Support Django 2.0

This is the final change required for Django 2.0 support. Instead of using
MIDDLEWARE_CLASSES use MIDDLEWARE setting. Support for new style middleware was
provided in version 0.3.0, so depend on that version. Django built-in middleware
already supports new style and plinth middleware will now support new style.

The actual semantics of the middleware don't need changes. See:
https://docs.djangoproject.com/en/2.0/topics/http/middleware/#upgrading-pre-django-1-10-style-middleware

Signed-off-by: Sunil Mohan Adapa <sunil@medhas.org>
Reviewed-by: James Valleroy <jvalleroy@mailbox.org>

debian/control

@@ -28,7 +28,7 @@ Build-Depends: debhelper (>= 10~)
  , python3-django (>= 1.11)
  , python3-django-axes (>= 3.0.3)
  , python3-django-captcha
- , python3-django-stronghold
+ , python3-django-stronghold (>= 0.3.0)
  , python3-gi
  , python3-psutil
  , python3-requests

plinth/__main__.py

@@ -277,7 +277,7 @@ def configure_django():
         LOGIN_URL='users:login',
         LOGIN_REDIRECT_URL='index',
         MESSAGE_TAGS={message_constants.ERROR: 'danger'},
-        MIDDLEWARE_CLASSES=(
+        MIDDLEWARE=(
             'django.middleware.security.SecurityMiddleware',
             'django.contrib.sessions.middleware.SessionMiddleware',
             'django.middleware.locale.LocaleMiddleware',

plinth/middleware.py

@@ -24,6 +24,7 @@ from django.contrib import messages
 from django.contrib.auth.decorators import login_required
 from django.core.exceptions import PermissionDenied
 from django.shortcuts import render
+from django.utils.deprecation import MiddlewareMixin
 from django.utils.translation import ugettext_lazy as _
 import logging
 
@@ -38,7 +39,7 @@ from . import views
 logger = logging.getLogger(__name__)
 
 
-class SetupMiddleware(object):
+class SetupMiddleware(MiddlewareMixin):
     """Django middleware to show pre-setup message and setup progress."""
 
     @staticmethod
@@ -92,7 +93,7 @@ class SetupMiddleware(object):
         return view(request, setup_helper=module.setup_helper)
 
 
-class AdminRequiredMiddleware(object):
+class AdminRequiredMiddleware(MiddlewareMixin):
     """Django middleware for authenticating requests for admin areas."""
 
     @staticmethod
@@ -106,7 +107,7 @@ class AdminRequiredMiddleware(object):
             raise PermissionDenied
 
 
-class FirstSetupMiddleware(object):
+class FirstSetupMiddleware(MiddlewareMixin):
     """Django middleware to block all interactions before first setup."""
 
     @staticmethod

plinth/modules/first_boot/middleware.py

@@ -20,17 +20,19 @@ Django middleware to redirect to firstboot wizard if it has not be run
 yet.
 """
 
+import logging
+
+from django.conf import settings
 from django.http.response import HttpResponseRedirect
 from django.urls import reverse
-from django.conf import settings
-import logging
+from django.utils.deprecation import MiddlewareMixin
 
 from plinth.modules import first_boot
 
 LOGGER = logging.getLogger(__name__)
 
 
-class FirstBootMiddleware(object):
+class FirstBootMiddleware(MiddlewareMixin):
     """Forward to firstboot page if firstboot isn't finished yet."""
 
     @staticmethod

setup.py

@@ -212,7 +212,7 @@ setuptools.setup(
         'django >= 1.11.0',
         'django-bootstrap-form',
         'django-simple-captcha',
-        'django-stronghold',
+        'django-stronghold >= 0.3.0',
         'psutil',
         'python-apt',
         'python-augeas',