Logging

Logging to Syslog service

It is possible to configure Django to output log to a local or remote syslog service. This configuration uses the python builtin SysLogHandler.

from logging.handlers import SysLogHandler
LOGGING = {
    'version': 1,
    'disable_existing_loggers': True,
    'formatters': {
        'standard': {
            'format' : "[YOUR PROJECT NAME] [%(asctime)s] %(levelname)s [%(name)s:%(lineno)s] %(message)s",
            'datefmt' : "%d/%b/%Y %H:%M:%S"
        }
    },
    'handlers': {
        'console': {
            'class': 'logging.StreamHandler',
        },
        'syslog': {
            'class': 'logging.handlers.SysLogHandler',
            'formatter': 'standard',
            'facility': 'user',
            # uncomment next line if rsyslog works with unix socket only (UDP reception disabled)
            #'address': '/dev/log'
        }
    },
    'loggers': {
        'django':{
            'handlers': ['syslog'],
            'level': 'INFO',
            'disabled': False,
            'propagate': True
        }
    }
}

# loggers for my apps, uses INSTALLED_APPS in settings
# each app must have a configured logger
# level can be changed as desired: DEBUG, INFO, WARNING...
MY_LOGGERS = {}
for app in INSTALLED_APPS:
    MY_LOGGERS[app] = {
        'handlers': ['syslog'],
        'level': 'DEBUG',
        'propagate': True,
    }
LOGGING['loggers'].update(MY_LOGGERS)

Django basic logging configuration

Internally, Django uses the Python logging system. There is many way to configure the logging of a project. Here is a base:

LOGGING = {
    'version': 1,
    'disable_existing_loggers': False,
    'formatters': {
        'default': {
            'format': "[%(asctime)s] %(levelname)s [%(name)s:%(lineno)s] %(message)s",
            'datefmt': "%Y-%m-%d %H:%M:%S"
        },
    },
    'handlers': {
        'console': {
            'level': 'INFO',
            'class': 'logging.StreamHandler',
            'formatter': 'default'
        },
    },
    'loggers': {
        'django': {
            'handlers': ['console'],
            'propagate': True,
            'level': 'INFO',
        },
    }
}

Formatters

It can be used to configure logs appearence when they are printed to output. You can define many formatters by setting a key string to each different formatter. A formatter is then used when declaring a handler.

Handlers

Can be used to configure where the logs will be printed. In the example above, they are sent to stdout and stderr. There is various handler classes:

'rotated_logs': {
    'class': 'logging.handlers.RotatingFileHandler',
    'filename': '/var/log/my_project.log',
    'maxBytes': 1024 * 1024 * 5,  # 5 MB
    'backupCount': 5,
    'formatter': 'default'
    'level': 'DEBUG',
},

This will produce logs in file tergeted by filename. In this example, a new log file will be created when the current reach the size of 5 MB (the old one is renamed to my_project.log.1) and the latest 5 files will be kept for archive.

'mail_admins': {
    'level': 'ERROR',
    'class': 'django.utils.log.AdminEmailHandler'
},

This will send each log by eamil to users specified in ADMINS setting variable. The level is set to ERROR, so only logs with level ERROR will be sent by e-mail. This is extremely useful to stay informed on potential errors 50x on a production server.

Other handlers can be used with Django. For a full list, please read the corresponding documentation. Like formatters, you can define many handlers in a same project, setting for each a different key string. Each handler can be used in a specific logger.

Loggers

In LOGGING, the last part configure for each module the minimal logging level, the handlers(s) to use, etc.