refactor lookup_model out so it can be used by vector dbs routing table

llama_stack/distribution/routing_tables/common.py

@@ -6,6 +6,7 @@
 
 from typing import Any
 
+from llama_stack.apis.models import Model
 from llama_stack.apis.resource import ResourceType
 from llama_stack.apis.scoring_functions import ScoringFn
 from llama_stack.distribution.access_control.access_control import AccessDeniedError, is_action_allowed
@@ -235,3 +236,23 @@ class CommonRoutingTableImpl(RoutingTable):
             ]
 
         return filtered_objs
+
+
+async def lookup_model(routing_table: CommonRoutingTableImpl, model_id: str) -> Model:
+    # first try to get the model by identifier
+    # this works if model_id is an alias or is of the form provider_id/provider_model_id
+    model = await routing_table.get_object_by_identifier("model", model_id)
+    if model is not None:
+        return model
+
+    # if not found, this means model_id is an unscoped provider_model_id, we need
+    # to iterate (given a lack of an efficient index on the KVStore)
+    models = await routing_table.get_all_with_type("model")
+    matching_models = [m for m in models if m.provider_resource_id == model_id]
+    if len(matching_models) == 0:
+        raise ValueError(f"Model '{model_id}' not found")
+
+    if len(matching_models) > 1:
+        raise ValueError(f"Multiple providers found for '{model_id}': {[m.provider_id for m in matching_models]}")
+
+    return matching_models[0]