Python 3.12.2 : Python and the Fedora Messaging Infrastructure - part 001.

I tried using the Fedora Messaging online tool with the python package of the same name on Python version 3.12.2.

You can find the documentation on the official page./div>

I created a working folder called FedoraMessaging:

[mythcat@fedora PythonProjects]$ mkdir FedoraMessaging
[mythcat@fedora PythonProjects]$ cd FedoraMessaging

You need to install the fedora-messaging and rabbitmq-server packages.

[root@fedora FedoraMessaging]# dnf5 install fedora-messaging
Updating and loading repositories:
Repositories loaded.
Package                             Arch    Version                       Repository         Size
Installing:                                                                                      
 fedora-messaging                   noarch  3.5.0-1.fc41                  rawhide        38.6 KiB
...
[root@fedora FedoraMessaging]# dnf install rabbitmq-server

At some point it will ask for a reboot.

You need to install the python package named fedora-messaging.

[root@fedora FedoraMessaging]# pip install --user fedora-messaging
Collecting fedora-messaging
...
Installing collected packages: pytz, incremental, wrapt, tomli, rpds-py, pyasn1, pika, hyperlink, constantly, attrs, 
referencing, pyasn1-modules, automat, twisted, jsonschema-specifications, service-identity, jsonschema, crochet, 
fedora-messaging
Successfully installed attrs-23.2.0 automat-22.10.0 constantly-23.10.4 crochet-2.1.1 fedora-messaging-3.5.0 
hyperlink-21.0.0 incremental-22.10.0 jsonschema-4.21.1 jsonschema-specifications-2023.12.1 pika-1.3.2 pyasn1-0.6.0 
pyasn1-modules-0.4.0 pytz-2024.1 referencing-0.34.0 rpds-py-0.18.0 service-identity-24.1.0 tomli-2.0.1 twisted-24.3.0 
wrapt-1.16.0

You need to start the broker:

[mythcat@fedora FedoraMessaging]$ sudo systemctl start rabbitmq-server

I used the source code from the documentation to test its functionality with a python script named hello_test.py.

from fedora_messaging import api, config

config.conf.setup_logging()
api.consume(lambda message: print(message))

from fedora_messaging import api, config

config.conf.setup_logging()
api.publish(api.Message(topic="hello by mythcat", body={"Hello": "world!"}))

I ran it and got this response:

[mythcat@fedora FedoraMessaging]$ python hello_test.py
[fedora_messaging.message INFO] Registering the 'base.message' key as the '<class 'fedora_messaging.message.Message'>' 
class in the Message class registry
[fedora_messaging.twisted.protocol INFO] Waiting for 0 consumer(s) to finish processing before halting
[fedora_messaging.twisted.protocol INFO] Finished canceling 0 consumers
[fedora_messaging.twisted.protocol INFO] Disconnect requested, but AMQP connection already gone

I created another python script named my_consumer.py, to check if this works:

from fedora_messaging import api, config
# Setup logging
config.conf.setup_logging()
# Define the callback function to process messages
def process_message(message):
    # Check if the message topic matches "hello by mythcat"
    if message.topic == "hello by mythcat":
        print(f"Received message: {message.body}")
    else:
        print(f"Ignoring message with topic: {message.topic}")
# Consume messages
api.consume(process_message)

I ran it and got this response:

[mythcat@fedora FedoraMessaging]$ python my_consumer.py
[fedora_messaging.twisted.protocol INFO] Successfully registered AMQP consumer Consumer(queue=amq.gen-9lKk7sGeYY5I40bdc5VrzQ,
callback=<function process_message at 0x7fdb0f5da160>)
[fedora_messaging.message INFO] Registering the 'base.message' key as the '<class 'fedora_messaging.message.Message'>'
class in the Message class registry
[fedora_messaging.twisted.consumer INFO] Consuming message from topic hello by mythcat 
(message id 800a1540-1e91-4b4a-a125-15e33eebb699)
Received message: {'Hello': 'world!'}
[fedora_messaging.twisted.consumer INFO] Successfully consumed message from topic hello by mythcat 
(message id 800a1540-1e91-4b4a-a125-15e33eebb699)

It can be seen that the answer is received and displayed correctly.