#!/bin/bash
# LDAP Backup Cron Script
# 26 Nov 2012
# NDP, LLC

# Set the name of the LDAP instance
export LDAPINSTANCE=tao

# set the number of hourly backups to keep
export QUOTA=72

# set the path to the native LDAP backup command (i.e. db2bak)
export BKUPCMD=/usr/lib64/dirsrv/slapd-$LDAPINSTANCE/db2bak

if [ ! -x "$BKUPCMD" ]; then
   die "Backup command $BKUPCMD does not exist or is not executable"
fi

# set the location of db2bak backups
export BKUPSRCDIR=/var/lib/dirsrv

if [ ! -d "$BKUPSRCDIR" ]; then
   die "Backup source location $BKUPSRCDIR does not exist or is not a directory"
fi

# set the location where to transfer backups
export BKUPTGTDIR=/data/backups/ldap/$LDAPINSTANCE

if [ ! -d "$BKUPSTGTDIR" ]; then
   warn "Backup target location $BKUPTGTDIR does not exist or is not a directory.  If possible it will be created."
fi

# Set the path and args for copy command (i.e. rsync vs cp)
export COPYCMD=`which rsync`
export COPYARG="-avp"

if [ ! -x "$COPYCMD" ]; then
   die "Backup command $COPYCMD does not exist or is not executable"
fi

# die function to echo a message and exit
function die () {
   echo "[FATAL] - $@ ...exiting."
   exit 1
}

# warn function for non-catastrophic errors
function warn () {
   echo "[WARN] - $@."
}

# info function for conditional verbose output
function info () {
   echo "[INFO] - $@"
}

# truncate function to remove old files in a directory
function truncate () {
   if [ ! -d "$@" ]; then
      die "$@ is not a directory that can be trimmed as per quota."
   fi
   pushd $@ > /dev/null 2>&1 || die "cannot pushd $BKUPSRCDIR/slapd-$LDAPINSTANCE/bak/"
   info "Maximum number of files to retain in $@: $QUOTA"
   LOGCOUNT=`ls -1 | wc -l`
   info "Current number of backup files: $LOGCOUNT"
   while (( $LOGCOUNT >=  $QUOTA ))
    do
	oldfile=`ls -1t | tail -1`
	info "Truncating old backup: $oldfile "
	rm -rf $oldfile
	((LOGCOUNT = LOGCOUNT - 1))
    done
    popd >/dev/null
}

# Run the builtin backup script, which will backup to the /var filesystem
$BKUPCMD

# Copy the changes to the dedicated backup disks
if (! -d "$BKUPTGTDIR"); then
   mkdir -p $BKUPTGTDIR || die "Cannot create backup target: $BKUPTGTDIR"
fi

$COPYCMD $COPYARG $BKUPSRCDIR/slapd-$LDAPINSTANCE/bak/* $BKUPTGTDIR

# Delete old backups

truncate $BKUPSRCDIR
truncate $BKUPTGTDIR

info "Backup complete"