Fedora Messaging

3.9.0 verified Mon Apr 27 auth: no python

A set of tools for using Fedora's messaging infrastructure, based on RabbitMQ and AMQP. Current version 3.9.0, updated frequently with releases every few months.

pip install fedora-messaging

Common errors

error ModuleNotFoundError: No module named 'fedora_messaging.twisted' ↓

cause The 'twisted' extra is not installed. The twisted submodule requires optional dependencies.

fix

pip install fedora-messaging[twisted]

error KeyError: 'amqp_url' ↓

cause Configuration was not set before calling connect().

fix

Set config.conf['amqp_url'] = 'your_url' before calling connect().

Warnings

breaking Version 3.0 removed the 'fedora_messaging.twisted.service' module; use 'fedora_messaging.twisted.service_factory' instead. ↓

fix Replace imports of fedora_messaging.twisted.service with fedora_messaging.twisted.service_factory.

deprecated The 'fedora_messaging.message.Message' class is deprecated in favor of schema-based messages. Use 'from fedora_messaging.message import Message' will still work but emit a deprecation warning. ↓

fix Use fedora_messaging.schema.Message or define custom messages via schema.

gotcha The configuration file must be loaded before any other imports or calls. Calling config.setup() is not enough; use config.conf to set options directly. ↓

fix Set config.conf['key'] = value before importing other modules that use configuration.

Imports

twisted
wrong
```
import fedora_messaging.twisted
```
correct
```
from fedora_messaging import twisted
```
Submodules must be imported explicitly; direct import may fail.

connect

wrong

from fedora_messaging import connect

correct

from fedora_messaging.api import connect

connect() is in the api submodule, not top-level.

Quickstart

Basic consumer setup. Ensure RabbitMQ is running.

from fedora_messaging import config
from fedora_messaging.api import connect, consume

# Configure connection
config.conf['amqp_url'] = 'amqp://guest:guest@localhost:5672/%2F'

# Define a callback
def callback(message):
    print(f"Received: {message.body}")

# Consume a queue
with connect() as connection:
    consume(connection, callback, queue='my_queue')