Commit 32260503 authored by Claude Paroz's avatar Claude Paroz
Browse files

Fixed #24791 -- Added fallback when 'postgres' database isn't available 

Thanks Carl Meyer and Tim Graham for the reviews.
parent 2dee853e

django/db/backends/base/creation.py

+1 −1
Original line number Diff line number Diff line
@@ -217,7 +217,7 @@ class BaseDatabaseCreation(object): 
        # ourselves. Connect to the previous database (not the test database)

        # to do so, because it's not allowed to delete a database while being

        # connected to it.

        with self._nodb_connection.cursor() as cursor:

        with self.connection._nodb_connection.cursor() as cursor:

            # Wait to avoid "database is being accessed by other users" errors.

            time.sleep(1)

            cursor.execute("DROP DATABASE %s"

django/db/backends/postgresql_psycopg2/base.py

+26 −0
Original line number Diff line number Diff line
@@ -4,10 +4,14 @@ PostgreSQL database backend for Django. 
Requires psycopg 2: http://initd.org/projects/psycopg2

"""



import warnings



from django.conf import settings

from django.core.exceptions import ImproperlyConfigured

from django.db import DEFAULT_DB_ALIAS

from django.db.backends.base.base import BaseDatabaseWrapper

from django.db.backends.base.validation import BaseDatabaseValidation

from django.db.utils import DatabaseError as WrappedDatabaseError

from django.utils.encoding import force_str

from django.utils.functional import cached_property

from django.utils.safestring import SafeBytes, SafeText
@@ -230,6 +234,28 @@ class DatabaseWrapper(BaseDatabaseWrapper): 
        else:

            return True



    @cached_property

    def _nodb_connection(self):

        nodb_connection = super(DatabaseWrapper, self)._nodb_connection

        try:

            nodb_connection.ensure_connection()

        except (DatabaseError, WrappedDatabaseError):

            warnings.warn(

                "Normally Django will use a connection to the 'postgres' database "

                "to avoid running initialization queries against the production "

                "database when it's not needed (for example, when running tests). "

                "Django was unable to create a connection to the 'postgres' database "

                "and will use the default database instead.",

                RuntimeWarning

            )

            settings_dict = self.settings_dict.copy()

            settings_dict['NAME'] = settings.DATABASES[DEFAULT_DB_ALIAS]['NAME']

            nodb_connection = self.__class__(

                self.settings_dict.copy(),

                alias=self.alias,

                allow_thread_sharing=False)

        return nodb_connection



    @cached_property

    def psycopg2_version(self):

        return PSYCOPG2_VERSION

docs/releases/1.8.2.txt

+4 −0
Original line number Diff line number Diff line
@@ -33,3 +33,7 @@ Bugfixes 


* Fixed session cookie deletion when using :setting:`SESSION_COOKIE_DOMAIN`

  (:ticket:`24799`).



* On PostgreSQL, when no access is granted for the ``postgres`` database,

  Django now falls back to the default database when it normally requires a

  "no database" connection (:ticket:`24791`).

tests/backends/tests.py

+26 −0
Original line number Diff line number Diff line
@@ -161,6 +161,32 @@ class PostgreSQLTests(TestCase): 
        self.assert_parses("PostgreSQL 9.4beta1", 90400)

        self.assert_parses("PostgreSQL 9.3.1 on i386-apple-darwin9.2.2, compiled by GCC i686-apple-darwin9-gcc-4.0.1 (GCC) 4.0.1 (Apple Inc. build 5478)", 90301)



    def test_nodb_connection(self):

        """

        Test that the _nodb_connection property fallbacks to the default connection

        database when access to the 'postgres' database is not granted.

        """

        def mocked_connect(self):

            if self.settings_dict['NAME'] is None:

                raise DatabaseError()

            return ''



        nodb_conn = connection._nodb_connection

        self.assertIsNone(nodb_conn.settings_dict['NAME'])



        # Now assume the 'postgres' db isn't available

        del connection._nodb_connection

        with warnings.catch_warnings(record=True) as w:

            with mock.patch('django.db.backends.base.base.BaseDatabaseWrapper.connect',

                            side_effect=mocked_connect, autospec=True):

                nodb_conn = connection._nodb_connection

        del connection._nodb_connection

        self.assertIsNotNone(nodb_conn.settings_dict['NAME'])

        self.assertEqual(nodb_conn.settings_dict['NAME'], settings.DATABASES[DEFAULT_DB_ALIAS]['NAME'])

        # Check a RuntimeWarning nas been emitted

        self.assertEqual(len(w), 1)

        self.assertEqual(w[0].message.__class__, RuntimeWarning)



    def test_version_detection(self):

        """Test PostgreSQL version detection"""