Munin contributed plugins

#!/usr/bin/python3 -tt

# -*- coding: utf-8 -*-

"""Munin plugin to monitor stratis pools and filesystems.

Copyright 2020 Kim B. Heino, Foobar Oy

License GPLv2+

#%# capabilities=autoconf

#%# family=auto

"""

import os

import subprocess

import sys

def safename(variable):

    """Return safe variable name."""

    ret = []

    for letter in variable:

        if letter.isalnum():

            ret.append(letter)

        else:

            ret.append('_')

    return ''.join(ret)

def run_binary(arg):

    """Run binary and return output."""

    try:

        cmd = subprocess.Popen(

            arg, shell=False, close_fds=True, bufsize=-1,

            stdout=subprocess.PIPE, stderr=subprocess.PIPE)

        return cmd.communicate()[0].decode('utf-8', 'ignore')

    except OSError:

        return ''

def parse_unit(number, unit):

    """Parse "1.60 TiB" to bytes."""

    number = float(number)

    if unit == 'TiB':

        return number * 1024 * 1024 * 1024 * 1024

    if unit == 'GiB':

        return number * 1024 * 1024 * 1024

    if unit == 'MiB':

        return number * 1024 * 1024

    if unit == 'KiB':

        return number * 1024

    return number

def find_pools():

    """Return list of found pools and filesystems."""

    pool = []

    for line in run_binary(['/usr/bin/stratis', 'pool']).splitlines():

        if line.startswith('Name  '):

            continue

        line = line.split()

        total = parse_unit(line[1], line[2])

        used = parse_unit(line[4], line[5])

        free = parse_unit(line[7], line[8])

        pool.append((line[0], total, used, free))

    files = []

    dflist = run_binary(['/usr/bin/df']).splitlines()

    for line in run_binary(['/usr/bin/stratis', 'filesystem']).splitlines():

        if line.startswith('Pool Name ') or '-snap-' in line:

            continue

        line = line.split()

        df_used = used = parse_unit(line[2], line[3])

        for dfline in dflist:

            if line[9] not in dfline:  # match by uuid

                continue

            df_used = int(dfline.split()[2]) * 1024

        files.append((line[0], line[1], used, df_used))

    return sorted(pool), sorted(files)

def config(pools, files):

    """Print plugin config."""

    print('multigraph stratis_pool')

    print('graph_title Stratis pools usage')

    print('graph_info Stratis pools usage in percent.')

    print('graph_category disk')

    print('graph_vlabel %')

    print('graph_args --lower-limit 0 --upper-limit 100')

    print('graph_scale no')

    for item in pools:

        name = safename(item[0])

        print('{}.label Pool {} usage'.format(name, item[0]))

        print('{}.warning 92'.format(name))

        print('{}.critical 98'.format(name))

    print('multigraph stratis_fs')

    print('graph_title Stratis filesystems usage')

    print('graph_info Stratis filesystems pool usage.')

    print('graph_category disk')

    print('graph_vlabel Pool usage')

    print('graph_args --base 1024 --lower-limit 0')

    first = True

    for item in files:

        name = safename(item[0] + '_' + item[1])

        print('{}.label Filesystem {}/{}'.format(name, item[0], item[1]))

        if first:

            print('{}.draw AREA'.format(name))

            first = False

        else:

            print('{}.draw STACK'.format(name))

    print('multigraph stratis_thin')

    print('graph_title Stratis thin filesystems usage vs df')

    print('graph_info Stratis thin filesystems usage divided by df, in '

          'percents.')

    print('graph_category disk')

    print('graph_vlabel %')

    print('graph_args --base 1000')

    for item in files:

        name = safename(item[0] + '_' + item[1])

        print('{}.label {}/{} usage vs df'.format(name, item[0], item[1]))

        print('{}.warning 150'.format(name))

    if os.environ.get('MUNIN_CAP_DIRTYCONFIG') == '1':

        fetch(pools, files)

def fetch(pools, files):

    """Print values."""

    print('multigraph stratis_pool')

    for item in pools:

        name = safename(item[0])

        print('{}.value {}'.format(name, item[2] * 100 / item[1]))

    print('multigraph stratis_fs')

    for item in files:

        name = safename(item[0] + '_' + item[1])

        print('{}.value {}'.format(name, item[2]))

    print('multigraph stratis_thin')

    for item in files:

        name = safename(item[0] + '_' + item[1])

        print('{}.value {}'.format(name, item[2] * 100 / item[3]))

if __name__ == '__main__':

    if len(sys.argv) > 1 and sys.argv[1] == 'autoconf':

        print('yes' if find_pools()[0] else 'no')

    elif len(sys.argv) > 1 and sys.argv[1] == 'config':

        config(*find_pools())

    else:

        fetch(*find_pools())