|
| 1 | +"""User-oriented helper functions.""" |
| 2 | + |
| 3 | +import asyncio |
| 4 | +import warnings |
| 5 | +from contextlib import asynccontextmanager |
| 6 | +from typing import ( |
| 7 | + Any, |
| 8 | + AsyncContextManager, |
| 9 | + AsyncIterator, |
| 10 | + Awaitable, |
| 11 | + Callable, |
| 12 | + Iterable, |
| 13 | + Literal, |
| 14 | + Optional, |
| 15 | + Set, |
| 16 | + Tuple, |
| 17 | + TypeVar, |
| 18 | + Union, |
| 19 | +) |
| 20 | + |
| 21 | +import httpx |
| 22 | +from fastapi import APIRouter |
| 23 | +from starlette.requests import Request |
| 24 | +from starlette.responses import Response |
| 25 | +from starlette.websockets import WebSocket |
| 26 | +from typing_extensions import overload |
| 27 | + |
| 28 | +from fastapi_proxy.core.http import ForwardHttpProxy, ReverseHttpProxy |
| 29 | +from fastapi_proxy.core.websocket import ReverseWebSocketProxy |
| 30 | + |
| 31 | +_HttpProxyTypes = Union[ForwardHttpProxy, ReverseHttpProxy] |
| 32 | +_WebSocketProxyTypes = ReverseWebSocketProxy |
| 33 | + |
| 34 | + |
| 35 | +_T = TypeVar("_T") |
| 36 | +_T_co = TypeVar("_T_co", covariant=True) |
| 37 | +_LifeEventTypes = Callable[[_T_co], Awaitable[None]] |
| 38 | +_APIRouterTypes = TypeVar("_APIRouterTypes", bound=APIRouter) |
| 39 | + |
| 40 | + |
| 41 | +_HttpMethodTypes = Tuple[ |
| 42 | + Literal["get"], |
| 43 | + Literal["post"], |
| 44 | + Literal["put"], |
| 45 | + Literal["delete"], |
| 46 | + Literal["options"], |
| 47 | + Literal["head"], |
| 48 | + Literal["patch"], |
| 49 | + Literal["trace"], |
| 50 | +] |
| 51 | +HTTP_METHODS: _HttpMethodTypes = ( |
| 52 | + "get", |
| 53 | + "post", |
| 54 | + "put", |
| 55 | + "delete", |
| 56 | + "options", |
| 57 | + "head", |
| 58 | + "patch", |
| 59 | + "trace", |
| 60 | +) |
| 61 | + |
| 62 | + |
| 63 | +# https://fastapi.tiangolo.com/zh/advanced/events/ |
| 64 | +def lifespan_event_factory( |
| 65 | + *, |
| 66 | + startup_events: Optional[Iterable[_LifeEventTypes[_T]]] = None, |
| 67 | + shutdown_events: Optional[Iterable[_LifeEventTypes[_T]]] = None, |
| 68 | +) -> Callable[[_T], AsyncContextManager[None]]: |
| 69 | + """Create lifespan event for app. |
| 70 | +
|
| 71 | + When the app startup, await all the startup events. |
| 72 | + When the app shutdown, await all the shutdown events. |
| 73 | +
|
| 74 | + The `app` will pass into the event as the first argument. |
| 75 | +
|
| 76 | + Args: |
| 77 | + startup_events: |
| 78 | + An iterative container, |
| 79 | + where each element is an asynchronous function |
| 80 | + that needs to accept first positional parameter for `app`. |
| 81 | + shutdown_events: |
| 82 | + The same as `startup_events`. |
| 83 | +
|
| 84 | + Returns: |
| 85 | + app lifespan event. |
| 86 | + """ |
| 87 | + |
| 88 | + @asynccontextmanager |
| 89 | + async def lifespan(app: _T) -> AsyncIterator[None]: |
| 90 | + if startup_events is not None: |
| 91 | + await asyncio.gather(*[event(app) for event in startup_events]) |
| 92 | + yield |
| 93 | + if shutdown_events is not None: |
| 94 | + await asyncio.gather(*[event(app) for event in shutdown_events]) |
| 95 | + |
| 96 | + return lifespan |
| 97 | + |
| 98 | + |
| 99 | +def _http_register_router( |
| 100 | + proxy: _HttpProxyTypes, |
| 101 | + router: APIRouter, |
| 102 | + **kwargs: Any, |
| 103 | +) -> None: |
| 104 | + kwargs.pop("path", None) |
| 105 | + |
| 106 | + @router.get("/{path:path}", **kwargs) |
| 107 | + @router.post("/{path:path}", **kwargs) |
| 108 | + @router.put("/{path:path}", **kwargs) |
| 109 | + @router.delete("/{path:path}", **kwargs) |
| 110 | + @router.options("/{path:path}", **kwargs) |
| 111 | + @router.head("/{path:path}", **kwargs) |
| 112 | + @router.patch("/{path:path}", **kwargs) |
| 113 | + @router.trace("/{path:path}", **kwargs) |
| 114 | + async def http_proxy( # pyright: ignore[reportUnusedFunction] |
| 115 | + request: Request, path: str = "" |
| 116 | + ) -> Response: |
| 117 | + """HTTP proxy endpoint.""" |
| 118 | + return await proxy.proxy(request=request, path=path) |
| 119 | + |
| 120 | + |
| 121 | +def _ws_register_router( |
| 122 | + proxy: _WebSocketProxyTypes, |
| 123 | + router: APIRouter, |
| 124 | + **kwargs: Any, |
| 125 | +) -> None: |
| 126 | + kwargs.pop("path", None) |
| 127 | + |
| 128 | + @router.websocket("/{path:path}", **kwargs) |
| 129 | + async def ws_proxy( # pyright: ignore[reportUnusedFunction] |
| 130 | + websocket: WebSocket, path: str = "" |
| 131 | + ) -> Union[Response, Literal[True]]: |
| 132 | + """WebSocket proxy endpoint.""" |
| 133 | + return await proxy.proxy(websocket=websocket, path=path) |
| 134 | + |
| 135 | + |
| 136 | +class RouterHelper: |
| 137 | + """Helper class to register proxy to fastapi router.""" |
| 138 | + |
| 139 | + def __init__(self): |
| 140 | + """Initialize RouterHelper.""" |
| 141 | + self._registered_clients: Set[httpx.AsyncClient] = set() |
| 142 | + self._registered_router_id: Set[int] = set() |
| 143 | + |
| 144 | + @property |
| 145 | + def registered_clients(self) -> Set[httpx.AsyncClient]: |
| 146 | + """The httpx.AsyncClient that has been registered.""" |
| 147 | + return self._registered_clients |
| 148 | + |
| 149 | + @overload |
| 150 | + def register_router( |
| 151 | + self, |
| 152 | + proxy: Union[_HttpProxyTypes, _WebSocketProxyTypes], |
| 153 | + router: Optional[None] = None, |
| 154 | + **endpoint_kwargs: Any, |
| 155 | + ) -> APIRouter: |
| 156 | + ... |
| 157 | + |
| 158 | + @overload |
| 159 | + def register_router( |
| 160 | + self, |
| 161 | + proxy: Union[_HttpProxyTypes, _WebSocketProxyTypes], |
| 162 | + router: _APIRouterTypes, |
| 163 | + **endpoint_kwargs: Any, |
| 164 | + ) -> _APIRouterTypes: |
| 165 | + ... |
| 166 | + |
| 167 | + def register_router( |
| 168 | + self, |
| 169 | + proxy: Union[_HttpProxyTypes, _WebSocketProxyTypes], |
| 170 | + router: Optional[APIRouter] = None, |
| 171 | + **endpoint_kwargs: Any, |
| 172 | + ) -> APIRouter: |
| 173 | + """Register proxy to router. |
| 174 | +
|
| 175 | + Args: |
| 176 | + proxy: The http/websocket proxy to register. |
| 177 | + router: The fastapi router to register. |
| 178 | + If None, will create a new router. |
| 179 | + Usually, you don't need to set the argument, unless you want set some arguments to router. |
| 180 | + Note: the same router can only be registered once. |
| 181 | + endpoint_kwargs: The kwargs to pass to router endpoint(e.g `router.get()`). |
| 182 | +
|
| 183 | + Raises: |
| 184 | + TypeError: If pass a unknown proxy type. |
| 185 | +
|
| 186 | + Returns: |
| 187 | + A fastapi router. |
| 188 | + """ |
| 189 | + router = APIRouter() if router is None else router |
| 190 | + |
| 191 | + # 检查传入的 router 是否已经被注册过，因为 router 不能hash，所以只能用id来判断 |
| 192 | + # HACK: 如果之前记录的router已经被销毁了，新的router可能会有相同的id |
| 193 | + router_id = id(router) |
| 194 | + if id(router) in self._registered_router_id: |
| 195 | + msg = ( |
| 196 | + f"The router {router} (id: {router_id}) has been registered, " |
| 197 | + f"\033[33myou should not use it to register again in any case\033[m." |
| 198 | + ) |
| 199 | + warnings.warn(msg, stacklevel=2) |
| 200 | + else: |
| 201 | + self._registered_router_id.add(router_id) |
| 202 | + |
| 203 | + if isinstance(proxy, (ForwardHttpProxy, ReverseHttpProxy)): |
| 204 | + _http_register_router(proxy, router, **endpoint_kwargs) |
| 205 | + elif isinstance( |
| 206 | + proxy, ReverseWebSocketProxy |
| 207 | + ): # pyright: ignore[reportUnnecessaryIsInstance] |
| 208 | + _ws_register_router(proxy, router, **endpoint_kwargs) |
| 209 | + else: |
| 210 | + msg = ( |
| 211 | + f"Unknown proxy type: {type(proxy)}, " |
| 212 | + f"only support: {_HttpProxyTypes} and {_WebSocketProxyTypes}" |
| 213 | + ) |
| 214 | + raise TypeError(msg) |
| 215 | + self._registered_clients.add(proxy.client) |
| 216 | + return router |
| 217 | + |
| 218 | + def get_lifespan(self) -> Callable[[Any], AsyncContextManager[None]]: |
| 219 | + """The lifespan event for close registered clients.""" |
| 220 | + |
| 221 | + async def shutdown_clients(_: Any): |
| 222 | + await asyncio.gather( |
| 223 | + *[client.aclose() for client in self.registered_clients] |
| 224 | + ) |
| 225 | + |
| 226 | + return lifespan_event_factory(shutdown_events=[shutdown_clients]) |
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