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|
#!/bin/bash
# Informational output w/ happy colors
DEBUG=true
debug () {
[[ $DEBUG ]] && echo -e '\033[1;33mDEBUG ::\033[1;m ' $*
}
info () {
echo -e '\033[1;34m::\033[1;m ' $*
}
die () {
echo -e '\033[1;31mERROR ::\033[1;m ' $*
exit 1
}
CONFIG=/etc/squashfu
source $CONFIG
[[ $? -gt 0 ]] && die "Error in config file. Please check your syntax"
mount_union_ro () {
# build branch string
branches="br="
for i in `seq $1 -1 1`; do
branches="${branches}${BKUP_ROOT}/bins/${i}=ro:"
done
branches="${branches}${BKUP_ROOT}/ro=ro"
# build and execute mount command
debug "Mounting union as entirely read only"
mount -t aufs none $BKUP_ROOT/rw -o udba=reval,$branches
}
mount_union_branch_rw () {
debug "Remount branch $i as read-write"
mount -o remount,mod:bins/$1=rw "${BKUP_ROOT}/rw"
}
create_new_seed () {
# Create a new squashfs based on the contents of the union
# It's okay if we make an empty squash, we'll tell the user
# about it at the end and suggest --resquash
debug "Making new squash seed $(basename $SEED)"
mksquashfs "${BKUP_ROOT}/rw" "$SEED" -b 65536
# Delete the rsync source since its now squashed
#[[ "$1" == "--initial" ]] && rm -rf "${BKUP_ROOT}/rw/*"
}
move_old_tree () {
storage="${BKUP_ROOT}/bkup-$(date +%Y-%m-%d)"
mkdir "$storage"
cd "$BKUP_ROOT" && mv {$SEED,bins/} "$storage"
}
mount_seed () {
debug "Mounting seed"
# Mount the squashed seed, failing if we can't
mount -o loop,ro "${SEED}" "${BKUP_ROOT}/ro" || {
die FATAL: Error mounting $SEED;
}
}
mount_aufs_by_day() {
# convert DoW to a number
mount_union_ro `date --date=$1 +%u`
}
run_rsync() {
# Gather includes and excludes from config file
# No error checking here -- user better not have
# effed up the config
INCLUDES=($(grep ^#+ $CONFIG | cut -d+ -f2-))
EXCLUDES=($(grep ^#- $CONFIG | cut -d- -f2-))
# rsync source to $BKUP_ROOT/rw
debug "Rsync executing with:"
debug " Options: ${RSYNC_OPTS[@]}"
debug " Includes: ${INCLUDES[@]}"
debug " Excludes: ${EXCLUDES[@]}"
rsync ${RSYNC_OPTS[@]} ${INCLUDES[@]} ${EXCLUDES[@]} ${BKUP_ROOT}/rw || return 1
}
# Unmount union and squash
unmount_all () {
#Union must be unmounted first, or bad things happen
grep "${BKUP_ROOT}/rw" /proc/mounts &&
{ debug Unmounting union...; umount "$BKUP_ROOT/rw"; }
grep "${SEED}" /proc/mounts &&
{ debug Unmounting squash...; umount "${SEED}"; }
}
finish_routine () {
# Do another sanity check -- check sizes of bins versus squash.
bin_size=$(du -s ${BKUP_ROOT}/bins | awk '{print $1}')
sfs_size=$(du -s $SEED | awk '{print $1}')
if [[ $bin_size -gt $sfs_size ]]; then
info "Your incrementals are larger than your seed! You might consider resquashing your backup with $0 --resquash"
fi
unmount_all
}
usage () {
info "This is what happens when you can't read"
exit
}
# The meat and potatoes of the script.
do-backup () {
################################
# Sanity checks
################################
# - Are we root?
# - is our BKUP_ROOT valid? (FAIL)
# - Check for pre-existing mounts just in case (and unmount them)
# - do we have a proper (expected) directory structure in place?
# (Use cd to BKUP_ROOT to avoid issues with brace expansion in a quoted path)
[[ $UID -eq 0 ]] || die Must be root!
[[ -w "${BKUP_ROOT}" ]] ||
die "Backup root is not accessible. Please check your setting in /etc/squashfu"
unmount_all
cd "$BKUP_ROOT" && mkdir -p {rw,ro,bins/{1,2,3,4,5,6,7}}
################################
# Prep work
################################
# - does seed exist? (if not, our backup is creating the seed)
# - Prepare union mount with proper bins
[[ -f "$SEED" ]] || {
debug "No seed found -- creating a new one...";
create_new_seed;
}
mount_union_ro $(( $(date +%u) + $MODIFIER ))
mount_union_branch_rw $(( $(date +%u) + $MODIFIER ))
################################
# Ready for backup!
################################
run_rsync
################################
# Cleanup
################################
# - Is this resquash day? If so, we need a new squash
# - If new squash creation fails, we're in trouble. (by default, keep previous week)
[[ $(date +%u) -eq $RESQUASH_DAY ]] && {
create_new_seed
# Set aside last week's tree if user opted to, else delete it all
if [[ $KEEP_LAST_WEEK -eq 1 ]]; then
move_old_tree
else
find "${BKUP_ROOT}/bins/" -type f -delete
rm $SEED
fi
}
finish_routine
}
#Option parsing / Decision making
[[ $# -eq 0 ]] && usage
while [[ $# -gt 0 ]]; do
case $1 in
"-c") ;;
*) usage ;;
esac
shift
done
|
