✨(user) add user route

Add a user api route. The first route is `/user/me` to retrieve session user
info and a JWT access token which could be used by third party application to
make REST requests.

CHANGELOG.md

@@ -9,6 +9,11 @@ Versioning](https://semver.org/spec/v2.0.0.html).
 
 ## [Unreleased]
 
+### Added
+
+- Add an User API endpoint to fisrt generate a JWT for Authentication purpose
+  from Third Party Application
+
 ## [0.2.1] - 2019-10-10
 
 ### Fixed

edx-platform/config/lms/docker_run_development.py

@@ -10,21 +10,19 @@
 STATIC_ROOT = "/edx/app/edxapp/data/static"
 STATIC_URL = "/static/"
 MEDIA_ROOT = "/edx/app/edxapp/data/media"
-LOG_DIR = '/data/log'
+LOG_DIR = "/data/log"
 
 EMAIL_BACKEND = "django.core.mail.backends.console.EmailBackend"
 SECRET_KEY = "foo"
 
 ALLOWED_HOSTS = ["*"]
 
-LOGGING['handlers'].update(
-    local={'class': 'logging.NullHandler'},
-    tracking={'class': 'logging.NullHandler'},
+LOGGING["handlers"].update(
+    local={"class": "logging.NullHandler"},
+    tracking={"class": "logging.NullHandler"},
 )
 
-INSTALLED_APPS += (
-    'fonzie',
-)
+INSTALLED_APPS += ("fonzie",)
 
 ROOT_URLCONF = "fonzie.urls.lms_root"
 
@@ -34,12 +32,17 @@
 
 # Django Rest Framework (aka DRF)
 REST_FRAMEWORK = {
-    'ALLOWED_VERSIONS': ('1.0', ),
-    'DEFAULT_VERSION': '1.0',
-    'DEFAULT_VERSIONING_CLASS': 'rest_framework.versioning.URLPathVersioning',
+    "ALLOWED_VERSIONS": ("1.0",),
+    "DEFAULT_VERSION": "1.0",
+    "DEFAULT_VERSIONING_CLASS": "rest_framework.versioning.URLPathVersioning",
+    "DEFAULT_AUTHENTICATION_CLASSES": [
+        "rest_framework.authentication.SessionAuthentication"
+    ],
 }
 
-FEATURES['ENABLE_DISCUSSION_SERVICE'] = False
+JWT_PRIVATE_SIGNING_KEY = "ThisIsAnExampleKeyForDevPurposeOnly"
+
+FEATURES["ENABLE_DISCUSSION_SERVICE"] = False
 
 FEATURES["AUTOMATIC_AUTH_FOR_TESTING"] = True
 FEATURES["RESTRICT_AUTOMATIC_AUTH"] = False
@@ -50,9 +53,9 @@
 FEATURES["ENABLE_INSTRUCTOR_BACKGROUND_TASKS"] = False
 
 GRADES_DOWNLOAD = {
-   "STORAGE_CLASS": "django.core.files.storage.FileSystemStorage",
-   "STORAGE_KWARGS": {
-       "location": "/data/export",
-       "base_url": "/api/v1.0/acl/report",
-   }
+    "STORAGE_CLASS": "django.core.files.storage.FileSystemStorage",
+    "STORAGE_KWARGS": {
+        "location": "/data/export",
+        "base_url": "/api/v1.0/acl/report",
+    },
 }

fonzie/urls/__init__.py

@@ -9,6 +9,7 @@
 from ..apps import FonzieConfig
 from . import acl as acl_urls
 from . import status as status_urls
+from . import user as user_urls
 
 app_name = FonzieConfig.name
 
@@ -26,4 +27,5 @@
         r"{}/acl/".format(API_PREFIX),
         include(acl_urls, namespace="acl"),
     ),
+    url(r"{}/user/".format(API_PREFIX), include(user_urls, namespace="user")),
 ]

fonzie/urls/user.py

@@ -0,0 +1,13 @@
+# coding: utf-8
+"""
+API user endpoints
+"""
+from __future__ import absolute_import, unicode_literals
+
+from django.conf.urls import url
+
+from ..apps import FonzieConfig
+from ..views.user import UserSessionView
+
+app_name = FonzieConfig.name
+urlpatterns = [url(r"^me/?$", UserSessionView.as_view(), name="me")]

fonzie/views/user.py

@@ -0,0 +1,49 @@
+# coding: utf-8
+"""
+API user views
+"""
+
+from __future__ import absolute_import, unicode_literals
+
+from datetime import datetime
+
+import jwt
+from rest_framework.permissions import IsAuthenticated
+from rest_framework.response import Response
+from rest_framework.views import APIView
+
+from django.conf import settings
+
+
+class UserSessionView(APIView):
+    """API endpoint to get the authenticated user information."""
+
+    permission_classes = [IsAuthenticated]
+
+    # pylint: disable=redefined-builtin
+    def get(self, request, version, format=None):
+        """
+        Retrieve logged in user, then generate a JWT with a claim containing its
+        username (unique identifier) and its email. The token's expiration is
+        synchronized with the user session expiration date.
+        """
+        user = request.user
+        issued_at = datetime.utcnow()
+        expired_at = request.session.get_expiry_date()
+        token = jwt.encode(
+            {
+                "email": user.email,
+                "username": user.username,
+                "exp": expired_at,
+                "iat": issued_at,
+            },
+            getattr(settings, "JWT_PRIVATE_SIGNING_KEY", None),
+            algorithm="HS256",
+        )
+
+        return Response(
+            {
+                "access_token": token,
+                "username": user.username,
+            }
+        )

setup.cfg

@@ -25,6 +25,7 @@ classifiers =
 include_package_data = true
 install_requires =
     # Add direct dependencies here
+    djangorestframework-simplejwt
 packages = find:
 zip_safe = False
 

tests/views/test_user.py

@@ -0,0 +1,61 @@
+# coding: utf-8
+"""
+Tests for the `fonzie` user module.
+"""
+
+# pylint: disable=no-member,import-error
+from __future__ import absolute_import, unicode_literals
+
+import jwt
+from rest_framework import status
+from rest_framework.test import APITestCase
+
+from django.conf import settings
+from django.core.urlresolvers import reverse
+
+from student.tests.factories import UserFactory
+
+
+class UserViewTestCase(APITestCase):
+    """Tests for the User API endpoint"""
+
+    def setUp(self):
+        """
+        Set common parameters for the test suite.
+        """
+        super(UserViewTestCase, self).setUp()
+
+        self.url = reverse("fonzie:user:me", kwargs={"version": "1.0"})
+
+    def test_user_me_with_anonymous_user(self):
+        """
+        If user is not authenticated, view should return a 403 status
+        """
+        response = self.client.get(self.url)
+        self.assertEqual(response.status_code, status.HTTP_403_FORBIDDEN)
+
+    def test_user_me_with_logged_in_user(self):
+        """
+        If user is authenticated through Django session, view should return
+        a JSON object containing the username and a JWT access token
+        """
+        user = UserFactory(username="fonzie", email="arthur_fonzarelli@fun-mooc.fr")
+        self.client.force_authenticate(user=user)
+
+        response = self.client.get(self.url)
+        token = jwt.decode(
+            response.data["access_token"],
+            getattr(
+                settings,
+                "JWT_PRIVATE_SIGNING_KEY",
+                "ThisIsAnExampleKeyForDevPurposeOnly",
+            ),
+            options={"require": ["exp", "iat", "email", "username"]},
+        )
+
+        self.assertEqual(response.status_code, status.HTTP_200_OK)
+        self.assertEqual(response.data["username"], "fonzie")
+        self.assertEqual(token["username"], "fonzie")
+        self.assertEqual(token["email"], "arthur_fonzarelli@fun-mooc.fr")
+        self.assertIsInstance(token["iat"], int)
+        self.assertIsInstance(token["exp"], int)