lollercoaster lollercoaster - 22 days ago 6
Python Question

Logging in Django on Heroku not appearing

I have created an app on Heroku and I push my Django app to it.

I monitor the logs using

heroku logs --tail
to see them in real time.

Then, in my
settings.py
, I have the following:

LOGGING = {
'version': 1,
'disable_existing_loggers': False,
'formatters': {
'verbose': {
'format': ('%(asctime)s [%(process)d] [%(levelname)s] ' +
'pathname=%(pathname)s lineno=%(lineno)s ' +
'funcname=%(funcName)s %(message)s'),
'datefmt': '%Y-%m-%d %H:%M:%S'
},
'simple': {
'format': '%(levelname)s %(message)s'
}
},
'handlers': {
'null': {
'level': 'DEBUG',
'class': 'logging.NullHandler',
},
'console': {
'level': 'INFO',
'class': 'logging.StreamHandler',
'formatter': 'verbose',
'stream': sys.stdout,
}
},
'loggers': {
'MYAPP': {
'handlers': ['console'],
'level': 'INFO',
}
}
}


Then, when I want to log something, I use the following:

import logging
import sys

logger = logging.getLogger('MYAPP')
logger.info('My message here...')
sys.stdout.flush()


but it isn't reflected in my logs.

My
Procfile
:

web: gunicorn myapp.wsgi --log-file=-


EDIT: Curiously, I can actually change "myapp" to "django" when I define my logging config and also
logging.getLogger('django')
and that allows me to see anything using
print
in my logs, but nothing from the formatted logger I've defined.

I even have
PYTHONUNBUFFERED=true
and
DEBUG=1
set for my staging environment, but I don't see any of the logs that I see when using my local version with
foreman start web
.

What is causing this and how do I see my logs live in Heroku?

Answer

Your Procfile is probably at fault here:

If you want to have gunicorn log to stdout you have to use the --logfile=- command line option (you are missing the = !) according to this answer.

So your entire Procfile should look like this:

web: gunicorn myapp.wsgi --log-file=-

EDIT:

Since print statements are working for you, but logging is not, your logging setup is probably at fault. Make sure that you set up logging during the startup of your app (where are you calling dictConfig in your code?):

import logging
logging.config.dictConfig(LOGGING)
logger = logging.getLogger('MYAPP')
logger.info("Just testing")