MQTT to InfluxDB¶
For storing data from our sensors we like to use InfluxDB - time-series database.
As a bridge between MQTT and InfluxDB we created a mqtt2influxdb.
Service connects to InfluxDB and MQTT broker and by users config subscribe MQTT topics and store data from messages.
Installation¶
Step 1: Install the MQTT to InfluxDB service¶
sudo pip3 install --upgrade mqtt2influxdb
Step 2: Create the /etc/hardwario directory¶
sudo mkdir /etc/hardwario
Step 3: Open the configuration file¶
Tip
For text editing, we use nano editor. You can save changes by pressing key combination Ctrl + O and exit editor by pressing Ctrl + X.
sudo nano /etc/hardwario/mqtt2influxdb.yml
Step 4: Paste this snippet to the configuration file¶
1mqtt:
2 host: 127.0.0.1
3 port: 1883
4
5influxdb:
6 host: 127.0.0.1
7 port: 8086
8 database: node
9
10points:
11 - measurement: temperature
12 topic: node/+/thermometer/+/temperature
13 fields:
14
15 value: $.payload
16
17 tags:
18 id: $.topic[1]
19 channel: $.topic[3]
20
21 - measurement: relative-humidity
22 topic: node/+/hygrometer/0:4/relative-humidity
23 fields:
24
25 value: $.payload
26
27 tags:
28 id: $.topic[1]
29
30 - measurement: illuminance
31 topic: node/+/lux-meter/0:0/illuminance
32 fields:
33
34 value: $.payload
35
36 tags:
37 id: $.topic[1]
38
39 - measurement: pressure
40 topic: node/+/barometer/0:0/pressure
41 fields:
42
43 value: $.payload
44
45 tags:
46 id: $.topic[1]
47
48 - measurement: co2
49 topic: node/+/co2-meter/-/concentration
50 fields:
51
52 value: $.payload
53
54 tags:
55 id: $.topic[1]
56
57 - measurement: voltage
58 topic: node/+/battery/+/voltage
59 fields:
60
61 value: $.payload
62
63 tags:
64 id: $.topic[1]
65
66 - measurement: button
67 topic: node/+/push-button/+/event-count
68 fields:
69
70 value: $.payload
71
72 tags:
73 id: $.topic[1]
74 channel: $.topic[3]
Note
In the section tags you can use identifiers, e.g.: tags: room: bedroom
Step 5: Configuration file test¶
mqtt2influxdb -c /etc/hardwario/mqtt2influxdb.yml --test
Step 6: Start the MQTT to InfluxDB service¶
pm2 start `which python3` --name "mqtt2influxdb" -- `which mqtt2influxdb` -c /etc/hardwario/mqtt2influxdb.yml
Step 7: Save the PM2 state (so it will start after reboot)¶
pm2 save
Tip
If you want to see temperature records from the database in CSV format, use this command:
influx -database node -execute "select * from temperature;" -format csv
Then you must restart the service when you change the configuration file
pm2 restart mqtt2influxdb
Configuration file structure and possibilities¶
In Step 4 we paste the configuration file, here will be described possibilities in the configuration. In configuration you can use JSONPath. For example in measurement you can identify tag id from MQTT topic by syntax $.topic[1] as you can see in Step 4.
MQTT¶
MQTT part of the configuration file is where you define a connection to MQTT broker. mqtt2influxdb supports secured connection! This section is required.
1mqtt:
2 host: MQTT Broker adress (required)
3 port: MQTT Broker port (required)
4 username: Username to secured MQTT broker (optional)
5 password: Users password to secured MQTT broker (optional)
6 cafile: CA to secured MQTT broker (optional)
7 certfile: Certificate to secured MQTT broker (optional)
8 keyfile: Certificate Key file to secured MQTT broker (optional)
HTTP¶
You can define web hooks so data can be posted to your endpoint. This section is optional.
1http:
2 destination: Endpoint url (required)
3 action: Request type (required)
4 username: Username for secured request (optional)
5 password: Password for secured request (optional)
InfluxDB¶
An important part of the config is of course the definition of InfluxDB connection. This section is required.
1influxdb:
2 host: InfluxDB adress (required)
3 port: InfluxDB port (required)
4 database: Database name (required)
5 username: Username to InfluxDB (optional)
6 password: Users password to InfluxDB (optional)
7 ssl: SSL connection (optional)
Base64 Decode¶
Decode base64 messages. This section is optional.
1base64decode:
2 source: base64 coded message (required)
3 target: encoded message (required)
Points¶
Points section is where you define messages you want to store in database. This section is required.
1points:
2 measurement: Measurement name in database (required)
3 topic: Define MQTT topic where messages are posting to (required)
4 httpcontent: Define payload in http request if filled in HTTP chapter (optional)
5fields:
6 value: Value field in InfluxDB (required)
7 type: Variable type (required)
Tags¶
Tags are for identification measurement in database. This section is optional.
1tags:
2 id: ID field in InfluxDB (optional)
Database¶
For every measurement you can define specific database name. This field is optional.
database: Specific database to store measurement (optional)