Backup files cleaning script

backup-clean.sh

#!/bin/bash

##############################################################################
# This script is meant to be run once a day.
#
#  Backup files name format must be: database-%Y-%m-%dT%H:%M.bz2
#
#  It deletes backup files that does not match one of these conditions:
#  - backup every 15 minutes during one week
#  - backup every day during 3 months
#  - backup every week during 1 year
#
##############################################################################

# Import parameters
current_directory="$(dirname $([ -L $0 ] && readlink -f $0 || echo $0))"
. "$current_directory/parameters.sh"
set -x

# Define variables
DELETE_SCRIPT="$current_directory/backup-delete.sh"
LAST_WEEK=$(date -d "1 week ago" +%Y%m%d%H%M)
LAST_THREE_MONTHS=$(date -d "3 months ago" +%Y%m%d%H%M)
LAST_YEAR=$(date -d "1 year ago" +%Y%m%d%H%M)

# Do deletion
FILES=$(ssh $parameters_backup_user@$parameters_backup_host "ls -1 $parameters_backup_path")
echo "$FILES" | while read line; do
    # extract date from filename
    # ie: database-2017-10-26T12:20.bz2 → 201710261220
    DATE=$(echo $line | sed 's/database-\([0-9]\{4\}\)-\([0-9]\{2\}\)-\([0-9]\{2\}\)T\([0-9]\{2\}\):\([0-9]\{2\}\).bz2/\1\2\3\4\5/g')
    KEEP_DAY=$(echo $line | sed 's/database-\([0-9]\{4\}\)-\([0-9]\{2\}\)-\([0-9]\{2\}\)T\([0-9]\{2\}\):\([0-9]\{2\}\).bz2/\1\2\30000/g')
    DAY_OF_WEEK=$(echo $line | sed 's/database-\([0-9]\{4\}\)-\([0-9]\{2\}\)-\([0-9]\{2\}\)T\([0-9]\{2\}\):\([0-9]\{2\}\).bz2/\1-\2-\3 \4:\5/g' | date +%u --date=$1)
    # delete backups older than one year ago
    if [[ "$DATE" < "$LAST_YEAR" ]]; then
        $DELETE_SCRIPT $line
    fi
    # delete backups within last year that did not occur a monday
    if [[ "$DATE" > "$LAST_YEAR" ]] && [[ "$DATE" < "$LAST_THREE_MONTHS" ]] && [[ "$DAY_OF_WEEK" != "1" ]]; then
        $DELETE_SCRIPT $line
    fi
    # delete backups within 3 months that did not occur at midnight
    if [[ "$DATE" > "$LAST_THREE_MONTHS" ]] && [[ "$DATE" < "$LAST_WEEK" ]] && [[ "$DATE" != "$KEEP_DAY" ]]; then
        $DELETE_SCRIPT $line
    fi
done