This package provides a handler and subscriber for multiprocess
logbook
logging that runs on the
asyncio
event loop. It uses
aiopipe
to transfer log messages from the child
process to the parent process.
The following example shows a typical application of multiprocess logging. It results in
two log messages, hello from parent process
and hello from child process
, being
printed in some order.
from contextlib import closing
from multiprocessing import Process
import asyncio
from aiopipe import aiopipe
from logbook_aiopipe import AioPipeSubscriber, \
AioPipeHandler
from logbook import Logger, StderrHandler
async def mainTask(eventLoop):
# The parent process logger can be set up as normal.
log = Logger()
log.handlers.append(StderrHandler())
rx, tx = aiopipe()
sub = AioPipeSubscriber(await rx.open(eventLoop), log)
with closing(sub):
subTask = eventLoop.create_task(sub.run())
with tx.send() as tx:
proc = Process(target=childProc, args=(tx,))
proc.start()
log.info("hello from parent process")
proc.join()
await subTask
def childProc(tx):
eventLoop = asyncio.new_event_loop()
eventLoop.run_until_complete(childTask(eventLoop, tx))
async def childTask(eventLoop, tx):
log = Logger()
# The child process should use only `AioPipeHandler` as
# its handler.
handler = AioPipeHandler(await tx.open(eventLoop))
log.handlers.append(handler)
with closing(handler):
log.info("hello from child process")
eventLoop = asyncio.get_event_loop()
eventLoop.run_until_complete(mainTask(eventLoop))
This package requires Python >= 3.5.0 and can be installed with pip
:
pip install logbook_aiopipe