PikaBus 1.3.7

Description:

PikaBus 1.3.7

The PikaBus library is a wrapper around pika
to make it easy to implement the messages, events and command pattern, as described in detail here:

https://pikabus.readthedocs.io/en/latest/guidelines_amqp.html


Features


Secure messaging with amqp enabled by default, which includes:

Durable and mirrored queues on all nodes.
Persistent messages, meaning no messages are lost after a node restart.
Delivery confirms with RabbitMq publisher confirms.
Mandatory delivery turned on by default to guarantee at least once delivery.




Object oriented API with short and easy-to-use interface.
Fault-tolerant with auto-reconnect retry logic and state recovery.



Installation
pip install PikaBus


Example
import pika
import datetime
from PikaBus.abstractions.AbstractPikaBus import AbstractPikaBus
from PikaBus.PikaBusSetup import PikaBusSetup


def MessageHandlerMethod(**kwargs):
"""
A message handler method may simply be a method with som **kwargs.
The **kwargs will be given all incoming pipeline data, the bus and the incoming payload.
"""
data: dict = kwargs['data']
bus: AbstractPikaBus = kwargs['bus']
payload: dict = kwargs['payload']
print(payload)
if payload['reply']:
payload['reply'] = False
bus.Reply(payload=payload)


# Use pika connection params to set connection details
credentials = pika.PlainCredentials('amqp', 'amqp')
connParams = pika.ConnectionParameters(
host='localhost',
port=5672,
virtual_host='/',
credentials=credentials)

# Create a PikaBusSetup instance with a listener queue, and add the message handler method.
pikaBusSetup = PikaBusSetup(connParams,
defaultListenerQueue='myQueue',
defaultSubscriptions='myTopic')
pikaBusSetup.AddMessageHandler(MessageHandlerMethod)

# Start consuming messages from the queue.
pikaBusSetup.StartConsumers()

# Create a temporary bus to subscribe on topics and send, defer or publish messages.
bus = pikaBusSetup.CreateBus()
bus.Subscribe('myTopic')
payload = {'hello': 'world!', 'reply': True}

# To send a message means sending a message explicitly to one receiver.
bus.Send(payload=payload, queue='myQueue')

# To defer a message means sending a message explicitly to one receiver with some delay before it is processed.
bus.Defer(payload=payload, delay=datetime.timedelta(seconds=1), queue='myQueue')

# To publish a message means publishing a message on a topic received by any subscribers of the topic.
bus.Publish(payload=payload, topic='myTopic')

input('Hit enter to stop all consuming channels \n\n')
pikaBusSetup.StopConsumers()


Quick Start
Clone PikaBus repo:
git clone https://github.com/hansehe/PikaBus.git
Start local RabbitMq instance with Docker:
docker run -d --name rabbit -e RABBITMQ_DEFAULT_USER=amqp -e RABBITMQ_DEFAULT_PASS=amqp -p 5672:5672 -p 15672:15672 rabbitmq:3-management
Open RabbitMq admin (user=amqp, password=amqp) at:
http://localhost:15672/
Then, run the example:
pip install PikaBus
python ./Examples/basic_example.py
Try restarting RabbitMq to notice how PikaBus tolerates downtime:
docker stop rabbit
docker start rabbit
Send or publish more messages to the running PikaBus consumer with:
python ./Examples/send_example.py
python ./Examples/publish_example.py


Contribute

Issue Tracker: https://github.com/hansehe/PikaBus/issues
Source Code: https://github.com/hansehe/PikaBus



License
The project is licensed under the MIT license.


Versioning
This software follows Semantic Versioning