#!/usr/bin/env python
#####################################################################
# $Id$
#
# Stefano Rivera's DiskFull Warning script
# Version 0.0.1
# Copyright (C) 2003, 2004 Stefano Rivera <scripts "at" rivera.za.net>
#
# This program is free software; you can redistribute it and/or
# modify it under the terms of the GNU General Public License as
# published by the Free Software Foundation; version 2 of the
# License.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
# General Public License for more details.
#
# You should have received a copy of the GNU General Public
# License along with this program; if not, write to the Free
# Software Foundation, Inc., 59 Temple Place, Suite 330, Boston,
# MA 02111-1307 USA
#####################################################################

import email.MIMEText
import optparse
import os
import re
import smtplib
import socket
import sys

# Version
__version__ = "0.0.1"

#####################################################################
def main():
  parseOptions()
  
  df = os.popen("df -P")
  mounts = []
  dfRE = re.compile("^.*\s+\d+\s+\d+\s+\d+\s+(\d+)%\s+(.*)$")
  for line in df.readlines():
    m = dfRE.match(line)
    if m != None:
      mpoint = m.group(2)
      mpercent = int(m.group(1))

      if options.verbose:
        print "Found that %s is %d%% full." % (mpoint, mpercent)
      
      if mpoint in options.overrides:
        wpercent = options.overrides[mpoint]
      else:
        wpercent = options.percentage
      
      if mpercent >= wpercent:
        warn(mpoint, mpercent, wpercent)

#####################################################################
def warn(mpoint, full, warnlevel):
  "Warn the user"
  
  sys.stderr.write("Filesystem %s is %d%% full!\n" % (mpoint, full))
  
  hostname = socket.gethostname()
  fromAddr = "root@" + hostname
  toAddr = options.mail
  
  msg = email.MIMEText.MIMEText("""This is an automatically generated mail message from df-warn
running on %s

Filesystem %s is %d%% full!

I was told to tell you when it reached %d%% full.

Faithfully yours, etc.
""" % (hostname, mpoint, full, warnlevel))
  
  msg['Subject'] = "%s is %d%% full on %s" % (mpoint, full, hostname)
  msg['From'] = "df-warn monitoring <%s>" % fromAddr
  msg['To'] = toAddr
  
  if options.verbose:
    print "Sending message: " + msg.as_string()
  
  s = smtplib.SMTP()
  s.connect()
  s.sendmail(fromAddr, toAddr, msg.as_string())
  s.close()
  
#####################################################################
def parseOptions():
  "Parse the command line options"

  global options
  
  usage = """%prog [OPTION]... [MOUNT=PERCENTAGE]...

  Warn root when a mount point reaches 80% capacity.

  Mount points can be individually overriden with the MOUNT=PERCENTAGE options
  i.e. /tmp=50
  
  0 ignores a mountpoint"""
  version = "%prog " + __version__
  
  parser = optparse.OptionParser(usage=usage, version=version)
  parser.add_option("-v", "--verbose",
                    dest = "verbose",
                    action = "store_true",
                    default = False,
                    help = "Be verbose")
  parser.add_option("-m", "--mail",
                    dest = "mail",
                    metavar = "ADDRESS",
                    default = "root",
                    help = "The address to email when there is a warning")
  parser.add_option("-p", "--percentage",
                    dest = "percentage",
                    metavar = "DEFAULT_PERCENTAGE",
                    default = 80,
                    type = "int",
                    help = "Change the default warn percentage from 80%")
  (options, args) = parser.parse_args()
  
  options.overrides = {}
  overrideRE=re.compile("^(.*)=(\d\d?)$")
  for opt in args:
    m = overrideRE.match(opt)
    if m != False:
      options.overrides[m.group(1)] = int(m.group(2))
  
  if options.verbose:
    print "Options: " + str(options)

#####################################################################
#####################################################################
#####################################################################
if __name__ == '__main__':
  main()