refactor: Align build and run provider datatypes

introduce the concept of a `module` for users to specify for a provider upon build time.
In order to facilitate this, align the build and run spec to use `Provider` class rather than the stringified provider_type that build currently uses.

Signed-off-by: Charlie Doern <cdoern@redhat.com>

llama_stack/distribution/configure.py

@@ -91,21 +91,21 @@ def configure_api_providers(config: StackRunConfig, build_spec: DistributionSpec
 
             logger.info(f"Configuring API `{api_str}`...")
             updated_providers = []
-            for i, provider_type in enumerate(plist):
+            for i, provider in enumerate(plist):
                 if i >= 1:
-                    others = ", ".join(plist[i:])
+                    others = ", ".join(p.provider_type for p in plist[i:])
                     logger.info(
                         f"Not configuring other providers ({others}) interactively. Please edit the resulting YAML directly.\n"
                     )
                     break
 
-                logger.info(f"> Configuring provider `({provider_type})`")
+                logger.info(f"> Configuring provider `({provider.provider_type})`")
                 updated_providers.append(
                     configure_single_provider(
                         provider_registry[api],
                         Provider(
-                            provider_id=(f"{provider_type}-{i:02d}" if len(plist) > 1 else provider_type),
-                            provider_type=provider_type,
+                            provider_id=(f"{provider.provider_id}-{i:02d}" if len(plist) > 1 else provider.provider_id),
+                            provider_type=provider.provider_type,
                             config={},
                         ),
                     )

llama_stack/distribution/datatypes.py

@@ -136,29 +136,40 @@ class RoutingTableProviderSpec(ProviderSpec):
     pip_packages: list[str] = Field(default_factory=list)
 
 
+class Provider(BaseModel):
+    # provider_id of None means that the provider is not enabled - this happens
+    # when the provider is enabled via a conditional environment variable
+    provider_id: str | None
+    provider_type: str
+    config: dict[str, Any] = {}
+    module: str | None = Field(
+        default=None,
+        description="""
+ Fully-qualified name of the external provider module to import. The module is expected to have:
+
+  - `get_adapter_impl(config, deps)`: returns the adapter implementation
+
+  Example: `module: ramalama_stack`
+ """,
+    )
+
+
 class DistributionSpec(BaseModel):
     description: str | None = Field(
         default="",
         description="Description of the distribution",
     )
     container_image: str | None = None
-    providers: dict[str, str | list[str]] = Field(
+    providers: dict[str, list[Provider]] = Field(
         default_factory=dict,
         description="""
-Provider Types for each of the APIs provided by this distribution. If you
-select multiple providers, you should provide an appropriate 'routing_map'
-in the runtime configuration to help route to the correct provider.""",
+        Provider Types for each of the APIs provided by this distribution. If you
+        select multiple providers, you should provide an appropriate 'routing_map'
+        in the runtime configuration to help route to the correct provider.
+        """,
     )
 
 
-class Provider(BaseModel):
-    # provider_id of None means that the provider is not enabled - this happens
-    # when the provider is enabled via a conditional environment variable
-    provider_id: str | None
-    provider_type: str
-    config: dict[str, Any]
-
-
 class LoggingConfig(BaseModel):
     category_levels: dict[str, str] = Field(
         default_factory=dict,

llama_stack/distribution/library_client.py

@@ -249,15 +249,9 @@ class AsyncLlamaStackAsLibraryClient(AsyncLlamaStackClient):
                 file=sys.stderr,
             )
             if self.config_path_or_template_name.endswith(".yaml"):
-                # Convert Provider objects to their types
-                provider_types: dict[str, str | list[str]] = {}
-                for api, providers in self.config.providers.items():
-                    types = [p.provider_type for p in providers]
-                    # Convert single-item lists to strings
-                    provider_types[api] = types[0] if len(types) == 1 else types
                 build_config = BuildConfig(
                     distribution_spec=DistributionSpec(
-                        providers=provider_types,
+                        providers=self.config.providers,
                     ),
                     external_providers_dir=self.config.external_providers_dir,
                 )

llama_stack/distribution/resolver.py

@@ -345,7 +345,7 @@ async def instantiate_provider(
     policy: list[AccessRule],
 ):
     provider_spec = provider.spec
-    if not hasattr(provider_spec, "module"):
+    if not hasattr(provider_spec, "module") or provider_spec.module is None:
         raise AttributeError(f"ProviderSpec of type {type(provider_spec)} does not have a 'module' attribute")
 
     logger.debug(f"Instantiating provider {provider.provider_id} from {provider_spec.module}")