rsync_backup_alternative

#!/bin/sh
#
# This maintains a one week rotating backup. This will normalize permissions on
# all files and directories on backups. It has happened that someone removed
# owner write permissions on some files, thus breaking the backup process. This
# prevents that from happening. All this permission changing it tedious, but it
# eliminates any doubts. I could have done this with "chmod -R +X", but I
# wanted to explicitly set the permission bits.
#
# Pass two arguments: rsync_backup SOURCE_PATH BACKUP_PATH
#
# $Id: rsync_backup 222 2008-02-21 22:05:30Z noah $

usage() {
    echo "usage: rsync_backup [-v] [-n] SOURCE_PATH BACKUP_PATH [[DIR_LIST_PATH]]"
    echo "    SOURCE_PATH and BACKUP_PATH may be ssh-style remote paths; although,"
    echo "    BACKUP_PATH is usually a local directory where you want the"
    echo "    backup set stored."
    echo "    -v : set verbose mode"
    echo "    -n : normalize directory and file permissions to 755 for dirs and 644 for files."
}

VERBOSE=0
NORMALIZE_PERMS=0
while getopts ":vnh" options; do
    case $options in
        v ) VERBOSE=1;;
        n ) NORMALIZE_PERMS=1;;
        h ) usage
            exit 1;;
        \? ) usage
            exit 1;;
        * ) usage
            exit 1;;
    esac
done
shift $(($OPTIND - 1))
SOURCE_PATH=$1
BACKUP_PATH=$2
if [ $3 ] && [ -f $3 ] ; then
    DIR_LIST=$3
elif [ ! $3 ] || [ ! -f $3 ] ; then
    echo "$3 is not a file"
    exit 1
fi
if [ -z $SOURCE_PATH ] ; then
    echo "Missing argument. Give source path and backup path."
    usage
    exit 1
fi
if [ -z $BACKUP_PATH ] ; then
    echo "Missing argument. Give source path and backup path."
    usage
    exit 1
fi

SOURCE_BASE=`basename $SOURCE_PATH`
PERMS_DIR=755
PERMS_FILE=644
if [ $VERBOSE -eq 1 ]; then
    if [ $DIR_LIST ] && [ -f $DIR_LIST ] ; then
        # having files-from needs -r set
        echo "Using --files-from $DIR_LIST with $SOURCE_BASE as the top path"
        RSYNC_OPTS="-a --recursive --delete -v --files-from=$DIR_LIST"
    else
        # -a includes -r
        RSYNC_OPTS="-a --delete -v"
    fi
    date
else
    if [ $DIR_LIST ] && [ -f $DIR_LIST ] ; then
        # having files-from needs -r set
        RSYNC_OPTS="-a --recursive --delete -q --files-from=$DIR_LIST"
    else
        # -a includes -r
        RSYNC_OPTS="-a --delete -q"
    fi
fi

# Create the rotation directories if they don't exist.
if [ ! -d $BACKUP_PATH ] ; then
    mkdir $BACKUP_PATH
fi
if [ ! -d $BACKUP_PATH/$SOURCE_BASE.0 ] ; then
    mkdir $BACKUP_PATH/$SOURCE_BASE.0
fi
if [ ! -d $BACKUP_PATH/$SOURCE_BASE.1 ] ; then
    mkdir $BACKUP_PATH/$SOURCE_BASE.1
fi
if [ ! -d $BACKUP_PATH/$SOURCE_BASE.2 ] ; then
    mkdir $BACKUP_PATH/$SOURCE_BASE.2
fi
if [ ! -d $BACKUP_PATH/$SOURCE_BASE.3 ] ; then
    mkdir $BACKUP_PATH/$SOURCE_BASE.3
fi
if [ ! -d $BACKUP_PATH/$SOURCE_BASE.4 ] ; then
    mkdir $BACKUP_PATH/$SOURCE_BASE.4
fi
if [ ! -d $BACKUP_PATH/$SOURCE_BASE.5 ] ; then
    mkdir $BACKUP_PATH/$SOURCE_BASE.5
fi
if [ ! -d $BACKUP_PATH/$SOURCE_BASE.6 ] ; then
    mkdir $BACKUP_PATH/$SOURCE_BASE.6
fi
if [ ! -d $BACKUP_PATH/$SOURCE_BASE.7 ] ; then
    mkdir $BACKUP_PATH/$SOURCE_BASE.7
fi
if [ ! -d $BACKUP_PATH/$SOURCE_BASE.8 ] ; then
    mkdir $BACKUP_PATH/$SOURCE_BASE.8
fi
if [ ! -d $BACKUP_PATH/$SOURCE_BASE.9 ] ; then
    mkdir $BACKUP_PATH/$SOURCE_BASE.9
fi

# TODO All these find operations to clean up permissions is going to add a lot
# of overhead as the backup set gets bigger. At 100 GB it's not a big deal. The
# correct thing would be to have an exception based system where I correct
# permissions when/if they cause a problem.

# Rotate backups.
if [ $NORMALIZE_PERMS -eq 1 ]; then
    if [ $VERBOSE -eq 1 ]; then
        echo "Normalizing file permissions."
    fi
    find $BACKUP_PATH/$SOURCE_BASE.9 -type d -exec chmod $PERMS_DIR {} \;
    find $BACKUP_PATH/$SOURCE_BASE.9 -type f -exec chmod $PERMS_FILE {} \;
fi
rm -rf $BACKUP_PATH/$SOURCE_BASE.9
mv     $BACKUP_PATH/$SOURCE_BASE.8 $BACKUP_PATH/$SOURCE_BASE.9
mv     $BACKUP_PATH/$SOURCE_BASE.7 $BACKUP_PATH/$SOURCE_BASE.8
mv     $BACKUP_PATH/$SOURCE_BASE.6 $BACKUP_PATH/$SOURCE_BASE.7
mv     $BACKUP_PATH/$SOURCE_BASE.5 $BACKUP_PATH/$SOURCE_BASE.6
mv     $BACKUP_PATH/$SOURCE_BASE.4 $BACKUP_PATH/$SOURCE_BASE.5
mv     $BACKUP_PATH/$SOURCE_BASE.3 $BACKUP_PATH/$SOURCE_BASE.4
mv     $BACKUP_PATH/$SOURCE_BASE.2 $BACKUP_PATH/$SOURCE_BASE.3
mv     $BACKUP_PATH/$SOURCE_BASE.1 $BACKUP_PATH/$SOURCE_BASE.2
cp -al $BACKUP_PATH/$SOURCE_BASE.0 $BACKUP_PATH/$SOURCE_BASE.1

# Backup.
if [ $NORMALIZE_PERMS -eq 1 ]; then
    if [ $VERBOSE -eq 1 ]; then
        echo "Normalizing file permissions."
    fi
    find $BACKUP_PATH/$SOURCE_BASE.0 -type d -exec chmod $PERMS_DIR {} \;
    find $BACKUP_PATH/$SOURCE_BASE.0 -type f -exec chmod $PERMS_FILE {} \;
fi
rsync $RSYNC_OPTS $SOURCE_PATH/. $BACKUP_PATH/$SOURCE_BASE.0/.
RSYNC_EXIT_STATUS=$?
if [ $NORMALIZE_PERMS -eq 1 ]; then
    if [ $VERBOSE -eq 1 ]; then
        echo "Normalizing file permissions."
    fi
    find $BACKUP_PATH/$SOURCE_BASE.0 -type d -exec chmod $PERMS_DIR {} \;
    find $BACKUP_PATH/$SOURCE_BASE.0 -type f -exec chmod $PERMS_FILE {} \;
fi

# Ignore error code 24, "rsync warning: some files vanished before they could be transferred".
if [ $RSYNC_EXIT_STATUS = 24 ] ; then
    RSYNC_EXIT_STATUS=0
fi

# Create a timestamp file to show when backup process completed successfully.
if [ $RSYNC_EXIT_STATUS = 0 ] ; then
    rm -f $BACKUP_PATH/$SOURCE_BASE.0/BACKUP_ERROR
    date > $BACKUP_PATH/$SOURCE_BASE.0/BACKUP_TIMESTAMP
else # Create a timestamp if there was an error.
    rm -f $BACKUP_PATH/$SOURCE_BASE.0/BACKUP_TIMESTAMP
    echo "rsync failed" > $BACKUP_PATH/$SOURCE_BASE.0/BACKUP_ERROR
    date >> $BACKUP_PATH/$SOURCE_BASE.0/BACKUP_ERROR
    echo $RSYNC_EXIT_STATUS >> $BACKUP_PATH/$SOURCE_BASE.0/BACKUP_ERROR
fi

if [ $VERBOSE -eq 1 ]; then
    date
fi

exit $RSYNC_EXIT_STATUS