1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
|
"""
Script reading from mqtt broker and writing to rrd database.
"""
#########################################################
# IMPORTS #
#########################################################
import os
import ssl
from configparser import ConfigParser
from time import time
import rrdtool
from paho.mqtt.client import Client as MQTTClient
#########################################################
# SETTINGS #
#########################################################
CONFIG_FILE = 'settings.cfg'
USER = os.getlogin()
RRD_DATABASE = f"/home/{USER}/w1_database.rrd"
#########################################################
# CODE #
#########################################################
SSL_SET = None
CERT_DIR = None
CA_CERT = None
CERT_FILE = None
KEY_FILE = None
ONE_WIRE_UPPER = None
ONE_WIRE_LOWER = None
HOSTNAME = None
PORT = None
KEEPALIVE = None
DATA_LENGTH_LIMIT = None
TOPIC = None
TIMEFORMAT = None
Y_LIMIT = None
X_LIMIT = None
INTERVAL = None
def get_settings(config_file):
"""
Get settings from configparser.
"""
cfg = ConfigParser(interpolation=None)
cfg.read(config_file)
global SSL_SET
global CERT_DIR
global CA_CERT
global CERT_FILE
global KEY_FILE
global ONE_WIRE_UPPER
global ONE_WIRE_LOWER
global HOSTNAME
global PORT
global KEEPALIVE
global DATA_LENGTH_LIMIT
global TOPIC
global TIMEFORMAT
global Y_LIMIT
global X_LIMIT
global INTERVAL
# SSL certificates:
SSL_SET = cfg.getboolean('Certificates', 'ssl')
CERT_DIR = cfg.get('Certificates', 'certificate_directory')
CA_CERT_PATH = os.path.join(
CERT_DIR,
cfg.get('Certificates', 'ca_crt')
)
CERT_FILE_PATH = os.path.join(
CERT_DIR,
cfg.get('Certificates', 'cert_file'),
)
KEY_FILE_PATH = os.path.join(
CERT_DIR,
cfg.get('Certificates', 'key_file')
)
CA_CERT = CA_CERT_PATH if CA_CERT_PATH else None
CERT_FILE = CERT_FILE_PATH if CERT_FILE_PATH else None
KEY_FILE = KEY_FILE_PATH if KEY_FILE_PATH else None
# One wire mapping:
ONE_WIRE_UPPER = cfg.get('Sensor_mapping', 'upper')
ONE_WIRE_LOWER = cfg.get('Sensor_mapping', 'lower')
# MQTT host:
HOSTNAME = cfg.get('Mqtt', 'hostname')
PORT = cfg.getint('Mqtt', 'port')
KEEPALIVE = cfg.getint('Mqtt', 'keepalive')
DATA_LENGTH_LIMIT = cfg.get('Main', 'data_length_limit')
TOPIC = cfg.get('Main', 'topic')
TIMEFORMAT = cfg.get('Main', 'timeformat')
# Plot settings:
Y_LIMIT = (
cfg.getint('Main', 'y_min'),
cfg.getint('Main', 'y_max')
)
X_LIMIT = cfg.getint('Main', 'x_limit')
INTERVAL = cfg.getint('Main', 'interval')
class MyMQTTClient(MQTTClient):
"""
MQTT client class on_message writing to rrd database.
"""
def __init__(self, *args, **kwargs):
super().__init__(*args, **kwargs)
self.data_limit = DATA_LENGTH_LIMIT
if SSL_SET:
self.tls_set(
ca_certs=CA_CERT,
certfile=CERT_FILE,
keyfile=KEY_FILE,
cert_reqs=ssl.CERT_REQUIRED,
)
self.connect(host=HOSTNAME, port=PORT, keepalive=KEEPALIVE)
self.bare_topic = TOPIC.strip("/#")
self.full_topic = f'{self.bare_topic}/{ONE_WIRE_UPPER}'
self.subscribe(self.full_topic)
self.on_message = self.onmessage
self.on_disconnect = self.ondisconnect
def ondisconnect(self, client):
print("Disconnected from MQTT")
client.loop_stop()
def on_connect(self, client, userdata, flags, rc):
print("Connected to MQTT, returncode: ", str(rc))
# Subscribing in on_connect() means that if we lose the connection and
# reconnect then subscriptions will be renewed.
client.subscribe("$SYS/#")
def onmessage(self, client, userdata, msg):
"""
On message update rrd database.
"""
temperature = msg.payload.decode("utf-8")
if msg.topic == self.full_topic:
now = time() # TODO: pass timestamp in the message body
rrdtool.update(RRD_DATABASE, '%s:%s' % (now, temperature))
def main():
"""Main loop"""
get_settings(CONFIG_FILE)
client = MyMQTTClient()
client.loop_forever()
if __name__ == '__main__':
main()
|
