Django Scrubber
django_scrubber
is a django app meant to help you anonymize your project's database data. It destructively alters data
directly on the DB and therefore should not be used on production.
The main use case is providing developers with realistic data to use during development, without having to distribute
your customers' or users' potentially sensitive information.
To accomplish this, django_scrubber
should be plugged in a step during the creation of your database dumps.
Simply mark the fields you want to anonymize and call the scrub_data
management command. Data will be replaced based
on different scrubbers (see below), which define how the anonymous content will be generated.
If you want to be sure that you don't forget any fields in the ongoing development progress, you can use the
management command scrub_validation
in your CI/CD pipeline to check for any missing fields.
Installation
Simply run:
pip install django-scrubber
And add django_scrubber
to your django INSTALLED_APPS
. I.e.: in settings.py
add:
INSTALLED_APPS = [
...
'django_scrubber',
...
]
Scrubbing data
In order to scrub data, i.e.: to replace DB data with anonymized versions, django-scrubber
must know which models and
fields it should act on, and how the data should be replaced.
There are a few different ways to select which data should be scrubbed, namely: explicitly per model field; or globally per name or field type.
Adding scrubbers directly to model, matching scrubbers to fields by name:
class MyModel(Model):
somefield = CharField()
class Scrubbers:
somefield = scrubbers.Hash('somefield')
Adding scrubbers globally, either by field name or field type:
# (in settings.py)
SCRUBBER_GLOBAL_SCRUBBERS = {
'name': scrubbers.Hash,
EmailField: scrubbers.Hash,
}
Model scrubbers override field-name scrubbers, which in turn override field-type scrubbers.
To disable global scrubbing in some specific model, simply set the respective field scrubber to None
.
Scrubbers defined for non-existing fields will raise a warning but not fail the scubbing process.
Which mechanism will be used to scrub the selected data is determined by using one of the provided scrubbers
in django_scrubber.scrubbers
. See below for a list.
Alternatively, values may be anything that can be used as a value in a QuerySet.update()
call (like Func
instances,
string literals, etc), or any callable
that returns such an object when called with a Field
object as argument.
By default, django_scrubber
will affect all models from all registered apps. This may lead to issues with third-party
apps if the global scrubbers are too general. This can be avoided with the SCRUBBER_APPS_LIST
setting. Using this, you
might for instance split your INSTALLED_APPS
into multiple SYSTEM_APPS
and LOCAL_APPS
, then
set SCRUBBER_APPS_LIST = LOCAL_APPS
, to scrub only your own apps.
Finally just run ./manage.py scrub_data
to destructively scrub the registered fields.
Arguments to the scrub_data command
--model
Scrub only a single model (format
--keep-sessions
Will NOT truncate all (by definition critical) session data.
--remove-fake-data
Will truncate the database table storing preprocessed data for the Faker library.
Built-In scrubbers
Empty/Null
The simplest scrubbers: replace the field's content with the empty string or NULL
, respectively.
class Scrubbers:
somefield = scrubbers.Empty
someother = scrubbers.Null
These scrubbers have no options.
Keeper
When running the validation or want to work in strict mode, you maybe want to actively decide to keep certain data
instead of scrubbing them. In this case, you can just define scrubbers.Keep
.
class Scrubbers:
non_critical_field = scrubbers.Keep
These scrubber doesn't have any options.
Hash
Simple hashing of content:
class Scrubbers:
somefield = scrubbers.Hash # will use the field itself as source
someotherfield = scrubbers.Hash('somefield') # can optionally pass a different field name as hashing source
Currently, this uses the MD5 hash which is supported in a wide variety of DB engines. Additionally, since security is not the main objective, a shorter hash length has a lower risk of being longer than whatever field it is supposed to replace.
Lorem
Simple scrubber meant to replace TextField
with a static block of text. Has no options.
class Scrubbers:
somefield = scrubbers.Lorem
Concat
Wrapper around django.db.functions.Concat
to enable simple concatenation of scrubbers. This is useful if you want to
ensure a fields uniqueness through composition of, for instance, the Hash
and Faker
(see below) scrubbers.
The following will generate random email addresses by hashing the user-part and using faker
for the domain part:
class Scrubbers:
email = scrubbers.Concat(scrubbers.Hash('email'), models.Value('@'), scrubbers.Faker('domain_name'))
Faker
Replaces content with the help of faker.
class Scrubbers:
first_name = scrubbers.Faker('first_name')
last_name = scrubbers.Faker('last_name')
past_date = scrubbers.Faker('past_date', start_date="-30d", tzinfo=None)
The replacements are done on the database-level and should therefore be able to cope with large amounts of data with reasonable performance.
The Faker
scrubber requires at least one argument: the faker provider used to generate random data.
All faker providers are supported, and you can also register
your own custom providers.
Any remaining arguments will be passed through to that provider. Please refer to the faker docs if a provider accepts
arguments and what to do with them.
Locales
Faker will be initialized with the current django LANGUAGE_CODE
and will populate the DB with localized data. If you
want localized scrubbing, simply set it to some other value.
Idempotency
By default, the faker instance used to populate the DB uses a fixed random seed, in order to ensure different scrubbings of the same data generate the same output. This is particularly useful if the scrubbed data is imported as a dump by developers, since changing data during troubleshooting would otherwise be confusing.
This behaviour can be changed by setting SCRUBBER_RANDOM_SEED=None
, which ensures every scrubbing will generate random
source data.
Limitations
Scrubbing unique fields may lead to IntegrityError
s, since there is no guarantee that the random content will not be
repeated. Playing with different settings for SCRUBBER_RANDOM_SEED
and SCRUBBER_ENTRIES_PER_PROVIDER
may alleviate
the problem.
Unfortunately, for performance reasons, the source data for scrubbing with faker is added to the database, and
arbitrarily increasing SCRUBBER_ENTRIES_PER_PROVIDER
will significantly slow down scrubbing (besides still not
guaranteeing uniqueness).
When using django < 2.1
and working on sqlite
a bug within django causes field-specific scrubbing (
e.g. date_object
) to fail. Please consider using a different database backend or upgrade to the latest django version.
Scrubbing third-party models
Sometimes you just don't have control over some code, but you still want to scrub the data of a given model.
A good example is the Django user model. It contains sensitive data, and you would have to overwrite the whole model just to add the scrubber metaclass.
That's the way to go:
- Define your Scrubber class somewhere in your codebase (like a
scrubbers.py
)
# scrubbers.py
class UserScrubbers:
scrubbers.Faker('de_DE')
first_name = scrubbers.Faker('first_name')
last_name = scrubbers.Faker('last_name')
username = scrubbers.Faker('uuid4')
password = scrubbers.Faker('sha1')
last_login = scrubbers.Null
email = scrubbers.Concat(first_name, models.Value('.'), last_name, models.Value('@'),
models.Value(settings.SCRUBBER_DOMAIN))
````
2. Set up a mapping between your third-party model and your scrubber class
```python
# settings.py
SCRUBBER_MAPPING = {
"auth.User": "apps.account.scrubbers.UserScrubbers",
}
Settings
SCRUBBER_GLOBAL_SCRUBBERS
:
Dictionary of global scrubbers. Keys should be either field names as strings or field type classes. Values should be one
of the scrubbers provided in django_scrubber.scrubbers
.
Example:
SCRUBBER_GLOBAL_SCRUBBERS = {
'name': scrubbers.Hash,
EmailField: scrubbers.Hash,
}
SCRUBBER_RANDOM_SEED
:
The seed used when generating random content by the Faker scrubber. Setting this to None
means each scrubbing will
generate different data.
(default: 42)
SCRUBBER_ENTRIES_PER_PROVIDER
:
Number of entries to use as source for Faker scrubber. Increasing this value will increase the randomness of generated data, but decrease performance.
(default: 1000)
SCRUBBER_SKIP_UNMANAGED
:
Do not attempt to scrub models which are not managed by the ORM.
(default: True)
SCRUBBER_APPS_LIST
:
Only scrub models belonging to these specific django apps. If unset, will scrub all installed apps.
(default: None)
SCRUBBER_ADDITIONAL_FAKER_PROVIDERS
:
Add additional fake providers to be used by Faker. Must be noted as full dotted path to the provider class.
(default: empty list)
SCRUBBER_FAKER_LOCALE
:
Set an alternative locale for Faker used during the scrubbing process.
(default: None, falls back to Django's default locale)
SCRUBBER_MAPPING
:
Define a class and a mapper which does not have to live inside the given model. Useful, if you have no control over the models code you'd like to scrub.
SCRUBBER_STRICT_MODE
:
When strict mode is activated, you have to define a scrubbing policy for every field of every type defined in
SCRUBBER_REQUIRED_FIELD_TYPES
. If you have unscrubbed fields and this flag is active, you can't run
python manage.py scrub_data
.
SCRUBBER_REQUIRED_FIELD_TYPES
:
Defaults to all text-based Django model fields. Usually, privacy-relevant data is only stored in text-fields, numbers
and booleans (usually) can't contain sensitive personal data. These fields will be checked when running
python manage.py scrub_validation
.
(default: (models.CharField, models.TextField, models.URLField, models.JSONField, models.GenericIPAddressField, models.EmailField,))
SCRUBBER_REQUIRED_FIELD_MODEL_WHITELIST
:
Whitelists a list of models which will not be checked during scrub_validation
and when
activating the strict mode. Defaults to the non-privacy-related Django base models.
Items can either be full model names (e.g. auth.Group
) or regular expression patterns matching
against the full model name (e.g. re.compile(auth.*)
to whitelist all auth models).
(default: ['auth.Group', 'auth.Permission', 'contenttypes.ContentType', 'sessions.Session', 'sites.Site', 'django_scrubber.FakeData',))
SCRUBBER_MAPPING = {
"auth.User": "my_app.scrubbers.UserScrubbers",
}
(default: {})
SCRUBBER_VALIDATION_WHITELIST
:
Whitelist models you want to exclude from the scrub_validation
checker command for scrubber-wise undeclared models.
By default, it contains only a test model from Django core which doesn't have to be anonymised.
(default: ['db.TestModel',])
Logging
Scrubber uses the default django logger. The logger name is django_scrubber.scrubbers
.
So if you want to log - for example - to the console, you could set up the logger like this:
LOGGING['loggers']['django_scrubber'] = {
'handlers': ['console'],
'propagate': True,
'level': 'DEBUG',
}
Making a new release
bumpversion is used to manage releases.
Add your changes to the CHANGELOG and run bumpversion <major|minor|patch>
, then push (including
tags)