amqp-rpc-client

AMQP RPC Client

This library offers a Remote-Procedure-Call client which communicates its messages via a message broker which uses the AMQPv0-9-1 protocol.

This library is currently only tested with RabbitMQ since the underlying package pika is only tested with the RabbitMQ server

Usage

General

This AMQP RPC Client uses an extra thread in which it handles data events like new messages or sending keep-alive messages. Therefore, your code will continue to execute after sending a message without waiting for a response. See the attached examples for how to use the library

Examples

Create a new client

from amqp_rpc_client import Client

# The Data Source Name which is used to connect to the message broker. The virtual host currently
# is "/". Special characters need to be url-encoded
AMQP_DSN = 'amqp://<<your-username>>:<<your-password>>@<<your-message-broker-address>>/%2F'

# Create the new client with the data source name
rpc_client = Client(AMQP_DSN)

Send a message to another exchange

from amqp_rpc_client import Client

# The Data Source Name which is used to connect to the message broker. The virtual host currently
# is "/". Special characters need to be url-encoded
AMQP_DSN = 'amqp://<<your-username>>:<<your-password>>@<<your-message-broker-address>>/%2F'

# The exchange into which the message shall be posted
TARGET_EXCHANGE = 'hello_world'

# Create the new client with the data source name
rpc_client = Client(AMQP_DSN)

# Send a message to the specified exchange
rpc_client.send('my_message_content_string', TARGET_EXCHANGE)

Send a message to another exchange and wait for the answer

from amqp_rpc_client import Client

# The Data Source Name which is used to connect to the message broker. The virtual host currently
# is "/". Special characters need to be url-encoded
AMQP_DSN = 'amqp://<<your-username>>:<<your-password>>@<<your-message-broker-address>>/%2F'

# The exchange into which the message shall be posted
TARGET_EXCHANGE = 'hello_world'

# Create the new client with the data source name
rpc_client = Client(AMQP_DSN)

# Send a message to the specified exchange. This will return a message id which can be used to wait
# for a response
message_id = rpc_client.send('my_message_content_string', TARGET_EXCHANGE)

# Wait indefinitely and receive the response bytes
response: bytes = rpc_client.await_response(message_id)

Send a message to another exchange and wait for the answer with an timeout

from amqp_rpc_client import Client

# The Data Source Name which is used to connect to the message broker. The virtual host currently
# is "/". Special characters need to be url-encoded
AMQP_DSN = 'amqp://<<your-username>>:<<your-password>>@<<your-message-broker-address>>/%2F'

# The exchange into which the message shall be posted
TARGET_EXCHANGE = 'hello_world'

# The timeout in seconds as to how long the answer shall be awaited
ANSWER_TIMEOUT: float = 10.0

# Create the new client with the data source name
rpc_client = Client(AMQP_DSN)

# Send a message to the specified exchange. This will return a message id which can be used to wait
# for a response
message_id = rpc_client.send('my_message_content_string', TARGET_EXCHANGE)

# Wait indefinitely and receive the response bytes
response: bytes = rpc_client.await_response(message_id, ANSWER_TIMEOUT)

# Check if a response was received
if response is None:
    print('No response received')
else:
    print(response)

Directly get the response content if it is available

from amqp_rpc_client import Client

# The Data Source Name which is used to connect to the message broker. The virtual host currently
# is "/". Special characters need to be url-encoded
AMQP_DSN = 'amqp://<<your-username>>:<<your-password>>@<<your-message-broker-address>>/%2F'

# The exchange into which the message shall be posted
TARGET_EXCHANGE = 'hello_world'

# The timeout in seconds as to how long the answer shall be awaited
ANSWER_TIMEOUT: float = 10.0

# Create the new client with the data source name
rpc_client = Client(AMQP_DSN)

# Send a message to the specified exchange. This will return a message id which can be used to wait
# for a response
message_id = rpc_client.send('my_message_content_string', TARGET_EXCHANGE)

# Try to get the response
response: bytes = rpc_client.get_response(message_id)

# Check if a response was received
if response is None:
    print('No response received')
else:
    print(response)