Django GUID

Django GUID attaches a unique correlation ID/request ID to all your log outputs for every request. In other words, all logs connected to a request now has a unique ID attached to it, making debugging simple.

Which version of Django GUID you should use depends on your Django version and whether you run ASGI or WSGI servers. To determine which Django-GUID version you should use, please see the table below.

Django version	Django-GUID version
3.1.1 or above	3.x.x - ASGI and WSGI
3.0.0 - 3.1.0	2.x.x - Only WSGI
2.2.x	2.x.x - Only WSGI

Django GUID >= 3.0.0 uses ContextVar to store and access the GUID. Previous versions stored the GUID to an object, making it accessible by using the ID of the current thread. (Version 2 of Django GUID is supported until Django2.2 LTS has passed.)

Resources:

Free software: BSD License
Documentation: https://django-guid.readthedocs.io
Homepage: https://github.com/snok/django-guid

Examples

Log output with a GUID:

INFO ... [773fa6885e03493498077a273d1b7f2d] project.views This is a DRF view log, and should have a GUID.
WARNING ... [773fa6885e03493498077a273d1b7f2d] project.services.file Some warning in a function
INFO ... [0d1c3919e46e4cd2b2f4ac9a187a8ea1] project.views This is a DRF view log, and should have a GUID.
INFO ... [99d44111e9174c5a9494275aa7f28858] project.views This is a DRF view log, and should have a GUID.
WARNING ... [0d1c3919e46e4cd2b2f4ac9a187a8ea1] project.services.file Some warning in a function
WARNING ... [99d44111e9174c5a9494275aa7f28858] project.services.file Some warning in a function

Log output without a GUID:

INFO ... project.views This is a DRF view log, and should have a GUID.
WARNING ... project.services.file Some warning in a function
INFO ... project.views This is a DRF view log, and should have a GUID.
INFO ... project.views This is a DRF view log, and should have a GUID.
WARNING ... project.services.file Some warning in a function
WARNING ... project.services.file Some warning in a function

See the documentation for more examples.

Installation

Install using pip:

pip install django-guid

Settings

Package settings are added in your settings.py:

DJANGO_GUID = {
    'GUID_HEADER_NAME': 'Correlation-ID',
    'VALIDATE_GUID': True,
    'RETURN_HEADER': True,
    'EXPOSE_HEADER': True,
    'INTEGRATIONS': [],
    'IGNORE_URLS': [],
    'UUID_LENGTH': 32,
}

Optional Parameters

GUID_HEADER_NAME

The name of the GUID to look for in a header in an incoming request. Remember that it’s case insensitive.

Default: Correlation-ID
VALIDATE_GUID

Whether the GUID_HEADER_NAME should be validated or not. If the GUID sent to through the header is not a valid GUID (uuid.uuid4).

Default: True
RETURN_HEADER

Whether to return the GUID (Correlation-ID) as a header in the response or not. It will have the same name as the GUID_HEADER_NAME setting.

Default: True
EXPOSE_HEADER

Whether to return Access-Control-Expose-Headers for the GUID header if RETURN_HEADER is True, has no effect if RETURN_HEADER is False. This is allows the JavaScript Fetch API to access the header when CORS is enabled.

Default: True
INTEGRATIONS

Whether to enable any custom or available integrations with django_guid. As an example, using SentryIntegration() as an integration would set Sentry’s transaction_id to match the GUID used by the middleware.

Default: []
IGNORE_URLS

URL endpoints where the middleware will be disabled. You can put your health check endpoints here.

Default: []
UUID_LENGTH

Lets you optionally trim the length of the package generated UUIDs.

Default: 32

Configuration

Once settings have set up, add the following to your projects’ settings.py:

1. Installed Apps

Add django_guid to your INSTALLED_APPS:

INSTALLED_APPS = [
    ...
    'django_guid',
]

2. Middleware

Add the django_guid.middleware.guid_middleware to your MIDDLEWARE:

MIDDLEWARE = [
    'django_guid.middleware.guid_middleware',
    ...
 ]

It is recommended that you add the middleware at the top, so that the remaining middleware loggers include the requests GUID.

3. Logging Configuration

Add django_guid.log_filters.CorrelationId as a filter in your LOGGING configuration:

LOGGING = {
    ...
    'filters': {
        'correlation_id': {
            '()': 'django_guid.log_filters.CorrelationId'
        }
    }
}

Put that filter in your handler:

LOGGING = {
    ...
    'handlers': {
        'console': {
            'class': 'logging.StreamHandler',
            'formatter': 'medium',
            'filters': ['correlation_id'],
        }
    }
}

And make sure to add the new correlation_id filter to one or all of your formatters:

LOGGING = {
    ...
    'formatters': {
        'medium': {
            'format': '%(levelname)s %(asctime)s [%(correlation_id)s] %(name)s %(message)s'
        }
    }
}

If these settings were confusing, please have a look in the demo projects’ settings.py file for a complete example.

4. Django GUID Logger (Optional)

If you wish to see the Django GUID middleware outputs, you may configure a logger for the module. Simply add django_guid to your loggers in the project, like in the example below:

LOGGING = {
    ...
    'loggers': {
        'django_guid': {
            'handlers': ['console', 'logstash'],
            'level': 'WARNING',
            'propagate': False,
        }
    }
}

This is especially useful when implementing the package, if you plan to pass existing GUIDs to the middleware, as misconfigured GUIDs will not raise exceptions, but will generate warning logs.