Allow specifying resources in StackRunConfig (#425)

# What does this PR do? 

This PR brings back the facility to not force registration of resources
onto the user. This is not just annoying but actually not feasible
sometimes. For example, you may have a Stack which boots up with private
providers for inference for models A and B. There is no way for the user
to actually know which model is being served by these providers now (to
be able to register it.)

How will this avoid the users needing to do registration? In a follow-up
diff, I will make sure I update the sample run.yaml files so they list
the models served by the distributions explicitly. So when users do
`llama stack build --template <...>` and run it, their distributions
come up with the right set of models they expect.

For self-hosted distributions, it also allows us to have a place to
explicit list the models that need to be served to make the "complete"
stack (including safety, e.g.)

## Test Plan

Started ollama locally with two lightweight models: Llama3.2-3B-Instruct
and Llama-Guard-3-1B.

Updated all the tests including agents. Here's the tests I ran so far:

```bash
pytest -s -v -m "fireworks and llama_3b" test_text_inference.py::TestInference \
  --env FIREWORKS_API_KEY=...

pytest -s -v -m "ollama and llama_3b" test_text_inference.py::TestInference 

pytest -s -v -m ollama test_safety.py

pytest -s -v -m faiss test_memory.py

pytest -s -v -m ollama  test_agents.py \
  --inference-model=Llama3.2-3B-Instruct --safety-model=Llama-Guard-3-1B
```

Found a few bugs here and there pre-existing that these test runs fixed.

llama_stack/distribution/datatypes.py

@@ -151,6 +151,14 @@ Configuration for the persistence store used by the distribution registry. If no
 a default SQLite store will be used.""",
     )
 
+    # registry of "resources" in the distribution
+    models: List[Model] = Field(default_factory=list)
+    shields: List[Shield] = Field(default_factory=list)
+    memory_banks: List[MemoryBank] = Field(default_factory=list)
+    datasets: List[Dataset] = Field(default_factory=list)
+    scoring_fns: List[ScoringFn] = Field(default_factory=list)
+    eval_tasks: List[EvalTask] = Field(default_factory=list)
+
 
 class BuildConfig(BaseModel):
     version: str = LLAMA_STACK_BUILD_CONFIG_VERSION

llama_stack/distribution/server/server.py

@@ -27,12 +27,7 @@ from pydantic import BaseModel, ValidationError
 from termcolor import cprint
 from typing_extensions import Annotated
 
-from llama_stack.distribution.distribution import (
-    builtin_automatically_routed_apis,
-    get_provider_registry,
-)
-
-from llama_stack.distribution.store.registry import create_dist_registry
+from llama_stack.distribution.distribution import builtin_automatically_routed_apis
 
 from llama_stack.providers.utils.telemetry.tracing import (
     end_trace,
@@ -42,14 +37,15 @@ from llama_stack.providers.utils.telemetry.tracing import (
 )
 from llama_stack.distribution.datatypes import *  # noqa: F403
 from llama_stack.distribution.request_headers import set_request_provider_data
-from llama_stack.distribution.resolver import InvalidProviderError, resolve_impls
+from llama_stack.distribution.resolver import InvalidProviderError
+from llama_stack.distribution.stack import construct_stack
 
 from .endpoints import get_all_api_endpoints
 
 
 def create_sse_event(data: Any) -> str:
     if isinstance(data, BaseModel):
-        data = data.json()
+        data = data.model_dump_json()
     else:
         data = json.dumps(data)
 
@@ -281,12 +277,8 @@ def main(
 
     app = FastAPI()
 
-    dist_registry, dist_kvstore = asyncio.run(create_dist_registry(config))
-
     try:
-        impls = asyncio.run(
-            resolve_impls(config, get_provider_registry(), dist_registry)
-        )
+        impls = asyncio.run(construct_stack(config))
     except InvalidProviderError:
         sys.exit(1)
 

llama_stack/distribution/stack.py

@@ -0,0 +1,100 @@
+# Copyright (c) Meta Platforms, Inc. and affiliates.
+# All rights reserved.
+#
+# This source code is licensed under the terms described in the LICENSE file in
+# the root directory of this source tree.
+
+from typing import Any, Dict
+
+from termcolor import colored
+
+from llama_models.llama3.api.datatypes import *  # noqa: F403
+from llama_stack.apis.agents import *  # noqa: F403
+from llama_stack.apis.datasets import *  # noqa: F403
+from llama_stack.apis.datasetio import *  # noqa: F403
+from llama_stack.apis.scoring import *  # noqa: F403
+from llama_stack.apis.scoring_functions import *  # noqa: F403
+from llama_stack.apis.eval import *  # noqa: F403
+from llama_stack.apis.inference import *  # noqa: F403
+from llama_stack.apis.batch_inference import *  # noqa: F403
+from llama_stack.apis.memory import *  # noqa: F403
+from llama_stack.apis.telemetry import *  # noqa: F403
+from llama_stack.apis.post_training import *  # noqa: F403
+from llama_stack.apis.synthetic_data_generation import *  # noqa: F403
+from llama_stack.apis.safety import *  # noqa: F403
+from llama_stack.apis.models import *  # noqa: F403
+from llama_stack.apis.memory_banks import *  # noqa: F403
+from llama_stack.apis.shields import *  # noqa: F403
+from llama_stack.apis.inspect import *  # noqa: F403
+from llama_stack.apis.eval_tasks import *  # noqa: F403
+
+from llama_stack.distribution.datatypes import StackRunConfig
+from llama_stack.distribution.distribution import get_provider_registry
+from llama_stack.distribution.resolver import resolve_impls
+from llama_stack.distribution.store.registry import create_dist_registry
+from llama_stack.providers.datatypes import Api
+
+
+class LlamaStack(
+    MemoryBanks,
+    Inference,
+    BatchInference,
+    Agents,
+    Safety,
+    SyntheticDataGeneration,
+    Datasets,
+    Telemetry,
+    PostTraining,
+    Memory,
+    Eval,
+    EvalTasks,
+    Scoring,
+    ScoringFunctions,
+    DatasetIO,
+    Models,
+    Shields,
+    Inspect,
+):
+    pass
+
+
+# Produces a stack of providers for the given run config. Not all APIs may be
+# asked for in the run config.
+async def construct_stack(run_config: StackRunConfig) -> Dict[Api, Any]:
+    dist_registry, _ = await create_dist_registry(
+        run_config.metadata_store, run_config.image_name
+    )
+
+    impls = await resolve_impls(run_config, get_provider_registry(), dist_registry)
+
+    objects = [
+        *run_config.models,
+        *run_config.shields,
+        *run_config.memory_banks,
+        *run_config.datasets,
+        *run_config.scoring_fns,
+        *run_config.eval_tasks,
+    ]
+    for obj in objects:
+        await dist_registry.register(obj)
+
+    resources = [
+        ("models", Api.models),
+        ("shields", Api.shields),
+        ("memory_banks", Api.memory_banks),
+        ("datasets", Api.datasets),
+        ("scoring_fns", Api.scoring_functions),
+        ("eval_tasks", Api.eval_tasks),
+    ]
+    for rsrc, api in resources:
+        if api not in impls:
+            continue
+
+        method = getattr(impls[api], f"list_{api.value}")
+        for obj in await method():
+            print(
+                f"{rsrc.capitalize()}: {colored(obj.identifier, 'white', attrs=['bold'])} served by {colored(obj.provider_id, 'white', attrs=['bold'])}",
+            )
+
+    print("")
+    return impls

llama_stack/distribution/store/registry.py

@@ -5,14 +5,11 @@
 # the root directory of this source tree.
 
 import json
-from typing import Dict, List, Protocol
+from typing import Dict, List, Optional, Protocol
 
 import pydantic
 
-from llama_stack.distribution.datatypes import (
-    RoutableObjectWithProvider,
-    StackRunConfig,
-)
+from llama_stack.distribution.datatypes import KVStoreConfig, RoutableObjectWithProvider
 from llama_stack.distribution.utils.config_dirs import DISTRIBS_BASE_DIR
 
 from llama_stack.providers.utils.kvstore import (
@@ -144,17 +141,16 @@ class CachedDiskDistributionRegistry(DiskDistributionRegistry):
 
 
 async def create_dist_registry(
-    config: StackRunConfig,
+    metadata_store: Optional[KVStoreConfig],
+    image_name: str,
 ) -> tuple[CachedDiskDistributionRegistry, KVStore]:
     # instantiate kvstore for storing and retrieving distribution metadata
-    if config.metadata_store:
-        dist_kvstore = await kvstore_impl(config.metadata_store)
+    if metadata_store:
+        dist_kvstore = await kvstore_impl(metadata_store)
     else:
         dist_kvstore = await kvstore_impl(
             SqliteKVStoreConfig(
-                db_path=(
-                    DISTRIBS_BASE_DIR / config.image_name / "kvstore.db"
-                ).as_posix()
+                db_path=(DISTRIBS_BASE_DIR / image_name / "kvstore.db").as_posix()
             )
         )