aMQTT¶

aMQTT is an open source MQTT client and broker implementation.

Built on top of asyncio, Python’s standard asynchronous I/O framework, aMQTT provides a straightforward API based on coroutines, making it easy to write highly concurrent applications.

Features¶

aMQTT implements the full set of MQTT 3.1.1 protocol specifications and provides the following features:

Support QoS 0, QoS 1 and QoS 2 messages flow
Client auto-reconnection on network lost
Authentication through password file (more methods can be added through a plugin system)
Basic $SYS topics
TCP and websocket support
SSL support over TCP and websocket
Plugin system

Requirements¶

aMQTT is built on Python’s asyncio. It requires Python 3.6 or newer.

Installation¶

It is not recommended to install third-party library in Python system packages directory. The preferred way for installing aMQTT is to create a virtual environment and then install all the dependencies you need. Refer to PEP 405 to learn more.

Once you have a environment setup and ready, aMQTT can be installed with the following command

(venv) $ pip install amqtt

pip will download and install aMQTT and all its dependencies.

User guide¶

If you need aMQTT for running a MQTT client or deploying a MQTT broker, the Quickstart describes how to use console scripts provided by aMQTT.

If you want to develop an application which needs to connect to a MQTT broker, the MQTTClient API documentation explains how to use aMQTT API for connecting, publishing and subscribing with a MQTT broker.

If you want to run you own MQTT broker, th Broker API reference reference documentation explains how to embed a MQTT broker inside a Python application.

News and updates are listed in the Changelog.

Quickstart¶

A quick way for getting started with aMQTT is to use console scripts provided for :

publishing a message on some topic on an external MQTT broker.
subscribing some topics and getting published messages.
running a autonomous MQTT broker

These scripts are installed automatically when installing aMQTT with the following command

(venv) $ pip install amqtt

Publishing messages¶

hbmqtt_pub is a command-line tool which can be used for publishing some messages on a topic. It requires a few arguments like broker URL, topic name, QoS and data to send. Additional options allow more complex use case.

Publishing `some_data to as /test topic on is as simple as :

$ hbmqtt_pub --url mqtt://test.mosquitto.org -t /test -m some_data
[2015-11-06 22:21:55,108] :: INFO - hbmqtt_pub/5135-MacBook-Pro.local Connecting to broker
[2015-11-06 22:21:55,333] :: INFO - hbmqtt_pub/5135-MacBook-Pro.local Publishing to '/test'
[2015-11-06 22:21:55,336] :: INFO - hbmqtt_pub/5135-MacBook-Pro.local Disconnected from broker

This will use insecure TCP connection to connect to test.mosquitto.org. hbmqtt_pub also allows websockets and secure connection:

$ hbmqtt_pub --url ws://test.mosquitto.org:8080 -t /test -m some_data
[2015-11-06 22:22:42,542] :: INFO - hbmqtt_pub/5157-MacBook-Pro.local Connecting to broker
[2015-11-06 22:22:42,924] :: INFO - hbmqtt_pub/5157-MacBook-Pro.local Publishing to '/test'
[2015-11-06 22:22:52,926] :: INFO - hbmqtt_pub/5157-MacBook-Pro.local Disconnected from broker

hbmqtt_pub can read from file or stdin and use data read as message payload:

$ some_command | hbmqtt_pub --url mqtt://localhost -t /test -l

See hbmqtt_pub reference documentation for details about available options and settings.

Subscribing a topic¶

hbmqtt_sub is a command-line tool which can be used to subscribe for some pattern(s) on a broker and get date from messages published on topics matching these patterns by other MQTT clients.

Subscribing a /test/# topic pattern is done with :

$ hbmqtt_sub --url mqtt://localhost -t /test/#

This command will run forever and print on the standard output every messages received from the broker. The -n option allows to set a maximum number of messages to receive before stopping.

See hbmqtt_sub reference documentation for details about available options and settings.

URL Scheme¶

aMQTT command line tools use the --url to establish a network connection with the broker. The --url parameter value must conform to the MQTT URL scheme. The general accepted form is :

[mqtt|ws][s]://[username][:password]@host.domain[:port]

Here are some examples of URL:

mqtt://localhost
mqtt://localhost:1884
mqtt://user:password@localhost
ws://test.mosquitto.org
wss://user:password@localhost

Running a broker¶

hbmqtt is a command-line tool for running a MQTT broker:

$ hbmqtt
[2015-11-06 22:45:16,470] :: INFO - Listener 'default' bind to 0.0.0.0:1883 (max_connections=-1)

See hbmqtt reference documentation for details about available options and settings.

Changelog¶

0.10.1 - 2022-04-29¶

Fixed a major bug in plugin api, see https://github.com/Yakifo/amqtt/pull/92

0.10.0 - 2021-08-04¶

first release under new package name: amqtt

reworked unit tests

dropped support for python3.5 and earlier

added support for python3.8 and 3.9

Pass in loop to PluginManager, from https://github.com/beerfactory/hbmqtt/pull/126

Fixes taboo topic checking without session username, from https://github.com/beerfactory/hbmqtt/pull/151

Move scripts module into hbmqtt module, from https://github.com/beerfactory/hbmqtt/pull/167

Download mosquitto certificate on the fly

importing hbmqtt is deprecated, use amqtt

Security fix: If an attacker could produce a KeyError inside an authentication plugin, the authentication was accepted instead of rejected

0.9.5¶

fix more issues
fix a few issues

0.9.2¶

fix a few issues

0.9.1¶

See commit log

0.9.0¶

fix a serie of issues
improve plugin performance
support Python 3.6
upgrade to websockets 3.3.0

0.8.0¶

fix a serie of issues

0.7.3¶

fix deliver message client method to raise TimeoutError (#40)
fix topic filter matching in broker (#41)

Version 0.7.2 has been jumped due to troubles with pypi…

0.7.1¶

Fix duplicated $SYS topic name .

0.7.0¶

Fix a serie of issues reported by Christoph Krey

0.6.3¶

Fix issue #22.

0.6.2¶

Fix issue #20 (mqtt subprotocol was missing).
Upgrade to websockets 3.0.

0.6.1¶

Fix issue #19

0.6¶

Added compatibility with Python 3.5.
Rewritten documentation.
Add command-line tools hbmqtt, hbmqtt_pub and hbmqtt_sub.

Transitioning from HBMQTT to aMQTT¶

This document is for those porting from HBMQTT to aMQTT. Basically you can search and replace hbmqtt with amqtt and all should work out. Details below.

Imports¶

The module changed from hbmqtt to amqtt. For the 0.10.x releases it will still be possible to import hbmqtt. In 0.11.x only amqtt will work.

Since the amqtt package does provide a hbmqtt module, installing the hbmqtt package in the same python installation is not possible.

Random Client ID¶

When not providing a client_id, a random id is automatically generated. These names were also changed from hbmqtt/<random> to amqtt/<random>.

plugins / entrypoints¶

If you make use of python’s entrypoint system to build aMQTT plugins, make sure to use the amqtt.*.plugins names instead of hbmqtt.*.plugins names. During the transition plugins with hbmqtt entrypoint should keep working for 0.10.x releases.

CLI tools¶

Will also be renamed.

References¶

Reference documentation for HBMQTT console scripts and programming API.

Console scripts¶

hbmqtt_pub : MQTT client for publishing messages to a broker
hbmqtt_sub : MQTT client for subscribing to a topics and retrieved published messages
hbmqtt : Autonomous MQTT broker

Programming API¶

MQTTClient API : MQTT client API reference
Broker API reference : MQTT broker API reference
Common API : Common API

TBD

hbmqtt_pub¶

hbmqtt_pub is a MQTT client that publishes simple messages on a topic from the command line.

Usage¶

hbmqtt_pub usage :

hbmqtt_pub --version
hbmqtt_pub (-h | --help)
hbmqtt_pub --url BROKER_URL -t TOPIC (-f FILE | -l | -m MESSAGE | -n | -s) [-c CONFIG_FILE] [-i CLIENT_ID] [-d]
           [-q | --qos QOS] [-d] [-k KEEP_ALIVE] [--clean-session]
           [--ca-file CAFILE] [--ca-path CAPATH] [--ca-data CADATA]
           [ --will-topic WILL_TOPIC [--will-message WILL_MESSAGE] [--will-qos WILL_QOS] [--will-retain] ]
           [--extra-headers HEADER]

Note that for simplicity, hbmqtt_pub uses mostly the same argument syntax as mosquitto_pub.

Options¶

--version: HBMQTT version information
-h, --help: Display hbmqtt_pub usage help
-c: Set the YAML configuration file to read and pass to the client runtime.
-d: Enable debugging informations.
--ca-file: Define the path to a file containing PEM encoded CA certificates that are trusted. Used to enable SSL communication.
--ca-path: Define the path to a directory containing PEM encoded CA certificates that are trusted. Used to enable SSL communication.
--ca-data: Set the PEM encoded CA certificates that are trusted. Used to enable SSL communication.
--clean-session: If given, set the CONNECT clean session flag to True.
-f: Send the contents of a file as the message. The file is read line by line, and hbmqtt_pub will publish a message for each line read.
-i: The id to use for this client. If not given, defaults to hbmqtt_pub/ appended with the process id and the hostname of the client.
-l: Send messages read from stdin. hbmqtt_pub will publish a message for each line read. Blank lines won’t be sent.
-k: Set the CONNECT keep alive timeout.
-m: Send a single message from the command line.
-n: Send a null (zero length) message.
-q, --qos: Specify the quality of service to use for the message, from 0, 1 and 2. Defaults to 0.
-s: Send a message read from stdin, sending the entire content as a single message.
-t: The MQTT topic on which to publish the message.
--url: Broker connection URL, conforming to MQTT URL scheme.
--will-topic: The topic on which to send a Will, in the event that the client disconnects unexpectedly.
--will-message: Specify a message that will be stored by the broker and sent out if this client disconnects unexpectedly. This must be used in conjunction with --will-topic.
--will-qos: The QoS to use for the Will. Defaults to 0. This must be used in conjunction with --will-topic.
--will-retain: If given, if the client disconnects unexpectedly the message sent out will be treated as a retained message. This must be used in conjunction with --will-topic.
--extra-headers: Specify a JSON object string with key-value pairs representing additional headers that are transmitted on the initial connection, but only when using a websocket connection

Configuration¶

If -c argument is given, hbmqtt_pub will read specific MQTT settings for the given configuration file. This file must be a valid YAML file which may contains the following configuration elements :

keep_alive : Keep-alive timeout sent to the broker. Defaults to 10 seconds.
ping_delay : Auto-ping delay before keep-alive timeout. Defaults to 1. Setting to 0 will disable to 0 and may lead to broker disconnection.
default_qos : Default QoS for messages published. Defaults to 0.
default_retain : Default retain value to messages published. Defaults to false.
auto_reconnect : Enable or disable auto-reconnect if connectection with the broker is interrupted. Defaults to false.
reconnect_retries : Maximum reconnection retries. Defaults to 2. Negative value will cause client to reconnect infinietly.
reconnect_max_interval : Maximum interval between 2 connection retry. Defaults to 10.

Examples¶

Examples below are adapted from mosquitto_pub documentation.

Publish temperature information to localhost with QoS 1:

hbmqtt_pub --url mqtt://localhost -t sensors/temperature -m 32 -q 1

Publish timestamp and temperature information to a remote host on a non-standard port and QoS 0:

hbmqtt_pub --url mqtt://192.168.1.1:1885 -t sensors/temperature -m "1266193804 32"

Publish light switch status. Message is set to retained because there may be a long period of time between light switch events:

hbmqtt_pub --url mqtt://localhost -r -t switches/kitchen_lights/status -m "on"

Send the contents of a file in two ways:

hbmqtt_pub --url mqtt://localhost -t my/topic -f ./data

hbmqtt_pub --url mqtt://localhost -t my/topic -s < ./data

Publish temperature information to localhost with QoS 1 over mqtt encapsulated in a websocket connection and additional headers:

hbmqtt_pub --url wss://localhost -t sensors/temperature -m 32 -q 1 --extra-headers '{"Authorization": "Bearer <token>"}'

hbmqtt_sub¶

hbmqtt_sub is a command line MQTT client that subscribes to some topics and output data received from messages published.

Usage¶

hbmqtt_sub usage :

hbmqtt_sub --version
hbmqtt_sub (-h | --help)
hbmqtt_sub --url BROKER_URL -t TOPIC... [-n COUNT] [-c CONFIG_FILE] [-i CLIENT_ID] [-q | --qos QOS] [-d]
           [-k KEEP_ALIVE] [--clean-session] [--ca-file CAFILE] [--ca-path CAPATH] [--ca-data CADATA]
           [ --will-topic WILL_TOPIC [--will-message WILL_MESSAGE] [--will-qos WILL_QOS] [--will-retain] ]
           [--extra-headers HEADER]

Note that for simplicity, hbmqtt_sub uses mostly the same argument syntax as mosquitto_sub.

Options¶

--version: HBMQTT version information
-h, --help: Display hbmqtt_sub usage help
-c: Set the YAML configuration file to read and pass to the client runtime.
-d: Enable debugging informations.
--ca-file: Define the path to a file containing PEM encoded CA certificates that are trusted. Used to enable SSL communication.
--ca-path: Define the path to a directory containing PEM encoded CA certificates that are trusted. Used to enable SSL communication.
--ca-data: Set the PEM encoded CA certificates that are trusted. Used to enable SSL communication.
--clean-session: If given, set the CONNECT clean session flag to True.
-i: The id to use for this client. If not given, defaults to hbmqtt_sub/ appended with the process id and the hostname of the client.
-k: Set the CONNECT keep alive timeout.
-n: Number of messages to read before ending. Read forever if not given.
-q, --qos: Specify the quality of service to use for receiving messages. This QoS is sent in the subscribe request.
-t: Topic filters to subcribe.
--url: Broker connection URL, conforming to MQTT URL scheme.
--will-topic: The topic on which to send a Will, in the event that the client disconnects unexpectedly.
--will-message: Specify a message that will be stored by the broker and sent out if this client disconnects unexpectedly. This must be used in conjunction with --will-topic.
--will-qos: The QoS to use for the Will. Defaults to 0. This must be used in conjunction with --will-topic.
--will-retain: If given, if the client disconnects unexpectedly the message sent out will be treated as a retained message. This must be used in conjunction with --will-topic.
--extra-headers: Specify a JSON object string with key-value pairs representing additional headers that are transmitted on the initial connection, but only when using a websocket connection

Configuration¶

If -c argument is given, hbmqtt_sub will read specific MQTT settings for the given configuration file. This file must be a valid YAML file which may contains the following configuration elements :

keep_alive : Keep-alive timeout sent to the broker. Defaults to 10 seconds.
ping_delay : Auto-ping delay before keep-alive timeout. Defaults to 1. Setting to 0 will disable to 0 and may lead to broker disconnection.
default_qos : Default QoS for messages published. Defaults to 0.
default_retain : Default retain value to messages published. Defaults to false.
auto_reconnect : Enable or disable auto-reconnect if connectection with the broker is interrupted. Defaults to false.
reconnect_retries : Maximum reconnection retries. Defaults to 2. Negative value will cause client to reconnect infinietly.
reconnect_max_interval : Maximum interval between 2 connection retry. Defaults to 10.

Examples¶

Examples below are adapted from mosquitto_sub documentation.

Subscribe with QoS 0 to all messages published under $SYS/:

hbmqtt_sub --url mqtt://localhost -t '$SYS/#' -q 0

Subscribe to 10 messages with QoS 2 from /#:

hbmqtt_sub --url mqtt://localhost -t /# -q 2 -n 10

Subscribe with QoS 0 to all messages published under $SYS/: over mqtt encapsulated in a websocket connection and additional headers:

hbmqtt_sub --url wss://localhost -t '$SYS/#' -q 0 --extra-headers '{"Authorization": "Bearer <token>"}'

hbmqtt¶

hbmqtt is a command-line script for running a MQTT 3.1.1 broker.

Usage¶

hbmqtt usage :

hbmqtt --version
hbmqtt (-h | --help)
hbmqtt [-c <config_file> ] [-d]

Options¶

--version: HBMQTT version information
-h, --help: Display hbmqtt_sub usage help
-c: Set the YAML configuration file to read and pass to the client runtime.

Configuration¶

If -c argument is given, hbmqtt will read specific MQTT settings for the given configuration file. This file must be a valid YAML file which may contains the following configuration elements :

listeners : network bindings configuration list
timeout-disconnect-delay : client disconnect timeout after keep-alive timeout
auth : authentication configuration

Without the -c argument, the broker will run with the following default configuration:

listeners:
    default:
        type: tcp
        bind: 0.0.0.0:1883
sys_interval: 20
auth:
    allow-anonymous: true
plugins:
    - auth_file
    - auth_anonymous

Using this configuration, hbmqtt will start a broker :

listening on TCP port 1883 on all network interfaces.
Publishing $SYS``_ update messages every ``20 seconds.
Allowing anonymous login, and password file bases authentication.

Configuration example¶

listeners:
    default:
        max-connections: 50000
        type: tcp
    my-tcp-1:
        bind: 127.0.0.1:1883
        my-tcp-2:
        bind: 1.2.3.4:1883
        max-connections: 1000
    my-tcp-ssl-1:
        bind: 127.0.0.1:8883
        ssl: on
        cafile: /some/cafile
        capath: /some/folder
        capath: certificate data
        certfile: /some/certfile
        keyfile: /some/key
    my-ws-1:
        bind: 0.0.0.0:8080
        type: ws
timeout-disconnect-delay: 2
auth:
    plugins: ['auth.anonymous']
    allow-anonymous: true
    password-file: /some/passwd_file

This configuration example shows use case of every parameter.

The listeners section define 3 bindings :

my-tcp-1 : a unsecured TCP listener on port 1883 allowing 1000 clients connections simultaneously
my-tcp-ssl-1 : a secured TCP listener on port 8883 allowing 50000 clients connections simultaneously
my-ws-1 : a unsecured websocket listener on port 8080 allowing 50000 clients connections simultaneously

Authentication allows anonymous logins and password file based authentication. Password files are required to be text files containing user name and password in the form of :

username:password

where password should be the encrypted password. Use the mkpasswd -m sha-512 command to build encoded passphrase. Password file example:

# Test user with 'test' password encrypted with sha-512
test:$6$l4zQEHEcowc1Pnv4$HHrh8xnsZoLItQ8BmpFHM4r6q5UqK3DnXp2GaTm5zp5buQ7NheY3Xt9f6godVKbEtA.hOC7IEDwnok3pbAOip.

MQTTClient API¶

The MQTTClient class implements the client part of MQTT protocol. It can be used to publish and/or subscribe MQTT message on a broker accessible on the network through TCP or websocket protocol, both secured or unsecured.

Usage examples¶

Subscriber¶

The example below shows how to write a simple MQTT client which subscribes a topic and prints every messages received from the broker :

import logging
import asyncio

from hbmqtt.client import MQTTClient, ClientException
from hbmqtt.mqtt.constants import QOS_1, QOS_2

logger = logging.getLogger(__name__)

async def uptime_coro():
    C = MQTTClient()
    await C.connect('mqtt://test.mosquitto.org/')
    # Subscribe to '$SYS/broker/uptime' with QOS=1
    # Subscribe to '$SYS/broker/load/#' with QOS=2
    await C.subscribe([
            ('$SYS/broker/uptime', QOS_1),
            ('$SYS/broker/load/#', QOS_2),
         ])
    try:
        for i in range(1, 100):
            message = await C.deliver_message()
            packet = message.publish_packet
            print("%d:  %s => %s" % (i, packet.variable_header.topic_name, str(packet.payload.data)))
        await C.unsubscribe(['$SYS/broker/uptime', '$SYS/broker/load/#'])
        await C.disconnect()
    except ClientException as ce:
        logger.error("Client exception: %s" % ce)

if __name__ == '__main__':
    formatter = "[%(asctime)s] %(name)s {%(filename)s:%(lineno)d} %(levelname)s - %(message)s"
    logging.basicConfig(level=logging.DEBUG, format=formatter)
    asyncio.get_event_loop().run_until_complete(uptime_coro())

When executed, this script gets the default event loop and asks it to run the uptime_coro until it completes. uptime_coro starts by initializing a MQTTClient instance. The coroutine then call connect() to connect to the broker, here test.mosquitto.org. Once connected, the coroutine subscribes to some topics, and then wait for 100 messages. Each message received is simply written to output. Finally, the coroutine unsubscribes from topics and disconnects from the broker.

Publisher¶

The example below uses the MQTTClient class to implement a publisher. This test publish 3 messages asynchronously to the broker on a test topic. For the purposes of the test, each message is published with a different Quality Of Service. This example also shows to method for publishing message asynchronously.

import logging
import asyncio

from hbmqtt.client import MQTTClient
from hbmqtt.mqtt.constants import QOS_0, QOS_1, QOS_2

logger = logging.getLogger(__name__)

async def test_coro():
    C = MQTTClient()
    await C.connect('mqtt://test.mosquitto.org/')
    tasks = [
        asyncio.ensure_future(C.publish('a/b', b'TEST MESSAGE WITH QOS_0')),
        asyncio.ensure_future(C.publish('a/b', b'TEST MESSAGE WITH QOS_1', qos=QOS_1)),
        asyncio.ensure_future(C.publish('a/b', b'TEST MESSAGE WITH QOS_2', qos=QOS_2)),
    ]
    await asyncio.wait(tasks)
    logger.info("messages published")
    await C.disconnect()


async def test_coro2():
    try:
        C = MQTTClient()
        ret = await C.connect('mqtt://test.mosquitto.org:1883/')
        message = await C.publish('a/b', b'TEST MESSAGE WITH QOS_0', qos=QOS_0)
        message = await C.publish('a/b', b'TEST MESSAGE WITH QOS_1', qos=QOS_1)
        message = await C.publish('a/b', b'TEST MESSAGE WITH QOS_2', qos=QOS_2)
        #print(message)
        logger.info("messages published")
        await C.disconnect()
    except ConnectException as ce:
        logger.error("Connection failed: %s" % ce)
        asyncio.get_event_loop().stop()


if __name__ == '__main__':
    formatter = "[%(asctime)s] %(name)s {%(filename)s:%(lineno)d} %(levelname)s - %(message)s"
    logging.basicConfig(level=logging.DEBUG, format=formatter)
    asyncio.get_event_loop().run_until_complete(test_coro())
    asyncio.get_event_loop().run_until_complete(test_coro2())

As usual, the script runs the publish code through the async loop. test_coro() and test_coro() are ran in sequence. Both do the same job. test_coro() publish 3 messages in sequence. test_coro2() publishes the same message asynchronously. The difference appears the looking at the sequence of MQTT messages sent.

test_coro() achieves:

hbmqtt/YDYY;NNRpYQSy3?o -out-> PublishPacket(ts=2015-11-11 21:54:48.843901, fixed=MQTTFixedHeader(length=28, flags=0x0), variable=PublishVariableHeader(topic=a/b, packet_id=None), payload=PublishPayload(data="b'TEST MESSAGE WITH QOS_0'"))
hbmqtt/YDYY;NNRpYQSy3?o -out-> PublishPacket(ts=2015-11-11 21:54:48.844152, fixed=MQTTFixedHeader(length=30, flags=0x2), variable=PublishVariableHeader(topic=a/b, packet_id=1), payload=PublishPayload(data="b'TEST MESSAGE WITH QOS_1'"))
hbmqtt/YDYY;NNRpYQSy3?o <-in-- PubackPacket(ts=2015-11-11 21:54:48.979665, fixed=MQTTFixedHeader(length=2, flags=0x0), variable=PacketIdVariableHeader(packet_id=1), payload=None)
hbmqtt/YDYY;NNRpYQSy3?o -out-> PublishPacket(ts=2015-11-11 21:54:48.980886, fixed=MQTTFixedHeader(length=30, flags=0x4), variable=PublishVariableHeader(topic=a/b, packet_id=2), payload=PublishPayload(data="b'TEST MESSAGE WITH QOS_2'"))
hbmqtt/YDYY;NNRpYQSy3?o <-in-- PubrecPacket(ts=2015-11-11 21:54:49.029691, fixed=MQTTFixedHeader(length=2, flags=0x0), variable=PacketIdVariableHeader(packet_id=2), payload=None)
hbmqtt/YDYY;NNRpYQSy3?o -out-> PubrelPacket(ts=2015-11-11 21:54:49.030823, fixed=MQTTFixedHeader(length=2, flags=0x2), variable=PacketIdVariableHeader(packet_id=2), payload=None)
hbmqtt/YDYY;NNRpYQSy3?o <-in-- PubcompPacket(ts=2015-11-11 21:54:49.092514, fixed=MQTTFixedHeader(length=2, flags=0x0), variable=PacketIdVariableHeader(packet_id=2), payload=None)fixed=MQTTFixedHeader(length=2, flags=0x0), variable=PacketIdVariableHeader(packet_id=2), payload=None)

while test_coro2() runs:

hbmqtt/LYRf52W[56SOjW04 -out-> PublishPacket(ts=2015-11-11 21:54:48.466123, fixed=MQTTFixedHeader(length=28, flags=0x0), variable=PublishVariableHeader(topic=a/b, packet_id=None), payload=PublishPayload(data="b'TEST MESSAGE WITH QOS_0'"))
hbmqtt/LYRf52W[56SOjW04 -out-> PublishPacket(ts=2015-11-11 21:54:48.466432, fixed=MQTTFixedHeader(length=30, flags=0x2), variable=PublishVariableHeader(topic=a/b, packet_id=1), payload=PublishPayload(data="b'TEST MESSAGE WITH QOS_1'"))
hbmqtt/LYRf52W[56SOjW04 -out-> PublishPacket(ts=2015-11-11 21:54:48.466695, fixed=MQTTFixedHeader(length=30, flags=0x4), variable=PublishVariableHeader(topic=a/b, packet_id=2), payload=PublishPayload(data="b'TEST MESSAGE WITH QOS_2'"))
hbmqtt/LYRf52W[56SOjW04 <-in-- PubackPacket(ts=2015-11-11 21:54:48.613062, fixed=MQTTFixedHeader(length=2, flags=0x0), variable=PacketIdVariableHeader(packet_id=1), payload=None)
hbmqtt/LYRf52W[56SOjW04 <-in-- PubrecPacket(ts=2015-11-11 21:54:48.661073, fixed=MQTTFixedHeader(length=2, flags=0x0), variable=PacketIdVariableHeader(packet_id=2), payload=None)
hbmqtt/LYRf52W[56SOjW04 -out-> PubrelPacket(ts=2015-11-11 21:54:48.661925, fixed=MQTTFixedHeader(length=2, flags=0x2), variable=PacketIdVariableHeader(packet_id=2), payload=None)
hbmqtt/LYRf52W[56SOjW04 <-in-- PubcompPacket(ts=2015-11-11 21:54:48.713107, fixed=MQTTFixedHeader(length=2, flags=0x0), variable=PacketIdVariableHeader(packet_id=2), payload=None)

Both coroutines have the same results except that test_coro2() manages messages flow in parallel which may be more efficient.

Reference¶

MQTTClient API¶

MQTTClient configuration¶

The MQTTClient __init__ method accepts a config parameter which allow to setup some behaviour and defaults settings. This argument must be a Python dict object which may contain the following entries:

keep_alive: keep alive (in seconds) to send when connecting to the broker (defaults to 10 seconds). MQTTClient will auto-ping the broker if not message is sent within the keep-alive interval. This avoids disconnection from the broker.
ping_delay: auto-ping delay before keep-alive times out (defaults to 1 seconds).
default_qos: Default QoS (0) used by publish() if qos argument is not given.
default_retain: Default retain (False) used by publish() if qos argument is not given.,
auto_reconnect: enable or disable auto-reconnect feature (defaults to True).
reconnect_max_interval: maximum interval (in seconds) to wait before two connection retries (defaults to 10).
reconnect_retries: maximum number of connect retries (defaults to 2). Negative value will cause client to reconnect infinietly.

Default QoS and default retain can also be overriden by adding a topics with may contain QoS and retain values for specific topics. See the following example:

config = {
    'keep_alive': 10,
    'ping_delay': 1,
    'default_qos': 0,
    'default_retain': False,
    'auto_reconnect': True,
    'reconnect_max_interval': 5,
    'reconnect_retries': 10,
    'topics': {
        '/test': { 'qos': 1 },
        '/some_topic': { 'qos': 2, 'retain': True }
    }
}

With this setting any message published will set with QOS_0 and retain flag unset except for :

messages sent to /test topic : they will be sent with QOS_1
messages sent to /some_topic topic : they will be sent with QOS_2 and retain flag set

In any case, the qos and retain argument values passed to method publish() will override these settings.

Broker API reference¶

The Broker class provides a complete MQTT 3.1.1 broker implementation. This class allows Python developers to embed a MQTT broker in their own applications.

Usage example¶

The following example shows how to start a broker using the default configuration:

import logging
import asyncio
import os
from hbmqtt.broker import Broker


async def broker_coro():
    broker = Broker()
    await broker.start()


if __name__ == '__main__':
    formatter = "[%(asctime)s] :: %(levelname)s :: %(name)s :: %(message)s"
    logging.basicConfig(level=logging.INFO, format=formatter)
    asyncio.get_event_loop().run_until_complete(broker_coro())
    asyncio.get_event_loop().run_forever()

When executed, this script gets the default event loop and asks it to run the broker_coro until it completes. broker_coro creates Broker instance and then start() the broker for serving. Once completed, the loop is ran forever, making this script never stop …

Reference¶

Broker API¶

Broker configuration¶

The Broker __init__ method accepts a config parameter which allow to setup some behaviour and defaults settings. This argument must be a Python dict object. For convinience, it is presented below as a YAML file 1.

listeners:
    default:
        max-connections: 50000
        type: tcp
    my-tcp-1:
        bind: 127.0.0.1:1883
    my-tcp-2:
        bind: 1.2.3.4:1884
        max-connections: 1000
    my-tcp-ssl-1:
        bind: 127.0.0.1:8885
        ssl: on
        cafile: /some/cafile
        capath: /some/folder
        capath: certificate data
        certfile: /some/certfile
        keyfile: /some/key
    my-ws-1:
        bind: 0.0.0.0:8080
        type: ws
timeout-disconnect-delay: 2
auth:
    plugins: ['auth.anonymous'] #List of plugins to activate for authentication among all registered plugins
    allow-anonymous: true / false
    password-file: /some/passwd_file
topic-check:
    enabled: true / false  # Set to False if topic filtering is not needed
    plugins: ['topic_acl'] #List of plugins to activate for topic filtering among all registered plugins
    acl:
        # username: [list of allowed topics]
        username1: ['repositories/+/master', 'calendar/#', 'data/memes']  # List of topics on which client1 can publish and subscribe
        username2: ...
        anonymous: []  # List of topics on which an anonymous client can publish and subscribe

The listeners section allows to define network listeners which must be started by the Broker. Several listeners can be setup. default subsection defines common attributes for all listeners. Each listener can have the following settings:

bind: IP address and port binding.
max-connections: Set maximum number of active connection for the listener. 0 means no limit.
type: transport protocol type; can be tcp for classic TCP listener or ws for MQTT over websocket.
ssl enables (on) or disable secured connection over the transport protocol.
cafile, cadata, certfile and keyfile : mandatory parameters for SSL secured connections.

The auth section setup authentication behaviour:

plugins: defines the list of activated plugins. Note the plugins must be defined in the amqtt.broker.plugins entry point.
allow-anonymous : used by the internal hbmqtt.plugins.authentication.AnonymousAuthPlugin plugin. This parameter enables (on) or disable anonymous connection, ie. connection without username.
password-file : used by the internal hbmqtt.plugins.authentication.FileAuthPlugin plugin. This parameter gives to path of the password file to load for authenticating users.

The topic-check section setup access control policies for publishing and subscribing to topics:

enabled: set to true if you want to impose an access control policy. Otherwise, set it to false.
plugins: defines the list of activated plugins. Note the plugins must be defined in the amqtt.broker.plugins entry point.
additional parameters: depending on the plugin used for access control, additional parameters should be added.
- In case of topic_acl plugin, the Access Control List (ACL) must be defined in the parameter acl.
  
  For each username, a list with the allowed topics must be defined.
  
  If the client logs in anonymously, the anonymous entry within the ACL is used in order to grant/deny subscriptions.

1: See PyYAML for loading YAML files as Python dict.

Common API¶

This document describes HBMQTT common API both used by MQTTClient API and Broker API reference.

Reference¶

ApplicationMessage¶

License¶

The MIT License (MIT)

Copyright (c) 2015 Nicolas JOUANIN
Copyright (c) 2021 aMQTT Contributers (https://github.com/Yakifo/amqtt/graphs/contributors)

Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in
all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
THE SOFTWARE.