Munin contributed plugins

#!/usr/bin/env python3

"""Munin plugin to monitor NGINX Unit applications.

=head1 NAME

unit - monitor NGINX Unit applications

=head1 APPLICABLE SYSTEMS

Systems with NGINX Unit running.

=head1 CONFIGURATION

No configuration is required for this plugin.

=head1 AUTHOR

Kim B. Heino <b@bbbs.net>

=head1 LICENSE

GPLv2

=head1 MAGIC MARKERS

 #%# family=auto

 #%# capabilities=autoconf

=cut

"""

import re

import subprocess

import sys

import unicodedata

def safename(name):

    """Return safe variable name."""

    # Convert ä->a as isalpha('ä') is true

    value = unicodedata.normalize('NFKD', name)

    value = value.encode('ASCII', 'ignore').decode('utf-8')

    # Remove non-alphanumeric chars

    return ''.join(char.lower() if char.isalnum() else '_' for char in value)

def run_binary(arg):

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

    try:

        return subprocess.run(arg, stdout=subprocess.PIPE, check=False,

                              encoding='utf-8', errors='ignore').stdout

    except FileNotFoundError:

        return ''

def parse_time(value):

    """Parse "dd-hh:mm:ss", "hh:mm:ss" and "mm:ss" to seconds."""

    days = hours = '0'

    if '-' in value:

        days, value = value.split('-', 1)

    if value.count(':') == 2:

        hours, value = value.split(':', 1)

    minutes, seconds = value.split(':')

    return (int(days) * 86400 + int(hours) * 3600 + int(minutes) * 60 +

            int(seconds))

def find_apps():

    """Return dict of found unit applications."""

    apps = {}

    ps_lines = run_binary(['ps', '-eo', '%cpu,etime,rss,command']).splitlines()

    for line in ps_lines:

        appmatch = re.match(r' *([.0-9]+) +([-:0-9]+) +([0-9]+) '

                            r'unit: "(.*)" application', line)

        if not appmatch:

            continue

        cpu = float(appmatch.group(1))

        age = parse_time(appmatch.group(2))

        memory = int(appmatch.group(3))  # KiB

        appname = appmatch.group(4)

        if appname in apps:

            apps[appname]['count'] += 1

            apps[appname]['cpu'] += cpu

            apps[appname]['age'] += age

            apps[appname]['memory'] += memory

        else:

            apps[appname] = {

                'count': 1,

                'cpu': cpu,

                'age': age,

                'memory': memory,

            }

    return apps

def config(apps):

    """Print plugin config."""

    print('multigraph unit_process')

    print('graph_title Unit application processes')

    print('graph_info NGINX Unit application process counts.')

    print('graph_category appserver')

    print('graph_vlabel processes')

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

    print('graph_scale no')

    for app in sorted(apps):

        safe = safename(app)

        print(f'{safe}.label {app} processes')

        print(f'{safe}.draw AREASTACK')

    print('multigraph unit_cpu')

    print('graph_title Unit application average CPU usage')

    print('graph_info NGINX Unit application average CPU usage per process.')

    print('graph_category appserver')

    print('graph_vlabel %')

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

    print('graph_scale no')

    for app in sorted(apps):

        safe = safename(app)

        print(f'{safe}.label {app} CPU')

    print('multigraph unit_age')

    print('graph_title Unit application average age')

    print('graph_info NGINX Unit application average age per process.')

    print('graph_category appserver')

    print('graph_vlabel seconds')

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

    print('graph_scale no')

    for app in sorted(apps):

        safe = safename(app)

        print(f'{safe}.label {app} age')

    print('multigraph unit_memory')

    print('graph_title Unit application average memory')

    print('graph_info NGINX Unit application average memory per process.')

    print('graph_category appserver')

    print('graph_vlabel MiB')

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

    print('graph_scale no')

    for app in sorted(apps):

        safe = safename(app)

        print(f'{safe}.label {app} memory')

    print('multigraph unit_total_memory')

    print('graph_title Unit application total memory')

    print('graph_info NGINX Unit application total memory.')

    print('graph_category appserver')

    print('graph_vlabel MiB')

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

    print('graph_scale no')

    for app in sorted(apps):

        safe = safename(app)

        print(f'{safe}.label {app} memory')

        print(f'{safe}.draw AREASTACK')

def fetch(apps):

    """Print values."""

    print('multigraph unit_process')

    for app, values in apps.items():

        safe = safename(app)

        print(f'{safe}.value {values["count"]}')

    print('multigraph unit_cpu')

    for app, values in apps.items():

        safe = safename(app)

        print(f'{safe}.value {values["cpu"] / values["count"]}')

    print('multigraph unit_age')

    for app, values in apps.items():

        safe = safename(app)

        print(f'{safe}.value {values["age"] / values["count"]}')

    print('multigraph unit_memory')

    for app, values in apps.items():

        safe = safename(app)

        print(f'{safe}.value {values["memory"] / values["count"] / 1024}')

    print('multigraph unit_total_memory')

    for app, values in apps.items():

        safe = safename(app)

        print(f'{safe}.value {values["memory"] / 1024}')

if __name__ == '__main__':

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

        print('yes' if find_apps() else 'no (NGINX Unit is not running)')

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

        config(find_apps())

    else:

        fetch(find_apps())