django-rest-microservice 1.0

Facilitating microservice architecture in Django REST framework

django-rest-microservice

This package is built on the djangorestframework-simplejwt package, which provides some JWT authentication mechanisms with Django REST framework. This package offers the following features:

• Provides refresh cookie in HttpOnly cookie, and access token in response body, for better security when implemented properly with SPA.
• Provides an easier approach to customizing token claims than the standard mechanism described in djangorestframework-simplejwt documentation.
• Provides a mechanism for authentication with a third-party IDP, before issuing internal JWT to your users.
• Currently, supports authentication with AWS Cognito using OAuth 2 Code Grant with PKCE for best security practices.

Installation

Install package to environment:

pip install django-rest-microservice

In the main urls.py, include the default package url routes:

from django.urls import path, include

urlpatterns = [
    path("auth/", include("rest_framework_microservice.urls"))
]

In Django settings, include the following:

REST_FRAMEWORK = {
    'DEFAULT_AUTHENTICATION_CLASSES': (
        'rest_framework_simplejwt.authentication.JWTTokenUserAuthentication',
    )
}

Settings

Settings are specified in Django settings.py under REST_FRAMEWORK_MICROSERVICE, the defaults are the following:

REST_FRAMEWORK_MICROSERVICE = {
    "REFRESH_COOKIE_NAME": "refresh_cookie",
    "IDP": {
        "PROVIDER": "aws",
        "USER_POOL": "us-west-2_abcdefg",
        "CLIENT_ID": "abcdefg",
    },
    "CUSTOM_TOKEN_USER_ATTRIBUTES": [],
    "CUSTOM_TOKEN_CALLABLE_ATTRIBUTES": [],
    "COOKIE_SALT": "extra",
    "USER_SERIALIZER_CLASS": None,
}

REFRESH_COOKIE_NAME

Name of refresh cookie to set in HTTP header.

IDP

A dictionary containing IDP attributes:

• PROVIDER: a string identifying what IDP backend to use, defaults to 'aws' (Currently only AWS Cognito is supported.)
• USER_POOL: user pool identifier used with the IDP.
• CLIENT_ID: IDP client id for your application.

CUSTOM_TOKEN_USER_ATTRIBUTES

The list of Django user attributes to be copied to token as claims. i.e.: ['is_active',].

CUSTOM_TOKEN_CALLABLE_ATTRIBUTES

This is used to customize claims which cannot be done by simply using CUSTOM_TOKEN_USER_ATTRIBUTES setting. This should be a list of dictionaries containing attr_name and attr_getter. i.e. : [{'attr_name': 'preferences', 'attr_getter': 'my_module.some_file.get_user_preferences'}, ...]

The function specified in attr_getter should accept an argument of a Django user instance.

COOKIE_SALT

Salt to be used when signing cookie.

USER_SERIALIZER_CLASS

Defaults to None. If specified, the default view serializers will try to add a user object representing the user. The content of the user object is defined by USER_SERIALIZER_CLASS.

Customizing token claims

You can include additional user attributes in the token claims by specifying them in the CUSTOM_TOKEN_USER_ATTRIBUTES.

You can also specify functions to return the value for custom claims by using CUSTOM_TOKEN_CALLABLE_ATTRIBUTES.

# settings.py
REST_FRAMEWORK_MICROSERVICE = {
  ...,
  'CUSTOM_TOKEN_CALLABLE_ATTRIBUTES': [
        {'attr_name': 'user_services',
         'attr_getter': 'my_module.token_claims.get_user_subscribed_services'
         }
    ]
}

# my_module.token_claims.py
def get_user_subscribed_services(user):
  return user.subscribed_services

If you are using djangorestframework-simplejwt version <= 5.0.0, you will also need to extend the rest_framework_simplejwt.models.TokenUser to include the additional claims. This is only applicable when using older versions.

from functools import cached_property
from rest_framework_simplejwt.models import TokenUser

class CustomTokenUser(TokenUser):
    """
    Extend TokenUser and adds custom attributes to be pulled from TokenUser.
    This class should be specified in Django settings SIMPLE_JWT.TOKEN_USER_CLASS
    """

    @cached_property
    def first_name(self):
        return self.token.get('first_name', None)

and include the following Django setting:

SIMPLE_JWT = {
    'TOKEN_USER_CLASS': 'microservice.models.CustomTokenUser'
}