If your logger uses a own format include "aws_request_id", an error will occur.

[belgh]

In the production Lambda environment I am changing the format of the root logger.

Original format in aws lambda:

print(str( logging.getLogger('').handlers[0].formatter._fmt ))
#-> [%(levelname)s]	%(asctime)s.%(msecs)dZ	%(aws_request_id)s	%(message)s

Format I changed:

formatter = logging.Formatter(
  fmt='%(asctime)s.%(msecs)03d [%(aws_request_id)s] %(levelname)s [%(name)s:%(lineno)s] %(message)s\n',
  datefmt='%Y-%m-%d %H:%M:%S'
)
handler = logging.getLogger('').handlers[0]
handler.setFormatter(formatter)

and when this script is executed, the following error occurs.

--- Logging error ---
Traceback (most recent call last):
  File "/usr/lib64/python3.6/logging/__init__.py", line 992, in emit
    msg = self.format(record)
  File "/usr/lib64/python3.6/logging/__init__.py", line 838, in format
    return fmt.format(record)
  File "/usr/lib64/python3.6/logging/__init__.py", line 578, in format
    s = self.formatMessage(record)
  File "/usr/lib64/python3.6/logging/__init__.py", line 547, in formatMessage
    return self._style.format(record)
  File "/usr/lib64/python3.6/logging/__init__.py", line 391, in format
    return self._fmt % record.__dict__
KeyError: 'aws_request_id'

Sorry for the report only.

[yxd-hde]

Would you please post the log output of a Lambda function call on AWS here?

[belgh]

It is described below.
(It is a log output by business, so I am editing it)

2018-11-07 07:43:19.314 [74b70065-a260-c148-a552-1d024c701016] INFO [module_name:100] hello hoge

[yxd-hde]

Fixed by #41 .