Check free space and print error message if it is below a threshold

check-free-space.py

#!/usr/bin/env python
from __future__ import division

import os
import sys
import optparse 

"""
Designed for use with cron scripts, as in the default state it only prints output
when the free space it below the requested threshold.
"""

def main():
	parser = optparse.OptionParser()
	parser.add_option("-r", dest='required_free', type="float", default=0.15, help=
		"A floating point value for the proportion of free "
		"space required [default: %default]")
	parser.add_option("-p", dest='freepath', type="string", default='/', help=
		"The path to check [default: %default]")
	parser.add_option("-v", dest='verbose', action='store_true', default=False, help=
		"Show free amount even when it is above the threshold")
	options, _ = parser.parse_args()
	check_free_proportion(options.freepath, options.required_free, options.verbose)

def check_free_proportion(freepath, req_free, verbose=False):
	freeprop = get_free_proportion(freepath)
	if freeprop < req_free:
		print >> sys.stderr, "Path '%s' has only %0.1f%% free space remaining, which is less than the requested %0.1f%%" % (freepath, 100.0 * freeprop, 100.0 * req_free)
	elif verbose:
		print >> sys.stderr, "Path '%s' has %0.1f%% free space remaining, which is more than the requested %0.1f%%" % (freepath, 100.0 * freeprop, 100.0 * req_free)

	

def get_free_proportion(freepath):
	statres = os.statvfs(freepath)
	return statres.f_bavail / statres.f_blocks

if __name__ == "__main__":
	main()