expyre 0.1.4

What is expyre ?

expyre is a python module that provides a command line as well as a contextmanager which enables you to schedule files/directories for deletion at some point in the future. It does this by relying on the atd(8) service for the scheduling of jobs.

Since usually examples are better than a long README

Command line usage

# - schedule a file for deletion 2 days from now
$ expyre -p path/to/file0 @now + 2days
[212] /home/steve/src/venvs/expyre/path/to/file0 will expire at 2016-05-16 19:10

# - schedule a file for deletion a minute befor new year 2018
$ expyre --unless-modified -p path/to/file1 @23:59 2017-12-31
[213] /home/steve/src/venvs/expyre/path/to/file1 will expire at 2017-12-31 23:59

# - list the current expiry schedule
$ expyre -l
/home/steve/src/venvs/expyre/path/to/file1 scheduled to expire at 2017-01-01 19:07 unless modified after 19:07 2016-05-14
/home/steve/src/venvs/expyre/path/to/file0 scheduled to expire at 2016-05-16 19:10

# - remove a file from the expiry schedule
$ expyre -r /home/steve/src/venvs/expyre/path/to/file0
Successfully removed these paths from expiry list:
/home/steve/src/venvs/expyre/path/to/file0

Python usage

from datetime import datetime, timedelta
from expyre.helpers import open_expiring, expire_path, get_scheduled_jobs, remove_from_schedule

# - as a contextmanager
filename = '/path/to/file'
with open_expiring(filename, 'w', at='now + 3days', unless_accessed=True) as fd:
    # - create a file with a scheduled deletion time exactly 3 days from
    # time of creation unless it has been accessed before the deletion time.
    pass  # - do stuff with file

# - schedule a file for deletion providing time as a string
expire_path('./path/to/file0', 'now + 2days')
JobSpec(job_id='216', path='/home/steve/src/venvs/expyre/path/to/file0', timestamp=datetime.datetime(2016, 5, 16, 19, 20), conditions='unless accessed after 19:20 2016-05-14 or unless modified after 19:20 2016-05-14')

# - schedule a file for deletion providing time as a datetime object
expire_path('./path/to/file1', (datetime.now() + timedelta(days=3)), unless_modified=True)
JobSpec(job_id='217', path='/home/steve/src/venvs/expyre/path/to/file1', timestamp=datetime.datetime(2016, 5, 17, 19, 20), conditions='unless accessed after 19:20 2016-05-14 or unless modified after 19:20 2016-05-14')

# - Get the expiry schedule as a dict
get_scheduled_jobs()
{'/home/steve/src/venvs/expyre/path/to/file0': JobSpec(job_id='216', path='/home/steve/src/venvs/expyre/path/to/file0', timestamp=datetime.datetime(2016, 5, 16, 19, 20), conditions='unless accessed after 19:20 2016-05-14 or unless modified after 19:20 2016-05-14'),
 '/home/steve/src/venvs/expyre/path/to/file1': JobSpec(job_id='217', path='/home/steve/src/venvs/expyre/path/to/file1', timestamp=datetime.datetime(2016, 5, 17, 19, 20), conditions='unless accessed after 19:20 2016-05-14 or unless modified after 19:20 2016-05-14')}

# - remove a file from the expiry schedule
remove_from_schedule(['/home/steve/src/venvs/expyre/path/to/file0'])
(['/home/steve/src/venvs/expyre/path/to/file0'], [])

A few things to note

• This has only be tested on my local dev box (Fedora 23 with python 2.7). So, YMMV. Please do some cursory testing before relying on this tool.

• Since (AFAICT), atd(8) has only minute level precision, the same limitation applies to expyre.

• Directories will be deleted with a rm -rf option ! So, you need to be careful when scheduling those for deletion.

• The --unless_accessed and --unless_modified options to directories imply the access time and modification time for the directory, not the files under them.

• Currently no checks are done to see whether there is already an existing job for a path being scheduled for deletion. I am not yet convinced that this is really necessary to be done as a default action.

• Please, please, please do report bugs or send in suggestions for improvements if you can. This would be greatly appreciated.

• Patches and code reviews would be even more appreciated.

TODO

• More tests

• Write docs