astarte_flow
astarte_flow v0.1.0

mqtt_sink

  • type: consumer
  • input: binary messages

This is a consumer block that takes data from an incoming message and publishes it using an MQTT connection.

This block supports only incoming messages with type binary, so serialization of different message types must be handled in a preceding block.

This block has been implemented using the Elixir tortoise MQTT client application.

Properties

  • broker_url: The URL of the broker the source will connect to. (required, string)
  • client_id: The client id used to connect. Defaults to a random string. (optional, string)
  • ignore_ssl_errors: If true, accept invalid certificates (e.g. self-signed) when using SSL. (optional, boolean, default: false)
  • username: Username used to authenticate to the broker. (optional, string)
  • password: Password used to authenticate to the broker. (optional, string)
  • ca_cert_pem: PEM encoded CA certificate. (optional, string)
  • client_cert_pem: PEM encoded client certificate, used for mutual SSL authentication. (optional, string)
  • private_key_pem: PEM encoded private key, used for mutual SSL authentication. (optional, string)
  • qos: The QoS used when publishing (optional, integer, default: 0)

broker_url

 broker_url

The URL of the broker the source will connect to. The transport will be deduced by the URL: if mqtts:// is used, SSL transport will be used, if mqtt:// is used, TCP transport will be used.

client_id

 client_id

The client id used to connect. Defaults to a random string.

ignore_ssl_errors

 ignore_ssl_errors

If true, accept invalid certificates (e.g. self-signed) when using SSL.

username

 username

Username used to authenticate to the broker.

password

 password

Password used to authenticate to the broker.

ca_cert_pem

 ca_cert_pem

A PEM encoded CA certificate. If not provided, the default CA trust store provided by :certifi will be used.

client_cert_pem

 client_cert_pem

A PEM encoded client certificate, used for mutual SSL authentication. If this is provided, also private_key_pem must be provided.

private_key_pem

 private_key_pem

A PEM encoded private key, used for mutual SSL authentication. If this is provided, also client_cert_pem must be provided.

qos

 qos

The MQTT QoS used when publishing. Defaults to 0, possible valid values are 0, 1 or 2.

Accepted input message

This block supports only messages with a binary type. Serialization must be explicitly handled in another block. Messages with a different type are discarded by the block.

The message fields are used as follows:

  • key becomes the MQTT topic for the published message
  • data is used as message payload
  • type must always be binary, otherwise the message is discarded

Examples

This example uses the mqtt_sink block to connect to an MQTT broker with host example.com on port 8883 and publish incoming messages with QoS 1

[...]
| mqtt_sink
  .broker_url("mqtts://example.com:8883")
  .qos(1)