Bash script to backup WordPress sites. Add this to a cron job and run it every day

backup.sh

#!/bin/bash

NOW=$(date +%Y-%m-%d-%H-%M-%S)
SQL_FILE=${NOW}_db.sql

# Backup database
/usr/local/bin/wp db export ../backups/$SQL_FILE --add-drop-table

# Compress the database file
gzip ../backups/$SQL_FILE

# Backup uploads directory
tar -zcf ../backups/${NOW}_uploads.tar.gz wp-content/uploads

# Remove backup files that are a month old
# If running on OS X, the date command is a bit different:
# rm -f ../backups/$(date -v-1m +%Y%m%d*).gz
rm -f ../backups/$(date +%Y-%m-%d* --date='1 month ago').gz