mqtt_publisher

Publish a message to a MQTT broker server

Input parameters

parameter	required	type	default	choices	comment
broker_ip	YES	string			IP address of the MQTT broker server
port	NO	int	1883		Port of the broker. By default 1883. 8883 when TLS is activated.
topic	YES	string			Topic name where the message will be published
payload	YES	string			Message to publish on the topic
qos	NO	int	0	0 or 1 or 2	The quality of service level to use
retain	NO	Boolean	FALSE	True, False	if set to True, the message will be set as the “last known good”/retained message for the topic.
client_id	NO	string	kalliope		The MQTT client id to use. If not set, the name will be set to "kalliope"
keepalive	NO	int	60		The keepalive timeout value for the client
username	NO	string			username for authenticating the client
password	NO	string			password for authenticating the client
ca_cert	NO	string			Path to the remote server CA certificate used for securing the transport
certfile	NO	string			Path to the client certificate file used for authentication
keyfile	NO	string			Path to the client key file attached to the client certificate
protocol	NO	string	MQTTv311	MQTTv31 or MQTTv311	Can be either MQTTv31 or MQTTv311
tls_insecure	NO	string	FALSE		Set the verification of the server hostname in the server certificate

Returned values

No returned values

Synapses example

Publish a message to the topic "my/topic" with minimal configuration

- name: "mqtt-publisher-1"
  signals:
    - order: "this is my order"
  neurons:
    - mqtt_publisher:
        broker_ip: "127.0.0.1"
        topic: "my/topic"
        payload: "my message"

Publish a json formatted message. Note that anti-slashes must be escaped.

- name: "mqtt-publisher-2"
  signals:
    - order: "this is my order"
  neurons:
    - mqtt_publisher:
        broker_ip: "127.0.0.1"
        topic: "mytopic"
        payload: "{\"mykey\": \"myvalue\"}"

The broker require authentication

- name: "mqtt-publisher-3"
  signals:
    - order: "this is my order"
  neurons:
    - mqtt_publisher:
        broker_ip: "127.0.0.1"
        topic: "my/topic"
        payload: "my message"
        username: "guest"
        password: "guest"

The broker require a secure TLS connection

- name: "mqtt-publisher-4"
  signals:
    - order: "this is my order"
  neurons:
    - mqtt_publisher:
        broker_ip: "127.0.0.1"
        topic: "my/topic"
        payload: "my message"
        ca_cert: "/path/to/ca.cert"

The broker require a secure TLS connection and authentication based on client certificate

- name: "mqtt-publisher-5"
  signals:
    - order: "this is my order"
  neurons:
    - mqtt_publisher:
        broker_ip: "127.0.0.1"
        topic: "my/topic"
        payload: "my message"
        ca_cert: "/path/to/ca.cert"
        certfile: "path/to/client.crt"
        keyfile: "path/to/client.key"

The broker require a secure TLS connection, an authentication based on client certificate and the CA is a self signed certificate

- name: "mqtt-publisher-6"
  signals:
    - order: "this is my order"
  neurons:
    - mqtt_publisher:
        broker_ip: "127.0.0.1"
        topic: "my/topic"
        payload: "my message"
        ca_cert: "/path/to/ca.cert"
        certfile: "path/to/client.crt"
        keyfile: "path/to/client.key"
        tls_insecure: True

Test with CLI

The following part of the documentation can help you to configure your synapse with right options. From here we suppose that you have already a running broker server on your local machine. If it's not the case, please refer to the documentation of the signal mqtt_subscriber to install a testing broker server.

Install a CLI mqtt client

sudo apt-get install mosquitto-clients

Run a subscriber

mosquitto_sub -t 'this/is/a/topic'

Then use your neuron. E.g

- name: "test-mqtt-publisher"
  signals:
    - order: "this is my order"
  neurons:
    - mqtt_publisher:
        broker_ip: "127.0.0.1"
        topic: "this/is/a/topic"
        payload: "info"