"""
ourobori use loguru to log.
The logger to be used by the service is created using :func:`default_logger`
defined in this module.
The logger is called inside :func:`ourobori.apps.http._create_app`
automatically so you only have to define the logfile_path where to log
in your service-rules in ``rules.py`` or by passing the argument ``--logfile``
on service-start.
"""
import sys
from typing import Optional
from pathlib import Path
from loguru import logger
from loguru._logger import Logger
try:
from logstash_async.formatter import LogstashFormatter
from logstash_async.handler import AsynchronousLogstashHandler
HAS_LOGSTASH = True
except ModuleNotFoundError:
HAS_LOGSTASH = False
[docs]def default_logger(*,
mode: str,
servicename: str,
logfile_path: Path,
min_level: Optional[str] = 'INFO',
rotation: Optional[str] = '1 day',
retention: Optional[str] = '1 month',
debug: Optional[bool] = False,
logstash_connection: Optional[dict] = None) -> Logger:
"""
Creates the logger based on ``loguru`` to be used inside a service
using the ourobori.
This function is called inside
:func:`ourobori.apps.http.create_app`.
The ``logfile_path`` is extracted from Rules-class inside the rules of
the service.
Parameters:
mode: The runtime mode of the service
servicename: The name of the service
logfile_path: The folder where to store the logfiles.
min_level: The minimal log-level to log.
rotation: How to rotate the logiles.
retention: How long the logfiles will be kept.
debug: Flag if debugmode is on or not.
logstash_connection: The logstash-connection to use for communicate
with logstash. Should be a dict containing the keys 'host" and
'port'.
Returns:
logger: The logger used for logging inside the service based on the
ourobori.
"""
if not logfile_path.exists():
raise FileNotFoundError(
f'logfolder {logfile_path} does not exist')
log_fmt = (
'<green>{time:YYMMDD_HHmmss.SSS}</green> | '
'<level>{level[0]}</level> | '
'<blue>{extra[api_id]}</blue> | '
'<cyan>{name}</cyan>:<cyan>{function}</cyan>:<cyan>{line}</cyan> - '
'<level>{message}</level>')
# the minimal logger-arguments to use in each logger added by this
# function.
log_args = dict(format=log_fmt,
enqueue=True,
backtrace=True,
level='DEBUG' if debug else min_level)
# Remove the default loguru-logger-definition
logger.remove()
# add the customized loguru-logger-definition
logger.add(sink=str((logfile_path / '{time:YYYY_MM_DD}.log').absolute()),
rotation=rotation,
retention=retention,
**log_args)
# define the logger to use for logstash-communication
if logstash_connection and HAS_LOGSTASH:
ls_handler = AsynchronousLogstashHandler(logstash_connection['host'],
logstash_connection['port'],
database_path='logstash.db')
ls_formatter = LogstashFormatter(message_type='python-logstash',
extra_prefix='service',
extra=dict(servicename=servicename,
mode=mode))
ls_handler.setFormatter(ls_formatter)
logger.add(ls_handler,
serialize=True,
**log_args)
# during in debug-mode use an additional logger to print the events to
# terminal
if debug:
logger.add(sink=sys.stdout,
**log_args)
logger_ctx = logger.bind(api_id=' ')
return logger_ctx
__all__ = ['default_logger']