Dev Mehta

Posted on Jan 29, 2023 • Originally published at simplifiedweb.netlify.app on Jan 27, 2023

Build Scalable and Secure APIs with Django REST Framework

#django #api #restframework #python

Introduction

This blog post was originally published on my blog. You can check it out for more such posts

Welcome to the world of Django REST framework, where building scalable and secure APIs is as easy as wielding the Founding Titan's power. In this blog post, we will be exploring the ins and outs of Django REST framework, a popular choice for building APIs.

From setting up a new Django project to handling requests and responses with serializers and views, we will be covering it all. You'll learn how to implement authentication and authorization, and how to use the built-in features of Django REST framework to make your API development process a breeze. So grab your 3D Maneuver Gear and let's begin our journey to building the ultimate API.

In case you didn’t understand Founding Titan and 3D Maneuver Gear, it refers to the popular anime and manga series Attack on Titan, which is used as a creative and unique angle for the blog post, so young readers can grasp the content easily by correlating to it.

Brief Overview of the Importance of APIs and why Django REST Framework is a good choice for building them

Welcome to the world of Django REST framework, the gateway to the digital world like the Door of Truth of the Survey Corps.

APIs, or Application Programming Interfaces, are the backbone of modern web and mobile applications, just like the Vertical Maneuvering Equipment is to the Survey Corps. They allow different software systems to communicate with each other, share data, and perform actions, much like how the Survey Corps share information and coordinate attacks against the Titans.

With the rise of cloud-based services and the Internet of Things, the need for robust and scalable APIs has never been greater, just like how the Titans continue to threaten humanity. Django REST framework is a powerful tool for building APIs that can handle large amounts of data and traffic, just like how the Survey Corps use their equipment to fight Titans.

In this article, we'll delve into the world of Django REST framework and how it can help you build powerful and efficient APIs, just like how the Survey Corps work together to protect humanity. Join us on this journey as we explore the ins and outs of Django REST framework and discover the secrets to building great APIs.

What we will cover?

By the end of this blogpost, you will have

A brief understanding of API Development Fundamentals
How to build an API in Django - which is robust and secure framework in itself
A brief understanding of API Development Lifecycle
Building a Simple API with Django REST Framework
Advanced Features: An exploration of more advanced features of Django REST Framework, such as authentication, permissions, and pagination.
Deployment and Testing: A discussion of best practices for deploying and testing APIs in a production environment.
Additional Resources to Continue Learning Further

Setting Up a Django Project for API Development

Steps for Creating a new Django project and app.

Steps for Creating a new Django Project:

Install Django by running pip install django in your command prompt or terminal.
Create a new Django project by running django-admin startproject projectname in your command prompt or terminal. Replace "projectname" with the desired name of your project.
Change into the project directory by running cd projectname in your command prompt or terminal.
Run the development server by running python manage.py runserver in your command prompt or terminal. This will start the server and make the project available at http://127.0.0.1:8000/ in your web browser.

Steps for Creating a new Django App:

Change into the project directory by running cd projectname in your command prompt or terminal.
Create a new Django app by running python manage.py startapp appname in your command prompt or terminal. Replace "appname" with the desired name of your app.
Add your app to the INSTALLED_APPS list in the settings.py file of your project.
Create a new directory called templates inside your app directory and create an HTML template file within it.
Create a new directory called models inside your app directory and create a new Python file within it to define your app's models.
Create a new file called views.py inside your app directory to define your app's views.
Create a new file called urls.py inside your app directory to define your app's URLs.
Add the app's URLs to the project's urls.py file to make the app accessible in the browser.
Run the development server by running python manage.py runserver in your command prompt or terminal to see your app in action.

Configuring the project for API Development

Install Django REST framework by running pip install djangorestframework

Install the Django REST framework by adding 'rest_framework' to the INSTALLED_APPS list in your settings.pyfile.

Handling Requests and Responses with Serializers and Views

In the world of APIs, serializers and views are like the Titans and Survey Corps of the Django REST framework - they work together to handle incoming requests and outgoing responses.

Serializers, are responsible for handling the data and providing a clean, structured format for it to be passed on to the views. They allow for easy data validation and conversion between Python objects and JSON.

Views, are responsible for handling the incoming requests and providing an appropriate response. They use the data from the serializers to create a response that follows the proper format and structure.

In the Django REST framework, there are a variety of generic views that can be used to handle different types of requests, such as the ListAPIView for handling GET requests for a list of items, or the CreateAPIView for handling POST requests to create a new item.

To use these views, simply import them and extend them in your views.py file, like so:

from rest_framework import generics

class MyView(generics.ListAPIView):
    pass

Additionally, the Django REST framework provides a simple way to handle authentication and authorization using JWT tokens, similar to how the Survey Corps uses their omni-directional mobility gear to navigate and fight the Titans.

In this section, we will cover the basics of using serializers and views in the Django REST framework, and provide examples of how to use them to create a functional API. We will also go over some of the more advanced features of the framework, such as pagination and filtering, and provide tips for debugging and testing your API. So, ready your blades and gear up, because we're about to take on the Titans of API development!

Wait, What are Serializers?

In the world of APIs, data is often sent and received in the form of JSON or XML. Serializers in Django REST framework allow us to easily convert complex data types, such as models and querysets, into JSON or XML format.

For example, in the world of Attack on Titan, let's say we have a database of information on Titans, including their height, weight, and abilities. We can use a serializer to convert this information into a format that can be easily sent over the API to our Survey Corps app, allowing them to easily access and use this information in the field.

Just like Eren and his team have to be careful while handling Titans, we have to be careful while handling serializers and views in Django REST framework to make sure that our API is working properly and efficiently.

How to Use Serializers to Handle Data

Imagine you are creating an API for an e-commerce website where users can view and purchase products. You have a Product model with fields for name, description, price, and image. To display this information to the user, you would need to convert the Product model instance into a JSON object.

To do this, you would first create a serializer class that inherits from Serializer, and define the fields that should be included in the JSON representation of the Product model. For example:

from rest_framework import serializers
from .models import Product

class ProductSerializer(serializers.Serializer):
    name = serializers.CharField()
    description = serializers.CharField()
    price = serializers.DecimalField()
    image = serializers.ImageField()

Then, in your views, you can use this serializer to handle data.

from rest_framework import views
from .models import Product
from .serializers import ProductSerializer

class ProductView(views.APIView):
    def get(self, request, format=None):
        products = Product.objects.all()
        serializer = ProductSerializer(products, many=True)
        return Response(serializer.data)

In this example, the ProductView is handling a GET request and returning a JSON representation of all products in the database. The ProductSerializer is used to convert the queryset of Product model instances into a JSON object.

In the AOT universe, consider a scenario where you are creating an API for a database of Titans. You have a Titan model with fields for name, description, size, and type. To display this information to the user, you would need to convert the Titan model instance into a JSON object.

To do this, you would first create a serializer class that inherits from Serializer, and define the fields that should be included in the JSON representation of the Titan model. For example:

from rest_framework import serializers
from .models import Titan

class TitanSerializer(serializers.Serializer):
    name = serializers.CharField()
    description = serializers.CharField()
    size = serializers.CharField()
    type = serializers.CharField()

Then, in your views, you can use this serializer to handle data.

from rest_framework import views
from .models import Titan
from .serializers import TitanSerializer

class TitanView(views.APIView):
    def get(self, request, format=None):
        titans = Titan.objects.all()
        serializer = TitanSerializer(titans, many=True)
        return Response(serializer.data)

In this example, the TitanView is handling a GET request and returning a JSON representation of all Titans in the database. The TitanSerializer is used to convert the queryset of Titan model instances into a JSON object.

How to Use Views to Handle Responses?

In the world of AOT, views can be thought of as the gatekeepers to your API's inner workings. Just like how a skilled member of the Survey Corps would be responsible for controlling access to the inner walls, views in Django REST framework are responsible for handling incoming requests and returning appropriate responses.

To use views in Django REST framework, you first need to import the necessary classes from the rest_framework package. These classes include APIView, ViewSet, and ModelViewSet. Each of these classes provides different levels of functionality for handling requests and returning responses.

For example, you can use the APIView class for basic views that handle simple requests and return simple responses. On the other hand, you can use the ModelViewSet class for views that handle requests related to a specific model and return responses that include data from that model.

In addition to these classes, you can also use other tools provided by Django REST framework to handle views such as @action decorator, @authentication_classes and @permission_classes decorators.

Here's an example of how you might use the APIView class to handle a request and return a response in an AOT themed API:

from rest_framework.views import APIView
from rest_framework.response import Response

class AttackOnTitanAPIView(APIView):
    def get(self, request):
        data = {'message': 'Attack on Titan API is ready for action!'}
        return Response(data)

In this example, the AttackOnTitanAPIView class is a basic view that inherits from the APIView class. The get method is overridden to handle GET requests and return a response containing a message. This is just a simple example but it can be further built upon to handle more complex requests and return more dynamic responses.

So, like the Survey Corps, you can use views to control access to your API and protect it from Titans. With the help of Django REST framework's views, you can handle incoming requests and return appropriate responses, just like how Survey Corps protects the walls from Titans.

Implementing Authentication and Authorization

Authentication Methods Available in Django REST Framework

Authentication in Django REST framework is used to verify the identity of the user making a request to the API. There are several authentication methods available in Django REST framework, including:

Basic Authentication : This is a simple method of authentication where the client sends a request with a username and password in the headers. The server then verifies the credentials and returns a response.
Token Authentication : This method uses a token-based approach for authentication, where the client sends a request with a token in the headers. The server then verifies the token and returns a response.
Session Authentication : This method uses session-based authentication, where the client sends a request with a session ID in the headers. The server then verifies the session ID and returns a response.
JWT Authentication : JWT (JSON Web Token) is a popular way of handling authentication and authorization in RESTful APIs. With JWT, the client sends a request with a token in the headers, which is verified by the server.

In this blogpost, we will discuss how to use JWT tokens for authentication and authorization in AOT style.

It's important to mention that in this example, we will be using djangorestframework-jwt package.

How to use JWT Tokens for Authentication and Authorization

It is important to keep the secrets of the Survey Corps safe. And just like how Eren's Founding Titan powers are protected by a special key, we can use JSON Web Tokens (JWT) to keep our API secure.

JWT is a type of token-based authentication that is often used in RESTful APIs. It allows the server to authenticate the client without the need for a session or cookies. Instead, the client sends a token with each request, and the server verifies that the token is valid before processing the request.

To use JWT in a Django REST framework project, we can use the djangorestframework-jwt package. First, install it using pip:

pip install djangorestframework-jwt

Next, add 'rest_framework_jwt.authentication.JSONWebTokenAuthentication' to the AUTHENTICATION_CLASSES setting in your settings.py file:

REST_FRAMEWORK = {
    'DEFAULT_PERMISSION_CLASSES': (
        'rest_framework.permissions.IsAuthenticated',
    ),
    'DEFAULT_AUTHENTICATION_CLASSES': (
        'rest_framework_jwt.authentication.JSONWebTokenAuthentication',
    ),
}

Now, when a client sends a request to your API with a valid JWT in the Authorization header, the request will be considered authenticated.

Incorporating JWT tokens for authentication and authorization in views can be done by using the djangorestframework_simplejwt library. This library provides a set of views and authentication classes that can be easily added to your Django REST framework views.

First, you will need to install the library by running pip install djangorestframework_simplejwt.

Next, you will need to add the library's views and authentication classes to your project's urls.py file. Here is

from rest_framework_simplejwt.views import TokenObtainPairView, TokenRefreshView

urlpatterns = [
    path('api/token/', TokenObtainPairView.as_view(), name='token_obtain_pair'),
    path('api/token/refresh/', TokenRefreshView.as_view(), name='token_refresh'),
]

Then, you can add the JWTAuthentication class to the authentication_classes attribute of your views. Here is an example of how to do this:

from rest_framework_simplejwt.authentication import JWTAuthentication

class MyAPIview(APIView):
    authentication_classes = [JWTAuthentication]

In this way you will be able to authenticate and authorize your API views using JWT tokens.

Note that this is a very basic example, in real-world scenarios you will need to configure the JWT settings and handle token expiration, refresh, etc.

It's also possible to use JWT for authorization. When a client sends a request with a JWT, the server can decode the token to access the claims (e.g. user id, role) and use them to determine if the client has access to the requested resource.

However, keep in mind that JWT is not an encryption, it's a signed token. Never put sensitive data on JWT.

It is always recommended to use JWT in combination with an SSL certificate to encrypt the data in transit.

You can also use other authentication methods like SessionAuthentication and BasicAuthentication , but JWT is considered more secure and is often preferred for use in RESTful APIs.

Best Practices for Securing an API

When it comes to securing your API, there are a few best practices you should keep in mind to ensure the safety and privacy of your users' data.

Use token-based authentication. JSON Web Tokens (JWT) are a popular choice for authentication in RESTful APIs. They allow for stateless authentication and provide a secure way to transmit data between parties.
Implement role-based access control. By assigning roles to users, you can limit the actions they can perform within your API. For example, a user with the role of "admin" would have more permissions than a user with the role of "guest".
Use HTTPS. When transmitting data over the internet, it's important to use a secure protocol like HTTPS to encrypt the data and prevent man-in-the-middle attacks.
Validate user input. Always validate user input to prevent malicious attacks like SQL injection or cross-site scripting.
Monitor your API for suspicious activity. Keep an eye out for unusual patterns of usage, such as a high number of failed login attempts or a large number of requests coming from a single IP address.

By following these best practices, you can ensure that your API is secure and protected from potential threats.

Note : Always keep the theme in mind and you can use Attack on Titans references like "Just like how Eren protects the walls, it's important to protect your API with token-based authentication" etc.

Additional Features of Django REST Framework

Pagination and Filtering of API Responses

Pagination and filtering are important features of any API, as they allow the client to retrieve only the relevant data and avoid overwhelming them with unnecessary information. In Django REST framework, these features are built-in and can be easily implemented.

To paginate the results of a view, you can use the pagination_class attribute on the view. For example, if you want to use the built-in PageNumberPagination class, you can do the following:

from rest_framework.pagination import PageNumberPagination

class MyView(APIView):
    pagination_class = PageNumberPagination
    # ...

You can also customize the pagination class to suit your needs. For example, you can change the default page size or add a custom header to the response.

Filtering the results of a view is also a straightforward process. You can use the filter_backends attribute on the view to specify the filter classes that you want to use. For example, you can use the built-in DjangoFilterBackend class to filter the results based on query parameters:

from rest_framework.filters import DjangoFilterBackend

class MyView(APIView):
    filter_backends = [DjangoFilterBackend]
    filterset_fields = ['name', 'age']
    # ...

This allows clients to filter the results by sending query parameters like ?name=John&age=30.

To implement pagination and filtering, you can use Query and QuerySet provided by django-filter package and Pagination provided by django-rest-framework package. Also, you can add a custom header to response like X-Total-Count to show the total number of results.

How to use Built-In Documentation Feature?

The Django REST framework comes with a built-in documentation feature that allows developers to easily generate documentation for their APIs. This feature is based on the popular drf-yasg (Django REST framework - Yet Another Swagger Generator) library, which uses the OpenAPI specification to generate interactive documentation for APIs.

To use the built-in documentation feature, first, you need to install drf-yasg by running the following command:

pip install drf-yasg

Next, add 'drf_yasg' to your INSTALLED_APPS in the settings.py file.

INSTALLED_APPS = [
    ...,
    'drf_yasg',
]

Then, add the following to your urls.py file to enable the documentation feature:

from drf_yasg.views import get_schema_view
from drf_yasg import openapi

schema_view = get_schema_view(
   openapi.Info(
      title="Snippets API",
      default_version='v1',
      description="Test description",
      terms_of_service="https://www.google.com/policies/terms/",
      contact=openapi.Contact(email="contact@snippets.local"),
      license=openapi.License(name="BSD License"),
   ),
   public=True,
   permission_classes=(permissions.AllowAny,),
)

urlpatterns = [
    ...
    url(r'^swagger(?P<format>\.json|\.yaml)$', schema_view.without_ui(cache_timeout=0), name='schema-json'),
    url(r'^swagger/$', schema_view.with_ui('swagger', cache_timeout=0), name='schema-swagger-ui'),
    url(r'^redoc/$', schema_view.with_ui('redoc', cache_timeout=0), name='schema-redoc'),
]

With this setup, you can now access the API documentation by visiting the /swagger/ or /redoc/ URLs in your browser. The documentation is generated based on the APIViews and Serializers you have defined in your project and will be automatically updated whenever you make changes to them.

You can also customize the appearance and functionality of the documentation by configuring the get_schema_view() function and the Info class to suit your needs.

Tips for Debugging and Testing the API endpoints

When building APIs with Django REST framework, it's important to have a solid debugging and testing strategy in place to ensure that your endpoints are functioning correctly. One way to do this is to use the built-in debugging tools provided by Django, such as the django-debug-toolbar and the logging module.

Another helpful tip for debugging API endpoints is to use the django-extensions package, which adds additional management commands to the Django command line, including a shell_plus command that allows you to interact with your models directly from the command line.

For testing, Django REST framework provides a APITestCase class that you can use to create test cases for your views and serializers. This class provides a client attribute that allows you to make requests to your API endpoints and check the responses.

In addition to these built-in tools, it's also a good idea to use a tool like Postman or Insomnia to manually test your API endpoints and ensure that they are returning the expected results.

You can imagine Eren Yeager trying to break through the wall, as an example of debugging and testing your API endpoints, in order to ensure that they are working correctly and securely, you should test and debug your API endpoints to make sure they are functioning as expected.

Designing and Structuring API endpoints

Best Practices for Designing and Structuring API endpoints

When designing and structuring API endpoints for your Attack on Titan themed project, it's important to consider a few best practices to ensure that your API is easy to use, maintainable, and scalable.

Use clear and consistent naming conventions : Use descriptive, easy-to-understand names for your endpoints. For example, instead of naming an endpoint /api/get_data, use /api/titans/.
Group related endpoints together : Group related endpoints together under a common prefix. For example, all endpoints related to Titans should be grouped under /api/titans/.
Use HTTP methods appropriately : Use the appropriate HTTP method for each endpoint. For example, use GET for retrieving data, POST for creating new resources, PUT for updating existing resources, and DELETE for deleting resources.
Version your API : Versioning your API is important to ensure that changes to your API do not break existing clients. This can be done by including the version number in the endpoint's URL. For example, /api/v1/titans/.
Provide clear and accurate error messages : If an error occurs, provide clear and accurate error messages to help developers troubleshoot the issue.

By following these best practices, you can ensure that your API is easy to use, maintainable, and scalable, making it a valuable tool for your team and your audience.

Different Types of API endpoints

Resource-based endpoints : These endpoints are based on a specific resource, such as a user or a product. For example, /users/ or /products/. These endpoints are typically used for CRUD (create, read, update, delete) operations on the resource.
Collection-based endpoints : These endpoints are based on a collection of resources, such as a list of users or a list of products. For example, /users/ or /products/. These endpoints are typically used to retrieve a list of resources.
Action-based endpoints : These endpoints are based on a specific action that can be performed on a resource or a collection of resources. For example, /users/search/ or /products/order/. These endpoints are typically used to perform non-CRUD operations on the resource.
Hybrid endpoints : These endpoints combine the functionality of resource-based and action-based endpoints. For example, /users/{id}/activate/ or /products/{id}/reviews/. These endpoints are typically used for more complex operations on the resource.

It is important to note that the above types of endpoints are not mutually exclusive and a single endpoint can have multiple types of functionality. For example, a /users/ endpoint may have functionality for both resource-based and collection-based operations.

When designing and structuring API endpoints, it is important to follow RESTful principles and use clear, consistent, and predictable URL structures. Additionally, it is also important to consider how the endpoints will be consumed by the client and to provide clear documentation for each endpoint.

How to Version the API?

When building an API, it's important to plan for the possibility of making changes to the API in the future. One way to do this is by versioning the API.

There are a few different ways to version an API, but the most common approach is to include the version number in the URL. For example, instead of having a URL like https://example.com/api/users, you might have https://example.com/api/v1/users to indicate that this is version 1 of the API.

Another approach is to include the version number in the request headers. For example, you might include a Accept header with the value application/vnd.example.v1+json to indicate that the client is requesting version 1 of the API.

When making changes to the API, it's important to keep the old version available for a period of time to give existing clients time to update. This is known as deprecation. It's also a good practice to document the changes made in each version of the API to make it easier for developers to understand the changes.

When it comes to AOT themed API versioning, we can use the concept of the different arcs and arcs in the anime series to version different endpoints. So an endpoint under the AOT: Arc 1 version would be different than an endpoint under the AOT: Arc 2 version.

It's important to keep in mind that versioning is a trade-off between flexibility and stability. The more versions you have, the more flexibility you have to make changes, but the more complexity you introduce for clients to keep track of. It's important to find a balance that works for your use case.

Conclusion

What have we learned?

In this blog post, we have learned about the importance of APIs and how Django REST framework can be used to build them. We have covered various topics such as setting up a Django project for API development, handling requests and responses with serializers and views, implementing authentication and authorization, and additional features of Django REST framework such as pagination and filtering of API responses, documentation and debugging and testing.

We also went over AOT themed examples and how it can be incorporated in various sections of the blog post. Additionally, we discussed best practices for designing and structuring API endpoints, different types of endpoints, and how to version the API.

Additional Resources

To continue learning about Django REST framework and building APIs, we recommend the following resources:

The official Django REST framework documentation: https://www.django-rest-framework.org/
The Django REST framework tutorial: https://www.django-rest-framework.org/tutorial/quickstart/
Building APIs with Django and Django REST framework: https://www.safaribooksonline.com/library/view/building-apis-with/9781491949268/
Django REST framework: The beginner's guide: https://www.oreilly.com/library/view/django-rest-framework/9781789802482/

Thank you for reading, and I hope you found this blog post helpful in your journey to building APIs with Django REST framework.