[Django]-How do you log server errors on django sites

Django Sentry is a good way to go, as already mentioned, but there is a bit of work involved in setting it up properly (as a separate website). If you just want to log everything to a simple text file here’s the logging configuration to put in your settings.py

LOGGING = {
    'version': 1,
    'disable_existing_loggers': False,
    'handlers': {
        # Include the default Django email handler for errors
        # This is what you'd get without configuring logging at all.
        'mail_admins': {
            'class': 'django.utils.log.AdminEmailHandler',
            'level': 'ERROR',
             # But the emails are plain text by default - HTML is nicer
            'include_html': True,
        },
        # Log to a text file that can be rotated by logrotate
        'logfile': {
            'class': 'logging.handlers.WatchedFileHandler',
            'filename': '/var/log/django/myapp.log'
        },
    },
    'loggers': {
        # Again, default Django configuration to email unhandled exceptions
        'django.request': {
            'handlers': ['mail_admins'],
            'level': 'ERROR',
            'propagate': True,
        },
        # Might as well log any errors anywhere else in Django
        'django': {
            'handlers': ['logfile'],
            'level': 'ERROR',
            'propagate': False,
        },
        # Your own app - this assumes all your logger names start with "myapp."
        'myapp': {
            'handlers': ['logfile'],
            'level': 'WARNING', # Or maybe INFO or DEBUG
            'propagate': False
        },
    },
}

django-db-log, mentioned in another answer, has been replaced with:

https://github.com/dcramer/django-sentry

Obviously James is correct, but if you wanted to log exceptions in a datastore, there are a few open source solutions already available:

1) CrashLog is a good choice: http://code.google.com/p/django-crashlog/

2) Db-Log is a good choice as well: http://code.google.com/p/django-db-log/

What is the difference between the two? Almost nothing that I can see, so either one will suffice.

I’ve used both and they work well.

Some time has passed since EMP’s most helpful code submission. I just now implemented it, and while thrashing around with some manage.py option, to try to chase down a bug, I got a deprecation warning to the effect that with my current version of Django (1.5.?) a require_debug_false filter is now needed for the mail_admins handler.

Here is the revised code:

LOGGING = {
    'version': 1,
    'disable_existing_loggers': False,
    'filters': {
         'require_debug_false': {
             '()': 'django.utils.log.RequireDebugFalse'
         }
     },
    'handlers': {
        # Include the default Django email handler for errors
        # This is what you'd get without configuring logging at all.
        'mail_admins': {
            'class': 'django.utils.log.AdminEmailHandler',
            'level': 'ERROR',
            'filters': ['require_debug_false'],
             # But the emails are plain text by default - HTML is nicer
            'include_html': True,
        },
        # Log to a text file that can be rotated by logrotate
        'logfile': {
            'class': 'logging.handlers.WatchedFileHandler',
            'filename': '/home/username/public_html/djangoprojectname/logfilename.log'
        },
    },
    'loggers': {
        # Again, default Django configuration to email unhandled exceptions
        'django.request': {
            'handlers': ['mail_admins'],
            'level': 'ERROR',
            'propagate': True,
        },
        # Might as well log any errors anywhere else in Django
        'django': {
            'handlers': ['logfile'],
            'level': 'ERROR',
            'propagate': False,
        },
        # Your own app - this assumes all your logger names start with "myapp."
        'myapp': {
            'handlers': ['logfile'],
            'level': 'DEBUG', # Or maybe INFO or WARNING
            'propagate': False
        },
    },
}

I just had an annoying problem with my fcgi script. It occurred before django even started. The lack of logging is sooo painful. Anyway, redirecting stderr to a file as the very first thing helped a lot:

#!/home/user/env/bin/python
sys.stderr = open('/home/user/fcgi_errors', 'a')

You can use the logging library in Python, no need to pip install anything.

Replace any print() with logging.debug()
but,

Django Sentry is a good way to go

as EMP said.