chore: use empty SecretStr values as default

Better than using SecretStr | None so we centralize the null handling.

Signed-off-by: Sébastien Han <seb@redhat.com>

llama_stack/providers/remote/inference/vllm/__init__.py

@@ -4,13 +4,16 @@
 # This source code is licensed under the terms described in the LICENSE file in
 # the root directory of this source tree.
 
-from pydantic import BaseModel
+from pydantic import BaseModel, Field, SecretStr
 
 from .config import VLLMInferenceAdapterConfig
 
 
 class VLLMProviderDataValidator(BaseModel):
-    vllm_api_token: str | None = None
+    vllm_api_token: SecretStr = Field(
+        default=SecretStr(""),
+        description="API token for vLLM models",
+    )
 
 
 async def get_adapter_impl(config: VLLMInferenceAdapterConfig, _deps):

llama_stack/providers/remote/inference/vllm/config.py

@@ -21,8 +21,8 @@ class VLLMInferenceAdapterConfig(BaseModel):
         default=4096,
         description="Maximum number of tokens to generate.",
     )
-    api_token: SecretStr | None = Field(
-        default=SecretStr("fake"),
+    api_token: SecretStr = Field(
+        default=SecretStr(""),
         description="The API token",
     )
     tls_verify: bool | str = Field(

llama_stack/providers/remote/inference/vllm/vllm.py

@@ -294,7 +294,7 @@ class VLLMInferenceAdapter(OpenAIMixin, LiteLLMOpenAIMixin, Inference, ModelsPro
             self,
             model_entries=build_hf_repo_model_entries(),
             litellm_provider_name="vllm",
-            api_key_from_config=config.api_token.get_secret_value(),
+            api_key_from_config=config.api_token,
             provider_data_api_key_field="vllm_api_token",
             openai_compat_api_base=config.url,
         )