This is an OctoPrint Plugin that adds support for MQTT to OctoPrint.

Out of the box OctoPrint will send all events including their payloads to the topic octoPrint/event/<event>, where <event> will be the name of the event. The message payload will be a JSON representation of the event's payload, with an additional property _event containing the name of the event and a property _timestamp containing the unix timestamp of when the message was created.

Examples:

The print progress and the slicing progress will also be send to the topic octoPrint/progress/printing and octoPrint/progress/slicing respectively. The payload will contain the progress as an integer between 0 and 100. Print progress will also contain information about the currently printed file (storage location and path on storage), slicing progress will contain information about the currently sliced file (storage source_location and destination_location, source_path and destination_path on storage, used slicer). The payload will also contain a property _timestamp containing the unix timestamp of when the message was created. The published progress messages will be marked as retained.

Examples:

The plugin also publishes the temperatures of the tools and the bed to octoPrint/temperature/<tool> where <tool> will either be 'bed' or 'toolX' (X is the number of the tool). The payload will contain the actual and the target temperature as floating point value plus the current time as unix timestamp in seconds. New messages will not be published constantly, but only when a value changes. The payload will also contain a property _timestamp containing the unix timestamp of when the message was created. The published messages will be marked as retained.

Examples:

You can also define keys from the print file's additional metadata to publish on print start. This is especially useful together with plugins like OctoPrint-SlicerSettingsParser. You can enter a comma separted list of keys in the plugin settings. The plugin will then publish the values of these keys to the topic octoprint/metadata/<key>. Collections (dictionaries, lists) will be json encoded. To get specific values from a dictionary, you can use a dot notation (e.g. dict.key.subkey).

Examples:

Additionally the plugin will publish connected to octoPrint/mqtt on connection and instruct the MQTT broker to publish disconnected there if the connection gets closed. The published messages will be marked as retained.

Examples:

You are able to deactivate topics and the status/last will in the settings. This allows you to e.g. only send temperature messages when you don't need event or progress messages.

If the Printer Data option is set, then extended printer information as outlined in the Common data model will be included in a printer_data attribute. Useful to get information such as print time remaining.

Example:

The plugin also offers several helpers that allow other plugins to both publish as well as subscribe to MQTT topics, see below for details and a usage example.

Install via the bundled Plugin Manager using this URL:

https://github.com/OctoPrint/OctoPrint-MQTT/archive/master.zip

The plugin offers a settings dialog that allows you to configure all relevant settings. If you want to configure things manually by editing config.yaml, this is the structure you'd find therein:

plugins:
    mqtt:
        broker:
            # the broker's url, mandatory, if not configured the plugin will do nothing
            url: 127.0.0.1

            # the broker's port
            #port: 1883

            # the username to use to connect with the broker, if not set no user
            # credentials will be sent
            #username: unset

            # the password to use to connect with the broker, only used if a
            # username is supplied too
            #password: unset

            # the keepalive value for the broker connection
            #keepalive: 60

            # tls settings
            #tls:
                # path to the server's certificate file
                #ca_certs: unset

                # paths to the PEM encoded client certificate and private keys
                # respectively, must not be password protected, only necessary
                # if broker requires client certificate authentication
                #certfile: unset
                #keyfile: unset

                # a string specifying which encryption ciphers are allowable for this connection
                #ciphers: unset

            # configure verification of the server hostname in the server certificate.
            #tls_insecure: false

            # configure protocol version to use, valid values: MQTTv31 and MQTTv311
            #protocol: MQTTv31

            # should mqtt connection status / last will be retained?
            #lwRetain: true

        publish:
            # base topic under which to publish OctoPrint's messages
            #baseTopic: octoPrint/

            # include extended printer data in a printer_data attribute, this will
            # greatly increase the size of each message
            # printerData: false

            # topic for events, appended to the base topic, '{event}' will
            # be substituted with the event name
            #eventTopic: event/{event}

            # should events be published?
            #eventActive: true

            # topic for print and slicer progress, appended to the base topic,
            # '{progress}' will be substituted with either 'printing' or 'slicing'
            #progressTopic: progress/{progress}

            # should progress be published?
            #progressActive: true

            # topic for temperatures, appended to the base topic,
            # '{temp}' will be substituted with either 'toolX' (X is the number of the tool) or 'bed'
            #temperatureTopic: temperature/{temp}

            # should temperatures be published?
            #temperatureActive: true

            # topic for additional metadata, appended to the base topic,
            # '{key}' will be substituted with the key from the additional metadata
            #metadataTopic: metadata/{key}

            # should additional metadata be published?
            #metadataActive: false

            # keys from the additional metadata to publish, comma separated string
            #metadataKeys: "slicer_settings.material_type"

            # should mqtt connection status / last will be published?
            #lwActive: true

            # topic for connection status / last will
            #lwTopic: mqtt

Publishes payload to topic. If retained is set to True, message will be flagged to be retained by the broker. The QOS setting can be overridden with the qos parameter.

payload may be a string in which case it will be sent as is. Otherwise a value conversion to JSON will be performed, unless you set raw_data to True.

If the MQTT plugin is currently not connected to the broker but allow_queueing is True, the message will be stored internally and published upon connection to the broker.

Returns True if the message was accepted to be published by the MQTT plugin, False if the message could not be accepted (e.g. due to the plugin being not connected to the broker and queueing not being allowed).

Publishes payload to topic including a timestamp. payload must be a Python dict and will be extended by a property _timestamp set to the provided timestamp or - if unset - the current timestamp.

If the publish.printerData option is set, then all of the data from self._printer.get_current_data() will be included as a printer_data attribute in the payload. Useful to get things such as time remaining.

Everything else behaves as mqtt_publish (which is also used internally).

Subscribes callback for messages published on topic. The MQTT plugin will call the callback for received messages like this:

callback(topic, payload, args..., retained=..., qos=..., kwargs...)

topic will be the exact topic the message was received for, payload the message's payload, retained whether the message was retained by the broker and qos the message's QOS setting.

The callback should therefore at least accept topic and payload of the message as positional arguments and retain and qos as keyword arguments. If additional positional arguments or keyword arguments where provided during subscription, they will be provided as outlined above.

Unsubscribes the callback. If not topic is provided all subscriptions for the callback will be removed, otherwise only those matching the topic exactly.

The following single file plugin demonstrates how to use the provided helpers. Place it as mqtt_test.py into your ~/.octoprint/plugins (or equivalent) folder.

import octoprint.plugin

class MqttTestPlugin(octoprint.plugin.StartupPlugin):

	def __init__(self):
		self.mqtt_publish = lambda *args, **kwargs: None
		self.mqtt_subscribe = lambda *args, **kwargs: None
		self.mqtt_unsubscribe = lambda *args, **kwargs: None

	def on_after_startup(self):
		helpers = self._plugin_manager.get_helpers("mqtt", "mqtt_publish", "mqtt_subscribe", "mqtt_unsubscribe")
		if helpers:
			if "mqtt_publish" in helpers:
				self.mqtt_publish = helpers["mqtt_publish"]
			if "mqtt_subscribe" in helpers:
				self.mqtt_subscribe = helpers["mqtt_subscribe"]
			if "mqtt_unsubscribe" in helpers:
				self.mqtt_unsubscribe = helpers["mqtt_unsubscribe"]

		self.mqtt_publish("octoPrint/plugin/mqtt_test/pub", "test plugin startup")
		self.mqtt_subscribe("octoPrint/plugin/mqtt_test/sub", self._on_mqtt_subscription)

	def _on_mqtt_subscription(self, topic, message, retained=None, qos=None, *args, **kwargs):
		self._logger.info("Yay, received a message for {topic}: {message}".format(**locals()))
		self.mqtt_publish("octoPrint/plugin/mqtt_test/pub", "echo: " + message)


__plugin_implementations__ = [MqttTestPlugin()]

OctoPrint-MQTT is licensed under the terms of the APGLv3 (also included).

OctoPrint-MQTT uses the Eclipse Paho Python Client under the hood, which is dual-licensed and used here under the terms of the EDL v1.0 (BSD).