Surrender

Returns the list of files which should be surrendered to the ether.

Installation

Add this line to your application's Gemfile:

gem 'surrender'

And then execute:

$ bundle

Or install it yourself as:

$ gem install surrender

Usage

Acts as a filter, returning files which should be removed from a backup scheme:

$ find /var/backup/database -type f | sort | surrender --most-recent=7 --weekly=5 --monthly=12 --yearly=2 | xargs rm

Would keep the most recent 7 files, irrespective of their dates, the 5 most recent weekly backups, the 12 most recent monthly backups, and the 2 most recent yearly backups. Backup dates are determined from the file's path, which must match the following regular expression:

/\b((?:19|2\d)\d{2})(.)?(0\d|1[012])\2?([012]\d|3[01])(?:T|\b)/

This regular expression matches schemes like this:

• /var/backup/database/contacts-20130811T130914.sql.gz
• /var/backup/database/contacts-2013-08-11.13-09-14.sql.gz
• /var/backup/database/contacts/2013/08/11.sql.gz

which seems to be common enough.

Anything that does not match the regular expression is reported as a warning on STDERR, and filtered from STDOUT, implying the file must be kept.

Incidentally, all parameters to surrender are optional. The default values are the ones expressed above. surrender uses a constant amount of memory, related to the total number of files in the input stream.

Contributing

1. Fork it
2. Create your feature branch (git checkout -b my-new-feature)
3. Commit your changes (git commit -am 'Add some feature')
4. Push to the branch (git push origin my-new-feature)
5. Create new Pull Request