#!/usr/bin/env python3

"""Munin plugin to monitor Hetzner Storagebox disk free.

=head1 NAME

storagebox_df - monitor Hetzner Storagebox disk free

=head1 APPLICABLE SYSTEMS

Systems with access to Hetzner Storagebox.

=head1 CONFIGURATION

Command to ssh+df must be specified. Plugin does not have access to munin's
home directory so ssh-key have to copied and specified.

    [storagebox_df]
    user root
    env.command ssh -i /etc/munin/id_ed25519 \
      -o UserKnownHostsFile=/etc/munin/known_hosts -p 23 \
      uXXXXXX@uXXXXXX.your-storagebox.de df

=head1 AUTHOR

Kim B. Heino <b@bbbs.net>

=head1 LICENSE

GPLv2

=cut
"""

import os
import subprocess
import sys


def run_binary(arg):
    """Run binary and return output."""
    try:
        return subprocess.run(arg, check=False, stdout=subprocess.PIPE,
                              stderr=subprocess.PIPE, encoding='utf-8').stdout
    except FileNotFoundError:
        return ''


def warning_critical(graph, name, warning=None, critical=None):
    """Print warning/critical config entries."""
    warning = os.environ.get(f'{graph}{name}_warning', warning)
    critical = os.environ.get(f'{graph}{name}_critical', critical)
    if warning and warning != ':':
        print(f'{name}.warning {warning}')
    if critical and critical != ':':
        print(f'{name}.critical {critical}')


def get_df():
    """Get and parse df status."""
    command = os.environ.get('command', '').split()
    if not command:
        return None
    for line in run_binary(command).splitlines():
        if '%' not in line or '/' not in line:
            continue
        items = line.split()
        return items[0], items[4][:-1]
    return None


def config(data):
    """Print plugin config."""
    print('graph_title Storagebox usage in percent')
    print('graph_info Storagebox device usage in percent.')
    print('graph_category disk')
    print('graph_vlabel %')
    print('graph_args --lower-limit 0 --upper-limit 100')
    print('graph_scale no')
    print(f'df.label {data[0] if data else "Unknown"}')
    warning_critical('', 'df', 92, 98)

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


def fetch(data):
    """Print values."""
    if data:
        print(f'df.value {data[1]}')


if __name__ == '__main__':
    if len(sys.argv) > 1 and sys.argv[1] == 'autoconf':
        print('no (not an autoconf plugin)')
    elif len(sys.argv) > 1 and sys.argv[1] == 'config':
        config(get_df())
    else:
        fetch(get_df())