opentelemetry.sdk._logs.LoggingHandler doesn't format

[a-recknagel]

Describe your environment

$ pip freeze
Deprecated==1.2.14
importlib-metadata==6.11.0
opentelemetry-api==1.22.0
opentelemetry-sdk==1.22.0
opentelemetry-semantic-conventions==0.43b0
typing_extensions==4.9.0
wrapt==1.16.0
zipp==3.17.0

$ python --version
Python 3.10.10

Steps to reproduce

import logging.config

from opentelemetry.sdk._logs import LoggerProvider
from opentelemetry.sdk._logs.export import ConsoleLogExporter, SimpleLogRecordProcessor
from opentelemetry.sdk.resources import Resource

logger_provider = LoggerProvider(resource=Resource.create({}))
logger_provider.add_log_record_processor(SimpleLogRecordProcessor(ConsoleLogExporter()))

logging.config.dictConfig({
    "version": 1,
    "formatters": {
        "simple": {"format": "%(name)s [%(module)s.%(lineno)s]: %(message)s"}
    },
    "handlers": {
        "console": {
            "level": "INFO",
            "formatter": "simple",
            "class": "opentelemetry.sdk._logs.LoggingHandler",
            "logger_provider": logger_provider,
        }
    },
    "loggers": {
        "__main__": {"handlers": ["console"], "level": "INFO"},
    }
})

logging.getLogger("__main__").info("foo")

What is the expected behavior?

{
    "body": "__main__ [otel_logging_example.28]: foo",
    "severity_number": "<SeverityNumber.INFO: 9>",
    "severity_text": "INFO",
    "attributes": null,
    "dropped_attributes": 0,
    "timestamp": "2024-02-02T16:11:47.407470Z",
    "trace_id": "0x00000000000000000000000000000000",
    "span_id": "0x0000000000000000",
    "trace_flags": 0,
    "resource": "BoundedAttributes({'telemetry.sdk.language': 'python', 'telemetry.sdk.name': 'opentelemetry', 'telemetry.sdk.version': '1.22.0', 'service.name': 'unknown_service'}, maxlen=None)"
}

What is the actual behavior?

{
    "body": "foo",
    "severity_number": "<SeverityNumber.INFO: 9>",
    "severity_text": "INFO",
    "attributes": null,
    "dropped_attributes": 0,
    "timestamp": "2024-02-02T16:11:47.407470Z",
    "trace_id": "0x00000000000000000000000000000000",
    "span_id": "0x0000000000000000",
    "trace_flags": 0,
    "resource": "BoundedAttributes({'telemetry.sdk.language': 'python', 'telemetry.sdk.name': 'opentelemetry', 'telemetry.sdk.version': '1.22.0', 'service.name': 'unknown_service'}, maxlen=None)"
}

Additional context
Given that I want to make use of the fact that these logs are structured, it would actually be more convenient to put the fields that I'm formatting into body right now into attributes instead:

[...]
logging.config.dictConfig({
    "version": 1,
    "handlers": {
        "console": {
            "level": "INFO",
            "class": "opentelemetry.sdk._logs.LoggingHandler",
            "logger_provider": logger_provider,
            "carry_over": ["name", "module", "lineno"],  # doesn't exist yet
        }
    },
[...]

Would result in

{
    "body": "foo",
    "severity_number": "<SeverityNumber.INFO: 9>",
    "severity_text": "INFO",
    "attributes": {
        "name": "__main__",
        "module": "otel_logging_example",
        "lineno": 28
    },
    "dropped_attributes": 0,
    "timestamp": "2024-02-02T16:11:47.407470Z",
    "trace_id": "0x00000000000000000000000000000000",
    "span_id": "0x0000000000000000",
    "trace_flags": 0,
    "resource": "BoundedAttributes({'telemetry.sdk.language': 'python', 'telemetry.sdk.name': 'opentelemetry', 'telemetry.sdk.version': '1.22.0', 'service.name': 'unknown_service'}, maxlen=None)"
}

And raising an error if someone tries to add a formatter to LoggingHandler.