Merge core functionality into configuration.py

Which is the file `docker/configuration.docker.py` in our repo.
The common code is then imported by `docker/ldap_config.docker.py`.

Author: cimnine

docker/configuration.docker.py

@@ -1,61 +1,79 @@
+## Generic Parts
+# These functions are providing the functionality to load
+# arbitrary configuration files.
+#
+# They can be imported by other code (see `ldap_config.py` for an example).
+
 from os.path import abspath, isfile
 from os import scandir
 import importlib.util
 import sys
 
-_CONFIG_DIR = '/etc/netbox/config/'
-_MAIN_CONFIG = 'configuration'
-_MODULE = 'netbox.configuration'
-_loaded_configurations = []
-
-
-def __getattr__(name):
-  for config in _loaded_configurations:
-    try:
-      return getattr(config, name)
-    except:
-      pass
-  raise AttributeError
-
-
 def _filename(f):
   return f.name
 
 
-def _import(module_name, path):
+def _import(module_name, path, loaded_configurations):
   spec = importlib.util.spec_from_file_location('', path)
   module = importlib.util.module_from_spec(spec)
   spec.loader.exec_module(module)
   sys.modules[module_name] = module
 
-  _loaded_configurations.insert(0, module)
+  loaded_configurations.insert(0, module)
 
   print(f"🧬 loaded config '{path}'")
 
 
-_main_config_path = abspath(f'{_CONFIG_DIR}/{_MAIN_CONFIG}.py')
-if isfile(_main_config_path):
-  _import(f'{_MODULE}.{_MAIN_CONFIG}', _main_config_path)
-else:
-  print(f"⚠️ Main configuration '{_main_config_path}' not found.")
+def read_configurations(config_module, config_dir, main_config):
+  loaded_configurations = []
+
+  main_config_path = abspath(f'{config_dir}/{main_config}.py')
+  if isfile(main_config_path):
+    _import(f'{config_module}.{main_config}', main_config_path, loaded_configurations)
+  else:
+    print(f"⚠️ Main configuration '{main_config_path}' not found.")
+
+  with scandir(config_dir) as it:
+    for f in sorted(it, key=_filename):
+      if not f.is_file():
+        continue
 
-with scandir(_CONFIG_DIR) as it:
-  for f in sorted(it, key=_filename):
-    if not f.is_file():
-      continue
+      if f.name.startswith('__'):
+        continue
 
-    if f.name.startswith('__'):
-      continue
+      if not f.name.endswith('.py'):
+        continue
 
-    if not f.name.endswith('.py'):
-      continue
+      if f.name == f'{config_dir}.py':
+        continue
 
-    if f.name == f'{_MAIN_CONFIG}.py':
-      continue
+      module_name = f"{config_module}.{f.name[:-len('.py')]}".replace(".", "_")
+      _import(module_name, f.path, loaded_configurations)
 
-    module_name = f"{_MODULE}.{f.name[:-len('.py')]}".replace(".", "_")
-    _import(module_name, f.path)
+  if len(loaded_configurations) == 0:
+    print(f"‼️ No configuration files found in '{config_dir}'.")
+    raise ImportError(f"No configuration files found in '{config_dir}'.")
 
-if len(_loaded_configurations) == 0:
-  print(f"‼️ No configuration files found in '{_CONFIG_DIR}'.")
-  raise ImportError(f"No configuration files found in '{_CONFIG_DIR}'.")
+  return loaded_configurations
+
+
+## Specific Parts
+# This section's code actually loads the various configuration files
+# into the module with the given name.
+# It contains the logic to resolve arbitrary configuration options by
+# levaraging dynamic programming using `__getattr__`.
+
+
+_loaded_configurations = read_configurations(
+  config_dir = '/etc/netbox/config/',
+  config_module = 'netbox.configuration',
+  main_config = 'configuration')
+
+
+def __getattr__(name):
+  for config in _loaded_configurations:
+    try:
+      return getattr(config, name)
+    except:
+      pass
+  raise AttributeError

docker/ldap_config.docker.py

@@ -1,12 +1,9 @@
-from os.path import abspath, isfile
-from os import scandir
-import importlib.util
-import sys
+from .configuration import read_configurations
 
-_CONFIG_DIR = '/etc/netbox/config/ldap/'
-_MAIN_CONFIG = 'ldap_config'
-_MODULE = 'netbox.configuration.ldap'
-_loaded_configurations = []
+_loaded_configurations = read_configurations(
+  config_dir = '/etc/netbox/config/ldap/',
+  config_module = 'netbox.configuration.ldap',
+  main_config = 'ldap_config')
 
 
 def __getattr__(name):
@@ -16,46 +13,3 @@ def __getattr__(name):
     except:
       pass
   raise AttributeError
-
-
-def _filename(f):
-  return f.name
-
-
-def _import(module_name, path):
-  spec = importlib.util.spec_from_file_location('', path)
-  module = importlib.util.module_from_spec(spec)
-  spec.loader.exec_module(module)
-  sys.modules[module_name] = module
-
-  _loaded_configurations.insert(0, module)
-
-  print(f"🧬 loaded config '{path}'")
-
-
-_main_config_path = abspath(f'{_CONFIG_DIR}/{_MAIN_CONFIG}.py')
-if isfile(_main_config_path):
-  _import(f'{_MODULE}.{_MAIN_CONFIG}', _main_config_path)
-else:
-  print(f"⚠️ Main configuration '{_main_config_path}' not found.")
-
-with scandir(_CONFIG_DIR) as it:
-  for f in sorted(it, key=_filename):
-    if not f.is_file():
-      continue
-
-    if f.name.startswith('__'):
-      continue
-
-    if not f.name.endswith('.py'):
-      continue
-
-    if f.name == f'{_MAIN_CONFIG}.py':
-      continue
-
-    module_name = f"{_MODULE}.{f.name[:-len('.py')]}".replace(".", "_")
-    _import(module_name, f.path)
-
-if len(_loaded_configurations) == 0:
-  print(f"‼️ No configuration files found in '{_CONFIG_DIR}'.")
-  raise ImportError(f"No configuration files found in '{_CONFIG_DIR}'.")