# mqtt – Publish a message on an MQTT topic for the IoT

- Synopsis

- Requirements

- Parameters

- Notes

- Examples

- Status

## Synopsis

- Publish a message on an MQTT topic.

## Requirements

The below requirements are needed on the host that executes this module.

- mosquitto

## Parameters

Parameter | Choices/Defaults | Comments
--- | --- | ---

ca_cert
-

The path to the Certificate Authority certificate files that are to be treated as trusted by this client. If this is the only option given then the client will operate in a similar manner to a web browser. That is to say it will require the broker to have a certificate signed by the Certificate Authorities in ca_certs and will communicate using TLS v1, but will not attempt any form of authentication. This provides basic network encryption but may not be sufficient depending on how the broker is configured.
aliases: ca_certs

client_cert - |  | The path pointing to the PEM encoded client certificate. If this is not None it will be used as client information for TLS based authentication. Support for this feature is broker dependent. aliases: certfile
client_id - | Default: "hostname + pid" | MQTT client identifier
client_key - |  | The path pointing to the PEM encoded client private key. If this is not None it will be used as client information for TLS based authentication. Support for this feature is broker dependent. aliases: keyfile
password - |  | Password for `username` to authenticate against the broker.
payload - / required |  | Payload. The special string `"None"` may be used to send a NULL (i.e. empty) payload which is useful to simply notify with the topic or to clear previously retained messages.
port - | Default: 1883 | MQTT broker port number

qos
-

Choices:
- 0
- 1
- 2

Default:
0

QoS (Quality of Service)

retain
boolean

Choices:
- no ←
- yes

Setting this flag causes the broker to retain (i.e. keep) the message so that applications that subsequently subscribe to the topic can received the last retained message immediately.

server - | Default: "localhost" | MQTT broker address/name

tls_version
string
added in 2.9

Choices:
- tlsv1.1
- tlsv1.2

Specifies the version of the SSL/TLS protocol to be used.
By default (if the python version supports it) the highest TLS version is detected. If unavailable, TLS v1 is used.

topic - / required |  | MQTT topic name
username - |  | Username to authenticate against the broker.

## Notes

Note

- This module requires a connection to an MQTT broker such as Mosquitto http://mosquitto.org and the Paho `mqtt` Python client (https://pypi.org/project/paho-mqtt/).

## Examples

    - mqtt:
        topic: 'service/ansible/{{ ansible_hostname }}'
        payload: 'Hello at {{ ansible_date_time.iso8601 }}'
        qos: 0
        retain: False
        client_id: ans001
      delegate_to: localhost

## Status

- This module is not guaranteed to have a backwards compatible interface. [preview]

- This module is maintained by the Ansible Community. [community]

### Authors

- Jan-Piet Mens (@jpmens)

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