This is my testing script (attention, its rather „Holzhacker“-Programming)
But its based on the python code I did for the hono quickstart Demo I did back then
I guess the crucial part is here
def on_start(self, event):
event.container: Container
conn = event.container.connect(url=self.server, user="consumer@HONO", password="verysecret")
event.container.create_receiver(conn, f"telemetry/{self.tenant}")
self.sender = event.container.create_sender(conn, target=f"command/{self.tenant}", options=[HelloWorld.SessionEnd()])
def on_message(self, event):
print(f"I got a telemetry message, sending command...")
self.accept(event.delivery)
message = Message(properties={
"to": f"command/{self.tenant}/{self.deviceId}",
"subject": "work",
# "content-type": "application/json",
# "messageId": "0",
# "userId": "null",
# "replyTo": "null",
# "correlationId": "0",
# "contentEncoding": "null",
# "absoluteExpiryTime": "null",
# "creationTime": "null",
# "groupId": 'null',
# "groupSequence": "null",
# "replyToGroupId": 'null',
})
print(f"Sending Command: {message}")
self.sender.send(message)
@JulianFeinauer I am using this code to (successfully) send a command to a device via the HTTP adapter. Maybe you can adapt your code accordingly?
from __future__ import print_function, unicode_literals
from proton import Message
from proton.handlers import MessagingHandler
from proton.reactor import Container
class HelloWorld(MessagingHandler):
def __init__(self, server, address):
super(HelloWorld, self).__init__()
self.server = server
self.address = address
def on_start(self, event):
print("connecting ...")
conn = event.container.connect(self.server, sasl_enabled=True, allowed_mechs="PLAIN", allow_insecure_mechs=True, user="consumer@HONO", password="verysecret")
event.container.create_sender(conn, self.address)
def on_sendable(self, event):
print("sending command")
event.sender.send(Message(body="Hello World!", address="command/DEFAULT_TENANT/4711", content_type="text/plain", subject="call"))
event.sender.close()
event.connection.close()
Container(HelloWorld("amqp://hono.eclipseprojects.io:15672", "command/DEFAULT_TENANT")).run()
maybe you need to use "address" instead of "to"?
Indeed I guess it was me using the lib incorrectly. with your handling of properties it works with mine it doesnt
@/all I will start the 1.8.3 build now ...
So i thought it might be „special“ fixed properties but it seems thats just an issue of qpid and not of Hono
From my understanding, it should be a valid AMQP message if I pass a
properties dict with keys to and subject but it seems that qpid wants it as separate properties address and subject directly (see here: https://qpid.apache.org/releases/qpid-proton-0.32.0/proton/python/docs/proton.html#proton.Message)
Another question regarding the command and control API from HONO. If the application wants to send a command to a device… it needs to implement a strategy to basically „retry“ it until it gets an answer accepted (and even if that, in case of one-way it needs to hope that it worked). Or is there anything more „intelligent“ that works with all adapters (in case of HTTP it could simply react to a message received event with a
ttd set
The "ttd" mechanism works for all protocol adapters. See https://www.eclipse.org/hono/docs/1.8/concepts/device-notifications/ An application simply need to check the ttd application property in messages from devices in order to determine if the device can currently accept commands ...
But I just discovered the command router API which should be some kind of generalization of this idea, right?
it depends. If a device maintains a permanent subscription for commands, e.g. using MQTT or AMQP 1.0, then your application can send commands at any time after it has received a notification containing a ttd value of -1 and before receiving a message with ttd = 0. For devices using stateless protocols like HTTP or CoAP, the application can send commands after it has received a message containing a ttd > 0 and before the ttd has been reached ...
But generally speaking I should implement some kind of „mailbox“ mechanism in my app that „buffers“ the commands (if they are NOT ephemeral)
Slowly I start to see how we would need to modify our application to get it working on HONO
That's the idea, yes. However, we are currently implementing support for using Apache Kafka as an alternative messaging infrastructure (i.e. replacing Dispatch Router and Artemis). This is already available in Hono 1.9 as a tech preview and I guess in the upcoming 1.10.0 version we will declare this fully supported ...
Yes. For that purpose we have also defined kafka based versions of the north bound APIs (e.g. https://www.eclipse.org/hono/docs/1.9/api/kafka-api/ and https://www.eclipse.org/hono/docs/1.9/api/telemetry-kafka/ and https://www.eclipse.org/hono/docs/1.9/api/command-and-control-kafka/)
Hi all, I've question concerning the quarkus images. Some time ago I noticed the quarkus images didn't do what I expected. Yesterday I installed the latest hono version on our test cluster and the quarkus images were used automatically. However, it seems some configuration is not passed to the container. I can't seem to find where the configuration (in code) is coming from. I found
QuarkusMqttProtocolAdapterProperties but couldn't find where this was populated. Do I have to provide the configuration in a different way for these quarkus containers?
17 replies
Short feedback after all my struggle with the initial setup and getting everything right in my tooling we finally start to use Hono and really like it. Very well done guys (special thanks to @sophokles73 for all the help). I try to prepare a little PR with some minor updates in the documentation (things that confused me) to help others to ease their „onboarding"
@sophokles73 Of course. We have a SaaS Offering for Machine Builders (not Factories) where we give them their own whitelabeled „Portal“ to communicate with their machines as well as their clients. So one part of the system is a little bit like the Azure IoTHUB / Boschs IoT Suite but more focused on Metadata and their relation with the Machine and so on. Another crucial part for us is the data history so we rely heavily on Apache IoTDB (there were / are also discussions in the #eclipse/ditto channel about some possibilities to integrate timeseries storage with Ditto in some way)
But simply put.. we have gateways that read data from machinery (a bit like Kura) and sends them via Messaging (currently MQTT only) to our backend where we then do several things with it
And we now decided to migrate to Hono for simple scaling reasons. Not about the infrastructure but the device management as our customer base (luckily) grows : )
