Django Web Authentication with Keycloak

August 31, 2023 · 6 min read

Hosted Keycloak and Keycloak Support

Django is a high-level, open-source web framework for building web applications using the Python programming language. It follows the Model-View-Controller (MVC) architectural pattern.

In this article we'll be using Keycloak to secure a Django Web application.

info

If you just want to skip to the code, visit the Phase Two Django example. We are also building Keycloak examples for other frameworks.

Setting up a Django Project

The following could be applied to an existing Django application, but we have chosen to use the excellent tutorial application built by Mozilla as our example. If you aren't yet familiar with Django, we encourage you to follow the tutorial there.

The completed code for that tutorial is available in their GitHub repository. We'll clone it to get started.

Quick Start

To get this project up and running locally on your computer:

Set up the Python development environment. We recommend using a Python virtual environment.

Assuming you have Python setup, run the following commands (if you're on Windows you may use py or py -3 instead of python to start Python):

pip install -r requirements.txt
python manage.py makemigrations
python manage.py migrate
python manage.py collectstatic
python manage.py test # Run the standard tests. These should all pass.
python manage.py createsuperuser # Create a superuser
python manage.py runserver

Open a browser to http://127.0.0.1:8000/admin/ to open the admin site
Create a few test objects of each type.
Open tab to http://127.0.0.1:8000 to see the main site, with your new objects.

Setting up a Keycloak Instance

Before customizing the Django app, we need to set up and configure our Keycloak instance.

Instructions

tip

If you already have a functioning Keycloak instance, you can skip to the next section.

Rather than trying to set up a "from scratch" instance of Keycloak, we're going to short-circuit that process by leveraging a free Phase Two Starter instance. The Starter provides a free hosted instance of Phase Two's enhanced Keycloak ready for light production use cases.

Visit the sign-up page.
Enter an email, use a Github account, or use an existing Google account to register.
Follow the register steps. This will include a sign-in link being sent to your email. Use that for password-less login.
After creating an account, a realm is automatically created for you with all of the Phase Two enhancements. You need to create a Deployment in the Shared Phase Two infrastructure in order to gain access to the realm. Without a deployment created, the Create Shared Deployment modal will automatically pop up.
Create a Shared Deployment by providing a region (pick something close to your existing infrastructure), a name for the deployment, and selecting the default organization that was created for you upon account creation. Hit "Confirm" when ready. Standby while our robots get to work generating your deployment. This can take a few seconds.
After the deployment is created and active, you can access the Keycloak Admin console by clicking "Open Console" for that deployment. Open it now to see the console.

At this point, move on to the next step in the tutorial. We'll be coming back to the Admin Console when its time to start connecting our App to the Keycloak instance.

Setting up an OIDC Client

Instructions

We need to create a OpenID Connect Client in Keycloak for the app to communicate with. Keycloak's docs provide steps for how to create an OIDC client and all the various configurations that can be introduced. Follow the steps below to create a client and get the right information necessary for app configuration.

Open the Admin UI by clicking Open Console in the Phase Two Dashboard.
Click Clients in the menu.
Click Create client.
Leave Client type set to OpenID Connect.
Enter a Client ID. This ID is an alphanumeric string that is used in OIDC requests and in the Keycloak database to identify the client.
Supply a Name for the client.
Click Next.
Under the Capability Config section, leave the defaults as selected. This can be configured further later.
- Client authentication to On.
- Authorization to Off.
- Standard flow checked. Direct access grants checked. All other items unchecked.
Click Next.
Under Login settings we need to add a redirect URI and Web origin in order. Assuming you are using the example applicaiton:

Valid redirect URI (allows redirect back to application)
```
http://localhost:3000/*
```
Web origins (allows for Token auth call)
```
http://localhost:3000
```
URI and Origin Details
The choice of localhost is arbitrary. If you are using an example application running locally, this will apply. If you are using an app that you actually have deployed somewhere, then you will need to substitute the appropriate URI for that.
Click Save

OIDC Config

We will need values to configure our application. To get these values follow the instructions below.

Click Clients in the menu.
Find the Client you just created and click on it. In the top right click the Action dropdown and select Download adapter config.
Select Keycloak OIDC JSON in the format option. The details section will populate with the details we will need.
- Note the realm, auth-server-url, and resource values.
You also need to copy the Client secret in the Credential tab for the client to use. Once on the Credential tab, click the copy button to copy the key to your clipboard. Save the key somewhere for use later in this tutorial

Adding a Non-Admin User

Instructions

tip

It is bad practice to use your Admin user to sign in to an Application.

Since we do not want to use our Admin user for signing into the app we will build, we need to add a another non-admin user.

Open the Admin UI by clicking Open Console in the Phase Two Dashboard.
Click Users in the menu.
Click Add user.
Fill out the information for Email, First name, and Last name. Click Create.
We will now set the password for this user manually. Click Credentials (tab) and click Set Password. Provide a password for this user. For our use case, as a tutorial, you can leave "Temporary" set to "Off".
Click Save and confirm the password by clicking Save password

Install and configure the Django OIDC library

Now that we've installed and configured Keycloak, we need to setup Django to replace the native authentication method provided by the framework. The first task is to install a library that is compatible with Keycloak's OIDC implementation.

The mozilla-django-oidc library provides an easy way to integrate Keycloak (or any OpenID Connect-compliant identity provider) with your Django app. It abstracts many of the complexities of integrating authentication and authorization. Here's how you can set it up:

Install the Package: Install the mozilla-django-oidc package using pip:
```
pip install mozilla-django-oidc
```

Configure Django Settings: Update your Django app's settings.py to include the necessary configurations for mozilla-django-oidc:

INSTALLED_APPS = [
    # ...
    'django.contrib.auth',
    'mozilla_django_oidc',  # Load after django.contrib.auth
    # ...
]

AUTHENTICATION_BACKENDS = (
    'mozilla_django_oidc.auth.OIDCAuthenticationBackend',
    # ...
)

OIDC_RP_CLIENT_ID = 'your-client-id'
OIDC_RP_CLIENT_SECRET = 'your-client-secret'
OIDC_OP_AUTHORIZATION_ENDPOINT = 'https://keycloak-url/auth/realms/your-realm/protocol/openid-connect/auth'
OIDC_OP_TOKEN_ENDPOINT = 'https://keycloak-url/auth/realms/your-realm/protocol/openid-connect/token'
OIDC_OP_USER_ENDPOINT = 'https://keycloak-url/auth/realms/your-realm/protocol/openid-connect/userinfo'
OIDC_OP_JWKS_ENDPOINT = 'https://keycloak-url/auth/realms/your-realm/protocol/openid-connect/certs'
OIDC_RP_SIGN_ALGO = 'RS256'

LOGIN_URL = 'oidc_authentication_init'
LOGOUT_REDIRECT_URL = '/'
LOGIN_REDIRECT_URL = '/'

Replace your-client-id, your-client-secret, and the Keycloak URLs with your actual Keycloak configurations.

Add URLs: Update your Django app's urls.py to include the authentication URLs provided by mozilla-django-oidc:
```
urlpatterns += [
    path('oidc/', include('mozilla_django_oidc.urls')),
]
```

Using it in your app

Protect your views

Use Decorators for Access Control. You can now use the @oidc_protected decorator to protect views that require authentication and potentially specific roles:

from mozilla_django_oidc.decorators import oidc_protected

@oidc_protected
def protected_view(request):
    # Your view logic

Accessing user information

You can access user information after authentication using the request.oidc_user attribute. For example:

def profile_view(request):
    user_info = request.oidc_user.userinfo
    # Access user_info['sub'], user_info['email'], etc.
    # Your view logic

By default, mozilla-django-oidc looks up a Django user matching the email field to the email address returned in the user info data from Keycloak.

If a user logs into your site and doesn’t already have an account, by default, mozilla-django-oidc will create a new Django user account. It will create the User instance filling in the username (hash of the email address) and email fields.

Use Username rather than Email

mozilla-django-oidc defaults to setting up Django users using the email address as the user name from keycloak was required. Fortunately, preferred_username is set up by default in Keycloak as a claim. The claim can used by overriding the OIDCAuthenticationBackend class in mozilla_django_oidc.auth and referring to this in AUTHENTICATION_BACKENDS as below:

# Classes to override default OIDCAuthenticationBackend (Keycloak authentication)
from mozilla_django_oidc.auth import OIDCAuthenticationBackend

class KeycloakOIDCAuthenticationBackend(OIDCAuthenticationBackend):

 def create_user(self, claims):
     """ Overrides Authentication Backend so that Django users are
         created with the keycloak preferred_username.
         If nothing found matching the email, then try the username.
     """
     user = super(KeycloakOIDCAuthenticationBackend, self).create_user(claims)
     user.first_name = claims.get('given_name', '')
     user.last_name = claims.get('family_name', '')
     user.email = claims.get('email')
     user.username = claims.get('preferred_username')
     user.save()
     return user

 def filter_users_by_claims(self, claims):
     """ Return all users matching the specified email.
         If nothing found matching the email, then try the username
     """
     email = claims.get('email')
     preferred_username = claims.get('preferred_username')

     if not email:
         return self.UserModel.objects.none()
     users = self.UserModel.objects.filter(email__iexact=email)

     if len(users) < 1:
         if not preferred_username:
             return self.UserModel.objects.none()
         users = self.UserModel.objects.filter(username__iexact=preferred_username)
     return users

 def update_user(self, user, claims):
     user.first_name = claims.get('given_name', '')
     user.last_name = claims.get('family_name', '')
     user.email = claims.get('email')
     user.username = claims.get('preferred_username')
     user.save()
     return user

In settings.py, overide the new library you have just added in AUTHENTICATION_BACKENDS :

 # mozilla_django_oidc - Keycloak authentication
 "fragalysis.auth.KeycloakOIDCAuthenticationBackend",

Logging out

You can use the @oidc_logout decorator to log the user out of both your app and Keycloak:

from mozilla_django_oidc.decorators import oidc_logout

@oidc_logout
def logout_view(request):
    # Your logout view logic

Add support for Django Rest Framework

Django Rest Framework (DRF) is a flexible toolkit built on top of Django, specifically designed for building RESTful APIs.

If you want DRF to authenticate users based on an OAuth access token provided in the Authorization header, you can use the DRF-specific authentication class which ships with the package.

Add this to your settings:

REST_FRAMEWORK = {
    'DEFAULT_AUTHENTICATION_CLASSES': [
        'mozilla_django_oidc.contrib.drf.OIDCAuthentication',
        'rest_framework.authentication.SessionAuthentication',
        # other authentication classes, if needed
    ],
}

Note that this only takes care of authenticating against an access token, and provides no options to create or renew tokens.

If you’ve created a custom Django OIDCAuthenticationBackend and added that to your AUTHENTICATION_BACKENDS, the DRF class should be smart enough to figure that out. Alternatively, you can manually set the OIDC backend to use:

OIDC_DRF_AUTH_BACKEND = 'mozilla_django_oidc.auth.OIDCAuthenticationBackend'

Learning more

Phase Two's enhanced Keycloak provides many ways to quickly control and tweak the log in and user management experience. Our blog has many use cases from customizing login pages, setting up magic links (passwordless sign in), and Organization workflows.

Setting up a Django Project​

Quick Start​

Setting up a Keycloak Instance​

Setting up an OIDC Client​

OIDC Config​

Adding a Non-Admin User​

Install and configure the Django OIDC library​

Using it in your app​

Protect your views​

Accessing user information​

Use Username rather than Email​

Logging out​

Add support for Django Rest Framework​

Learning more​

Setting up a Django Project

Quick Start

Setting up a Keycloak Instance

Setting up an OIDC Client

OIDC Config

Adding a Non-Admin User

Install and configure the Django OIDC library

Using it in your app

Protect your views

Accessing user information

Use Username rather than Email

Logging out

Add support for Django Rest Framework

Learning more