backup.sh

#!/bin/bash
# https://nicaw.wordpress.com/2013/04/18/bash-backup-rotation-script/
# Julius Zaromskis
# Backup rotation

# Storage folder where to move backup files
# Must contain backup.monthly backup.weekly backup.daily folders

# Source folder where files are backed
source=$1/incoming

drush ard --destination=$source/archive.tgz

# Destination file names
date_daily=`date +"%d-%m-%Y"`

# Get current month and week day number
month_day=`date +"%d"`
week_day=`date +"%u"`

# Optional check if source files exist. Email if failed.
if [ ! -f $source/archive.tgz ]; then
  ls -l $source/ | mail your@email.com -s "[backup script] Daily backup failed! Please check for missing files."
fi

# It is logical to run this script daily. We take files from source folder and move them to
# appropriate destination folder

# On first month day do
if [ "$month_day" -eq 1 ] ; then
  destination=backup.monthly/$date_daily
else
  # On saturdays do
  if [ "$week_day" -eq 6 ] ; then
    destination=backup.weekly/$date_daily
  else
    # On any regular day do
    destination=backup.daily/$date_daily
  fi
fi

# Move the files
mkdir $destination
mv -v $source/* $destination

# daily - keep for 14 days
find $1/backup.daily/ -maxdepth 1 -mtime +14 -type d -exec rm -rv {} \;

# weekly - keep for 60 days
find $1/backup.weekly/ -maxdepth 1 -mtime +60 -type d -exec rm -rv {} \;

# monthly - keep for 300 days
find $1/backup.monthly/ -maxdepth 1 -mtime +300 -type d -exec rm -rv {} \;