ref(grouping): Move grouping config to top level of grouping info (#101281)

This changes the format of the grouping info API response, so that instead of the full serialized grouping config being included in every variant, only the grouping config id is included at the top level of the JSON, and the variants in turn are included under a new `variants` key. In other words, it changes from a response that looks like this:

{
  app_exception_stacktrace: {
    ...,
    config: {
      id: "newstyle:whatever",  // the only part of `config` we actually care about
      ...
    }
  },
  system_exception_stacktrace:  {
    ...,
    config: {
      id: "newstyle:whatever",  // we don't need this twice
      ...
    }
  }
}

to one which looks like this:

{
  grouping_config: "newstyle:whatever",
  variants: {
    app_exception_stacktrace: {...},
    system_exception_stacktrace: {...}
  }
}

This not only removes redundancy (along with a bunch of information about the config we don't need), it also sets us up to be able to send other grouping-info-wide information in the response.

Note: Before this can be merged, the front end needs to be adjusted to [work with both the old and new formats](#102820). Once that's deployed, and this is merged and deployed, we can [remove old-format handling from the front end](#101223).

Author: lobsterkatie

src/sentry/grouping/grouping_info.py

@@ -12,7 +12,7 @@
 
 def get_grouping_info(
     grouping_config: StrategyConfiguration, project: Project, event: Event | GroupEvent
-) -> dict[str, dict[str, Any]]:
+) -> dict[str, Any]:
     # We always fetch the stored hashes here. The reason for this is
     # that we want to show in the UI if the forced grouping algorithm
     # produced hashes that would normally also appear in the event.
@@ -43,7 +43,7 @@ def _check_for_mismatched_hashes(
     The result is stored with each variant and recorded as a metric.
     """
 
-    for variant_dict in grouping_info.values():
+    for variant_dict in grouping_info["variants"].values():
         hash_value = variant_dict["hash"]
 
         # Since the hashes are generated on the fly and might no
@@ -125,18 +125,29 @@ def get_grouping_info_from_variants_legacy(
 
 def get_grouping_info_from_variants(
     variants: dict[str, BaseVariant],
-) -> dict[str, dict[str, Any]]:
+) -> dict[str, Any]:
     """
     Given a dictionary of variant objects, create and return a copy of the dictionary in which each
     variant object value has been transformed into an equivalent dictionary value, which knows the
     key under which it lives.
     """
 
-    return {
+    grouping_config_id = None
+    for variant in variants.values():
+        grouping_config_id = variant.config.id if hasattr(variant, "config") else None
+        if grouping_config_id:
+            break
+
+    variants_json = {
         # Overwrite the description with a new, improved version
         variant.key: {
             **variant.as_dict(),
             "description": _get_new_description(variant),
         }
         for variant in variants.values()
     }
+
+    return {
+        "grouping_config": grouping_config_id,
+        "variants": variants_json,
+    }

src/sentry/grouping/variants.py

@@ -154,7 +154,7 @@ def get_hash(self) -> str | None:
         return self.root_component.get_hash()
 
     def _get_metadata_as_dict(self) -> Mapping[str, Any]:
-        return {"component": self.root_component.as_dict(), "config": self.config.as_dict()}
+        return {"component": self.root_component.as_dict()}
 
     def __repr__(self) -> str:
         return super().__repr__() + f" contributes={self.contributes} ({self.description})"