Backend authentication using frontend (Mobile app) login

Mobile (FE) and BE social authentication using React-Native, Django and PostgreSQL

This is a general example for authentication a of mobile app (FE), using third party (Facebook, Google...) and a BE service (Djange-Rest-Framework). Will use google as an example, process is the same for all third party authenticatrion.

The highlevel flow is (App should already be registered - have app id):

1. Mobile App - user login to third party
2. Third party supplies a token
3. Pass token to BE
4. BE validates the token with third party, retrieves requested data.
5. BE supplies a new token for session.
6. App, user, uses token for communicating with backend API.

Instalation:

1. Python >= 3.6
2. virtual env:
   1. python.exe -m venv /venv/path
   2. source /venv/path/Scripts/activate
3. Install Django, Django-Rest-Famework
   1. pip install django
   2. pip install django-rest-framework
4. Install PostgreSQL
5. Install react-native

Implementation:

Backend app - Simple django REST app:

The examples are based on the following links:

https://docs.djangoproject.com/en/2.0/topics/auth/customizing/#using-a-custom-user-model-when-starting-a-project

https://www.django-rest-framework.org/tutorial/4-authentication-and-permissions/

https://www.django-rest-framework.org/api-guide/authentication/

The basic step for almost all apps is to create a user.

Luckily Django rest framework (drf) already supports such requirement.

1. Create a PostgreSQL DB. In my opinion, easiest way is to use pgadmin, lets call it 'authentication_example', also create a user for that db, lets call it 'auth_user_admin' with psw: '123456'
2. Create a simple django app - I am using Eclipse with Django SDK, but you can use django command list as well: https://www.django-rest-framework.org/tutorial/quickstart/
3. Install python pgsql: pip install psycopg2
4. Configure django app to worj with postgreSQL, changed the default sql section to pgsql:
   DATABASES = {
   'default': {
   'ENGINE': 'django.db.backends.postgresql_psycopg2',
   'NAME': 'authentication_example',
   'USER': 'auth_user_admin',
   'PASSWORD': '123456',
   'HOST': 'localhost',
   'PORT': '',
   }
   }
   
5. Update DB:
   • python manage.py makemigrations
   • python manage.py migrate