Configuration

Muffin gets configuration options from python files. You have to specify default configuration module name in your app initialization:

# Application arguments are configuration modules, first available will be used
app = muffin.Application('config.local', 'config.production')

This configuration module path could be overriden by MUFFIN_CONFIG environment variable:

$ MUFFIN_CONFIG=settings.local uvicorn your_project:app

Also you can redefine config parameters while initializing your application:

Configuration will be available through app.cfg attribute.

app = muffin.Application(DEBUG=True, ANY_OPTION='value', ONE_MORE='value2')

assert app.cfg.DEBUG is True
assert app.cfg.ANY_OPTION  == 'value'
assert app.cfg.ANY_OPTION  == 'value2'

Default Application Options

Base Muffin options and default values:

# Application name (used as prefix for env variables, for logging, for plugins)
'NAME': 'muffin',

# Configuration module
'CONFIG': None,

# Enable debug mode
'DEBUG': False

# Routing options
'TRIM_LAST_SLASH': True,

# Static files options
'STATIC_URL_PREFIX': '/static',
'STATIC_FOLDERS': [],

# Logging options
'LOG_LEVEL': 'WARNING',
'LOG_FORMAT': '%(asctime)s [%(process)d] [%(levelname)s] %(message)s',
'LOG_DATE_FORMAT': '[%Y-%m-%d %H:%M:%S]',
'LOG_CONFIG': None,

# Muffin shell context
'MANAGE_SHELL': lambda: {'app': app, 'run': aio_run, **app.plugins},

Environment variables

Muffin reads configuration values from the current environment’s variables using the form: {app.name}_{option_name}. By default Muffin parses env values as a JSON.

Consider the options file settings.py:

DEBUG = True
DB_PARAMS = {"pool": 10}
TOKEN: str = None

os.environ['TOKEN'] = 'value'  # simple strings supported as well
os.environ['DEBUG'] = 'false'  # json boolean value
os.environ['DB_PARAMS'] = '{"pool": 50}' # json too

app = Muffin('app', 'settings')

assert app.cfg.DEBUG is False
assert app.cfg.DB_PARAMS == {'pool': 50}
assert app.cfg.TOKEN == 'value'

Configuration precedence

The order in which configuration values are read is:

• From default config;

• From the given python modules;

• From environment variables;

• From the given paramenters when initializing the app;

Configuring logging

You can define your logging configurations with Python dictConfig format and place in LOG_CONFIG option:

LOG_CONFIG = {
    'version': 1,
    'disable_existing_loggers': False,
    'formatters': {
        'default': {
            'format': '%(asctime)s %(levelname)s %(name)s %(message)s'
        },
    },
    'handlers': {
        'logfile': {
            'level': 'DEBUG',
            'class': 'logging.handlers.RotatingFileHandler',
            'filename': 'my_log.log',
            'maxBytes': 50 * 1024 * 1024,
            'backupCount': 10
        },
    },
    'loggers': {
        '': {
            'handlers': ['logfile'],
            'level': 'ERROR'
        },
        'project': {
            'level': 'INFO',
            'propagate': True,
        },
    }
}