Avoid recursive include of DEFAULT_SETTINGS, add sanity test (#13236)

* Avoid recursive include of DEFAULT_SETTINGS, add sanity test to avoid similar surprises

* Implement review comments for more clear code order and readability

* Clarify comment about order of app name, which is last in order so that it can modify user settings

awx/main/tests/unit/test_settings.py

@@ -1,8 +1,31 @@
 from split_settings.tools import include
 
 
+LOCAL_SETTINGS = (
+    'ALLOWED_HOSTS',
+    'BROADCAST_WEBSOCKET_PORT',
+    'BROADCAST_WEBSOCKET_VERIFY_CERT',
+    'BROADCAST_WEBSOCKET_PROTOCOL',
+    'BROADCAST_WEBSOCKET_SECRET',
+    'DATABASES',
+    'DEBUG',
+    'NAMED_URL_GRAPH',
+)
+
+
 def test_postprocess_auth_basic_enabled():
     locals().update({'__file__': __file__})
 
     include('../../../settings/defaults.py', scope=locals())
     assert 'awx.api.authentication.LoggedBasicAuthentication' in locals()['REST_FRAMEWORK']['DEFAULT_AUTHENTICATION_CLASSES']
+
+
+def test_default_settings():
+    from django.conf import settings
+
+    for k in dir(settings):
+        if k not in settings.DEFAULTS_SNAPSHOT or k in LOCAL_SETTINGS:
+            continue
+        default_val = getattr(settings.default_settings, k, None)
+        snapshot_val = settings.DEFAULTS_SNAPSHOT[k]
+        assert default_val == snapshot_val, f'Setting for {k} does not match shapshot:\nsnapshot: {snapshot_val}\ndefault: {default_val}'

awx/settings/development.py

@@ -62,19 +62,6 @@ DEBUG_TOOLBAR_CONFIG = {'ENABLE_STACKTRACES': True}
 SYSTEM_UUID = '00000000-0000-0000-0000-000000000000'
 INSTALL_UUID = '00000000-0000-0000-0000-000000000000'
 
-# Store a snapshot of default settings at this point before loading any
-# customizable config files.
-DEFAULTS_SNAPSHOT = {}
-this_module = sys.modules[__name__]
-for setting in dir(this_module):
-    if setting == setting.upper():
-        DEFAULTS_SNAPSHOT[setting] = copy.deepcopy(getattr(this_module, setting))
-
-# If there is an `/etc/tower/settings.py`, include it.
-# If there is a `/etc/tower/conf.d/*.py`, include them.
-include(optional('/etc/tower/settings.py'), scope=locals())
-include(optional('/etc/tower/conf.d/*.py'), scope=locals())
-
 BASE_VENV_PATH = "/var/lib/awx/venv/"
 AWX_VENV_PATH = os.path.join(BASE_VENV_PATH, "awx")
 
@@ -105,11 +92,28 @@ AWX_CALLBACK_PROFILE = True
 AWX_DISABLE_TASK_MANAGERS = False
 # ======================!!!!!!! FOR DEVELOPMENT ONLY !!!!!!!=================================
 
-from .application_name import set_application_name
+# Store a snapshot of default settings at this point before loading any
+# customizable config files.
+this_module = sys.modules[__name__]
+local_vars = dir(this_module)
+DEFAULTS_SNAPSHOT = {}  # define after we save local_vars so we do not snapshot the snapshot
+for setting in local_vars:
+    if setting.isupper():
+        DEFAULTS_SNAPSHOT[setting] = copy.deepcopy(getattr(this_module, setting))
 
-set_application_name(DATABASES, CLUSTER_HOST_ID)
+del local_vars  # avoid temporary variables from showing up in dir(settings)
+del this_module
+#
+###############################################################################################
+#
+#  Any settings defined after this point will be marked as as a read_only database setting
+#
+################################################################################################
 
-del set_application_name
+# If there is an `/etc/tower/settings.py`, include it.
+# If there is a `/etc/tower/conf.d/*.py`, include them.
+include(optional('/etc/tower/settings.py'), scope=locals())
+include(optional('/etc/tower/conf.d/*.py'), scope=locals())
 
 # If any local_*.py files are present in awx/settings/, use them to override
 # default settings for development.  If not present, we can still run using
@@ -123,3 +127,11 @@ try:
 except ImportError:
     traceback.print_exc()
     sys.exit(1)
+
+# The below runs AFTER all of the custom settings are imported
+# because conf.d files will define DATABASES and this should modify that
+from .application_name import set_application_name
+
+set_application_name(DATABASES, CLUSTER_HOST_ID)
+
+del set_application_name

awx/settings/production.py

@@ -47,17 +47,21 @@ AWX_ISOLATION_SHOW_PATHS = [
 
 # Store a snapshot of default settings at this point before loading any
 # customizable config files.
+this_module = sys.modules[__name__]
+local_vars = dir(this_module)
+DEFAULTS_SNAPSHOT = {}  # define after we save local_vars so we do not snapshot the snapshot
+for setting in local_vars:
+    if setting.isupper():
+        DEFAULTS_SNAPSHOT[setting] = copy.deepcopy(getattr(this_module, setting))
+
+del local_vars  # avoid temporary variables from showing up in dir(settings)
+del this_module
 #
 ###############################################################################################
 #
 #  Any settings defined after this point will be marked as as a read_only database setting
 #
 ################################################################################################
-DEFAULTS_SNAPSHOT = {}
-this_module = sys.modules[__name__]
-for setting in dir(this_module):
-    if setting == setting.upper():
-        DEFAULTS_SNAPSHOT[setting] = copy.deepcopy(getattr(this_module, setting))
 
 # Load settings from any .py files in the global conf.d directory specified in
 # the environment, defaulting to /etc/tower/conf.d/.
@@ -98,8 +102,8 @@ except IOError:
     else:
         raise
 
-# The below runs AFTER all of the custom settings are imported.
-
+# The below runs AFTER all of the custom settings are imported
+# because conf.d files will define DATABASES and this should modify that
 from .application_name import set_application_name
 
 set_application_name(DATABASES, CLUSTER_HOST_ID)  # NOQA