Django 1.11 support (#463)

* Added Django 1.11 to Travis

- related to #435
- 😉 to tomturner/django-tenants#120

* Replace direct use of import_module by proper load_backend

Handle new 'django.db.backends.postgresql' name (Django 1.9)

* Fix 'default' already present in _fields in Django 1.11

* Fix not existing access to original_backend.DatabaseError (Django 1.11)

Removed exports because django.db.utils.DatabaseError and
django.db.utils.IntegrityError must be used instead.

This change must be stated in release notes.

* The signature of DatabaseWrapper._cursor has changed in Django 1.11

Use the public API

* Add missing allowed hosts for tests

* Don't override default user or blocks Unix socket DB connection

* Updated tox.ini for Django 1.11rc1

* Properly add '.test.com' to ALLOWED_HOSTS in test cases

* Internal tests don't use TenantTestCase so set allowed hosts manually

* Drop Django 1.9 support

Django 1.8 is still within LTS until the end of 2017.

.travis.yml

@@ -14,8 +14,8 @@ script:
 - tox -e py${TRAVIS_PYTHON_VERSION/./}-dj${DJANGO/./}
 env:
 - DJANGO=1.8
-- DJANGO=1.9
 - DJANGO=1.10
+- DJANGO=1.11
 deploy:
   provider: pypi
   user: bcarneiro

dts_test_project/dts_test_project/settings.py

@@ -82,10 +82,10 @@ DATABASES = {
     'default': {
         'ENGINE': 'tenant_schemas.postgresql_backend',
         'NAME': os.environ.get('PG_NAME', 'dts_test_project'),
-        'USER': os.environ.get('PG_USER', 'postgres'),
-        'PASSWORD': os.environ.get('PG_PASSWORD', 'root'),
-        'HOST': os.environ.get('PG_HOST', 'localhost'),
-        'PORT': int(os.environ.get('PG_PORT', '5432')),
+        'USER': os.environ.get('PG_USER'),
+        'PASSWORD': os.environ.get('PG_PASSWORD'),
+        'HOST': os.environ.get('PG_HOST'),
+        'PORT': int(os.environ.get('PG_PORT')) if os.environ.get('PG_PORT') else None,
     }
 }
 

tenant_schemas/postgresql_backend/base.py

@@ -1,21 +1,17 @@
 import re
 import warnings
-from django.conf import settings
-try:
-    # Django versions >= 1.9
-    from django.utils.module_loading import import_module
-except ImportError:
-    # Django versions < 1.9
-    from django.utils.importlib import import_module
-from django.core.exceptions import ImproperlyConfigured, ValidationError
-from tenant_schemas.utils import get_public_schema_name, get_limit_set_calls
-from tenant_schemas.postgresql_backend.introspection import DatabaseSchemaIntrospection
-import django.db.utils
 import psycopg2
 
-ORIGINAL_BACKEND = getattr(settings, 'ORIGINAL_BACKEND', 'django.db.backends.postgresql_psycopg2')
+from django.conf import settings
+from django.core.exceptions import ImproperlyConfigured, ValidationError
+import django.db.utils
 
-original_backend = import_module(ORIGINAL_BACKEND + '.base')
+from tenant_schemas.utils import get_public_schema_name, get_limit_set_calls
+from tenant_schemas.postgresql_backend.introspection import DatabaseSchemaIntrospection
+
+ORIGINAL_BACKEND = getattr(settings, 'ORIGINAL_BACKEND', 'django.db.backends.postgresql_psycopg2')
+# Django 1.9+ takes care to rename the default backend to 'django.db.backends.postgresql'
+original_backend = django.db.utils.load_backend(ORIGINAL_BACKEND)
 
 EXTRA_SEARCH_PATHS = getattr(settings, 'PG_EXTRA_SEARCH_PATHS', [])
 
@@ -109,12 +105,16 @@ class DatabaseWrapper(original_backend.DatabaseWrapper):
                       category=DeprecationWarning)
         return self.tenant
 
-    def _cursor(self):
+    def _cursor(self, name=None):
         """
         Here it happens. We hope every Django db operation using PostgreSQL
         must go through this to get the cursor handle. We change the path.
         """
-        cursor = super(DatabaseWrapper, self)._cursor()
+        if name:
+            # Only supported and required by Django 1.11 (server-side cursor)
+            cursor = super(DatabaseWrapper, self)._cursor(name=name)
+        else:
+            cursor = super(DatabaseWrapper, self)._cursor()
 
         # optionally limit the number of executions - under load, the execution
         # of `set search_path` can be quite time consuming
@@ -137,16 +137,28 @@ class DatabaseWrapper(original_backend.DatabaseWrapper):
                 search_paths = [self.schema_name]
 
             search_paths.extend(EXTRA_SEARCH_PATHS)
+
+            if name:
+                # Named cursor can only be used once
+                cursor_for_search_path = self.connection.cursor()
+            else:
+                # Reuse
+                cursor_for_search_path = cursor
+
             # In the event that an error already happened in this transaction and we are going
             # to rollback we should just ignore database error when setting the search_path
             # if the next instruction is not a rollback it will just fail also, so
             # we do not have to worry that it's not the good one
             try:
-                cursor.execute('SET search_path = {0}'.format(','.join(search_paths)))
+                cursor_for_search_path.execute('SET search_path = {0}'.format(','.join(search_paths)))
             except (django.db.utils.DatabaseError, psycopg2.InternalError):
                 self.search_path_set = False
             else:
                 self.search_path_set = True
+
+            if name:
+                cursor_for_search_path.close()
+
         return cursor
 
 
@@ -157,10 +169,3 @@ class FakeTenant:
     """
     def __init__(self, schema_name):
         self.schema_name = schema_name
-
-if ORIGINAL_BACKEND == "django.contrib.gis.db.backends.postgis":
-    DatabaseError = django.db.utils.DatabaseError
-    IntegrityError = psycopg2.IntegrityError
-else:
-    DatabaseError = original_backend.DatabaseError
-    IntegrityError = original_backend.IntegrityError

tenant_schemas/postgresql_backend/introspection.py

@@ -7,7 +7,11 @@ from django.db.backends.base.introspection import (
 )
 from django.utils.encoding import force_text
 
-FieldInfo = namedtuple('FieldInfo', FieldInfo._fields + ('default',))
+fields = FieldInfo._fields
+if 'default' not in fields:
+    fields += ('default',)
+
+FieldInfo = namedtuple('FieldInfo', fields)
 
 
 class DatabaseSchemaIntrospection(BaseDatabaseIntrospection):

tenant_schemas/test/cases.py

@@ -1,15 +1,30 @@
 from django.core.management import call_command
+from django.conf import settings
 from django.db import connection
 from django.test import TestCase
 
 from tenant_schemas.utils import get_public_schema_name
 from tenant_schemas.utils import get_tenant_model
 
+ALLOWED_TEST_DOMAIN = '.test.com'
+
 
 class TenantTestCase(TestCase):
+    @classmethod
+    def add_allowed_test_domain(cls):
+        # ALLOWED_HOSTS is a special setting of Django setup_test_environment so we can't modify it with helpers
+        if ALLOWED_TEST_DOMAIN not in settings.ALLOWED_HOSTS:
+            settings.ALLOWED_HOSTS += [ALLOWED_TEST_DOMAIN]
+
+    @classmethod
+    def remove_allowed_test_domain(cls):
+        if ALLOWED_TEST_DOMAIN in settings.ALLOWED_HOSTS:
+            settings.ALLOWED_HOSTS.remove(ALLOWED_TEST_DOMAIN)
+
     @classmethod
     def setUpClass(cls):
         cls.sync_shared()
+        cls.add_allowed_test_domain()
         tenant_domain = 'tenant.test.com'
         cls.tenant = get_tenant_model()(domain_url=tenant_domain, schema_name='test')
         cls.tenant.save(verbosity=0)  # todo: is there any way to get the verbosity from the test command here?
@@ -21,6 +36,7 @@ class TenantTestCase(TestCase):
         connection.set_schema_to_public()
         cls.tenant.delete()
 
+        cls.remove_allowed_test_domain()
         cursor = connection.cursor()
         cursor.execute('DROP SCHEMA IF EXISTS test CASCADE')
 
@@ -33,10 +49,10 @@ class TenantTestCase(TestCase):
 
 
 class FastTenantTestCase(TenantTestCase):
-
     @classmethod
     def setUpClass(cls):
         cls.sync_shared()
+        cls.add_allowed_test_domain()
         tenant_domain = 'tenant.test.com'
 
         TenantModel = get_tenant_model()
@@ -51,3 +67,4 @@ class FastTenantTestCase(TenantTestCase):
     @classmethod
     def tearDownClass(cls):
         connection.set_schema_to_public()
+        cls.remove_allowed_test_domain()

tenant_schemas/tests/testcases.py

@@ -20,6 +20,8 @@ class BaseTestCase(TestCase):
                                 'django.contrib.contenttypes',
                                 'django.contrib.auth', )
         settings.INSTALLED_APPS = settings.SHARED_APPS + settings.TENANT_APPS
+        if '.test.com' not in settings.ALLOWED_HOSTS:
+            settings.ALLOWED_HOSTS += ['.test.com']
 
         # Django calls syncdb by default for the test database, but we want
         # a blank public schema for this set of tests.
@@ -29,6 +31,13 @@ class BaseTestCase(TestCase):
                        % (get_public_schema_name(), get_public_schema_name()))
         super(BaseTestCase, cls).setUpClass()
 
+    @classmethod
+    def tearDownClass(cls):
+        super(BaseTestCase, cls).tearDownClass()
+
+        if '.test.com' in settings.ALLOWED_HOSTS:
+            settings.ALLOWED_HOSTS.remove('.test.com')
+
     def setUp(self):
         connection.set_schema_to_public()
         super(BaseTestCase, self).setUp()

tox.ini

@@ -1,21 +1,22 @@
 [tox]
-envlist = py{27,35}-dj{18,19,110}
+envlist = py{27,35}-dj{18,19,110,111}
 
 [testenv]
 usedevelop = True
 
-deps = 
+deps =
 	coverage
 	mock
 	tblib
 	dj18: Django~=1.8.0
 	dj19: Django~=1.9.0
 	dj110: Django~=1.10.0
+	dj111: Django~=1.11rc1
 
 changedir = dts_test_project
 
 passenv = PG_NAME PG_USER PG_PASSWORD PG_HOST PG_PORT
 
-commands = 
+commands =
 	coverage run manage.py test --noinput {posargs:tenant_schemas}
 	coverage report -m --include=../tenant_schemas/*