#!/bin/bash
#
# load global vars
#
. /etc/rsnbackup.conf

#
# function to add new host for backup
#  param: $1 = BACKUP_DIR, $2 = BACKUP_HOST
#
ADD_NEW_HOST(){

# create new backup directory
echo "1. Create new backup dir: $1"
mkdir -p $1

# create new rsnapshot config
echo "2. Create new rsnapshot-common.conf at $1/"

echo -e "

include_conf\t/etc/rsnapshot-common.conf
snapshot_root\t$1/

#retain\thourly\t24
retain\tdaily\t7
retain\tweekly\t4
retain\tmonthly\t3

logfile\t$1/rsnapshot.log
lockfile\t$1/rsnapshot.pid

exclude_file\t$1/exclude_file.txt

backup\troot@$2:/\t./" >> $1/rsnapshot.conf


# create the "exclude" file for this host.
echo "- /sys/*
- /proc/*
- /tmp/*
- /dev/*
- /var/lock/*
- /var/run/*
- lost+found
- /var/log/*
- /var/lib/mysql/*
- /var/lib/postgresql/*
- /media/*
- /restore/*
+ /* " >> $1/exclude_file.txt

#
# add this host to root's crontab file.
#
echo "3. Create new crontab for $2 backup."
echo "
# backup entrys for $2
00 04 * * * rsnbackup -b $2 -r daily
00 02 * * 0 rsnbackup -b $2 -r weekly
00 00 1 * * rsnbackup -b $2 -r monthly
" >> /var/spool/cron/crontabs/root

#
# Copy the Rsnapshot root's public key to the new host we are going to 
# back up. This is so it can be trusted by the host to run backups.
#
cd /root

echo "4. Create new .ssh dir if not exist on $2."
ssh root@$2 "test -d '.ssh' || ( mkdir .ssh; chmod 700 .ssh; touch .ssh/authorized_keys; )"

echo "5. Copy public_key to $2."
cat .ssh/id_dsa.pub | ssh root@$2 "cat >> ~/.ssh/authorized_keys"


#
# set customer mail file for backup status
#
echo "6. Create Mail-CC file."
echo "###
### set customer email for notification
###
### Example: user1@local user2@local
###
CC_MAIL='' " >> $1/mail-cc.txt


#
# create NFS exports file
#
echo "7. Create NFS exports entry."
if $(test -f /etc/exports) ; then
	echo "$1 $2(ro,sync,no_subtree_check)" >> "/etc/exports"
else
	touch /etc/exports
	echo "$1	$2(ro,sync,no_subtree_check)" >> "/etc/exports" 
fi
}


#
# run rsnapshot backup param: $1 = hostname, $2 = rotation 
# [daily|weekly|monthly]
#
RUN_BACKUP(){

#
# check advanced mailx package (heirloom-mailx) installed
#
if ! $(dpkg-query -Wf'${db:Status-abbrev}' heirloom-mailx 2>/dev/null | grep -q '^i') ; then
	echo "Error: Package heirloom-mailx not installed"
	exit
fi


#
# check free hd space
#
GET_PERCENTAGE='s/.* \([0-9]\{1,3\}\)%.*/\1/'

HD_SPACE_MAX_USED=`expr 100 - $HD_SPACE_MIN_FREE`

if $HD_SPACE_CHECK ; then
	KB_USED=`df /$BACKUP_BASE | tail -n1 | sed -e "$GET_PERCENTAGE"`
	INODE_USED=`df -i /$BACKUP_BASE | tail -n1 | sed -e "$GET_PERCENTAGE"`
	if [ $KB_USED -ge $HD_SPACE_MAX_USED -o $INODE_USED -ge $HD_SPACE_MAX_USED ] ; then
		echo "Fatal: Not enough space left for rsnbackup backups!"
		echo "Fatal: Not enough space left for rsnapshot backups!" > /tmp/rsnapshot.mail.txt
		SEND_EMAIL "Backup Error" "/tmp/rsnapshot.mail.txt" $1
		logger "Fatal: Not enough space left for rsnbackup backups!"
		exit
	fi
fi


#
# clean old log files
#
if $(test -f $BACKUP_BASE/$1/rsnapshot.log) ; then
	echo "" > $BACKUP_BASE/$1/rsnapshot.log
fi


#
# start rsnapshot backup
#
logger "Start rsnbackup for host: $1"

rsnapshot -c $BACKUP_BASE/$1/rsnapshot.conf $2

if [ $? = 0 ] ; then
	SEND_EMAIL "Success $2 Backup: $1" "$BACKUP_BASE/$1/rsnapshot.log" $1
else
	SEND_EMAIL "Error $2 Backup: $1" "$BACKUP_BASE/$1/rsnapshot.log" $1
fi

}



#
# send mail function param: $1 betreff, $2 content file $host
#
SEND_EMAIL(){

. $BACKUP_BASE/$3/mail-cc.txt

if [ "$CC_MAIL" == "" ] ; then
	mailx -s "$1" -S smtp=smtp://$MAIL_HOST:25 -S from="$MAIL_FROM" "$MAIL_TO" < "$2"
else
	mailx -s "$1" -S smtp=smtp://$MAIL_HOST:25 -S from="$MAIL_FROM" -c "$CC_MAIL" "$MAIL_TO" < "$2"
fi

}


PRINT_HELP(){ cat >&2 <<EOF

Usage: $0 [OPTION] Options:
  -b, --backup Backup the Host with rsnapshot
  -r, --rotate Backup rotation period
  -a, --add Add new host for backup
  -h, --help Print help and exit.
  -v, --version Print version and exit.

Example:
  Add new host configuration: rsnbackup -a HOSTNAME
  Run manually daily backup: rsnbackup -b HOSTNANE -r [daily|weekly|monthly]
EOF
}


PRINT_VERSION(){ cat >&2 <<EOF

rsnbackup version 0.0.1
Copyright (C)2014 by Ralf Kirchner <http://www.sns-systemhaus.de/>.

rsnbackup comes with ABSOLUTELY NO WARRANTY. This is free software, and you are welcome 
to redistribute it under certain conditions. See the GNU General Public Licence for details.
EOF
}


# Execute getopt on the arguments passed to this program, identified by 
# the special character $@
PARSED_OPTIONS=$(getopt -n "$0" -o b:r:a:hv --long "backup:,rotation;,add:,help,version" -- "$@")

#Bad arguments, something has gone wrong with the getopt command.
if [ $? -ne 0 ]; then
  exit 1
fi

# A little magic, necessary when using getopt.
eval set -- "$PARSED_OPTIONS"

while true; do
  case "$1" in

    -h|--help)
      PRINT_HELP
      shift;;

    -v|--version)
      PRINT_VERSION
      shift;;

    -a|--add)
      if [ -n "$2" ]; then
        BACKUP_DIR="$BACKUP_BASE/$2"
	BACKUP_HOST=$2
        ADD_NEW_HOST $BACKUP_DIR $BACKUP_HOST
      fi
      break;;

    -b|--backup)
      if [ -n "$2" ]; then
	RUN_BACKUP $2 $4
      fi
      shift 4;;

    --)
      shift
     break;;
  esac
done