [[ ${name} == `cat ${solr_root}/logs/snapshot.current 2>/dev/null` ]]
then
    logMessage latest snapshot ${name} already installed
    logExit ended 0
fi

# make sure master has directory for hold slaves stats/state
if
    ! ssh -o StrictHostKeyChecking=no ${master_host} mkdir -p ${master_status_dir}
then
    logMessage failed to ssh to master ${master_host}, snapshot status not updated on master
fi

# install using hard links into temporary directory
# remove original index and then atomically copy new one into place
logMessage installing snapshot ${name}
cp -lr ${name}/ ${data_dir}/index.tmp$$
/bin/rm -rf ${data_dir}/index
mv -f ${data_dir}/index.tmp$$ ${data_dir}/index

# update distribution stats
echo ${name} > ${solr_root}/logs/snapshot.current

# push stats/state to master
if
    ! scp -q -o StrictHostKeyChecking=no ${solr_root}/logs/snapshot.current ${master_host}:${master_status_dir}/snapshot.current.`uname -n`
then
    logMessage failed to ssh to master ${master_host}, snapshot status not updated on master
fi

# notify Solr to open a new Searcher
logMessage notifing Solr to open a new Searcher
${solr_root}/bin/commit
if [[ $? != 0 ]]
then
  logMessage failed to connect to Solr server
  logMessage snapshot installed but Solr server has not open a new Searcher
  logExit failed 1
fi

logExit ended 0