Improve how settings are loaded from config file

Update the way settings are loaded. Instead of loading the
entire config file now settings are loaded from the config
file on demand when the cache misses.

Improve the smart settings classes tests and add another test
for the config file loading.

Add support for variable config file path.

Signed-off-by: Roberto Rosario <Roberto.Rosario@mayan-edms.com>

mayan/apps/smart_settings/classes.py

@@ -13,6 +13,8 @@ from django.conf import settings
 from django.utils.functional import Promise
 from django.utils.encoding import force_text, python_2_unicode_compatible
 
+from .utils import read_configuration_file
+
 logger = logging.getLogger(__name__)
 
 
@@ -173,7 +175,13 @@ class Setting(object):
                     )
                 )
         else:
-            self.raw_value = getattr(settings, self.global_name, self.default)
+            self.raw_value = read_configuration_file(
+                path=settings.CONFIGURATION_FILEPATH
+            ).get(
+                self.global_name, getattr(
+                    settings, self.global_name, self.default
+                )
+            )
 
         self.yaml = Setting.serialize_value(self.raw_value)
         self.loaded = True

mayan/apps/smart_settings/literals.py

@@ -0,0 +1,12 @@
+from __future__ import unicode_literals
+
+DJANGO_SETTINGS_LIST = (
+    'ALLOWED_HOSTS', 'APPEND_SLASH', 'AUTH_PASSWORD_VALIDATORS',
+    'DATA_UPLOAD_MAX_MEMORY_SIZE', 'DATABASES', 'DEBUG', 'DEFAULT_FROM_EMAIL',
+    'DISALLOWED_USER_AGENTS', 'EMAIL_BACKEND', 'EMAIL_HOST',
+    'EMAIL_HOST_PASSWORD', 'EMAIL_HOST_USER', 'EMAIL_PORT', 'EMAIL_TIMEOUT',
+    'EMAIL_USE_SSL', 'EMAIL_USE_TLS', 'FILE_UPLOAD_MAX_MEMORY_SIZE',
+    'HOME_VIEW', 'INSTALLED_APPS', 'INTERNAL_IPS', 'LANGUAGES',
+    'LANGUAGE_CODE', 'LOGIN_REDIRECT_URL', 'LOGIN_URL', 'STATIC_URL',
+    'STATICFILES_STORAGE', 'TIME_ZONE', 'WSGI_APPLICATION',
+)

mayan/apps/smart_settings/tests/literals.py

@@ -1,4 +1,4 @@
 from __future__ import unicode_literals
 
-ENVIRONMENT_TEST_NAME = 'PAGINATE_BY'
-ENVIRONMENT_TEST_VALUE = '999999'
+TEST_SETTING_NAME = 'COMMON_PAGINATE_BY'
+TEST_SETTING_VALUE = 999999

mayan/apps/smart_settings/tests/test_classes.py

@@ -2,15 +2,39 @@ from __future__ import absolute_import, unicode_literals
 
 import os
 
+import yaml
+
+from django.conf import settings
+
 from mayan.apps.common.settings import setting_paginate_by
 from mayan.apps.common.tests import BaseTestCase
+from mayan.apps.common.utils import fs_cleanup, mkstemp
 
-from .literals import ENVIRONMENT_TEST_NAME, ENVIRONMENT_TEST_VALUE
+from .literals import TEST_SETTING_NAME, TEST_SETTING_VALUE
 
 
 class ClassesTestCase(BaseTestCase):
+    def test_config_file(self):
+        test_config_file_descriptor, test_config_filename = mkstemp()
+        with open(test_config_filename, mode='w') as file_object:
+            file_object.write(
+                yaml.safe_dump(
+                    {TEST_SETTING_NAME: TEST_SETTING_VALUE}
+                )
+            )
+
+        settings.CONFIGURATION_FILEPATH = test_config_filename
+        setting_value = setting_paginate_by.value
+        fs_cleanup(filename=test_config_filename)
+
+        self.assertEqual(setting_value, TEST_SETTING_VALUE)
+
     def test_environment_variable(self):
-        os.environ[
-            'MAYAN_{}'.format(ENVIRONMENT_TEST_NAME)
-        ] = ENVIRONMENT_TEST_VALUE
-        self.assertTrue(setting_paginate_by.value, ENVIRONMENT_TEST_VALUE)
+        os.environ['MAYAN_{}'.format(TEST_SETTING_NAME)] = '{}'.format(
+            TEST_SETTING_VALUE
+        )
+
+        setting_value = setting_paginate_by.value
+        os.environ.pop('MAYAN_{}'.format(TEST_SETTING_NAME))
+        self.assertEqual(setting_value, TEST_SETTING_VALUE)
+

mayan/settings/base.py

@@ -16,12 +16,14 @@ import sys
 
 from django.utils.translation import ugettext_lazy as _
 
+from mayan.apps.smart_settings.literals import DJANGO_SETTINGS_LIST
+from mayan.apps.smart_settings.utils import (
+    get_environment_variables, read_configuration_file, yaml_loads
+)
+
 from .literals import (
     CONFIGURATION_FILENAME, CONFIGURATION_LAST_GOOD_FILENAME,
-    DEFAULT_SECRET_KEY, DJANGO_SETTINGS_LIST, SECRET_KEY_FILENAME, SYSTEM_DIR
-)
-from .utils import (
-    get_environment_variables, read_configuration_file, yaml_loads
+    DEFAULT_SECRET_KEY, SECRET_KEY_FILENAME, SYSTEM_DIR
 )
 
 # Build paths inside the project like this: os.path.join(BASE_DIR, ...)
@@ -327,9 +329,15 @@ DATABASES = {
     }
 }
 
-CONFIGURATION_FILEPATH = os.path.join(MEDIA_ROOT, CONFIGURATION_FILENAME)
-CONFIGURATION_LAST_GOOD_FILEPATH = os.path.join(
-    MEDIA_ROOT, CONFIGURATION_LAST_GOOD_FILENAME
+CONFIGURATION_FILEPATH = os.environ.get(
+    'MAYAN_CONFIGURATION_FILEPATH', os.path.join(
+        MEDIA_ROOT, CONFIGURATION_FILENAME
+    )
+)
+CONFIGURATION_LAST_GOOD_FILEPATH = os.environ.get(
+    'MAYAN_CONFIGURATION_LAST_GOOD_FILEPATH', os.path.join(
+        MEDIA_ROOT, CONFIGURATION_LAST_GOOD_FILENAME
+    )
 )
 
 if 'revertsettings' not in sys.argv:

mayan/settings/literals.py

@@ -1,16 +1,5 @@
 from __future__ import unicode_literals
 
-DJANGO_SETTINGS_LIST = (
-    'ALLOWED_HOSTS', 'APPEND_SLASH', 'AUTH_PASSWORD_VALIDATORS',
-    'DATA_UPLOAD_MAX_MEMORY_SIZE', 'DATABASES', 'DEBUG', 'DEFAULT_FROM_EMAIL',
-    'DISALLOWED_USER_AGENTS', 'EMAIL_BACKEND', 'EMAIL_HOST',
-    'EMAIL_HOST_PASSWORD', 'EMAIL_HOST_USER', 'EMAIL_PORT', 'EMAIL_TIMEOUT',
-    'EMAIL_USE_SSL', 'EMAIL_USE_TLS', 'FILE_UPLOAD_MAX_MEMORY_SIZE',
-    'HOME_VIEW', 'INSTALLED_APPS', 'INTERNAL_IPS', 'LANGUAGES',
-    'LANGUAGE_CODE', 'LOGIN_REDIRECT_URL', 'LOGIN_URL', 'STATIC_URL',
-    'STATICFILES_STORAGE', 'TIME_ZONE', 'WSGI_APPLICATION',
-)
-
 DEFAULT_SECRET_KEY = 'secret-key-missing!'
 SECRET_KEY_FILENAME = 'SECRET_KEY'
 SYSTEM_DIR = 'system'