nexiles / nxlogger

nexiles logger package

nxlogger

A Python Logging Handler for RabbitMQ (http://www.rabbitmq.com)

Usage

The RabbitMQLogHandler creates a named Exchange in RabbitMQ for Logging. By default, the Exchange is called logs and is defined as a topic Exchange. These Parameters can be changed in the constructor of the RabbitMQLogHandler:

RabbitMQLogHandler(host="localhost", port=5672, exchange="logs", type="topic")

As long as there are no Queues connected, the log messages get trashed.

Example Code:

import logging
from nexiles.logger.handler import RabbitMQLogHandler

logger = logging.getLogger("rabbitlog")
logger.setLevel(logging.INFO)

rabbitmq_handler = RabbitMQLogHandler()
logger.addHandler(rabbitmq_handler)

logger.info("Now logging to RabbitMQ, no matter if there are Queues or not...")

Receiving Logs

To receive logs, we have to connect to the named Exchange (default: logs). A Consumer can decide over the routing_key which type of logs it can handle, e.g. INFO for Info logs only or # for all logs.

Example code (receive_logs.py):

import pika

connection = pika.BlockingConnection(pika.ConnectionParameters(
        host='localhost'))
channel = connection.channel()

# just to be sure
channel.exchange_declare(exchange='logs', type='topic')

# queue will be deleted after disconnecting
result = channel.queue_declare(exclusive=True)

# creates a queue with a random name
queue_name = result.method.queue

# bind to the named **logs** exchange and accept all logging severities
# with the routing_key #
channel.queue_bind(exchange='logs',
                   routing_key="#",
                   queue=queue_name)

# simple print callback
def callback(ch, method, properties, body):
    print "%r" % (body,)

# we don't care about losing logs....
channel.basic_consume(callback,
                      queue=queue_name,
                      no_ack=True)

# consume forever
channel.start_consuming()