Fedora 41 : python and Federated Message Bus in Fedora Linux Distro.

Federated Message Bus is a library built on ZeroMQ using the PyZMQ Python bindings. fedmsg aims to make it easy to connect services together using ZeroMQ publishers and subscribers.

You can use this python package named fedmsg to use this functionality ...

This is the source code :

import fedmsg
from fedmsg import *

import os
# Set the routing_nitpicky flag to True
os.environ['FEDMSG_ROUTING_NITPICKY'] = 'True'


config = fedmsg.config.load_config([],None)
config['mute'] = True
config['timeout'] = 0

for name, endpoint, topic, msg in fedmsg.tail_messages(**config):
    print ("name ", name)

This is the result :

[mythcat@fedora FedoraMessaging]$ python fedmsg_001.py
No routing policy defined for "org.fedoraproject.prod.copr.build.start" but routing_nitpicky is False so the message is being treated as authorized.
name  fedora-infrastructure
No routing policy defined for "org.fedoraproject.prod.copr.chroot.start" but routing_nitpicky is False so the message is being treated as authorized.
name  fedora-infrastructure
No routing policy defined for "org.fedoraproject.prod.github.check_run" but routing_nitpicky is False so the message is being treated as authorized.
name  fedora-infrastructure
No routing policy defined for "org.fedoraproject.prod.github.pull_request_review" but routing_nitpicky is False so the message is being treated as authorized.
name  fedora-infrastructure
No routing policy defined for "org.fedoraproject.prod.github.pull_request_review_comment" but routing_nitpicky is False so the message is being treated as authorized.
name  fedora-infrastructure ... 

Fedora 40 : Fedora CoreOS - part 001.

The documentation for Fedora 40 CoreOS can be found on the official webpage.

I download the fedora-coreos-40.20240331.1.0-virtualbox.x86_64.ova file.

You can use double click to open with the VirtualBox application, see the next screenshot:

Fedora use ssh keys and a user named core, use these steps from the official webpage to change the password for this user.

The result will be this:

You need to use these steps to create a password based on the butane and ignition software to login with the ssh-rsa.

Fedora 41 : Python and the Fedora Messaging Infrastructure - part 001.

Yesterday I tried to use Fedora Messaging.

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.

Fedora 41 : Memstrack tool.

A runtime memory allocation tracer, like a hot spot analyzer for memory allocation, can help analyze overall memory usage, peak memory usage, kernel module memory usage, all combined with stacktrace. Userspace memory trace is planned and not yet implemented.

This tool works by tracing all page-level memory allocation events in kernel (currently supports using perf or ftrace), and actively integrate the events into a stack trace tree. It can also work with kernel's page owner log file and use as a memory usage viewer.

I tested this tool today and it is quite useful for development and monitoring the operating system, it seems to work very well, you can even see in the screenshot how ...

You can find this project on the GitHub repo.

Fedora 40 : Fix emergency run mode - part 001.

Run this commands to see errors and all failed systemd units:

[root@fedora mythcat]# dmesg | grep err
[root@fedora mythcat]# systemctl status --failed --all

If you get an error like this:

Recovery unable to mount /home

... check the /etc/fstab file to see how your home is set.

News : Fedora 40 Beta RC 1.10 compose ...

The Fedora Linux 40 Beta RC 1.10 compose is GO and will be shipped live on Tuesday, 26th March 2024.

This announcement was made on the devel-announce list by Aoife Moloney.

Aoife Moloney, the Fedora Operations Architect, has recently joined the Fedora community.

The Beta RC compose serves as a preliminary version of the upcoming Fedora release and allows Quality Engineering (QE) to thoroughly test the system and identify any critical issues before the final release.

You can find schedule for Fedora 40 on the official website.

News : Flutter on Fedora 40 - the run debug info.

The run command comes with info about the running process, see:

[mythcat@fedora examples]$ ../flutter/bin/flutter run
Launching lib/main.dart on Linux in debug mode...
Building Linux application...                                           
Syncing files to device Linux...                                 1,488ms

Flutter run key commands.
r Hot reload. 🔥🔥🔥
R Hot restart.
h List all available interactive commands.
d Detach (terminate "flutter run" but leave application running).
c Clear the screen
q Quit (terminate the application on the device).

A Dart VM Service on Linux is available at: http://127.0.0.1:38903/k8tmzU7n0NQ=/
The Flutter DevTools debugger and profiler on Linux is available at:
http://127.0.0.1:9100?uri=http://127.0.0.1:38903/k8tmzU7n0NQ=/

If you open that URL you will see this type of informations: