Stop writing settings files

More details on my blog: http://bruno.im/2013/may/18/django-stop-writing-settings-files/

Transcript

1. Stop writing
   settings
   files
   

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2. Settings
   

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3. local_settings
   # settings.py
   # settings goes here, and at the end…
   try:
   from local_settings import *
   except ImportError:
   pass
   

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4. # settings.py
   INSTALLED_APPS = …
   # local_settings.py
   INSTALLED_APPS = …
   How do I know what's
   in the base settings?
   

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5. # settings/base.py
   INSTALLED_APPS = …
   # settings/production.py
   from .base import *
   # override here with
   # production-specific settings
   Multiple settings files
   $ python manage.py shell --settings=settings.production
   

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6. settings/
   __init__.py
   base.py
   dev.py
   staging.py
   production.py
   other.py
   stuff.py
   whatever.py
   

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7. — 12factor.net
   " "
   … strict separation of config from
   code. Config varies substantially
   across deploys,code does not.
   

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8. Expose your configuration
   as environment variables
   Derive your settings from
   the environment
   DEBUG = bool(os.environ.get('DEBUG', False))
   Use one settings file
   

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9. ALLOWED_HOSTS
   AWS_ACCESS_KEY_ID
   AWS_SECRET_ACCESS_KEY
   DATABASE_URL
   DJANGO_SETTINGS_MODULE
   EMAIL_URL
   FROM_EMAIL
   HTTPS
   MEDIA_ROOT
   REDIS_URL
   SECRET_KEY
   SENTRY_DSN
   STATIC_ROOT
   

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10. What about development?
    Aren't environment variables a
    pain to work with?
    

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11. daemontools' envdir
    path/to/env/
    DATABASE_URL
    SENTRY_DSN
    …
    $ envdir path/to/env
    $ envdir path/to/env django-admin.py
    Sane defaults for development
    kept under version control
    

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12. envdir in ur manage.py
    if __name__ == "__main__":
    if 'test' in sys.argv:
    env_dir = os.path.join('tests', 'envdir')
    else:
    env_dir = 'envdir'
    env_vars = glob.glob(os.path.join(env_dir, '*'))
    for env_var in env_vars:
    with open(env_var, 'r') as env_var_file:
    os.environ.setdefault(env_var.split(os.sep)[-1],
    env_var_file.read().strip())
    from django.core.management import execute_from_command_line
    execute_from_command_line(sys.argv)
    

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13. One settings files, less moving parts
    Configuration as environment variables
    Production: set them with
    daemontools, circus, supervisor…
    Development: use envdir and/or
    a custom manage.py
    Your PaaS already supports them
    Easy to setup with Salt/Puppet/Chef
    Your sysadmin will thank you
    

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14. thanks!
    @brutasse
    

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