sag-py-logging 0.1.0

Initialize logging from a configuration json

sag_py_logging

This library can be used to initialize the python logging by loading a config json. Furthermore it provides a way to log extra fields.

What it does

• Initialize logging from configuration json
• Placeholder support for the config json
• A log filter to log extra fields

How to use

Installation

pip install sag_py_logging

Initialize logging from json

Add the following as early as possible to your application code:

from sag_py_logging.log_config_initializer import init_logging

placeholder_container = { "host": "myhost.com", ...}

init_logging("./log_config.json", config.logging_config)

The json configuration

{
    "version": 1,
    "disable_existing_loggers": "true",
    "root": {
        "handlers": ["myhandler"],
        "level": "INFO"
    },
    "handlers": {
        "myhandler": {
            "host": "${host}",
            "formatter": "handler_formatter"
        }
    }
}

This is a very basic sample on the format of the file including placeholders.

Read the following for a full schema reference: https://docs.python.org/3/library/logging.config.html#configuration-dictionary-schema

Configure extra field logging

It is possible to add a filter that extends log entries by a field for extra fields.

The filter is added like that if you initialize logging by code:

from sag_py_logging.console_extra_field_filter import ConsoleExtraFieldFilter

console_handler = logging.StreamHandler(sys.stdout)
console_handler.addFilter(ConsoleExtraFieldFilter())

If you init logging by config file the filter is added like that:

{
    "handlers": {
        "myhandler": {
            "filters": ["console_extra_field_filter"]
        }
    },
    "filters": {
        "console_extra_field_filter": {"()": "sag_py_logging.console_extra_field_filter.ConsoleExtraFieldFilter"}
    }
}

Afterwards you can use the field "stringified_extra" in your format string.

If you for example log the following:

logging.warning('Watch out!', extra={"keyOne": "valueOne", "keyTwo": 2})

The resulting log entry would look like that if stringified_extra is added to the end of the format string:

Watch out! {"keyOne": "valueOne", "keyTwo": 2}

Note: Internally json.dumps is used to convert the object/data to a string

How to publish

• Update the version in setup.py and commit your change
• Create a tag with the same version number
• Let github do the rest