django-logger-extra 1.1.1

A module that provides extras for logger.

Table of Contents generated with DocToc

• Logger extras for simplified structured logging.
  • Adding django-logger-extra your Django project
    • Adding django-resilient-logger Django apps
    • Configuring logger formatter in settings.py:
    • Configuring middleware in settings.py:
  • django-auditlog extra context.
  • Logger context usage
  • Gunicorn Logging Formatters
• Development
  • Running tests
  • Code format
  • Git blame ignore refs
  • Commit message format

Logger extras for simplified structured logging.

django-logger-extra is a collection of logger extras that makes structured logging setup easier.

Adding django-logger-extra your Django project

Add django-logger-extra in your project's dependencies.

Adding django-resilient-logger Django apps

To install this logger, add INSTALLED_APPS in settings.py:

INSTALLED_APPS = (
    "logger_extra",
    ...
)

Configuring logger formatter in settings.py:

To make use of the JSON formatter it must be configured in setting's LOGGING section. Filter is optional and brings logger_context() contexts available as logger extras.

LOGGING = {
    "filters": {
        "context": {
            "()": "logger_extra.filter.LoggerContextFilter",
        }
        ...
    },
    "formatters": {
        "json": {
            "()": "logger_extra.formatter.JSONFormatter",
        }
        ...
    },
    "handlers": {
        "console": {
            "class": "logging.StreamHandler",
            "formatter": "json",
            "filters": ["context"]
        },
        ...
    },
    ...
}

Configuring middleware in settings.py:

MIDDLEWARE = [
    "logger_extra.middleware.XRequestIdMiddleware",
    ...
]

django-auditlog extra context.

This library can also augment django-auditlog's additional_data fields with active context. To enable this, optional package django-auditlog must be installed and it must be explicitly enabled in settings.py file.

LOGGER_EXTRA_AUGMENT_DJANGO_AUDITLOG = True

Logger context usage

Active context can be appended with logger_context function. It will return current context as resource. The current context can also be read using function get_logger_context.

import logging
from django.http import HttpRequest, JsonResponse

from logger_extra.logger_context import logger_context

logger = logging.getLogger("audit")

def bar():
  with logger_context({ "who": "World" }) as ctx:
    logger.info(f"{ctx['greet']} {ctx['who']}")

def foo():
  with logger_context({ "greet": "Hello" }):
    bar()
    return JsonResponse({})

Will result log entry that looks like: {"message": "Hello World", "level": "INFO", "time": "2025-04-14T11:08:22.962222+00:00", "context": {"request_id": "95e787b5-4ce8-46ef-bb6e-31651fc8774b", "greet": "Hello", "who": "World"}}

Gunicorn Logging Formatters

This package includes two helpers to format Gunicorn access and error logs as structured JSON: JsonFormatter and JsonErrorFormatter (available at logger_extra.extras.gunicorn).

Use the following logconfig_dict in your Gunicorn configuration (default: gunicorn.conf.py) to enable JSON output and include the logger context filter so request context is available in logs:

from logger_extra.extras.gunicorn import JsonErrorFormatter, JsonFormatter

logconfig_dict = {
    "version": 1,
    "disable_existing_loggers": False,
    "filters": {
        "context": {
            "()": "logger_extra.filter.LoggerContextFilter",
        }
    },
    "formatters": {
        "json": {
            "()": JsonFormatter,
        },
        "json_error": {
            "()": JsonErrorFormatter,
        },
    },
    "handlers": {
        "console": {
            "class": "logging.StreamHandler",
            "formatter": "json",
            "filters": ["context"],
            "stream": "ext://sys.stdout",
        },
        "error_console": {
            "class": "logging.StreamHandler",
            "formatter": "json_error",
            "filters": ["context"],
            "stream": "ext://sys.stderr",
        },
    },
    "root": {
        "handlers": ["console"],
        "level": "INFO",
    },
    "loggers": {
        "gunicorn.access": {
            "level": "INFO",
            "handlers": ["console"],
            "propagate": False,
        },
        "gunicorn.error": {
            "level": "INFO",
            "handlers": ["error_console"],
            "propagate": False,
        },
    },
}

Notes:

• Access logs: JsonFormatter expects Gunicorn access log fields and will produce a JSON object containing time (in UTC), request/response metadata, and any active logger context.
• Error logs: JsonErrorFormatter formats error messages with an ISO 8601 UTC timestamp and the log message. Also note that despite the name, all records logged in gunicorn.error are not errors, e.g. gunicorn's start-up messages are logged through this.
• Context filter: Adding logger_extra.filter.LoggerContextFilter to the filters and attaching it to handlers ensures context created by logger_extra.logger_context is included under request_id and other context keys.
• Gunicorn usage: If you're using a non-default name for your config file, point Gunicorn to your config file when starting, e.g. gunicorn -c my_gunicorn_conf.py myapp.wsgi:application.

Development

Virtual Python environment can be used. For example:

python3 -m venv .venv
source .venv/bin/activate

Install package requirements:

pip install -e .

Install development requirements:

pip install -r requirements-test.txt

Running tests

pytest

Code format

This project uses Ruff for code formatting and quality checking.

Basic ruff commands:

• lint: ruff check
• apply safe lint fixes: ruff check --fix
• check formatting: ruff format --check
• format: ruff format

pre-commit can be used to install and run all the formatting tools as git hooks automatically before a commit.

Git blame ignore refs

Project includes a .git-blame-ignore-revs file for ignoring certain commits from git blame. This can be useful for ignoring e.g. formatting commits, so that it is more clear from git blame where the actual code change came from. Configure your git to use it for this project with the following command:

git config blame.ignoreRevsFile .git-blame-ignore-revs

Commit message format

New commit messages must adhere to the Conventional Commits specification, and line length is limited to 72 characters.

When pre-commit is in use, commitlint checks new commit messages for the correct format.