remove studio signin and signup pages

This completes the work started in https://github.com/edx/edx-platform/pull/19453
to use the LMS login and registration for Studio, rather than Studio
providing its own implementation.

LMS login/registration are being used for the following reasons:
1. LMS logistration properly handles all SSO integrations.
2. A single logistration is simpler to maintain and understand.
3. Allows Studio to work more like all other IDAs that use LMS
logistration.

The original switch to use LMS logistration for Studio also added the
toggle `DISABLE_STUDIO_SSO_OVER_LMS` to provide the community some
additional time for switching. This commit removes this toggle, which
at this point means all deployments will use the LMS logistration.

This change requires sharing cookies across LMS and Studio. Should that
prove to be a problem for certain Open edX instances, there are
discussions of possible alternative solutions.
See https://github.com/edx/edx-platform/pull/19845#issuecomment-559154256

Detailed changes:
* Fix some Studio links that still went to old Studio signin and signup.
* Remove DISABLE_STUDIO_SSO_OVER_LMS feature toggle.
* Remove old studio signin and signup pages and templates.
* Fix url name "login", which had different meanings for Studio and LMS.
* Use the following settings: LOGIN_URL, FRONTEND_LOGIN_URL,
FRONTEND_LOGOUT_URL, and FRONTEND_REGISTER_URL.
* Redirect /signin and /signup to the LMS logistration.
* Add custom metric `uses_pattern_library`.
* Add custom metric `student_activate_account`.
* Add Django Settings to allow /signin, /signup, and /login_post to be
disabled once ready.

This work also relates to ARCH-218 and DEPR-6.

ARCH-1253

common/djangoapps/student/tests/test_helpers.py

@@ -10,7 +10,6 @@ from django.contrib.sessions.middleware import SessionMiddleware
 from django.test import TestCase
 from django.test.client import RequestFactory
 from django.test.utils import override_settings
-from django.urls import reverse
 from mock import patch
 from testfixtures import LogCapture
 
@@ -57,7 +56,7 @@ class TestLoginHelper(TestCase):
     def test_next_failures(self, log_level, log_name, unsafe_url, http_accept, user_agent, expected_log):
         """ Test unsafe next parameter """
         with LogCapture(LOGGER_NAME, level=log_level) as logger:
-            req = self.request.get(reverse("login") + "?next={url}".format(url=unsafe_url))
+            req = self.request.get(settings.LOGIN_URL + "?next={url}".format(url=unsafe_url))
             req.META["HTTP_ACCEPT"] = http_accept  # pylint: disable=no-member
             req.META["HTTP_USER_AGENT"] = user_agent  # pylint: disable=no-member
             get_next_url_for_login_page(req)
@@ -75,7 +74,7 @@ class TestLoginHelper(TestCase):
     @override_settings(LOGIN_REDIRECT_WHITELIST=['test.edx.org', 'test2.edx.org'])
     def test_safe_next(self, next_url, host):
         """ Test safe next parameter """
-        req = self.request.get(reverse("login") + "?next={url}".format(url=next_url), HTTP_HOST=host)
+        req = self.request.get(settings.LOGIN_URL + "?next={url}".format(url=next_url), HTTP_HOST=host)
         req.META["HTTP_ACCEPT"] = "text/html"  # pylint: disable=no-member
         next_page = get_next_url_for_login_page(req)
         self.assertEqual(next_page, next_url)
@@ -103,7 +102,7 @@ class TestLoginHelper(TestCase):
         mock_running_pipeline.return_value = running_pipeline
 
         def validate_login():
-            req = self.request.get(reverse("login") + "?next={url}".format(url=next_url))
+            req = self.request.get(settings.LOGIN_URL + "?next={url}".format(url=next_url))
             req.META["HTTP_ACCEPT"] = "text/html"  # pylint: disable=no-member
             self._add_session(req)
             next_page = get_next_url_for_login_page(req)

common/djangoapps/student/views/management.py

@@ -14,10 +14,7 @@ from django.conf import settings
 from django.contrib import messages
 from django.contrib.auth.decorators import login_required
 from django.contrib.auth.models import AnonymousUser, User
-from django.contrib.auth.views import password_reset_confirm
 from django.contrib.sites.models import Site
-from django.core import mail
-from django.core.exceptions import ObjectDoesNotExist
 from django.core.validators import ValidationError, validate_email
 from django.db import transaction
 from django.db.models.signals import post_save
@@ -25,10 +22,7 @@ from django.dispatch import Signal, receiver
 from django.http import Http404, HttpResponse, HttpResponseBadRequest, HttpResponseForbidden
 from django.shortcuts import redirect
 from django.template.context_processors import csrf
-from django.template.response import TemplateResponse
 from django.urls import reverse
-from django.utils.encoding import force_bytes, force_text
-from django.utils.http import base36_to_int, urlsafe_base64_encode
 from django.utils.translation import ugettext as _
 from django.views.decorators.csrf import csrf_exempt, ensure_csrf_cookie
 from django.views.decorators.http import require_GET, require_http_methods, require_POST
@@ -53,16 +47,11 @@ from openedx.core.djangoapps.ace_common.template_context import get_base_templat
 from openedx.core.djangoapps.catalog.utils import get_programs_with_type
 from openedx.core.djangoapps.embargo import api as embargo_api
 from openedx.core.djangoapps.lang_pref import LANGUAGE_KEY
-from openedx.core.djangoapps.oauth_dispatch.api import destroy_oauth_tokens
 from openedx.core.djangoapps.programs.models import ProgramsApiConfig
 from openedx.core.djangoapps.site_configuration import helpers as configuration_helpers
 from openedx.core.djangoapps.theming import helpers as theming_helpers
-from openedx.core.djangoapps.theming.helpers import get_current_site
-from openedx.core.djangoapps.user_api.accounts.utils import is_secondary_email_feature_enabled
 from openedx.core.djangoapps.user_api.config.waffle import PREVENT_AUTH_USER_WRITES, SYSTEM_MAINTENANCE_MSG, waffle
-from openedx.core.djangoapps.user_api.models import UserRetirementRequest
 from openedx.core.djangoapps.user_api.preferences import api as preferences_api
-from openedx.core.djangoapps.user_authn.message_types import PasswordReset
 from openedx.core.djangolib.markup import HTML, Text
 from student.helpers import DISABLE_UNENROLL_CERT_STATES, cert_info, generate_activation_email_context
 from student.message_types import AccountActivation, EmailChange, EmailChangeConfirmation, RecoveryEmailCreate
@@ -83,10 +72,8 @@ from student.models import (
 from student.signals import REFUND_ORDER
 from student.tasks import send_activation_email
 from student.text_me_the_app import TextMeTheAppFragmentView
-from util.request_rate_limiter import BadRequestRateLimiter, PasswordResetEmailRateLimiter
 from util.db import outer_atomic
 from util.json_request import JsonResponse
-from util.password_policy_validators import normalize_password, validate_password
 from xmodule.modulestore.django import modulestore
 
 log = logging.getLogger("edx.student")
@@ -519,8 +506,12 @@ def activate_account(request, key):
     """
     # If request is in Studio call the appropriate view
     if theming_helpers.get_project_root_name().lower() == u'cms':
+        monitoring_utils.set_custom_metric('student_activate_account', 'cms')
         return activate_account_studio(request, key)
 
+    # TODO: Use metric to determine if there are any `activate_account` calls for cms in Production.
+    # If not, the templates wouldn't be needed for cms, but we still need a way to activate for cms tests.
+    monitoring_utils.set_custom_metric('student_activate_account', 'lms')
     try:
         registration = Registration.objects.get(activation_key=key)
     except (Registration.DoesNotExist, Registration.MultipleObjectsReturned):