Add pip install helper for test and direct scenarios (#404)

* initial branch commit

* pip install helptext

* remove print

* pre-commit

llama_stack/distribution/build.py

@@ -48,18 +48,14 @@ class ApiInput(BaseModel):
     provider: str
 
 
-def build_image(build_config: BuildConfig, build_file_path: Path):
-    package_deps = Dependencies(
-        docker_image=build_config.distribution_spec.docker_image or "python:3.10-slim",
-        pip_packages=SERVER_DEPENDENCIES,
-    )
-
-    # extend package dependencies based on providers spec
+def get_provider_dependencies(
+    config_providers: Dict[str, List[Provider]]
+) -> tuple[list[str], list[str]]:
+    """Get normal and special dependencies from provider configuration."""
     all_providers = get_provider_registry()
-    for (
-        api_str,
-        provider_or_providers,
-    ) in build_config.distribution_spec.providers.items():
+    deps = []
+
+    for api_str, provider_or_providers in config_providers.items():
         providers_for_api = all_providers[Api(api_str)]
 
         providers = (
@@ -69,25 +65,55 @@ def build_image(build_config: BuildConfig, build_file_path: Path):
         )
 
         for provider in providers:
-            if provider not in providers_for_api:
+            # Providers from BuildConfig and RunConfig are subtly different – not great
+            provider_type = (
+                provider if isinstance(provider, str) else provider.provider_type
+            )
+
+            if provider_type not in providers_for_api:
                 raise ValueError(
                     f"Provider `{provider}` is not available for API `{api_str}`"
                 )
 
-            provider_spec = providers_for_api[provider]
-            package_deps.pip_packages.extend(provider_spec.pip_packages)
+            provider_spec = providers_for_api[provider_type]
+            deps.extend(provider_spec.pip_packages)
             if provider_spec.docker_image:
                 raise ValueError("A stack's dependencies cannot have a docker image")
 
+    normal_deps = []
     special_deps = []
-    deps = []
-    for package in package_deps.pip_packages:
+    for package in deps:
         if "--no-deps" in package or "--index-url" in package:
             special_deps.append(package)
         else:
-            deps.append(package)
-    deps = list(set(deps))
-    special_deps = list(set(special_deps))
+            normal_deps.append(package)
+
+    return list(set(normal_deps)), list(set(special_deps))
+
+
+def print_pip_install_help(providers: Dict[str, List[Provider]]):
+    normal_deps, special_deps = get_provider_dependencies(providers)
+
+    print(
+        f"Please install needed dependencies using the following commands:\n\n\tpip install {' '.join(normal_deps)}"
+    )
+    for special_dep in special_deps:
+        print(f"\tpip install {special_dep}")
+    print()
+
+
+def build_image(build_config: BuildConfig, build_file_path: Path):
+    package_deps = Dependencies(
+        docker_image=build_config.distribution_spec.docker_image or "python:3.10-slim",
+        pip_packages=SERVER_DEPENDENCIES,
+    )
+
+    # extend package dependencies based on providers spec
+    normal_deps, special_deps = get_provider_dependencies(
+        build_config.distribution_spec.providers
+    )
+    package_deps.pip_packages.extend(normal_deps)
+    package_deps.pip_packages.extend(special_deps)
 
     if build_config.image_type == ImageType.docker.value:
         script = pkg_resources.resource_filename(
@@ -99,7 +125,7 @@ def build_image(build_config: BuildConfig, build_file_path: Path):
             package_deps.docker_image,
             str(build_file_path),
             str(BUILDS_BASE_DIR / ImageType.docker.value),
-            " ".join(deps),
+            " ".join(normal_deps),
         ]
     else:
         script = pkg_resources.resource_filename(
@@ -109,7 +135,7 @@ def build_image(build_config: BuildConfig, build_file_path: Path):
             script,
             build_config.name,
             str(build_file_path),
-            " ".join(deps),
+            " ".join(normal_deps),
         ]
 
     if special_deps:

llama_stack/providers/tests/resolver.py

@@ -13,6 +13,7 @@ from typing import Any, Dict, List, Optional
 import yaml
 
 from llama_stack.distribution.datatypes import *  # noqa: F403
+from llama_stack.distribution.build import print_pip_install_help
 from llama_stack.distribution.configure import parse_and_maybe_upgrade_config
 from llama_stack.distribution.distribution import get_provider_registry
 from llama_stack.distribution.request_headers import set_request_provider_data
@@ -37,7 +38,11 @@ async def resolve_impls_for_test_v2(
     sqlite_file = tempfile.NamedTemporaryFile(delete=False, suffix=".db")
     dist_kvstore = await kvstore_impl(SqliteKVStoreConfig(db_path=sqlite_file.name))
     dist_registry = CachedDiskDistributionRegistry(dist_kvstore)
+    try:
         impls = await resolve_impls(run_config, get_provider_registry(), dist_registry)
+    except ModuleNotFoundError as e:
+        print_pip_install_help(providers)
+        raise e
 
     if provider_data:
         set_request_provider_data(
@@ -66,7 +71,11 @@ async def resolve_impls_for_test(api: Api, deps: List[Api] = None):
         providers=chosen,
     )
     run_config = parse_and_maybe_upgrade_config(run_config)
+    try:
         impls = await resolve_impls(run_config, get_provider_registry())
+    except ModuleNotFoundError as e:
+        print_pip_install_help(providers)
+        raise e
 
     if "provider_data" in config_dict:
         provider_id = chosen[api.value][0].provider_id