Logging

Logging is a great way to track what is going on with your app.

This makes it easier for other developers to debug what’s going on without resorting to print statements or pdb calls. It also makes it easier to diagnose failures in production.

Playdoh supports logging out of the box.

Note

This is similar to Django Logging, but we make it easier to setup loggers and handlers.

How to log

Logging is provided via commonware.

Within our webapps we typically use a small namespace prefix for logging:

m: mozillians
k: kitsune
i: input
z: zamboni

When we log in our app we can do the following:

import commonware.log

log = commonware.log.getLogger('i.myapp')


def my_view(request):
    log.info('%s got here' % request.user)
    pass

Anytime someone goes to myapp.views.my_view a log entry at level INFO will be made.

In development this shows up as standard output.

Silence Logging

Sometimes logging can be noisy:

elasticsearch: DEBUG: Search disabled for <function add_to_index at 0x102e58848>.

Commonware as configured in playdoh, allows you to configure logging via a dict in your settings (preferrably settings/local.py):

error = dict(level=logging.ERROR)
info = dict(level=logging.INFO)

LOGGING = {
    'loggers': {
        'product_details': error,
        'nose.plugins.manager': error,
        'django.db.backends': error,
        'elasticsearch': info,
    },
}

This configuration says:

  • Only tell me if there are errors with any logs in the product_details, nose.plugins.manager and django.db.backends namespace
  • Only tell me if there are INFO, WARNING or ERROR messages with ElasticSearch.