MQTT Translator

MQTT topic translator which can act as a MQTT bridge.

Launch

Download all files and execute:

python -m mqtt_translator -c /config/configuration.yaml

or use the docker image: https://hub.docker.com/r/mrtncls/mqtt-translator

Configuration

Available translator modules:

Topic

Replaces a part (from) of the MQTT topic with another part (to).

Example config:

topic:
  - from: lookup
    to: replace
  - from: lookup2
    to: replace2

Payload

Replaces a part (from) of a stringtype payload with another part (to).

Example config:

payload:
  - from: old_value
    to: new_value
  - from: old_value2
    to: new_value2

Regular expression

Matches MQTT message by topic_search and payload_search expressions (https://docs.python.org/3/library/re.html). Renders topic_template and payload_template by using the found regexp groups.

With [topic.1] and [topic.99] in your template, the first and 99th group from the topic_search expression will be substituted. This works the same for payload with [payload.x].

A template will substitute only the found part. So, remaining pre- and/or suffixes will stay.

In case no search was done (topic_search or payload_search missing) but a template is supplied, it will replace the whole topic or payload.

Example config:

regexp:
  - topic_search: temp/(auto)
    payload_search: (heat) (\d+)
    topic_template: temp/[payload.1]
    payload_template: [payload.2] - [topic.1]
  - ...

Example with result:

regexp:
  - payload_search: (\w+)|(\d+)|(\w+)
    topic_template: house/[payload.1]/temperature
    payload_template: [payload.2] [payload.3]
  - ...

	Topic	Payload
Original	house/87946548/auto	bedroom,24,auto
Translated	house/bedroom/temperature	24 auto

Set retain

Set retain flag of a message. Messages are matching on topic by using a RE fullmatch expression (see https://docs.python.org/3/library/re.html#re.fullmatch)

Example config:

set_retain:
  - topic_fullsearch: .*temp
    retain: True
  - ...

Examples

Bridging with space replacement

source:
  id: MQTT-Translator-Source
  host: source_mqttbroker
  port: 1883
  keepalive_interval: 60
  topics:
    - world/#
  publish:
    cooldown: 2
    convert:
      - topic:
        - from: '_' 
          to: ' '
target:
  id: MQTT-Translator-Target
  host: target_mqttbroker
  port: 1883
  keepalive_interval: 60
  topics:
    - world/#
  publish:
    cooldown: 2
    convert:
      - topic:
        - from: ' ' 
          to: '_'

Topic replace

source:
  id: MQTT-Translator-Source
  host: mqttbroker
  port: 1883
  keepalive_interval: 60
  topics:
    - 1235332/#
  publish:
    cooldown: 2
    convert:
      - topic:
        - from: '1235332' 
          to: 'temp_sensor'
target:
  id: MQTT-Translator-Target
  host: mqttbroker
  port: 1883
  keepalive_interval: 60
  topics:
  publish:
    cooldown: 2
    convert:
      - topic:
        - from: '1235332' 
          to: 'temp_sensor'