import logging
from config import get_config, WithLogger
class SlackHandler(logging.Handler, WithLogger):
"""
A logging.Handler subclass for logging messages into a Slack channel.
See also: https://docs.python.org/3/library/logging.html#handler-objects
"""
def __init__(self, slackbot, level):
"""
`slackbot` is an initialized Slackbot() object
`log_channel` is the name of a channel that should receive log messages
`level` is the log level to use for logging to the Slack channel
"""
super(self.__class__, self).__init__(level) # pylint: disable=E1003
self.slackbot = slackbot
def emit(self, record):
"""Do whatever it takes to actually log the specified logging record."""
self.slackbot.say(self.config.log_channel, record.getMessage())
def set_up_slack_logger(slackbot=None):
"""
Sets up a handler and formatter on a given `logging.Logger` object.
* `log_level_env_var` - Grabs logging level from this ENV var. Possible values are standard: "debug", "error", etc.
* `log_to_slack_env_var` - Points to an ENV var that indicates whether to log to a Slack channel.
* `log_channel` - Indicates the name of the Slack channel to which we'll send logs.
* `default_level` - The default log level if one is not set in the environment.
* `slackbot` - A slackbot.Slackbot() object ready to send messages to a Slack channel.
"""
logger = logging.getLogger()
if logger.handlers:
# We've likely already ran through the rest of this method:
return
_config = get_config()
slack_log_level = getattr(logging, _config.log_level.upper(), logging.INFO)
formatter = logging.Formatter('%(asctime)s [%(levelname)s]: %(message)s')
logger.setLevel(logging.DEBUG)
stream_handler = logging.StreamHandler()
stream_handler.setFormatter(formatter)
logger.addHandler(stream_handler)
if _config.log_to_channel and _config.log_channel and slackbot:
logger.debug("Logging to slack channel: %s", _config.log_channel)
slack_handler = SlackHandler(slackbot=slackbot, level=slack_log_level)
slack_handler.setFormatter(formatter)
logger.addHandler(slack_handler)
