Configure Django to log exceptions in production

Django default logging behaviour for unhandled exceptions is:

With DEBUG=True (Development)

  • Log the exception on console/stream.
  • Show the exception on page, i.e in http response.

With DEBUG=False (Production)

  • Do not log the exception on console/stream.
  • Do not show the exception in response.
  • Send an email to admin if email settings are configured correctly.

Usually not logging the exception on console isn’t a problem since an exception email is sent to you which can help you know the source of exception. But this assumes that email settings are configured correctly else you will not receive the exception email.

You might not have email settings configured correctly and don’t want to get into that right away. You might instead want to log the exception on console even with DEBUG=False. This post would help you in such scenario.

Default logging configuration

Django’s default logging setting is:

DEFAULT_LOGGING = {
	'version': 1,
	'disable_existing_loggers': False,
	'filters': {
		'require_debug_false': {
			'()': 'django.utils.log.RequireDebugFalse',
		},
		'require_debug_true': {
			'()': 'django.utils.log.RequireDebugTrue',
		},
	},
	'formatters': {
		'django.server': {
			'()': 'django.utils.log.ServerFormatter',
			'format': '[%(server_time)s] %(message)s',
		}
	},
	'handlers': {
		'console': {
			'level': 'INFO',
			'filters': ['require_debug_true'],
			'class': 'logging.StreamHandler',
		},
		'django.server': {
			'level': 'INFO',
			'class': 'logging.StreamHandler',
			'formatter': 'django.server',
		},
		'mail_admins': {
			'level': 'ERROR',
			'filters': ['require_debug_false'],
			'class': 'django.utils.log.AdminEmailHandler'
		}
	},
	'loggers': {
		'django': {
			'handlers': ['console', 'mail_admins'],
			'level': 'INFO',
		},
		'django.server': {
			'handlers': ['django.server'],
			'level': 'INFO',
			'propagate': False,
		},
	}
}

Without any explicit settings.LOGGING configured in settings.py, this is the default logging configuration Django works with. You can ignore django.server part.

Any unhandled Django exception is handled in function handle_uncaught_exception. The relevant code is on Github

Error is logged using logger.error in this function. This logger is an instance of django.request. Since logger django is a parent of django.request, so log records are propogated to logger django.

As you can see from DEFAULT_LOGGING, logger django has two handlers.

  • console
  • mail_admins

As you can see from DEFAULT_LOGGING, handler console has a filter called require_debug_true because of which this handler doesn’t handle log records in production, i.e when DEBUG=False.

Logging to console in production

So you can create a new handler which directs ERROR log records to Stream when DEBUG=False.

This handler would look like

'console_debug_false': {
	'level': 'ERROR',
	'filters': ['require_debug_false'],
	'class': 'logging.StreamHandler',
}

And you can ask logger django to use this handler by adding this handler in loggers['django']['handlers'].

Your final settings.LOGGING would look like following:

LOGGING = {
	'version': 1,
	'disable_existing_loggers': False,
	'filters': {
		'require_debug_false': {
			'()': 'django.utils.log.RequireDebugFalse',
		},
		'require_debug_true': {
			'()': 'django.utils.log.RequireDebugTrue',
		},
	},
	'formatters': {
		'django.server': {
			'()': 'django.utils.log.ServerFormatter',
			'format': '[%(server_time)s] %(message)s',
		}
	},
	'handlers': {
		'console': {
			'level': 'INFO',
			'filters': ['require_debug_true'],
			'class': 'logging.StreamHandler',
		},
		'console_debug_false': {
			'level': 'ERROR',
			'filters': ['require_debug_false'],
			'class': 'logging.StreamHandler',
		},
		'django.server': {
			'level': 'INFO',
			'class': 'logging.StreamHandler',
			'formatter': 'django.server',
		},
		'mail_admins': {
			'level': 'ERROR',
			'filters': ['require_debug_false'],
			'class': 'django.utils.log.AdminEmailHandler'
		}
	},
	'loggers': {
		'django': {
			'handlers': ['console', 'console_debug_false', 'mail_admins'],
			'level': 'INFO',
		},
		'django.server': {
			'handlers': ['django.server'],
			'level': 'INFO',
			'propagate': False,
		}
	}
}

If you don’t want emails to be sent to admins, in case email settings aren’t configured correctly, then you should remove mail_admins from loggers['django']['handlers'].

Buy Django ORM Cookbook

Thank you for reading the Agiliq blog. This article was written by Akshar on Dec 2, 2017 in django .

You can subscribe ⚛ to our blog.

We love building amazing apps for web and mobile for our clients. If you are looking for development help, contact us today ✉.

Would you like to download 10+ free Django and Python books? Get them here