Logging to JSON

Yet another log to JSON library for Python. I needed a library that integrated well with applications that mixed logging using built-in logging outputs and JSON output. I was also unable to find a library that worked with logging.QueueHandler Thus this library was born.

Install

pip install log-to-json

or

conda install log-to-json -c conda-forge

Example

Basic Usage

from log_to_json import JsonFormatter
import logging

logger = logging.getLogger()
handler = logging.StreamHandler()
json_formatter = JsonFormatter(keys=("name",))
handler.setFormatter(json_formatter)

logger.critical({"app-name": "my-app", "app_version": "1.0"})

# produces the log
{"app-name": "my-app", "app_version": "1.0", "name": "root"}

Slightly more advanced Usage

from log_to_json import JsonFormatter
import logging

logger = logging.getLogger()
handler = logging.StreamHandler()

def finalizer(message_dict):
    """rename name to logger_name"""
    message_dict["logger_name"] = message_dict.pop("name")
    return message_dict

json_formatter = JsonFormatter(
    keys=("message", "name", "user"),
    formatters={"user": str.upper},
    finalizer=finalizer
)
handler.setFormatter(json_formatter)

logger.critical("critical failure", extra={"user": "guest"})

# produces the message

{"message": "critical failure", "user": "GUEST", "logger_name": "root"}

Notable Features

Individual Key Formatters

Finalizer

Per Message Prefix

Integrates with non-JSON Logging

Pluggable Serializer