Munin contributed plugins

#!/usr/bin/env python3

"""

=pod

=head1 NAME

btrfs_device_usage - Script to monitor usage of btrfs devices

=head1 CONFIGURATION

Simply create a symlink in your plugins directory like with any other plugin.

Must be run as root.

[btrfs_device_usage]

user root

You can optionaly configure the warning and critical limits for byte and

percentage graphs. By default percent_warning is set to 95 and percent_critical

is 98. For the byte-graphs there are no default limits set. You can set the

limits either for the entire graph (byte_ percent_) or per individual filesystem

using it's UUID (replace minus with underscore). The individual values take

precedence over the general ones. See the following example:

btrfs_device_usage]

user root

env.byte_warning 400300200100

env.percent_critical 97

env.percent_10164f3f_6670_4982_a941_bffb50d27f29_warning 23

env.byte_10164f3f_6670_4982_a941_bffb50d27f29_critical 5000000000

=head2 DEFAULT CONFIGURATION

=head1 BUGS

=head1 AUTHOR

2019-2021, HaseHarald

=head1 MAGIC MARKERS

 #%# family=auto

 #%# capabilities=autoconf

=head1 LICENSE

LGPLv3

=cut

"""

# This file contains a munin-plugin to gather btrfs statistics per device.

#

# This is free software: you can redistribute it and/or modify

# it under the terms of the GNU Lesser General Public License as published by

# the Free Software Foundation, either version 3 of the License, or

# (at your option) any later version.

#

# This 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 Lesser General Public License for more details.

#

# You should have received a copy of the GNU Lesser General Public License

# along with this plugin.  If not, see <http://www.gnu.org/licenses/>.

import btrfs

import os

import sys

def munin_config(fs):

    fsid = str(fs.fsid).replace('-', '_')

    byte_warning = os.getenv('byte_warning', default=False)

    byte_critical = os.getenv('byte_critical', default=False)

    byte_warning = os.getenv('byte_' + fsid + '_warning',

                             default=byte_warning)

    byte_critical = os.getenv('byte_' + fsid + '_critical',

                              default=byte_critical)

    percent_warning = os.getenv('percent_warning', default=95)

    percent_critical = os.getenv('percent_critical', default=98)

    percent_warning = os.getenv('percent_' + fsid + '_warning',

                                default=percent_warning)

    percent_critical = os.getenv('percent_' + fsid + '_critical',

                                 default=percent_critical)

    print("multigraph btrfs_device_usage_byte_" + fsid)

    print("graph_title btrfs usage by device in bytes on " + fs.path)

    print("graph_args --base 1024 -l 0")

    print("graph_scale yes")

    print("graph_vlabel bytes")

    print("graph_category disk")

    print("graph_info This graph shows bytes used by btrfs on every device")

    devices = fs.devices()

    for this_device in devices:

        this_dev_info = fs.dev_info(this_device.devid)

        this_dev_name = this_dev_info.path.replace('/dev/', '')

        print("btrfs_bytes_" + fsid + "_" + str(this_device.devid) +

              ".label " + this_dev_name)

        if byte_warning:

            print("btrfs_bytes_" + fsid + "_" + str(this_device.devid) +

                  ".warning " + str(byte_warning))

        if byte_critical:

            print("btrfs_bytes_" + fsid + "_" + str(this_device.devid) +

                  ".critical " + str(byte_critical))

    print("")

    print("multigraph btrfs_device_usage_percent_" + fsid)

    print("graph_title btrfs usage by device in percent on " + fs.path)

    print("graph_args --base 1000 -l 0")

    print("graph_scale no")

    print("graph_vlabel %")

    print("graph_category disk")

    print("graph_info This graph shows percentage used by btrfs on every \

          device. Maesured in percentage of device capacity.")

    devices = fs.devices()

    for this_device in devices:

        this_dev_info = fs.dev_info(this_device.devid)

        this_dev_name = this_dev_info.path.replace('/dev/', '')

        print("btrfs_percent_" + fsid + "_" + str(this_device.devid) +

              ".label " + this_dev_name)

        print("btrfs_percent_" + fsid + "_" + str(this_device.devid) +

              ".warning " + str(percent_warning))

        print("btrfs_percent_" + fsid + "_" + str(this_device.devid) +

              ".critical " + str(percent_critical))

    print("")

def munin_values(fs):

    fsid = str(fs.fsid).replace('-', '_')

    devices = fs.devices()

    print("multigraph btrfs_device_usage_byte_" + fsid)

    for this_device in devices:

        this_dev_info = fs.dev_info(this_device.devid)

        print("btrfs_bytes_" + fsid + "_" + str(this_device.devid) +

              ".value " + str(this_dev_info.bytes_used))

    print("")

    # Reset device iterator

    devices = fs.devices()

    print("multigraph btrfs_device_usage_percent_" + fsid)

    for this_device in devices:

        this_dev_info = fs.dev_info(this_device.devid)

        if this_dev_info.total_bytes > 0:

            usage = 100.0 * this_dev_info.bytes_used / this_dev_info.total_bytes

            print("btrfs_percent_" + fsid + "_" + str(this_device.devid) +

                  ".value " + str(round(usage, 2)))

        else:

            print("btrfs_percent_" + fsid + "_" + str(this_device.devid) +

                  ".value U")

    print("")

def main():

    for path in btrfs.utils.mounted_filesystem_paths():

        with btrfs.FileSystem(path) as fs:

            if len(sys.argv) > 1 and sys.argv[1] == "config":

                munin_config(fs)

            else:

                munin_values(fs)

if __name__ == "__main__":

    main()

exit(0)