view mod_pubsub_mqtt/README.markdown @ 4537:53ee391ca689

mod_smacks: Fix traceback due to session being destroyed in send() Sending something can cause the OS to notice that the connection is dead and then the connection can be dead at this point. More likely if opportunistic_writes is enabled.
author Kim Alvefur <zash@zash.se>
date Thu, 01 Apr 2021 11:35:26 +0200
parents 2333e384409d
children 58df53eefa28
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---
labels:
- 'Stage-Beta'
summary: 'MQTT interface to Prosody''s pubsub'
...

Introduction
------------

[MQTT](http://mqtt.org/) is a lightweight binary pubsub protocol suited
to embedded devices. This module provides a way for MQTT clients to
connect to Prosody and publish or subscribe to local pubsub nodes.

Details
-------

MQTT has the concept of 'topics' (similar to XMPP's pubsub 'nodes').
mod\_pubsub\_mqtt maps pubsub nodes to MQTT topics of the form
`HOST/NODE`, e.g.`pubsub.example.org/mynode`.

### Limitations

The current implementation is quite basic, and in particular:

-   Authentication is not supported
-   SSL/TLS is not supported
-   Only QoS level 0 is supported

### Payloads

XMPP payloads are always XML, but MQTT does not define a payload format.
Therefore mod\_pubsub\_mqtt will attempt to convert data of certain
recognised payload types. Currently supported:

-   JSON (see [XEP-0335](http://xmpp.org/extensions/xep-0335.html) for
    the format)
-   Plain UTF-8 text (wrapped inside
    `<data xmlns="https://prosody.im/protocol/mqtt"/>`)

All other XMPP payload types are sent to the client directly as XML.
Data published by MQTT clients is currently never translated, and always
treated as UTF-8 text.

Configuration
-------------

There is no special configuration for this module. Simply load it on
your pubsub host like so:

    Component "pubsub.example.org" "pubsub"
        modules_enabled = { "pubsub_mqtt" }

You may also configure which port(s) mod\_pubsub\_mqtt listens on using
Prosody's standard config directives, such as `mqtt_ports`. Network
settings **must** be specified in the global section of the config file,
not under any particular pubsub component. The default port is 1883
(MQTT's standard port number).

Compatibility
-------------

  ------- --------------
  trunk   Works
  0.9     Works
  0.8     Doesn't work
  ------- --------------