Introduction

A library from RCTI+ to handle RabbitMQ tasks (connect, send, receive, etc) in Python.

Requirements

• Python >=3.7.3
• Pika ==1.2.0
• Aio-pika ==6.8.0
• Requests >=2.25.1

Installation

pip install rctiplus-rabbitmq-python-sdk

Getting latest version

pip install rctiplus-rabbitmq-python-sdk --upgrade

Usage

To start using this SDK, you may follow given instructions bellow in order.

Payload handler

First, you need to create a payload class handler that implement MessagePayload. For example, we want to make a class to handle JSON payload:

import json
from rctiplus_rabbitmq_python_sdk import MessagePayload

class JSONPayload(MessagePayload):
    """Example class to handle JSON payload
    """

    def __init__(self, firstname: str, lastname: str) -> None:
        self.firstname = firstname
        self.lastname = lastname

    def __str__(self) -> str:
        """Convert JSON to string payload message

        Returns:
            str: String payload message
        """
        return json.dumps({
            'firstname': self.firstname,
            'lastname': self.lastname
        })
    
    @classmethod
    def from_str(cls, message: str) -> 'JSONPayload':
        """Generate data from JSON string payload message

        Returns:
            JSONPayload: Generated data
        """
        payload = json.loads(message)
        return cls(firstname=payload['firstname'], lastname=payload['lastname'])

MessagePayload class from the SDK's core has this functions that require to implemented:

class MessagePayload:
    """Python RabbitMQ message payload
    """
    
    @classmethod
    def from_str(cls, message: str) -> 'MessagePayload':
        """Generate data from specified string payload message format

        Raises:
            NotImplementedError: Raise an error if not implemented
        """
        raise NotImplementedError()

    def __str__(self) -> str:
        """Convert specified data format to string payload message

        Raises:
            NotImplementedError: Raise an error if not implemented

        Returns:
            str: String payload message
        """
        raise NotImplementedError()

Connect to RabbitMQ

Making connection to RabbitMQ server can be done by doing this simple way:

from rctiplus_rabbitmq_python_sdk import RabbitMQ

conn = RabbitMQ()
conn.connect(host='localhost', port=5672, username='guest', password='guest')

Sending message

After you have payload class handler & connected to the RabbitMQ server, now you can try to send a messsage to queue channel. For example, we will send JSON payload message to test queue:

payload = JSONPayload('John', 'Doe')
print('payload:', payload)
conn.send('test', payload)

Receiving message

Great. Now, in our consumer app, we want to listen & receive that message, and then doing some stuff:

def callback(ch, method, properties, body):
    print("[x] Received %r" % body)
    data = JSONPayload.from_str(body)
    print(f'data: firstname={data.firstname}, lastname={data.lastname}')

conn.receive('test', callback)

For callback function, according to Pikas standart library, you need to pass 4 arguments ch, method, properties and body to catch all needed values from incomming message.

Putting it all together

Here is the complete example from the code above:

Complete example of sender or producer app:

import json
from rctiplus_rabbitmq_python_sdk import RabbitMQ, MessagePayload


# Create payload class handler that implement `MessagePayload`
class JSONPayload(MessagePayload):
    """Example class to handle JSON payload
    """

    def __init__(self, firstname: str, lastname: str) -> None:
        self.firstname = firstname
        self.lastname = lastname

    def __str__(self) -> str:
        """Convert JSON to string payload message

        Returns:
            str: String payload message
        """
        return json.dumps({
            'firstname': self.firstname,
            'lastname': self.lastname
        })
    
    @classmethod
    def from_str(cls, message: str) -> 'JSONPayload':
        """Generate data from JSON string payload message

        Returns:
            JSONPayload: Generated data
        """
        payload = json.loads(message)
        return cls(firstname=payload['firstname'], lastname=payload['lastname'])


# Connect to RabbitMQ
conn = RabbitMQ()
conn.connect(host='localhost', port=5672, username='guest', password='guest')

# Send payload to queue
payload = JSONPayload('John', 'Doe')
print('payload:', payload)
conn.send('test', payload)

Complete example of consumer or receiver app:

import json
from rctiplus_rabbitmq_python_sdk import RabbitMQ, MessagePayload


# Create payload class handler that implement `MessagePayload`
class JSONPayload(MessagePayload):
    """Example class to handle JSON payload
    """

    def __init__(self, firstname: str, lastname: str) -> None:
        self.firstname = firstname
        self.lastname = lastname

    def __str__(self) -> str:
        """Convert JSON to string payload message

        Returns:
            str: String payload message
        """
        return json.dumps({
            'firstname': self.firstname,
            'lastname': self.lastname
        })

    @classmethod
    def from_str(cls, message: str) -> 'JSONPayload':
        """Generate data from JSON string payload message

        Returns:
            JSONPayload: Generated data
        """
        payload = json.loads(message)
        return cls(firstname=payload['firstname'], lastname=payload['lastname'])


# Connect to RabbitMQ
conn = RabbitMQ()
conn.connect(host='localhost', port=5672, username='guest', password='guest')

# Create a callback to be executed immadiately after recieved a message
def callback(ch, method, properties, body):
    print("[x] Received %r" % body)
    
    # Generate data from string payload message
    data = JSONPayload.from_str(body)
    print(f'data: firstname={data.firstname}, lastname={data.lastname}')

# Receive & listen messages from queue channel
conn.receive('test', callback)

Asynchronous

This SDK also support asynchronous process. To use this feature, use AIORabbitMQ instead of RabbitMQ. All methods provided in AIORabbitMQ are treated as async function. So, when you calling the methods, you need to await them.

Async connect to RabbitMQ

from rctiplus_rabbitmq_python_sdk import AIORabbitMQ

conn = AIORabbitMQ(loop)
await conn.connect(host='localhost', port=5672, username='guest', password='guest')

loop is an asynchronous event loop, example: asyncio.get_event_loop()

Async sending message

payload = JSONPayload('John', 'Doe')
print('payload:', payload)
await conn.send('test', payload)

Async receiving message

async def callback(message):
    body = message.body
    print("[x] Received %r" % body)
    data = JSONPayload.from_str(body)
    print(f'data: firstname={data.firstname}, lastname={data.lastname}')

await conn.receive('test', callback)

In asynchronous process, you just need pass 1 argument on callback function. This argument is a representation of aio_pika.IncomingMessage to catch all needed values from incomming message.

Complete example of asynchronous process

Here is the complete example of asynchronous process above:

Complete example of asynchronous sender or producer app:

import json
import asyncio
from rctiplus_rabbitmq_python_sdk import AIORabbitMQ, MessagePayload


# Create payload class handler that implement `MessagePayload`
class JSONPayload(MessagePayload):
    """Example class to handle JSON payload
    """

    def __init__(self, firstname: str, lastname: str) -> None:
        self.firstname = firstname
        self.lastname = lastname

    def __str__(self) -> str:
        """Convert JSON to string payload message

        Returns:
            str: String payload message
        """
        return json.dumps({
            'firstname': self.firstname,
            'lastname': self.lastname
        })
    
    @classmethod
    def from_str(cls, message: str) -> 'JSONPayload':
        """Generate data from JSON string payload message

        Returns:
            JSONPayload: Generated data
        """
        payload = json.loads(message)
        return cls(firstname=payload['firstname'], lastname=payload['lastname'])


# Main function
async def main(loop):

    # Connect to RabbitMQ
    conn = AIORabbitMQ(loop)
    await conn.connect(host='localhost', port=5672, username='guest', password='guest')
    
    async with conn.connection:
        # Send payload to queue
        payload = JSONPayload('John', 'Doe')
        print('payload:', payload)
        await conn.send('test', payload)


# Event loop
loop = asyncio.get_event_loop()
loop.run_until_complete(main(loop))
loop.close()

Complete example of asynchronous consumer or receiver app:

import json
import asyncio
from rctiplus_rabbitmq_python_sdk import AIORabbitMQ, MessagePayload


# Create payload class handler that implement `MessagePayload`
class JSONPayload(MessagePayload):
    """Example class to handle JSON payload
    """

    def __init__(self, firstname: str, lastname: str) -> None:
        self.firstname = firstname
        self.lastname = lastname

    def __str__(self) -> str:
        """Convert JSON to string payload message

        Returns:
            str: String payload message
        """
        return json.dumps({
            'firstname': self.firstname,
            'lastname': self.lastname
        })
    
    @classmethod
    def from_str(cls, message: str) -> 'JSONPayload':
        """Generate data from JSON string payload message

        Returns:
            JSONPayload: Generated data
        """
        payload = json.loads(message)
        return cls(firstname=payload['firstname'], lastname=payload['lastname'])


# Main function
async def main(loop):

    # Connect to RabbitMQ
    conn = AIORabbitMQ(loop)
    await conn.connect(host='localhost', port=5672, username='guest', password='guest')
    
    # Create a callback to be executed immadiately after recieved a message
    async def callback(message):
        body = message.body
        print("[x] Received %r" % body)
        
        # Generate data from string payload message
        data = JSONPayload.from_str(body)
        print(f'data: firstname={data.firstname}, lastname={data.lastname}')

    # Receive & listen messages from queue channel
    await conn.receive('test', callback)

    return conn


# Event loop
loop = asyncio.get_event_loop()
connection = loop.run_until_complete(main(loop))
try:
    loop.run_forever()
finally:
    loop.run_until_complete(connection.disconnect())

License

GNU General Public License v3