add path grouping

litestar/contrib/prometheus/middleware.py

@@ -2,6 +2,7 @@
 
 import time
 from functools import wraps
+import re
 from typing import TYPE_CHECKING, Any, Callable, ClassVar, cast
 
 from litestar.connection.request import Request
@@ -115,6 +116,19 @@ def _get_default_labels(self, request: Request[Any, Any, Any]) -> dict[str, str
             A dictionary of default labels.
         """
 
+        path = request.url.path
+        if self._config.group_path:
+            path_parts = path.split("/")
+            if path_parts[0] == "":
+                path_parts = path_parts[1:]
+            path = ""
+            for path_parameter, path_parameter_value in request.scope.get("path_params", {}).items():
+                for path_part in path_parts:
+                    path_parameter_value = str(path_parameter_value)
+                    if path_part == path_parameter_value:
+                        path += f"/[{path_parameter}]"
+                    else:
+                        path += f"/{path_part}"
         return {
             "method": request.method if request.scope["type"] == ScopeType.HTTP else request.scope["type"],
             "path": request.url.path,