Daily ERPNext Full Backup Script

I need an automated script that grabs a full database backup of my ERPNext installation every single day and drops the resulting files onto an external hard drive attached to the server. The routine must run unattended, keep at least the last 30-days of archives, and clean up anything older so the drive never fills up.

Here’s what matters to me:

• The script must invoke ERPNext’s own backup utilities (or mysqldump + files) to guarantee the dump can be restored without extra tweaking.
• Scheduling through cron is fine—just include the entry in the deliverable.
• Clear logging: date-stamped success message, recorded size of the dump, and any error output saved to a log file.
• If the external drive is temporarily unavailable, the job should fail gracefully and alert via e-mail.
• A single command to restore from the most recent backup should be documented.

Deliverables:

1. The fully commented script (bash or Python).
2. A quick README outlining setup, configuration variables (paths, retention days, mail settings), and the one-line restore command.
3. Proof of concept: screenshots or log sample showing a successful run and rotation of old backups.

I have root access and can test promptly, so once you send the script I’ll run it right away and confirm.