django-structlog 1.2.3

Structured Logging for Django

django-structlog

django-structlog is a structured logging integration for Django project using structlog

Logging will then produce additional cohesive metadata on each logs that makes it easier to track events or incidents.

Logging comparison

Standard logging:

>>> import logging
>>> logger = logging.get_logger(__name__)
>>> logger.info("An error occurred")

An error occurred

Well… ok

With django-structlog and flat_line:

>>> import structlog
>>> logger = structlog.get_logger(__name__)
>>> logger.info("an_error_occurred", bar="Buz")

timestamp='2019-04-13T19:39:31.089925Z' level='info' event='an_error_occurred' logger='my_awesome_project.my_awesome_module' request_id='3a8f801c-072b-4805-8f38-e1337f363ed4' user_id=1 ip='0.0.0.0' bar='Buz'

Then you can search with commands like:

$ cat logs/flat_line.log | grep request_id='3a8f801c-072b-4805-8f38-e1337f363ed4'

With django-structlog and json

>>> import structlog
>>> logger = structlog.get_logger(__name__)
>>> logger.info("an_error_occurred", bar="Buz")

{"request_id": "3a8f801c-072b-4805-8f38-e1337f363ed4", "user_id": 1, "ip": "0.0.0.0", "event": "an_error_occurred", "timestamp": "2019-04-13T19:39:31.089925Z", "logger": "my_awesome_project.my_awesome_module", "level": "info", "bar": "Buz"}

Then you can search with commands like:

$ cat logs/json.log | jq '.[] | select(.request_id="3a8f801c-072b-4805-8f38-e1337f363ed4")' -s

Getting Started

These steps will show how to integrate the middleware to your awesome application.

Installation

Install the library

pip install django-structlog

Add middleware

MIDDLEWARE = [
    # ...
    'django_structlog.middlewares.RequestMiddleware',
]

Add appropriate structlog configuration to your settings.py

import structlog

LOGGING = {
    "version": 1,
    "disable_existing_loggers": False,
    "formatters": {
        "json_formatter": {
            "()": structlog.stdlib.ProcessorFormatter,
            "processor": structlog.processors.JSONRenderer(),
        },
        "plain_console": {
            "()": structlog.stdlib.ProcessorFormatter,
            "processor": structlog.dev.ConsoleRenderer(),
        },
        "key_value": {
            "()": structlog.stdlib.ProcessorFormatter,
            "processor": structlog.processors.KeyValueRenderer(key_order=['timestamp', 'level', 'event', 'logger']),
        },
    },
    "handlers": {
        "console": {
            "class": "logging.StreamHandler",
            "formatter": "plain_console",
        },
        "json_file": {
            "class": "logging.handlers.WatchedFileHandler",
            "filename": "logs/json.log",
            "formatter": "json_formatter",
        },
        "flat_line_file": {
            "class": "logging.handlers.WatchedFileHandler",
            "filename": "logs/flat_line.log",
            "formatter": "key_value",
        },
    },
    "loggers": {
        "django_structlog": {
            "handlers": ["console", "flat_line_file", "json_file"],
            "level": "INFO",
        },
        "django_structlog_demo_project": {
            "handlers": ["console", "flat_line_file", "json_file"],
            "level": "INFO",
        },
    }
}

structlog.configure(
    processors=[
        structlog.stdlib.filter_by_level,
        structlog.processors.TimeStamper(fmt="iso"),
        structlog.stdlib.add_logger_name,
        structlog.stdlib.add_log_level,
        structlog.stdlib.PositionalArgumentsFormatter(),
        structlog.processors.StackInfoRenderer(),
        structlog.processors.format_exc_info,
        structlog.processors.UnicodeDecoder(),
        structlog.processors.ExceptionPrettyPrinter(),
        structlog.stdlib.ProcessorFormatter.wrap_for_formatter,
    ],
    context_class=structlog.threadlocal.wrap_dict(dict),
    logger_factory=structlog.stdlib.LoggerFactory(),
    wrapper_class=structlog.stdlib.BoundLogger,
    cache_logger_on_first_use=True,
)

Start logging with structlog instead of logging.

import structlog
logger = structlog.get_logger(__name__)

Extending Request Log Metadata

By default only a request_id and the user_id are bound from the request but pertinent log metadata may vary from a project to another.

If you need to add more metadata from the request you can implement a convenient signal receiver to bind them.

from django.dispatch import receiver

from django_structlog.signals import bind_extra_request_metadata


@receiver(bind_extra_request_metadata)
def bind_user_email(request, logger, **kwargs):
    logger.bind(user_email=getattr(request.user, 'email', ''))

Example outputs

Flat lines file (logs/flat_lines.log)

timestamp='2019-04-13T19:39:29.321453Z' level='info' event='request_started' logger='django_structlog.middlewares.request' request_id='c53dff1d-3fc5-4257-a78a-9a567c937561' user_id=1 ip='0.0.0.0' request=<WSGIRequest: GET '/'> user_agent='Mozilla/5.0 (Macintosh; Intel Mac OS X 10_14_4) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/73.0.3683.86 Safari/537.36'
timestamp='2019-04-13T19:39:29.345207Z' level='info' event='request_finished' logger='django_structlog.middlewares.request' request_id='c53dff1d-3fc5-4257-a78a-9a567c937561' user_id=1 ip='0.0.0.0' code=200
timestamp='2019-04-13T19:39:31.086155Z' level='info' event='request_started' logger='django_structlog.middlewares.request' request_id='3a8f801c-072b-4805-8f38-e1337f363ed4' user_id=1 ip='0.0.0.0' request=<WSGIRequest: POST '/success_task'> user_agent='Mozilla/5.0 (Macintosh; Intel Mac OS X 10_14_4) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/73.0.3683.86 Safari/537.36'
timestamp='2019-04-13T19:39:31.089925Z' level='info' event='Enqueuing successful task' logger='django_structlog_demo_project.home.views' request_id='3a8f801c-072b-4805-8f38-e1337f363ed4' user_id=1 ip='0.0.0.0'
timestamp='2019-04-13T19:39:31.147590Z' level='info' event='task_enqueued' logger='django_structlog.middlewares.celery' request_id='3a8f801c-072b-4805-8f38-e1337f363ed4' user_id=1 ip='0.0.0.0' child_task_id='6b11fd80-3cdf-4de5-acc2-3fd4633aa654'
timestamp='2019-04-13T19:39:31.153081Z' level='info' event='This is a successful task' logger='django_structlog_demo_project.taskapp.celery' task_id='6b11fd80-3cdf-4de5-acc2-3fd4633aa654' request_id='3a8f801c-072b-4805-8f38-e1337f363ed4' user_id=1 ip='0.0.0.0'
timestamp='2019-04-13T19:39:31.160043Z' level='info' event='request_finished' logger='django_structlog.middlewares.request' request_id='3a8f801c-072b-4805-8f38-e1337f363ed4' user_id=1 ip='0.0.0.0' code=201
timestamp='2019-04-13T19:39:31.162372Z' level='info' event='task_succeed' logger='django_structlog.middlewares.celery' task_id='6b11fd80-3cdf-4de5-acc2-3fd4633aa654' request_id='3a8f801c-072b-4805-8f38-e1337f363ed4' user_id=1 ip='0.0.0.0' result='None'

Json file (logs/json.log)

{"request_id": "c53dff1d-3fc5-4257-a78a-9a567c937561", "user_id": 1, "ip": "0.0.0.0", "request": "<WSGIRequest: GET '/'>", "user_agent": "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_14_4) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/73.0.3683.86 Safari/537.36", "event": "request_started", "timestamp": "2019-04-13T19:39:29.321453Z", "logger": "django_structlog.middlewares.request", "level": "info"}
{"request_id": "c53dff1d-3fc5-4257-a78a-9a567c937561", "user_id": 1, "ip": "0.0.0.0", "code": 200, "event": "request_finished", "timestamp": "2019-04-13T19:39:29.345207Z", "logger": "django_structlog.middlewares.request", "level": "info"}
{"request_id": "3a8f801c-072b-4805-8f38-e1337f363ed4", "user_id": 1, "ip": "0.0.0.0", "request": "<WSGIRequest: POST '/success_task'>", "user_agent": "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_14_4) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/73.0.3683.86 Safari/537.36", "event": "request_started", "timestamp": "2019-04-13T19:39:31.086155Z", "logger": "django_structlog.middlewares.request", "level": "info"}
{"request_id": "3a8f801c-072b-4805-8f38-e1337f363ed4", "user_id": 1, "ip": "0.0.0.0", "event": "Enqueuing successful task", "timestamp": "2019-04-13T19:39:31.089925Z", "logger": "django_structlog_demo_project.home.views", "level": "info"}
{"request_id": "3a8f801c-072b-4805-8f38-e1337f363ed4", "user_id": 1, "ip": "0.0.0.0", "child_task_id": "6b11fd80-3cdf-4de5-acc2-3fd4633aa654", "event": "task_enqueued", "timestamp": "2019-04-13T19:39:31.147590Z", "logger": "django_structlog.middlewares.celery", "level": "info"}
{"task_id": "6b11fd80-3cdf-4de5-acc2-3fd4633aa654", "request_id": "3a8f801c-072b-4805-8f38-e1337f363ed4", "user_id": 1, "ip": "0.0.0.0", "event": "This is a successful task", "timestamp": "2019-04-13T19:39:31.153081Z", "logger": "django_structlog_demo_project.taskapp.celery", "level": "info"}
{"request_id": "3a8f801c-072b-4805-8f38-e1337f363ed4", "user_id": 1, "ip": "0.0.0.0", "code": 201, "event": "request_finished", "timestamp": "2019-04-13T19:39:31.160043Z", "logger": "django_structlog.middlewares.request", "level": "info"}
{"task_id": "6b11fd80-3cdf-4de5-acc2-3fd4633aa654", "request_id": "3a8f801c-072b-4805-8f38-e1337f363ed4", "user_id": 1, "ip": "0.0.0.0", "result": "None", "event": "task_succeed", "timestamp": "2019-04-13T19:39:31.162372Z", "logger": "django_structlog.middlewares.celery", "level": "info"}

Running the tests

Note: For the moment redis is needed to run the tests. The easiest way start docker’s demo.

docker-compose up --build

In another shell

pip install -r requirements/base.txt
pytest

Demo app

docker-compose up --build

Open http://0.0.0.0:8000/ in your browser.

Navigate while looking into the log files and shell’s output.

Authors

• Jules Robichaud-Gagnon - Initial work - jrobichaud

See also the list of contributors who participated in this project.

Acknowledgments

• Big thanks to @ferd for his bad opinions that inspired the author enough to spend time on this library.

• This issue helped the author to figure out how to integrate structlog in Django.

• This stack overflow question was also helpful.

License

This project is licensed under the MIT License - see the LICENSE file for details