Managing Authentication and Permissions

Tutorial 4 of 5

1. Introduction

1.1 Brief Explanation of the Tutorial's Goal

In this tutorial, we'll explore the concept of authentication and permissions in Django REST Framework. We aim to ensure that you understand how to implement security in your application by verifying user identities and managing access rights.

1.2 What the User Will Learn

By the end of this tutorial, you should be able to:
- Understand the basics of authentication and permissions in Django REST Framework.
- Implement basic user authentication.
- Define and manage access rights using permissions.

1.3 Prerequisites

Before proceeding, you should have:
- Basic knowledge of Python.
- Familiarity with Django and Django REST Framework.
- A working Django project to practice with.

2. Step-by-Step Guide

2.1 Authentication

Authentication in Django REST Framework is the mechanism of associating an incoming request with a set of identifying credentials. The authentication classes in Django REST Framework are used to provide a request.user property.

For example, you can use the TokenAuthentication class for token-based authentication. Here is a simple example:

from rest_framework.authentication import TokenAuthentication
from rest_framework.permissions import IsAuthenticated
from rest_framework.response import Response
from rest_framework.views import APIView

class ExampleView(APIView):
    authentication_classes = [TokenAuthentication]
    permission_classes = [IsAuthenticated]

    def get(self, request, format=None):
        content = {
            'user': str(request.user),  # `django.contrib.auth.User` instance.
            'auth': str(request.auth),  # None
        }
        return Response(content)

2.2 Permissions

Permissions determine whether a request should be granted or denied access. They are used in conjunction with authentication.

For example, the IsAuthenticated permission class makes a view only accessible to logged-in users.

3. Code Examples

3.1 Code Snippet

Here is an example of a viewset where we have set authentication and permissions:

from rest_framework.authentication import TokenAuthentication
from rest_framework.permissions import IsAdminUser
from rest_framework.viewsets import ModelViewSet

class UserViewSet(ModelViewSet):
    authentication_classes = [TokenAuthentication]
    permission_classes = [IsAdminUser]

In this example, the UserViewSet is only accessible to authenticated users with admin privileges.

3.2 Detailed Comments

  • authentication_classes = [TokenAuthentication]: This line sets the authentication class to TokenAuthentication. This means that the user will be authenticated using tokens.
  • permission_classes = [IsAdminUser]: This line sets the permission class to IsAdminUser. As a result, only admin users will be able to access this viewset.

3.3 Expected Output

If a non-admin user or an unauthenticated user tries to access this viewset, they will receive a 403 Forbidden error.

4. Summary

In this tutorial, we've learned about the basics of authentication and permissions in Django REST Framework. We've learned how to use authentication classes to identify incoming requests and permission classes to manage access rights.

5. Practice Exercises

5.1 Exercise 1: Basic Authentication

  • Implement a view that uses basic authentication.
  • Test your view using different credentials.

5.2 Exercise 2: Custom Permission

  • Create a custom permission class that only allows access to users with a certain attribute.
  • Apply this permission class to a view and test it.

5.3 Exercise 3: Combine Authentication and Permissions

  • Implement a view that uses both authentication and permissions.
  • Test your view with different users and roles.