optionally delete old backups

[sugoidogo]

Context

Optionally delete old backups when creating new ones, to prevent infinitely growing size of backup folder with automatic backups, such as when using cron to run the backup script

Choices

With the find command, you can filter for old files, print the file names, and delete them all at once. I also had previous backups of my own that I moved into the backup directory, which are folders instead of files, but will still be deleted by this command once their retention age has passed.

Test instructions

Create a backup, change time past retention time, create another backup, run find command

[sugoidogo@imac2 backups]$ sudo podman exec palworld backup
Complete Save
backup created at /palworld/backups/palworld-save-2024-01-28_11-04-01.tar.gz
[sugoidogo@imac2 backups]$ touch -d "1 year ago" palworld-save*
[sugoidogo@imac2 backups]$ sudo podman exec palworld backup
Complete Save
backup created at /palworld/backups/palworld-save-2024-01-28_11-09-11.tar.gz
[sugoidogo@imac2 backups]$ ls -l
total 1677852
-rw-r--r-- 1 sugoidogo sugoidogo 859054235 Jan 28  2023 palworld-save-2024-01-28_11-04-01.tar.gz
-rw-r--r-- 1 sugoidogo sugoidogo 859052913 Jan 28 11:09 palworld-save-2024-01-28_11-09-11.tar.gz
[sugoidogo@imac2 backups]$ find /opt/palworld/backups/ -mindepth 1 -maxdepth 1 -mtime +30 -print -delete
/opt/palworld/backups/palworld-save-2024-01-28_11-04-01.tar.gz
[sugoidogo@imac2 backups]$ ls -l
total 838924
-rw-r--r-- 1 sugoidogo sugoidogo 859052913 Jan 28 11:09 palworld-save-2024-01-28_11-09-11.tar.gz

Checklist before requesting a review

• I have performed a self-review of my code
• I've added documentation about this change to the README.
• I've not introduced breaking changes.