With Pytest and Lambda Powertools installed, run the following command to have human readable and highlighted log statements including stack traces:
POWERTOOLS_LOG_DEDUPLICATION_DISABLED="1" pytest -o log_cli=1 prod_no_swap.pyOutput should look like this:
| 2021-05-13 19:05:25,506+0200 — INFO — main:32 — Hello - {'context': {'device_id': '11e9034354f', 'device_location': 'London'}} - - | |
| 2021-05-13 19:05:25,507+0200 — ERROR — main:36 — Log stacktrace... - {} - ZeroDivisionError - Traceback (most recent call last): | |
| File "prod.py", line 34, in main | |
| 1 / 0 | |
| ZeroDivisionError: division by zero |
| from typing import Dict | |
| import logging | |
| import os | |
| from aws_lambda_powertools import Logger | |
| from aws_lambda_powertools.logging.formatter import LambdaPowertoolsFormatter | |
| class LocalPlainFormatter(LambdaPowertoolsFormatter): | |
| def serialize(self, log: Dict) -> str: | |
| timestamp = log.pop("timestamp", "") | |
| level = log.pop("level", "") | |
| funcNameLoc = log.pop("location", "") | |
| message = log.pop("message", "") | |
| exception = log.pop("exception", "") | |
| exception_name = log.pop("exception_name", "") | |
| extras = log | |
| return f"{timestamp} — {level} — {funcNameLoc} — {message} - {extras} - {exception_name} - {exception}" | |
| # use local formatter and local file only when PT_409 flag is set | |
| has_flag = os.getenv("PT_409") | |
| file_handler = logging.FileHandler("log.txt") if has_flag else None | |
| formatter = LocalPlainFormatter() if has_flag else None | |
| LOGGER = Logger(datefmt="%Y-%m-%dT%H:%M:%SZ", logger_formatter=formatter, logger_handler=file_handler) | |
| def main(): | |
| LOGGER.info("Hello") | |
| try: | |
| 1 / 0 | |
| except ZeroDivisionError: | |
| LOGGER.exception("Log stacktrace...") | |
| if __name__ == "__main__": | |
| main() |
| from aws_lambda_powertools import Logger | |
| LOGGER = Logger(datefmt="%Y-%m-%dT%H:%M:%SZ") | |
| def main(): | |
| LOGGER.info("Hello") | |
| try: | |
| 1 / 0 | |
| except ZeroDivisionError: | |
| LOGGER.exception("Log stacktrace...") |
Export custom flag PT_409 when running locally to log in plain text and write output into log.txt file
PT_409="1" python prod.py Output should look like this:
2021-05-13 19:05:25,506+0200 — INFO — main:32 — Hello - {'context': {'device_id': '11e9034354f', 'device_location': 'London'}} - -
2021-05-13 19:05:25,507+0200 — ERROR — main:36 — Log stacktrace... - {} - ZeroDivisionError - Traceback (most recent call last):
File "prod.py", line 34, in main
1 / 0
ZeroDivisionError: division by zero
| import prod | |
| def test_main_logger(): | |
| prod.main() |