Munin contributed plugins

#!/usr/bin/env python3

import re

import subprocess

import sys

import textwrap

'''

=head1 NAME

timesync_status - monitor ntp status with systemd-timesyncd

=head1 APPLICABLE SYSTEMS

All systems using systemd-timesyncd as its NTP-client. However, this

plugin itself also needs Python 3.5+ to call subprocess.run.

=head1 CONFIGURATION

This plugin should work out-of-the-box with autoconf. It does expect

timedatectl to be on $PATH, but that should always be the case in a

normal system.

=head1 INTERPRETATION

This plugin shows a graph with one line for every NTP metric it measure.

Metrics are shown with their usual name, and are explained in their

respective info fields.

This plugin issues no warnings or critical states.

=head1 MAGIC MARKERS

 #%# family=auto

 #%# capabilities=autoconf

=head1 VERSION

1.0

=head1 AUTHOR

Bert Peters <bert@bertptrs.nl>

=head1 LICENSE

GPLv2

'''

def parse_time(value):

    value = value.strip()

    if ' ' in value:

        return sum(parse_time(x) for x in value.split(' '))

    match = re.match(r'^([+-]?[0-9.]+)([a-z]+)$', value)

    if not match:

        raise ValueError('Invalid time ' + value)

    value = float(match.group(1))

    suffix = match.group(2)

    if suffix == 'min':

        value *= 60

    elif suffix == 'ms':

        value /= 1000

    elif suffix == 'us':

        value /= 1e6

    return value

def parse_response(data):

    values = {}

    for line in data.splitlines():

        k, v = line.split(': ', 1)

        values[k.strip()] = v.strip()

    return values

def retrieve():

    result = subprocess.run(['timedatectl', 'timesync-status'], capture_output=True)

    if result.returncode != 0:

        sys.exit('timedatectl failed')

    output = result.stdout.decode('utf-8')

    values = parse_response(output)

    print('offset.value', parse_time(values['Offset']))

    print('delay.value', parse_time(values['Delay']))

    print('delay.extinfo', 'Server', values['Server'])

    print('jitter.value', parse_time(values['Jitter']))

    print('poll.value', parse_time(values['Poll interval'].split('(')[0]))

def autoconf():

    result = subprocess.run(['timedatectl', 'status'], capture_output=True)

    if result.returncode != 0:

        print('no (failed to run timedatectl)')

        return

    values = parse_response(result.stdout.decode('utf-8'))

    if values['NTP service'] == 'active':

        print('yes')

    else:

        print('no (ntp service not running)')

def config():

    print(textwrap.dedent('''\

            graph_title Timesync status

            graph_vlabel s

            graph_category time

            offset.label Offset

            offset.info Time difference between source and local

            delay.label Delay

            delay.info Roundtrip time to the NTP-server

            jitter.label Jitter

            jitter.info Difference in offset between two subsequent samples

            poll.label Polling time

            poll.info Time between two subsequent NTP-polls

    '''))

if __name__ == '__main__':

    if len(sys.argv) == 1:

        retrieve()

    elif sys.argv[1] == 'config':

        config()

    elif sys.argv[1] == 'autoconf':

        autoconf()