#!/usr/bin/env python
#
# Authors:
# rafael@postgresql.org.es / http://www.postgresql.org.es/
#
# Copyright (c) 2015 USIT-University of Oslo
#
# zabbix_filesystem_not_monitored.py: Used by zabbix_agent to find out if
# a filesystem does not have to be monitored.
#
# zabbix_filesystem_not_monitored.py 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, either version
# 3 of the License, or (at your option) any later version.
#
# zabbix_filesystem_not_monitored.py 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 sms_send.  If not, see <http://www.gnu.org/licenses/>.
#

import os
import sys
import glob

# ###################################################################
# Method: get_filesystem_not_monitored_status()
# Parameters: filesystem
#
# Used to read the file /etc/zabbix_filesystems_not_monitored.conf if it
# exists.
#
# It will return 0 if filesystem is not defined in this file or if the
# file does not exist, 1 otherwise.
#
# The format used to define a filesystem that will not be monitored is a
# filesystem definition per line:
#
# <filesystem>
#
# Filesystems can match a specified pattern according to the rules
# used by the Unix shell. No tilde expansion is done, but *, ?, and
# character ranges expressed with [] will be correctly matched. For a
# literal match, wrap the meta-characters in brackets. For example,
# '[?]' matches the character '?'.
#
# Only mounted filesystem will be considered when reading filesystems
# limits definitions in /etc/zabbix_filesystems_not_monitored.conf.
#
# ###################################################################


def get_filesystem_not_monitored_status(filesystem):

    defined_filesystems = []
    config_file = '/etc/zabbix_filesystems_not_monitored.conf'

    try:

        if os.path.isfile(config_file):
            fd = open(config_file, "r")

            for line in fd:
                line = line.replace('\n', '').strip()

                #
                # Lines starting with # or empty lines are ignored.
                #

                if line.find('#', 0) == -1 and line.strip() != '':

                    defined_fs = line

                    # Normalized absolutized version of the pathname
                    # if filesystem does not include an absolute path

                    if not os.path.isabs(defined_fs):
                        defined_fs = os.path.abspath(defined_fs)

                    #
                    # Finds all the pathnames matching a specified
                    # pattern according to the rules used by the Unix
                    # shell. No tilde expansion is done, but *, ?, and
                    # character ranges expressed with [] will be
                    # correctly matched. For a literal match, wrap the
                    # meta-characters in brackets. For example, '[?]'
                    # matches the character '?'.
                    #

                    expanded_paths = glob.glob(defined_fs)

                    #
                    # Only mounted filesystem will be considered when
                    # reading filesystems  definitions in
                    # /etc/zabbix_filesystems_not_monitored.conf.
                    #

                    for expanded_fs in expanded_paths:
                        if os.path.ismount(expanded_fs):
                            defined_filesystems.append(expanded_fs)

            #
            # Find out if the filesystem we are asking for exists in
            # /etc/zabbix_filesystems_not_monitored.conf. If it does
            # not exists, return 0
            #

            if filesystem in defined_filesystems:
                print ("1")
            else:
                print ("0")

        else:
            #
            # Return 0 if the file /etc/filesystems_not_monitored.conf
            # does not exist.
            #

            print ("0")

    except Exception as exp:
        raise exp


# ############################################
# Main
# ############################################

if __name__ == '__main__':

    try:

        if len(sys.argv) == 2:
            fs = sys.argv[1]

            get_filesystem_not_monitored_status(fs)

        else:
            print ("Error: Wrong number of parameters")
            print ('Format: ' + sys.argv[0] + ' <filesystem>')
            sys.exit(1)

    except Exception as e:
        print (e)
        sys.exit(1)