|
1 | | -"""httpx transport that routes OpenAI-compatible requests through a Llama Stack library client.""" |
| 1 | +"""httpx transports for Llama Stack library and server modes.""" |
2 | 2 |
|
3 | 3 | from __future__ import annotations as _annotations |
4 | 4 |
|
5 | 5 | import json |
6 | | -from collections.abc import AsyncGenerator, AsyncIterator |
| 6 | +from collections.abc import AsyncGenerator, AsyncIterator, Mapping |
7 | 7 | from typing import Any |
8 | 8 |
|
9 | 9 | import httpx |
|
19 | 19 | from llama_stack.core.utils.context import preserve_contexts_async_generator |
20 | 20 | from starlette.responses import StreamingResponse |
21 | 21 |
|
| 22 | +_PROVIDER_DATA_HEADER_KEYS = ( |
| 23 | + "X-LlamaStack-Provider-Data", |
| 24 | + "x-llamastack-provider-data", |
| 25 | +) |
| 26 | + |
| 27 | + |
| 28 | +def decode_request_headers(request: httpx.Request) -> dict[str, str]: |
| 29 | + """Decode raw httpx request headers into a string-to-string mapping. |
| 30 | +
|
| 31 | + Args: |
| 32 | + request: The outgoing httpx request. |
| 33 | +
|
| 34 | + Returns: |
| 35 | + Request headers with byte keys and values decoded to UTF-8 strings. |
| 36 | + """ |
| 37 | + return { |
| 38 | + k.decode("utf-8") if isinstance(k, bytes) else k: ( |
| 39 | + v.decode("utf-8") if isinstance(v, bytes) else v |
| 40 | + ) |
| 41 | + for k, v in request.headers.raw |
| 42 | + } |
| 43 | + |
| 44 | + |
| 45 | +def inject_provider_data_into_headers( |
| 46 | + headers: Mapping[str, str], |
| 47 | + provider_data: Mapping[str, Any] | None, |
| 48 | +) -> dict[str, str]: |
| 49 | + """Add ``X-LlamaStack-Provider-Data`` when provider data is configured. |
| 50 | +
|
| 51 | + Args: |
| 52 | + headers: Existing request headers. |
| 53 | + provider_data: Provider credentials/metadata to forward to Llama Stack. |
| 54 | +
|
| 55 | + Returns: |
| 56 | + Headers with provider data injected when absent from the request. |
| 57 | + """ |
| 58 | + if not provider_data: |
| 59 | + return dict(headers) |
| 60 | + if any(key in headers for key in _PROVIDER_DATA_HEADER_KEYS): |
| 61 | + return dict(headers) |
| 62 | + result = dict(headers) |
| 63 | + result["X-LlamaStack-Provider-Data"] = json.dumps(provider_data) |
| 64 | + return result |
| 65 | + |
| 66 | + |
| 67 | +def request_with_provider_data_headers( |
| 68 | + request: httpx.Request, |
| 69 | + provider_data: Mapping[str, Any] | None, |
| 70 | +) -> httpx.Request: |
| 71 | + """Return a request copy with provider data headers injected when needed. |
| 72 | +
|
| 73 | + Args: |
| 74 | + request: The outgoing httpx request. |
| 75 | + provider_data: Provider credentials/metadata to forward to Llama Stack. |
| 76 | +
|
| 77 | + Returns: |
| 78 | + The original request, or a copy with provider data headers added. |
| 79 | + """ |
| 80 | + headers = inject_provider_data_into_headers( |
| 81 | + decode_request_headers(request), |
| 82 | + provider_data, |
| 83 | + ) |
| 84 | + if headers == decode_request_headers(request): |
| 85 | + return request |
| 86 | + return httpx.Request( |
| 87 | + method=request.method, |
| 88 | + url=request.url, |
| 89 | + headers=headers, |
| 90 | + content=request.content, |
| 91 | + extensions=request.extensions, |
| 92 | + ) |
| 93 | + |
| 94 | + |
| 95 | +def wrap_http_client_with_provider_data( |
| 96 | + http_client: httpx.AsyncClient, |
| 97 | + provider_data: Mapping[str, Any] | None, |
| 98 | +) -> httpx.AsyncClient: |
| 99 | + """Wrap an httpx client so outbound requests include provider data headers. |
| 100 | +
|
| 101 | + Args: |
| 102 | + http_client: The client whose transport will be wrapped. |
| 103 | + provider_data: Provider credentials/metadata to forward to Llama Stack. |
| 104 | +
|
| 105 | + Returns: |
| 106 | + The original client when ``provider_data`` is empty, otherwise a new |
| 107 | + client with a wrapping transport. |
| 108 | + """ |
| 109 | + if not provider_data: |
| 110 | + return http_client |
| 111 | + |
| 112 | + transport = LlamaStackServerTransport( |
| 113 | + http_client._transport, # pylint: disable=protected-access |
| 114 | + provider_data=provider_data, |
| 115 | + ) |
| 116 | + return httpx.AsyncClient( |
| 117 | + transport=transport, |
| 118 | + timeout=http_client.timeout, |
| 119 | + follow_redirects=http_client.follow_redirects, |
| 120 | + ) |
| 121 | + |
| 122 | + |
| 123 | +class LlamaStackServerTransport(httpx.AsyncBaseTransport): |
| 124 | + """httpx transport that injects provider data headers before delegating over HTTP.""" |
| 125 | + |
| 126 | + def __init__( |
| 127 | + self, |
| 128 | + transport: httpx.AsyncBaseTransport, |
| 129 | + *, |
| 130 | + provider_data: Mapping[str, Any] | None = None, |
| 131 | + ) -> None: |
| 132 | + """Initialize the wrapping transport. |
| 133 | +
|
| 134 | + Args: |
| 135 | + transport: The underlying transport used for real HTTP requests. |
| 136 | + provider_data: Provider credentials/metadata to forward to Llama Stack. |
| 137 | + """ |
| 138 | + self._transport = transport |
| 139 | + self._provider_data = provider_data |
| 140 | + |
| 141 | + async def handle_async_request(self, request: httpx.Request) -> httpx.Response: |
| 142 | + """Inject provider data headers and delegate to the wrapped transport. |
| 143 | +
|
| 144 | + Args: |
| 145 | + request: The outgoing httpx request. |
| 146 | +
|
| 147 | + Returns: |
| 148 | + The response from the wrapped transport. |
| 149 | + """ |
| 150 | + request = request_with_provider_data_headers(request, self._provider_data) |
| 151 | + return await self._transport.handle_async_request(request) |
| 152 | + |
| 153 | + async def aclose(self) -> None: |
| 154 | + """Close the wrapped transport.""" |
| 155 | + await self._transport.aclose() |
| 156 | + |
22 | 157 |
|
23 | 158 | class _AsyncByteStream(httpx.AsyncByteStream): |
24 | 159 | """Wraps an async byte generator as an httpx AsyncByteStream.""" |
@@ -80,19 +215,10 @@ async def handle_async_request(self, request: httpx.Request) -> httpx.Response: |
80 | 215 |
|
81 | 216 | body = json.loads(request.content) if request.content else {} |
82 | 217 |
|
83 | | - headers: dict[str, str] = { |
84 | | - k.decode("utf-8") if isinstance(k, bytes) else k: ( |
85 | | - v.decode("utf-8") if isinstance(v, bytes) else v |
86 | | - ) |
87 | | - for k, v in request.headers.raw |
88 | | - } |
89 | | - |
90 | | - if self._client.provider_data: |
91 | | - keys = ["X-LlamaStack-Provider-Data", "x-llamastack-provider-data"] |
92 | | - if all(key not in headers for key in keys): |
93 | | - headers["X-LlamaStack-Provider-Data"] = json.dumps( |
94 | | - self._client.provider_data |
95 | | - ) |
| 218 | + headers = inject_provider_data_into_headers( |
| 219 | + decode_request_headers(request), |
| 220 | + self._client.provider_data, |
| 221 | + ) |
96 | 222 |
|
97 | 223 | with request_provider_data_context(headers): |
98 | 224 | is_stream = body.get("stream", False) |
|
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