Add an introspection "Api.inspect" API

llama_stack/distribution/resolver.py

@@ -3,6 +3,7 @@
 #
 # This source code is licensed under the terms described in the LICENSE file in
 # the root directory of this source tree.
+import importlib
 
 from typing import Any, Dict, List, Set
 
@@ -11,7 +12,8 @@ from llama_stack.distribution.distribution import (
     builtin_automatically_routed_apis,
     get_provider_registry,
 )
-from llama_stack.distribution.utils.dynamic import instantiate_provider
+from llama_stack.distribution.inspect import DistributionInspectImpl
+from llama_stack.distribution.utils.dynamic import instantiate_class_type
 
 
 async def resolve_impls_with_routing(run_config: StackRunConfig) -> Dict[Api, Any]:
@@ -57,7 +59,6 @@ async def resolve_impls_with_routing(run_config: StackRunConfig) -> Dict[Api, An
         if info.router_api.value not in apis_to_serve:
             continue
 
-        print("router_api", info.router_api)
         if info.router_api.value not in run_config.routing_table:
             raise ValueError(f"Routing table for `{source_api.value}` is not provided?")
 
@@ -104,6 +105,14 @@ async def resolve_impls_with_routing(run_config: StackRunConfig) -> Dict[Api, An
 
         impls[api] = impl
 
+    impls[Api.inspect] = DistributionInspectImpl()
+    specs[Api.inspect] = InlineProviderSpec(
+        api=Api.inspect,
+        provider_type="__distribution_builtin__",
+        config_class="",
+        module="",
+    )
+
     return impls, specs
 
 
@@ -127,3 +136,60 @@ def topological_sort(providers: List[ProviderSpec]) -> List[ProviderSpec]:
             dfs(a, visited, stack)
 
     return [by_id[x] for x in stack]
+
+
+# returns a class implementing the protocol corresponding to the Api
+async def instantiate_provider(
+    provider_spec: ProviderSpec,
+    deps: Dict[str, Any],
+    provider_config: Union[GenericProviderConfig, RoutingTable],
+):
+    module = importlib.import_module(provider_spec.module)
+
+    args = []
+    if isinstance(provider_spec, RemoteProviderSpec):
+        if provider_spec.adapter:
+            method = "get_adapter_impl"
+        else:
+            method = "get_client_impl"
+
+        assert isinstance(provider_config, GenericProviderConfig)
+        config_type = instantiate_class_type(provider_spec.config_class)
+        config = config_type(**provider_config.config)
+        args = [config, deps]
+    elif isinstance(provider_spec, AutoRoutedProviderSpec):
+        method = "get_auto_router_impl"
+
+        config = None
+        args = [provider_spec.api, deps[provider_spec.routing_table_api], deps]
+    elif isinstance(provider_spec, RoutingTableProviderSpec):
+        method = "get_routing_table_impl"
+
+        assert isinstance(provider_config, List)
+        routing_table = provider_config
+
+        inner_specs = {x.provider_type: x for x in provider_spec.inner_specs}
+        inner_impls = []
+        for routing_entry in routing_table:
+            impl = await instantiate_provider(
+                inner_specs[routing_entry.provider_type],
+                deps,
+                routing_entry,
+            )
+            inner_impls.append((routing_entry.routing_key, impl))
+
+        config = None
+        args = [provider_spec.api, inner_impls, routing_table, deps]
+    else:
+        method = "get_provider_impl"
+
+        assert isinstance(provider_config, GenericProviderConfig)
+        config_type = instantiate_class_type(provider_spec.config_class)
+        config = config_type(**provider_config.config)
+        args = [config, deps]
+
+    fn = getattr(module, method)
+    impl = await fn(*args)
+    impl.__provider_spec__ = provider_spec
+    impl.__provider_config__ = config
+    return impl