add NVIDIA NIM inference adapter (#355)

# What does this PR do?

this PR adds a basic inference adapter to NVIDIA NIMs

what it does -
 - chat completion api
   - tool calls
   - streaming
   - structured output
   - logprobs
 - support hosted NIM on integrate.api.nvidia.com
 - support downloaded NIM containers

what it does not do -
 - completion api
 - embedding api
 - vision models
 - builtin tools
 - have certainty that sampling strategies are correct

## Feature/Issue validation/testing/test plan

`pytest -s -v --providers inference=nvidia
llama_stack/providers/tests/inference/ --env NVIDIA_API_KEY=...`

all tests should pass. there are pydantic v1 warnings.


## Before submitting
- [ ] This PR fixes a typo or improves the docs (you can dismiss the
other checks if that's the case).
- [x] Did you read the [contributor
guideline](https://github.com/meta-llama/llama-stack/blob/main/CONTRIBUTING.md),
      Pull Request section?
- [ ] Was this discussed/approved via a Github issue? Please add a link
      to it if that's the case.
- [ ] Did you make sure to update the documentation with your changes?
- [x] Did you write any new necessary tests?

Thanks for contributing 🎉!

llama_stack/providers/remote/inference/nvidia/nvidia.py

@@ -0,0 +1,183 @@
+# 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.
+
+import warnings
+from typing import AsyncIterator, List, Optional, Union
+
+from llama_models.datatypes import SamplingParams
+from llama_models.llama3.api.datatypes import (
+    InterleavedTextMedia,
+    Message,
+    ToolChoice,
+    ToolDefinition,
+    ToolPromptFormat,
+)
+from llama_models.sku_list import CoreModelId
+from openai import APIConnectionError, AsyncOpenAI
+
+from llama_stack.apis.inference import (
+    ChatCompletionRequest,
+    ChatCompletionResponse,
+    ChatCompletionResponseStreamChunk,
+    CompletionResponse,
+    CompletionResponseStreamChunk,
+    EmbeddingsResponse,
+    Inference,
+    LogProbConfig,
+    ResponseFormat,
+)
+from llama_stack.providers.utils.inference.model_registry import (
+    build_model_alias,
+    ModelRegistryHelper,
+)
+
+from . import NVIDIAConfig
+from .openai_utils import (
+    convert_chat_completion_request,
+    convert_openai_chat_completion_choice,
+    convert_openai_chat_completion_stream,
+)
+from .utils import _is_nvidia_hosted, check_health
+
+_MODEL_ALIASES = [
+    build_model_alias(
+        "meta/llama3-8b-instruct",
+        CoreModelId.llama3_8b_instruct.value,
+    ),
+    build_model_alias(
+        "meta/llama3-70b-instruct",
+        CoreModelId.llama3_70b_instruct.value,
+    ),
+    build_model_alias(
+        "meta/llama-3.1-8b-instruct",
+        CoreModelId.llama3_1_8b_instruct.value,
+    ),
+    build_model_alias(
+        "meta/llama-3.1-70b-instruct",
+        CoreModelId.llama3_1_70b_instruct.value,
+    ),
+    build_model_alias(
+        "meta/llama-3.1-405b-instruct",
+        CoreModelId.llama3_1_405b_instruct.value,
+    ),
+    build_model_alias(
+        "meta/llama-3.2-1b-instruct",
+        CoreModelId.llama3_2_1b_instruct.value,
+    ),
+    build_model_alias(
+        "meta/llama-3.2-3b-instruct",
+        CoreModelId.llama3_2_3b_instruct.value,
+    ),
+    build_model_alias(
+        "meta/llama-3.2-11b-vision-instruct",
+        CoreModelId.llama3_2_11b_vision_instruct.value,
+    ),
+    build_model_alias(
+        "meta/llama-3.2-90b-vision-instruct",
+        CoreModelId.llama3_2_90b_vision_instruct.value,
+    ),
+    # TODO(mf): how do we handle Nemotron models?
+    # "Llama3.1-Nemotron-51B-Instruct" -> "meta/llama-3.1-nemotron-51b-instruct",
+]
+
+
+class NVIDIAInferenceAdapter(Inference, ModelRegistryHelper):
+    def __init__(self, config: NVIDIAConfig) -> None:
+        # TODO(mf): filter by available models
+        ModelRegistryHelper.__init__(self, model_aliases=_MODEL_ALIASES)
+
+        print(f"Initializing NVIDIAInferenceAdapter({config.url})...")
+
+        if _is_nvidia_hosted(config):
+            if not config.api_key:
+                raise RuntimeError(
+                    "API key is required for hosted NVIDIA NIM. "
+                    "Either provide an API key or use a self-hosted NIM."
+                )
+        # elif self._config.api_key:
+        #
+        # we don't raise this warning because a user may have deployed their
+        # self-hosted NIM with an API key requirement.
+        #
+        #     warnings.warn(
+        #         "API key is not required for self-hosted NVIDIA NIM. "
+        #         "Consider removing the api_key from the configuration."
+        #     )
+
+        self._config = config
+        # make sure the client lives longer than any async calls
+        self._client = AsyncOpenAI(
+            base_url=f"{self._config.url}/v1",
+            api_key=self._config.api_key or "NO KEY",
+            timeout=self._config.timeout,
+        )
+
+    def completion(
+        self,
+        model_id: str,
+        content: InterleavedTextMedia,
+        sampling_params: Optional[SamplingParams] = SamplingParams(),
+        response_format: Optional[ResponseFormat] = None,
+        stream: Optional[bool] = False,
+        logprobs: Optional[LogProbConfig] = None,
+    ) -> Union[CompletionResponse, AsyncIterator[CompletionResponseStreamChunk]]:
+        raise NotImplementedError()
+
+    async def embeddings(
+        self,
+        model_id: str,
+        contents: List[InterleavedTextMedia],
+    ) -> EmbeddingsResponse:
+        raise NotImplementedError()
+
+    async def chat_completion(
+        self,
+        model_id: str,
+        messages: List[Message],
+        sampling_params: Optional[SamplingParams] = SamplingParams(),
+        response_format: Optional[ResponseFormat] = None,
+        tools: Optional[List[ToolDefinition]] = None,
+        tool_choice: Optional[ToolChoice] = ToolChoice.auto,
+        tool_prompt_format: Optional[
+            ToolPromptFormat
+        ] = None,  # API default is ToolPromptFormat.json, we default to None to detect user input
+        stream: Optional[bool] = False,
+        logprobs: Optional[LogProbConfig] = None,
+    ) -> Union[
+        ChatCompletionResponse, AsyncIterator[ChatCompletionResponseStreamChunk]
+    ]:
+        if tool_prompt_format:
+            warnings.warn("tool_prompt_format is not supported by NVIDIA NIM, ignoring")
+
+        await check_health(self._config)  # this raises errors
+
+        request = convert_chat_completion_request(
+            request=ChatCompletionRequest(
+                model=self.get_provider_model_id(model_id),
+                messages=messages,
+                sampling_params=sampling_params,
+                response_format=response_format,
+                tools=tools,
+                tool_choice=tool_choice,
+                tool_prompt_format=tool_prompt_format,
+                stream=stream,
+                logprobs=logprobs,
+            ),
+            n=1,
+        )
+
+        try:
+            response = await self._client.chat.completions.create(**request)
+        except APIConnectionError as e:
+            raise ConnectionError(
+                f"Failed to connect to NVIDIA NIM at {self._config.url}: {e}"
+            ) from e
+
+        if stream:
+            return convert_openai_chat_completion_stream(response)
+        else:
+            # we pass n=1 to get only one completion
+            return convert_openai_chat_completion_choice(response.choices[0])