Feature request: Include name of standard library loggers

[kbakk]

Use case

In order to locate the source of a log message, the name of the standard library logger often gives a hint of where it's coming from, as it's a convention to use logging.getLogger(__name__) to name the logger (see https://docs.python.org/3/howto/logging-cookbook.html#using-logging-in-multiple-modules for an example).

When following the FAQ guide step "How can I enable powertools logging for imported libraries? (permalink)"

(btw, logging.logger() needs to be changed to logger.getLogger("my.precious.logger"))

I will get a log message of

{
    "level": "INFO",
    "location": "<module>:12",
    "message": "test message",
    "timestamp": "2022-06-29 11:44:51,630+0000",
    "service": "abc-def",
    "sampling_rate": "0.1"
}

I am missing the name of the logger. In the above case it's not that difficult to locate where the log originated from, but take this example:

{
    "level": "DEBUG",
    "location": "parse:239",
    "message": "Response headers: {'x-amzn-RequestId': '446775e4-6fbc-59a4-8c88-2ed253d21d82', 'Date': 'Wed, 29 Jun 2022 11:40:30 GMT', 'Content-Type': 'text/xml', 'Content-Length': '378'}",
    "timestamp": "2022-06-29 11:40:30,927+0000",
    "service": "abc-def",
    "sampling_rate": "0.1",
    "cold_start": true,
    "function_name": "DevMyLambda-SFunction5A4552-bTFQOMC2LFTH",
    "function_memory_size": "128",
    "function_arn": "arn:aws:lambda:eu-west-1:0123456789:DevMyLambda-SFunction5A4552-bTFQOMC2LFTH",
    "function_request_id": "9963e4d9-40fb-444a-9023-5ab5c973da5c",
    "xray_trace_id": "1-62bc3a2b-6bb3afff1f9cf2d77b20c5fc"
}

It's difficult to see what library emitted that log message.

Solution/User Experience

Ideally, when aws-lambda-powertools-python is logging from standard library loggers, it should include the logger name as well.

Alternative solutions

Maybe this can be achieved using `LambdaPowertoolsFormatter` but I don't see the key available under https://awslabs.github.io/aws-lambda-powertools-python/latest/core/logger/#standard-structured-keys

Acknowledgment

• This feature request meets Lambda Powertools Tenets
• Should this be considered in other Lambda Powertools languages? i.e. Java, TypeScript

[boring-cyborg]

Thanks for opening your first issue here! We'll come back to you as soon as we can.

[heitorlessa]

hey @kbakk thank you for flagging this, and we appreciate even more for finding that logging.logger typo too!

You can include the logger name by ensuring your Powertools Logger has that attribute, this will ensure any registered standard library logger that receive a copy of your Powertools Logger config also has it.

Here's an example:

app.py

import logging

from aws_lambda_powertools import Logger

from aws_lambda_powertools.logging import utils

a_random_logger = logging.getLogger(__name__)  # could've been any other registered library logger, etc.

# NOTE: we're including `name` key which will be propagated to our Powertools Formatter
# and knowing it's a reserved log attribute it'll resolve for each log message accordingly
# https://docs.python.org/3/library/logging.html#logrecord-attributes
powertools_logger = Logger(service="payment", name="%(name)s")

utils.copy_config_to_registered_loggers(source_logger=powertools_logger, include={a_random_logger.name})

powertools_logger.info("Name should be equal service value")
a_random_logger.info("Something random")  # name will be __main__ because it's a single file/module

sample output

[
    {
        "level": "INFO",
        "location": "<module>:16",
        "message": "Name should be equal service value",
        "timestamp": "2022-06-29 16:56:11,789+0200",
        "service": "payment",
        "name": "payment"
    },
    {
        "level": "INFO",
        "location": "<module>:17",
        "message": "Something random",
        "timestamp": "2022-06-29 16:56:11,789+0200",
        "service": "payment",
        "name": "__main__"
    }
]

The reason we didn't do this before-hand was largely cost, because we couldn't predict whether that was going to be useful for customers - introducing a new key would mean an additional log ingestion/storage in CloudWatch Logs.

That being said, we could definitely make this easier by adjusting copy_config_to_registered_loggers logic to include a name module as a feature flag so customers could opt-in, evaluate the demand, and make it the default in a future v2 version.

Let me know if this helps or whether I misunderstood your issue. If it is helpful, we should surely add it in the docs ;)

Thank you!

[kbakk]

Thank you, that did the trick!

Is this behavior documented somewhere (I couldn't find it mentioned here https://awslabs.github.io/aws-lambda-powertools-python/latest/api/logging/index.html) or would I be using an undocumented feature? Should I leave this open until it's documented?

[heitorlessa]

Awesome! Let's improve the docs by creating a dedicated section to make it more explicit - it's briefly documented here (note location_format): https://awslabs.github.io/aws-lambda-powertools-python/latest/core/logger/#overriding-log-records

I can work on the docs tomorrow unless you'd like to try making that your first contribution with our guidance ;)

Fast forward after the pause (end of July), we should revisit it and implement a new field logger_name only when people use the config copy feature.

[kbakk]

Side-note: Reason I asked was that the pending-close-response-required label was added - I see now that the stale-bot removed it as I responded. Thought it meant I should close it if I was happy with the answer (which I was, but felt that an improvement could be made 😃).

[kbakk]

unless you'd like to try making that your first contribution with our guidance ;)

Sure, I'll try! I'll do a PR where I add a section following https://awslabs.github.io/aws-lambda-powertools-python/latest/core/logger/#overriding-log-records

Maybe it should be mentioned what kwargs does here as well: https://awslabs.github.io/aws-lambda-powertools-python/latest/core/logger/#lambdapowertoolsformatter (and the relation to kwargs in Logger).

[heitorlessa]

Perfect - thank you <3!! We can figure out the best naming and such afterwards. We can start by making sure everyone is aware all of the standard logging attributes can be added at any point - Logger & Powertools Formatter constructor, and append_keys/remove_keys.

https://docs.python.org/3/library/logging.html#logrecord-attributes

[kbakk]

PR created 🙂