Website rsync Backups the Time Machine Way

Continuing my recent rash of stupid coding, after Spellcheck the Shell Way, I decided for Website rsync Backups the Time Machine Way.

For a few years now, I’ve been using a bash script I bodged together that does incremental-ish backups of my websites using the rather formidable rsync. This week I’ve been working for maschinentempel.de, helping get frohstoff.de‘s WooCommerce shop from Trabant to Hoonage. Which required repeated backing up of the entire site and database, and made me realise the shoddiness of my original backup script.

I thought, “Wouldn’t it be awesome, instead of having to make those stupid ‘backup.blah’ folders, to let the script create a time-stamped folder like Time Machine for each backup, and use the most recent backup for the rsync hard links link destination?” Fukken wouldn’t it, eh?

Creating time-stamped folders was easy. Using the most recent backup folder — which has the most recent date, and in standard list view on my Mac, the last folder in a list — was a little trickier. Especially because once a new folder was created to backup into, that previously most recent was now second to last. tail and head feels hilariously bodgy, but works? Of course it does.

Bare bones explaining: The script needs to be in a folder with another folder called ‘backups’, and a text file called ‘excludes.txt’.  Needs to be given chmod +x to make it executable, and generally can be re-bodged to work on any server you can ssh into. Much faster, more reliable, increased laziness, time-stamped server backups.

#!/bin/sh
# ---------------------------------------------------------------
# A script to manually back up your entire website
# Backup will include everything from the user directory up
# excludes.txt lists files and folders not backed up
# Subsequent backups only download changes, but each folder is a complete backup
# ---------------------------------------------------------------
# get the folder we're in
this_dir="`dirname \"$0\"`"
# set the folder in that to backup into
backup_dir="$this_dir/backups"
# cd to that folder
echo "******************"
echo "cd-ing to $backup_dir"
echo "******************"
cd "$backup_dir" || exit 1
# make a new folder with timestamp
time_stamp=$(date +%Y-%m-%d-%H%M%S)
mkdir "$backup_dir/${backuppath}supernaut-${time_stamp}"
echo "created backup folder: supernaut-${time_stamp}"
echo "******************"
# set link destination for hard links to previous backup
# this gets the last two folders (including the one just made)
# and then the first of those, which is the most recent backup
link_dest=`ls | tail -2 | head -n 1`
echo "hardlink destination: $link_dest"
echo "******************"
# set rsync backup destination to the folder we just made
backup_dest=`ls | tail -1`
echo "backup destination: $backup_dest"
echo "******************"
# run rsync to do the backup via ssh with passwordless login
rsync -avvzc --hard-links --delete --delete-excluded --progress --exclude-from="$this_dir/excludes.txt" --link-dest="$backup_dir/$link_dest" -e ssh username@supernaut.info:~/ "$backup_dir/$backup_dest"
echo "******************"
echo "Backup complete"
echo "******************"
#------------------------------------------------
# info on the backup commands:
# -a --archive archive mode; same as -rlptgoD (no -H)
# -r --recursive recurse into directories
# -l --links copy symlinks as symlinks
# -p --perms preserve permissions
# -t --times preserve times
# -g --group preserve group
# -o --owner preserve owner (super-user only)
# -D same as --devices --specials
# --devices preserve device files (super-user only)
# --specials preserve special files
# -v --verbose increase verbosity - can increment for more detail i.e. -vv -vvv
# -z --compress compress file data during the transfer
# -c --checksum skip based on checksum, not mod-time & size – SLOWER
# -H --hard-links preserve hard links
# --delete delete extraneous files from dest dirs
# --delete-excluded also delete excluded files from dest dirs
# --progress show progress during transfer
# --exclude-from=FILE read exclude patterns from FILE – one file or folder per line
# --link-dest=DIR hardlink to files in DIR when unchanged – set as previous backup
# -e --rsh=COMMAND specify the remote shell to use – SSH
# -n --dry-run show what would have been transferred