First working version

docker/configuration.docker.py

@@ -0,0 +1,91 @@
+## 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).
+
+import importlib.util
+import sys
+from os import scandir
+from os.path import abspath, isfile
+
+
+def _filename(f):
+    return f.name
+
+
+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)
+
+    print(f"🧬 loaded config '{path}'")
+
+
+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
+
+            if f.name.startswith('__'):
+                continue
+
+            if not f.name.endswith('.py'):
+                continue
+
+            if f.name == f'{main_config}.py':
+                continue
+
+            if f.name == f'{config_dir}.py':
+                continue
+
+            module_name = f'{config_module}.{f.name[: -len(".py")]}'.replace('.', '_')
+            _import(module_name, f.path, loaded_configurations)
+
+    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
+
+
+def __dir__():
+    names = []
+    for config in _loaded_configurations:
+        names.extend(config.__dir__())
+    return names