simple error log message in django - django

Question

I've got error emails setup via Django's logging mechanism in 1.3. It sends me a nice email when an error happens. However, when I log a simple error message it's being formatted oddly and I'm not sure why.
For example, there's a condition in my app where if something doesn't exist in the DB I want to know about, but I have a suitable default value that will work fine. Thus, I want an email sent to me with some info; it's not necessarily happening on an Exception.
If I do something like this:
logger.error("fee did not exist in the database for action %s", "actionX")
The information in the logfile is fine, but the email is really lacking some information. Here's the subject line:
[Django] ERROR: Test this jazz %s
And then the body:
None
Request repr() unavailable
My question is, how do I get A) the value to show up in the subject and B) get some actual, relevant information in the body....like line number or something like that.

Answer 1

You need to acknowledge two things:
You want to send an email using Python's builtin logging system and
You are not logging a regular exception so the builtin mechanism for sending emails won't work since it's depending on an exception type-like object to be passed and stuff to be stored in a traceback.
Anyways, not impossible!
LOGGING = {
...
'handlers': {
...
'my_special_mail_handler': {
'level': 'ERROR',
'filters': [],
'class': 'myapp.loggers.MyEmailHandler',
'include_html': False,
},
},
'loggers': {
...
'my_special_logger': {
'handlers': ['console', 'my_special_mail_handler'],
'level': 'DEBUG',
'propagate': True,
},
}
}
MY_RECIPIENTS = (("Name of person", "email#example.com"),)
...that stuff is merged into your settings.
Then, there's your special logging class, MyEmailHandler:
from django.utils.log import AdminEmailHandler
from django.core.mail.message import EmailMultiAlternatives
from django.conf import settings
class MyEmailHandler(AdminEmailHandler):
def emit(self, record):
if not getattr(settings, "MY_RECIPIENTS", None):
return
subject = self.format_subject(record.getMessage())
message = getattr(record, "email_body", record.getMessage())
mail = EmailMultiAlternatives(u'%s%s' % (settings.EMAIL_SUBJECT_PREFIX, subject),
message, settings.SERVER_EMAIL, [a[1] for a in settings.MY_RECIPIENTS],)
mail.send(fail_silently=False)
Now you're able to create a special logging entry that's both emailed and output to the terminal this way:
import logging
logger = logging.getLogger("my_special_logger")
error = logger.makeRecord(
logger.name, logging.ERROR, 0, 0,
u"Subject: Some error occured",
None, None, "", None,
)
error.email_body = msg
logger.handle(error)
and to make stuff easy, use a utility function:
import logging
def my_log(msg, body, level=logging.ERROR):
logger = logging.getLogger("my_special_logger")
error = logger.makeRecord(
logger.name, level, 0, 0,
u"Subject: Some error occured",
None, None, "", None,
)
error.email_body = msg
logger.handle(error)

Answer 2

The Django Logging docs state:
Of course, it isn't enough to just put logging calls into your code. You also need to configure the loggers, handlers, filters and formatters to ensure that logging output is output in a useful way.
You need to tweak your settings in your logging.config() dictionary. That allows you to set out exactly what information you want and how to format.
Cutting a small bit from the docs:
'formatters': {
'verbose': {
'format': '%(levelname)s %(asctime)s %(module)s %(process)d %(thread)d %(message)s'
},
Gives you a bit of an idea how you can influence the output, and the logging.config docs for python will fill out the available options.