client: handle references in user config schema

Currently the client is not able to deal with references in the user
config schema, but will throw key errors. This will improve the
situation by traversing the original object until the actual definition
is found

aiven/client/cli.py

@@ -177,11 +177,29 @@ def add_args(self, parser: ArgumentParser) -> None:
             help="Wait for up to N seconds for a response to a request (default: infinite)",
         )
 
+    def _find_reference(self, obj_def: Mapping[str, Any], spec: Mapping[str, Any]) -> Mapping[str, Any] | None:
+        ref_prefix = "#/definitions/"
+
+        def traverse_obj(obj_def: Mapping[str, Any], spec: Mapping[str, Any]) -> Mapping[str, Any] | None:
+            if "definitions" not in obj_def:
+                return None
+            ref = spec["$ref"].removeprefix(ref_prefix)
+            return obj_def["definitions"][ref]
+
+        if "$ref" in spec:
+            return traverse_obj(obj_def, spec)
+        for entry in spec.get("allOf", []):
+            return traverse_obj(obj_def, entry)
+
     def collect_user_config_options(self, obj_def: Mapping[str, Any], prefixes: list[str] | None = None) -> dict[str, Any]:
         opts = {}
         for prop, spec in sorted(obj_def.get("properties", {}).items()):
             full_prop = prefixes + [prop] if prefixes else [prop]
             full_name = ".".join(full_prop)
+            if "type" not in spec:
+                # It is possible this is a reference, and if so we need to find the actual entry
+                if not (spec := self._find_reference(obj_def, spec)):
+                    continue
             types = spec["type"]
             if not isinstance(types, list):
                 types = [types]