#!/usr/bin/env python3 """ =head1 NAME feinstaubsensor - Plugin to monitor one or more environmental sensors =head1 APPLICABLE SYSTEMS The "Feinstaubsensor" was developed by the OK Lab Stuttgart and is part of the Citizen Science Project "luftdaten.info" (http://luftdaten.info). Data is retrieved via HTTP requests from the sensors itself. =head1 CONFIGURATION Place a configuration entry somewhere below /etc/munin/plugin-conf.d/: [feinstaubsensor] env.sensor_hosts foo=192.168.1.4 [fe80::1:2:3:4%eth0] bar=sensor2.lan The environment variable is a space separated list of . Each can be either a or a combination of label and (separated by the character "="). A may be an IPv4 address, an IPv6 address (enclosed in square brackets) or a name to be resolved via DNS. Examples for : * 192.168.1.4 * foo=192.168.1.4 * [fe80::1a:2b:3c:cafe] * bar=[fe80::1a:2b:3c:cafe] * feinstaubsensor-12345.local * baz=feinstaubsensor-12345.local =head1 AUTHOR Lars Kruse =head1 LICENSE GPLv3 =head1 MAGIC MARKERS #%# family=manual """ import collections import functools import json import os import re import sys import urllib.request graphs = [ { "name": "wireless_signal", "graph_title": "Feinstaub Wifi Signal", "graph_vlabel": "%", "graph_args": "-l 0", "graph_info": "Wifi signal strength", "api_value_name": "signal", "value_type": "GAUGE", }, { "name": "feinstaub_samples", "graph_title": "Feinstaub Sample Count", "graph_vlabel": "#", "graph_info": "Number of samples since bootup", "api_value_name": "samples", "value_type": "DERIVE", }, { "name": "feinstaub_humidity", "graph_title": "Feinstaub Humidity", "graph_vlabel": "% humidity", "graph_info": "Weather information: air humidity", "api_value_name": "humidity", "value_type": "GAUGE", }, { "name": "feinstaub_temperature", "graph_title": "Feinstaub Temperature", "graph_vlabel": "°C", "graph_info": "Weather information: temperature", "api_value_name": "temperature", "value_type": "GAUGE", }, { "name": "feinstaub_particles_pm10", "graph_title": "Feinstaub Particle Measurement P10", "graph_vlabel": "µg / m³", "graph_info": "Concentration of particles with a size between 2.5µm and 10µm", "api_value_name": "SDS_P1", "value_type": "GAUGE", }, { "name": "feinstaub_particles_pm2_5", "graph_title": "Feinstaub Particle Measurement P2.5", "graph_vlabel": "µg / m³", "graph_info": "Concentration of particles with a size up to 2.5µm", "api_value_name": "SDS_P2", "value_type": "GAUGE", }] SensorHost = collections.namedtuple("SensorHost", ("host", "label", "fieldname")) def clean_fieldname(text): if text == "root": # "root" is a magic (forbidden) word return "_root" else: return re.sub(r"(^[^A-Za-z_]|[^A-Za-z0-9_])", "_", text) def parse_sensor_hosts_from_description(hosts_description): """ parse sensor list from the environment variable 'sensor_hosts' and retrieve their data """ sensors = [] for token in hosts_description.split(): if "=" in token: label, host = token.strip().split("=", 1) else: host = token.strip() label = host fieldname = clean_fieldname("value_" + host) sensors.append(SensorHost(host, label, fieldname)) sensors.sort(key=lambda item: item.fieldname) return sensors @functools.lru_cache() def get_sensor_data(host): """ request the data from a sensor and return a dict (value_type -> value) The result is cached - thus we do not need to take care for efficiency. Example dataset returned by the sensor: {"software_version": "NRZ-2017-099", "age":"88", "sensordatavalues":[ {"value_type":"SDS_P1","value":"27.37"},{"value_type":"SDS_P2","value":"13.53"}, {"value_type":"temperature","value":"23.70"},{"value_type":"humidity","value":"69.20"}, {"value_type":"samples","value":"626964"},{"value_type":"min_micro","value":"225"}, {"value_type":"max_micro","value":"887641"},{"value_type":"signal","value":"-47"}]} """ try: with urllib.request.urlopen("http://{}/data.json".format(host)) as request: body = request.read() except IOError as exc: print("Failed to retrieve data from '{}': {}".format(host, exc), file=sys.stderr) return None try: data = json.loads(body.decode("utf-8")) except ValueError as exc: print("Failed to parse data from '{}': {}".format(host, exc), file=sys.stderr) return None return {item["value_type"]: item["value"] for item in data["sensordatavalues"]} def print_graph_section(graph_description, hosts, include_config, include_values): print("multigraph {}".format(graph_description["name"])) if include_config: # graph configuration print("graph_category sensors") for key in ("graph_title", "graph_vlabel", "graph_args", "graph_info"): if key in graph_description: print("{} {}".format(key, graph_description[key])) for host_info in hosts: print("{}.label {}".format(host_info.fieldname, host_info.label)) print("{}.type {}".format(host_info.fieldname, graph_description["value_type"])) if include_values: for host_info in hosts: # We cannot distinguish between fields that are not supported by the sensor (most are # optional) and missing data. Thus we cannot handle online/offline sensor data fields, # too. data = get_sensor_data(host_info.host) if data is not None: value = data.get(graph_description["api_value_name"]) if value is not None: print("{}.value {}".format(host_info.fieldname, value)) print() action = sys.argv[1] if (len(sys.argv) > 1) else "" sensor_hosts = parse_sensor_hosts_from_description(os.getenv("sensor_hosts", "")) if not sensor_hosts: print("ERROR: undefined or empty environment variable 'sensor_hosts'.", file=sys.stderr) sys.exit(1) if action == "config": is_dirty_config = (os.getenv("MUNIN_CAP_DIRTYCONFIG") == "1") for graph in graphs: print_graph_section(graph, sensor_hosts, True, is_dirty_config) elif action == "": for graph in graphs: print_graph_section(graph, sensor_hosts, False, True) else: print("ERROR: unsupported action requested ('{}')".format(action), file=sys.stderr) sys.exit(2)