aiormq 6.9.3

Pure python AMQP asynchronous client library

aiormq is a pure python AMQP client library.

Table of contents

• Status

• Features

• Tutorial

  • Introduction

    • Simple consumer

    • Simple publisher

  • Work Queues

    • Create new task

    • Simple worker

  • Publish Subscribe

    • Publisher

    • Subscriber

  • Routing

    • Direct consumer

    • Emitter

  • Topics

    • Publisher

    • Consumer

  • Remote procedure call (RPC)

    • RPC server

    • RPC client

Status

• 3.x.x branch - Production/Stable

• 4.x.x branch - Unstable (Experimental)

• 5.x.x and greater is only Production/Stable releases.

Features

• Connecting by URL

• amqp example: amqp://user:[e-mail]/vhost

• secure amqp example: amqps://user:[e-mail]/vhost?cafile=ca.pem&keyfile=key.pem&certfile=cert.pem&no_verify_ssl=0

• Buffered queue for received frames

• Only PLAIN auth mechanism support

• Publisher confirms support

• Transactions support

• Channel based asynchronous locks

  Note

  AMQP 0.9.1 requires serialize sending for some frame types on the channel. e.g. Content body must be following after content header. But frames might be sent asynchronously on another channels.

• Tracking unroutable messages (Use connection.channel(on_return_raises=False) for disabling)

• Full SSL/TLS support, using your choice of:

  • amqps:// url query parameters:

    • cafile= - string contains path to ca certificate file

    • capath= - string contains path to ca certificates

    • cadata= - base64 encoded ca certificate data

    • keyfile= - string contains path to key file

    • certfile= - string contains path to certificate file

    • no_verify_ssl - boolean disables certificates validation

  • context= SSLContext keyword argument to connect().

• Python type hints

• Uses pamqp as an AMQP 0.9.1 frame encoder/decoder

Tutorial

Introduction

Simple consumer

import asyncio
import aiormq

async def on_message(message):
    """
    on_message doesn't necessarily have to be defined as async.
    Here it is to show that it's possible.
    """
    print(f" [x] Received message {message!r}")
    print(f"Message body is: {message.body!r}")
    print("Before sleep!")
    await asyncio.sleep(5)   # Represents async I/O operations
    print("After sleep!")


async def main():
    # Perform connection
    connection = await aiormq.connect("amqp://guest:guest@localhost/")

    # Creating a channel
    channel = await connection.channel()

    # Declaring queue
    declare_ok = await channel.queue_declare('hello', auto_delete=True)
    consume_ok = await channel.basic_consume(
        declare_ok.queue, on_message, no_ack=True
    )


loop = asyncio.get_event_loop()
loop.run_until_complete(main())
loop.run_forever()

Simple publisher

import asyncio
from typing import Optional

import aiormq
from aiormq.abc import DeliveredMessage


MESSAGE: Optional[DeliveredMessage] = None


async def main():
    global MESSAGE

    body = b'Hello World!'

    # Perform connection
    connection = await aiormq.connect("amqp://guest:guest@localhost//")

    # Creating a channel
    channel = await connection.channel()

    declare_ok = await channel.queue_declare("hello", auto_delete=True)

    # Sending the message
    await channel.basic_publish(body, routing_key='hello')
    print(f" [x] Sent {body}")

    MESSAGE = await channel.basic_get(declare_ok.queue)
    print(f" [x] Received message from {declare_ok.queue!r}")


loop = asyncio.get_event_loop()
loop.run_until_complete(main())

assert MESSAGE is not None
assert MESSAGE.routing_key == "hello"
assert MESSAGE.body == b'Hello World!'

Work Queues

Create new task

import sys
import asyncio
import aiormq


async def main():
    # Perform connection
    connection = await aiormq.connect("amqp://guest:guest@localhost/")

    # Creating a channel
    channel = await connection.channel()

    body = b' '.join(sys.argv[1:]) or b"Hello World!"

    # Sending the message
    await channel.basic_publish(
        body,
        routing_key='task_queue',
        properties=aiormq.spec.Basic.Properties(
            delivery_mode=1,
        )
    )

    print(f" [x] Sent {body!r}")

    await connection.close()


loop = asyncio.get_event_loop()
loop.run_until_complete(main())

Simple worker

import asyncio
import aiormq
import aiormq.abc


async def on_message(message: aiormq.abc.DeliveredMessage):
    print(f" [x] Received message {message!r}")
    print(f"     Message body is: {message.body!r}")


async def main():
    # Perform connection
    connection = await aiormq.connect("amqp://guest:guest@localhost/")


    # Creating a channel
    channel = await connection.channel()
    await channel.basic_qos(prefetch_count=1)

    # Declaring queue
    declare_ok = await channel.queue_declare('task_queue', durable=True)

    # Start listening the queue with name 'task_queue'
    await channel.basic_consume(declare_ok.queue, on_message, no_ack=True)


loop = asyncio.get_event_loop()
loop.run_until_complete(main())

# we enter a never-ending loop that waits for data and runs
# callbacks whenever necessary.
print(" [*] Waiting for messages. To exit press CTRL+C")
loop.run_forever()

Publish Subscribe

Publisher

import sys
import asyncio
import aiormq


async def main():
    # Perform connection
    connection = await aiormq.connect("amqp://guest:guest@localhost/")

    # Creating a channel
    channel = await connection.channel()

    await channel.exchange_declare(
        exchange='logs', exchange_type='fanout'
    )

    body = b' '.join(sys.argv[1:]) or b"Hello World!"

    # Sending the message
    await channel.basic_publish(
        body, routing_key='info', exchange='logs'
    )

    print(f" [x] Sent {body!r}")

    await connection.close()


loop = asyncio.get_event_loop()
loop.run_until_complete(main())

Subscriber

import asyncio
import aiormq
import aiormq.abc


async def on_message(message: aiormq.abc.DeliveredMessage):
    print(f"[x] {message.body!r}")

    await message.channel.basic_ack(
        message.delivery.delivery_tag
    )


async def main():
    # Perform connection
    connection = await aiormq.connect("amqp://guest:guest@localhost/")

    # Creating a channel
    channel = await connection.channel()
    await channel.basic_qos(prefetch_count=1)

    await channel.exchange_declare(
        exchange='logs', exchange_type='fanout'
    )

    # Declaring queue
    declare_ok = await channel.queue_declare(exclusive=True)

    # Binding the queue to the exchange
    await channel.queue_bind(declare_ok.queue, 'logs')

    # Start listening the queue with name 'task_queue'
    await channel.basic_consume(declare_ok.queue, on_message)


loop = asyncio.get_event_loop()
loop.create_task(main())

# we enter a never-ending loop that waits for data
# and runs callbacks whenever necessary.
print(' [*] Waiting for logs. To exit press CTRL+C')
loop.run_forever()

Routing

Direct consumer

import sys
import asyncio
import aiormq
import aiormq.abc


async def on_message(message: aiormq.abc.DeliveredMessage):
    print(f" [x] {message.delivery.routing_key!r}:{message.body!r}"
    await message.channel.basic_ack(
        message.delivery.delivery_tag
    )


async def main():
    # Perform connection
    connection = aiormq.Connection("amqp://guest:guest@localhost/")
    await connection.connect()

    # Creating a channel
    channel = await connection.channel()
    await channel.basic_qos(prefetch_count=1)

    severities = sys.argv[1:]

    if not severities:
        sys.stderr.write(f"Usage: {sys.argv[0]} [info] [warning] [error]\n")
        sys.exit(1)

    # Declare an exchange
    await channel.exchange_declare(
        exchange='logs', exchange_type='direct'
    )

    # Declaring random queue
    declare_ok = await channel.queue_declare(durable=True, auto_delete=True)

    for severity in severities:
        await channel.queue_bind(
            declare_ok.queue, 'logs', routing_key=severity
        )

    # Start listening the random queue
    await channel.basic_consume(declare_ok.queue, on_message)


loop = asyncio.get_event_loop()
loop.run_until_complete(main())

# we enter a never-ending loop that waits for data
# and runs callbacks whenever necessary.
print(" [*] Waiting for messages. To exit press CTRL+C")
loop.run_forever()

Emitter

import sys
import asyncio
import aiormq


async def main():
    # Perform connection
    connection = await aiormq.connect("amqp://guest:guest@localhost/")

    # Creating a channel
    channel = await connection.channel()

    await channel.exchange_declare(
        exchange='logs', exchange_type='direct'
    )

    body = (
        b' '.join(arg.encode() for arg in sys.argv[2:])
        or
        b"Hello World!"
    )

    # Sending the message
    routing_key = sys.argv[1] if len(sys.argv) > 2 else 'info'

    await channel.basic_publish(
        body, exchange='logs', routing_key=routing_key,
        properties=aiormq.spec.Basic.Properties(
            delivery_mode=1
        )
    )

    print(f" [x] Sent {body!r}")

    await connection.close()


loop = asyncio.get_event_loop()
loop.run_until_complete(main())

Topics

Publisher

import sys
import asyncio
import aiormq


async def main():
    # Perform connection
    connection = await aiormq.connect("amqp://guest:guest@localhost/")

    # Creating a channel
    channel = await connection.channel()

    await channel.exchange_declare('topic_logs', exchange_type='topic')

    routing_key = (
        sys.argv[1] if len(sys.argv) > 2 else 'anonymous.info'
    )

    body = (
        b' '.join(arg.encode() for arg in sys.argv[2:])
        or
        b"Hello World!"
    )

    # Sending the message
    await channel.basic_publish(
        body, exchange='topic_logs', routing_key=routing_key,
        properties=aiormq.spec.Basic.Properties(
            delivery_mode=1
        )
    )

    print(f" [x] Sent {body!r}")

    await connection.close()


loop = asyncio.get_event_loop()
loop.run_until_complete(main())

Consumer

import asyncio
import sys
import aiormq
import aiormq.abc


async def on_message(message: aiormq.abc.DeliveredMessage):
    print(f" [x] {message.delivery.routing_key!r}:{message.body!r}")
    await message.channel.basic_ack(
        message.delivery.delivery_tag
    )


async def main():
    # Perform connection
    connection = await aiormq.connect(
        "amqp://guest:guest@localhost/", loop=loop
    )

    # Creating a channel
    channel = await connection.channel()
    await channel.basic_qos(prefetch_count=1)

    # Declare an exchange
    await channel.exchange_declare('topic_logs', exchange_type='topic')

    # Declaring queue
    declare_ok = await channel.queue_declare('task_queue', durable=True)

    binding_keys = sys.argv[1:]

    if not binding_keys:
        sys.stderr.write(
            f"Usage: {sys.argv[0]} [binding_key]...\n"
        )
        sys.exit(1)

    for binding_key in binding_keys:
        await channel.queue_bind(
            declare_ok.queue, 'topic_logs', routing_key=binding_key
        )

    # Start listening the queue with name 'task_queue'
    await channel.basic_consume(declare_ok.queue, on_message)


loop = asyncio.get_event_loop()
loop.create_task(main())

# we enter a never-ending loop that waits for
# data and runs callbacks whenever necessary.
print(" [*] Waiting for messages. To exit press CTRL+C")
loop.run_forever()

Remote procedure call (RPC)

RPC server

import asyncio
import aiormq
import aiormq.abc


def fib(n):
    if n == 0:
        return 0
    elif n == 1:
        return 1
    else:
        return fib(n-1) + fib(n-2)


async def on_message(message:aiormq.abc.DeliveredMessage):
    n = int(message.body.decode())

    print(f" [.] fib({n})")
    response = str(fib(n)).encode()

    await message.channel.basic_publish(
        response, routing_key=message.header.properties.reply_to,
        properties=aiormq.spec.Basic.Properties(
            correlation_id=message.header.properties.correlation_id
        ),

    )

    await message.channel.basic_ack(message.delivery.delivery_tag)
    print('Request complete')


async def main():
    # Perform connection
    connection = await aiormq.connect("amqp://guest:guest@localhost/")

    # Creating a channel
    channel = await connection.channel()

    # Declaring queue
    declare_ok = await channel.queue_declare('rpc_queue')

    # Start listening the queue with name 'hello'
    await channel.basic_consume(declare_ok.queue, on_message)


loop = asyncio.get_event_loop()
loop.create_task(main())

# we enter a never-ending loop that waits for data
# and runs callbacks whenever necessary.
print(" [x] Awaiting RPC requests")
loop.run_forever()

RPC client

import asyncio
import uuid
import aiormq
import aiormq.abc


class FibonacciRpcClient:
    def __init__(self):
        self.connection = None      # type: aiormq.Connection
        self.channel = None         # type: aiormq.Channel
        self.callback_queue = ''
        self.futures = {}
        self.loop = loop

    async def connect(self):
        self.connection = await aiormq.connect("amqp://guest:guest@localhost/")

        self.channel = await self.connection.channel()
        declare_ok = await self.channel.queue_declare(
            exclusive=True, auto_delete=True
        )

        await self.channel.basic_consume(declare_ok.queue, self.on_response)

        self.callback_queue = declare_ok.queue

        return self

    async def on_response(self, message: aiormq.abc.DeliveredMessage):
        future = self.futures.pop(message.header.properties.correlation_id)
        future.set_result(message.body)

    async def call(self, n):
        correlation_id = str(uuid.uuid4())
        future = loop.create_future()

        self.futures[correlation_id] = future

        await self.channel.basic_publish(
            str(n).encode(), routing_key='rpc_queue',
            properties=aiormq.spec.Basic.Properties(
                content_type='text/plain',
                correlation_id=correlation_id,
                reply_to=self.callback_queue,
            )
        )

        return int(await future)


async def main():
    fibonacci_rpc = await FibonacciRpcClient().connect()
    print(" [x] Requesting fib(30)")
    response = await fibonacci_rpc.call(30)
    print(r" [.] Got {response!r}")


loop = asyncio.get_event_loop()
loop.run_until_complete(main())