I have a FastAPI service that works as expected in every regard except the logging, only when it runs as a AWS Lambda function.
When running it locally the logs are displayed on the console as expected:
INFO: 127.0.0.1:62160 - "POST /api/v1/feature-requests/febbbc21-9650-44e6-8df5-80c8bb33b6ea/upvote HTTP/1.1" 200 OK
INFO: 127.0.0.1:62158 - "OPTIONS /api/v1/feature-requests HTTP/1.1" 200 OK
INFO: 127.0.0.1:62160 - "GET /api/v1/feature-requests HTTP/1.1" 200 OK
INFO: 127.0.0.1:62158 - "OPTIONS /api/v1/feature-requests-meta HTTP/1.1" 200 OK
INFO: 127.0.0.1:62160 - "GET /api/v1/feature-requests-meta HTTP/1.1" 200 OK
INFO: 127.0.0.1:62160 - "GET /api/v1/feature-requests/febbbc21-9650-44e6-8df5-80c8bb33b6ea HTTP/1.1" 200 OK
INFO: 127.0.0.1:62160 - "GET /api/v1/feature-requests-meta/febbbc21-9650-44e6-8df5-80c8bb33b6ea HTTP/1.1" 200 OK
However, when deployed as a Lambda function the logs are not there:
2022-09-07T10:44:57.426+02:00 START RequestId: fd44ae47-5bfb-42e3-aeb4-d9f29857bb39 Version: $LATEST
2022-09-07T10:44:57.604+02:00 END RequestId: fd44ae47-5bfb-42e3-aeb4-d9f29857bb39
2022-09-07T10:44:57.604+02:00 REPORT RequestId: fd44ae47-5bfb-42e3-aeb4-d9f29857bb39 Duration: 177.85 ms Billed Duration: 178 ms Memory Size: 2048 MB Max Memory Used: 152 MB Init Duration: 1733.88 ms
2022-09-07T10:45:00.299+02:00 START RequestId: 08a7a6da-c2c6-446c-baa3-1d08c9816f5b Version: $LATEST
2022-09-07T10:45:00.318+02:00 END RequestId: 08a7a6da-c2c6-446c-baa3-1d08c9816f5b
Even for the logs that are produced by our code (as opposed to the framework) are not visible when running as a Lambda function.
Configuration:
In app.py
LOG = logging.getLogger()
log_format = "%(asctime)s %(levelname)s %(message)s"
log_date_fmt = "%Y-%m-%d %H:%M:%S"
logging.basicConfig(
format=log_format,
level=logging.INFO,
datefmt=log_date_fmt,
)
In every other Python file:
LOG = logging.getLogger(__name__)
logging.conf
[loggers]
keys=root,api,config
[handlers]
keys=console_handler
[formatters]
keys=normal_formatter
[logger_root]
level=INFO
handlers=console_handler
[logger_api]
level=INFO
handlers=console_handler
qualname=api
propagate=0
[logger_config]
level=INFO
handlers=console_handler
qualname=config
propagate=0
[handler_console_handler]
class=StreamHandler
level=INFO
formatter=normal_formatter
args=(sys.stdout,)
[formatter_normal_formatter]
format=%(asctime)s %(levelname)s %(name)s %(message)s
datefmt=%Y-%m-%d %H:%M:%S
I am not sure what else needs to happen to get the logs in CloudWatch.
2
Answers
As it turns out the following setup is needed:
On the top of the logging.conf above uvicorn has to be imported that creates an extra property on logging and than fileConfig has to be used like this:
try
cloudwatch
libraryRun
pip install cloudwatch
in the consolethen in your code:
and then either use this logger to log to CloudWatch
logger.warning('I am here')
or add the handler to the root logger via logging configuration