Question regarding debugging options when using logconfig_dict

[ni-todo-spot]

Hello all,

As part of the gunicorn.conf.py file of a project I've been working on, I set the logconfig_dict to:

logconfig_dict = {
    "version": 1,
    "disable_existing_loggers": False,
    "formatters": {
        "js0": {"()": "app.logs.stackdriver_log_formatter.StackDriverJsonFormatter"}
    },
    "handlers": {
        "console": {
            "formatter": "js0",
            "class": "logging.StreamHandler",
            "stream": "ext://sys.stdout",
        }
    },
    "loggers": {
        "": {"handlers": ["console"], "level": "INFO"},
        "gunicorn": {"handlers": ["console"], "level": "INFO"},
        "gunicorn.access": {"handlers": ["console"], "level": "INFO"},
        "gunicorn.error": {"handlers": ["console"], "level": "INFO"},
        "uvicorn": {"handlers": ["console"], "level": "INFO"},
        "uvicorn.access": {"handlers": ["console"], "level": "INFO"},
        "uvicorn.error": {"handlers": ["console"], "level": "INFO"},
    },
}

# stackdriver_log_formatter.py

import datetime
import logging
from typing import Any, Dict

from pythonjsonlogger import jsonlogger


class StackDriverJsonFormatter(jsonlogger.JsonFormatter):
    """
    Based on:
        https://engineering.ziffmedia.com/formatting-python-logs-for-stackdriver-5a5ddd80761c
        https://pypi.org/project/python-json-logger/
    """

    def add_fields(
        self, log_record: Dict[str, Any], record: logging.LogRecord, message_dict: Dict[str, Any]
    ) -> None:
        super().add_fields(log_record, record, message_dict)
        log_record["severity"] = record.levelname.lower()
        log_record["levelname"] = record.levelname
        log_record["filename"] = record.filename
        log_record["funcName"] = record.funcName
        log_record["lineno"] = record.lineno
        log_record["message"] = record.message
        log_record["module"] = record.module
        log_record["name"] = record.name
        log_record["pathname"] = record.pathname
        log_record["process"] = record.process
        log_record["processName"] = record.processName
        log_record["stack_info"] = record.stack_info
        log_record["thread"] = record.thread
        log_record["threadName"] = record.threadName
        if not log_record.get("timestamp"):
            # this doesn't use record.created, so it is slightly off
            now = datetime.datetime.utcnow().strftime("%Y-%m-%dT%H:%M:%S.%fZ")
            log_record["timestamp"] = now

When trying to start the project, using gunicorn -c gunicorn.conf.py app.wsgi:app

I'm getting Error: Unable to configure formatter 'js0'

I'd like to debug and discover more about the problem so hopefully I'd be able to fix it.

Looking at the docs I came across with the spew setting - but looking at its output did not help me as I could not find anything relevant...

Is there perhaps additional way to get more context / stacktrace or any additional info why is this problem occurring?

Thanks in advance!