Merge pull request #680 from python-openapi/feature/starlette-middleware

Starlette middleware

Author: p1c2u

docs/integrations.rst

@@ -402,6 +402,57 @@ Starlette
 
 This section describes integration with `Starlette <https://www.starlette.io>`__  ASGI framework.
 
+Middleware
+~~~~~~~~~~
+
+Starlette can be integrated by middleware. Add ``StarletteOpenAPIMiddleware`` with ``spec`` to your ``middleware`` list.
+
+.. code-block:: python
+  :emphasize-lines: 1,6
+
+    from openapi_core.contrib.starlette.middlewares import StarletteOpenAPIMiddleware
+    from starlette.applications import Starlette
+    from starlette.middleware import Middleware
+
+    middleware = [
+        Middleware(StarletteOpenAPIMiddleware, spec=spec),
+    ]
+
+    app = Starlette(
+        # ...
+        middleware=middleware,
+    )
+
+After that you have access to unmarshal result object with all validated request data from endpoint through ``openapi`` key of request's scope directory.
+
+.. code-block:: python
+
+    async def get_endpoint(req):
+       # get parameters object with path, query, cookies and headers parameters
+       validated_params = req.scope["openapi"].parameters
+       # or specific location parameters
+       validated_path_params = req.scope["openapi"].parameters.path
+
+       # get body
+       validated_body = req.scope["openapi"].body
+
+       # get security data
+       validated_security = req.scope["openapi"].security
+
+You can skip response validation process: by setting ``response_cls`` to ``None``
+
+.. code-block:: python
+  :emphasize-lines: 2
+
+    middleware = [
+        Middleware(StarletteOpenAPIMiddleware, spec=spec, response_cls=None),
+    ]
+
+    app = Starlette(
+        # ...
+        middleware=middleware,
+    )
+
 Low level
 ~~~~~~~~~
 

openapi_core/contrib/starlette/handlers.py

@@ -0,0 +1,66 @@
+"""OpenAPI core contrib starlette handlers module"""
+from typing import Any
+from typing import Callable
+from typing import Dict
+from typing import Iterable
+from typing import Optional
+from typing import Type
+
+from starlette.middleware.base import RequestResponseEndpoint
+from starlette.requests import Request
+from starlette.responses import JSONResponse
+from starlette.responses import Response
+
+from openapi_core.templating.media_types.exceptions import MediaTypeNotFound
+from openapi_core.templating.paths.exceptions import OperationNotFound
+from openapi_core.templating.paths.exceptions import PathNotFound
+from openapi_core.templating.paths.exceptions import ServerNotFound
+from openapi_core.templating.security.exceptions import SecurityNotFound
+from openapi_core.unmarshalling.request.datatypes import RequestUnmarshalResult
+
+
+class StarletteOpenAPIErrorsHandler:
+    OPENAPI_ERROR_STATUS: Dict[Type[BaseException], int] = {
+        ServerNotFound: 400,
+        SecurityNotFound: 403,
+        OperationNotFound: 405,
+        PathNotFound: 404,
+        MediaTypeNotFound: 415,
+    }
+
+    def __call__(
+        self,
+        errors: Iterable[Exception],
+    ) -> JSONResponse:
+        data_errors = [self.format_openapi_error(err) for err in errors]
+        data = {
+            "errors": data_errors,
+        }
+        data_error_max = max(data_errors, key=self.get_error_status)
+        return JSONResponse(data, status_code=data_error_max["status"])
+
+    @classmethod
+    def format_openapi_error(cls, error: BaseException) -> Dict[str, Any]:
+        if error.__cause__ is not None:
+            error = error.__cause__
+        return {
+            "title": str(error),
+            "status": cls.OPENAPI_ERROR_STATUS.get(error.__class__, 400),
+            "type": str(type(error)),
+        }
+
+    @classmethod
+    def get_error_status(cls, error: Dict[str, Any]) -> str:
+        return str(error["status"])
+
+
+class StarletteOpenAPIValidRequestHandler:
+    def __init__(self, request: Request, call_next: RequestResponseEndpoint):
+        self.request = request
+        self.call_next = call_next
+
+    async def __call__(
+        self, request_unmarshal_result: RequestUnmarshalResult
+    ) -> Response:
+        self.request.scope["openapi"] = request_unmarshal_result
+        return await self.call_next(self.request)

openapi_core/contrib/starlette/middlewares.py

@@ -0,0 +1,75 @@
+"""OpenAPI core contrib starlette middlewares module"""
+from typing import Callable
+
+from aioitertools.builtins import list as alist
+from aioitertools.itertools import tee as atee
+from jsonschema_path import SchemaPath
+from starlette.middleware.base import BaseHTTPMiddleware
+from starlette.middleware.base import RequestResponseEndpoint
+from starlette.requests import Request
+from starlette.responses import Response
+from starlette.responses import StreamingResponse
+from starlette.types import ASGIApp
+
+from openapi_core.contrib.starlette.handlers import (
+    StarletteOpenAPIErrorsHandler,
+)
+from openapi_core.contrib.starlette.handlers import (
+    StarletteOpenAPIValidRequestHandler,
+)
+from openapi_core.contrib.starlette.requests import StarletteOpenAPIRequest
+from openapi_core.contrib.starlette.responses import StarletteOpenAPIResponse
+from openapi_core.unmarshalling.processors import AsyncUnmarshallingProcessor
+
+
+class StarletteOpenAPIMiddleware(
+    BaseHTTPMiddleware, AsyncUnmarshallingProcessor[Request, Response]
+):
+    request_cls = StarletteOpenAPIRequest
+    response_cls = StarletteOpenAPIResponse
+    valid_request_handler_cls = StarletteOpenAPIValidRequestHandler
+    errors_handler = StarletteOpenAPIErrorsHandler()
+
+    def __init__(self, app: ASGIApp, spec: SchemaPath):
+        BaseHTTPMiddleware.__init__(self, app)
+        AsyncUnmarshallingProcessor.__init__(self, spec)
+
+    async def dispatch(
+        self, request: Request, call_next: RequestResponseEndpoint
+    ) -> Response:
+        valid_request_handler = self.valid_request_handler_cls(
+            request, call_next
+        )
+        response = await self.handle_request(
+            request, valid_request_handler, self.errors_handler
+        )
+        return await self.handle_response(
+            request, response, self.errors_handler
+        )
+
+    async def _get_openapi_request(
+        self, request: Request
+    ) -> StarletteOpenAPIRequest:
+        body = await request.body()
+        return self.request_cls(request, body)
+
+    async def _get_openapi_response(
+        self, response: Response
+    ) -> StarletteOpenAPIResponse:
+        assert self.response_cls is not None
+        data = None
+        if isinstance(response, StreamingResponse):
+            body_iter1, body_iter2 = atee(response.body_iterator)
+            response.body_iterator = body_iter2
+            data = b"".join(
+                [
+                    chunk.encode(response.charset)
+                    if not isinstance(chunk, bytes)
+                    else chunk
+                    async for chunk in body_iter1
+                ]
+            )
+        return self.response_cls(response, data=data)
+
+    def _validate_response(self) -> bool:
+        return self.response_cls is not None

openapi_core/contrib/starlette/requests.py

@@ -8,7 +8,7 @@
 
 
 class StarletteOpenAPIRequest:
-    def __init__(self, request: Request):
+    def __init__(self, request: Request, body: Optional[bytes] = None):
         if not isinstance(request, Request):
             raise TypeError(f"'request' argument is not type of {Request}")
         self.request = request
@@ -19,7 +19,7 @@ def __init__(self, request: Request):
             cookie=self.request.cookies,
         )
 
-        self._get_body = AsyncToSync(self.request.body, force_new_loop=True)
+        self._body = body
 
     @property
     def host_url(self) -> str:
@@ -35,13 +35,7 @@ def method(self) -> str:
 
     @property
     def body(self) -> Optional[bytes]:
-        body = self._get_body()
-        if body is None:
-            return None
-        if isinstance(body, bytes):
-            return body
-        assert isinstance(body, str)
-        return body.encode("utf-8")
+        return self._body
 
     @property
     def content_type(self) -> str:

openapi_core/typing.py

@@ -1,3 +1,4 @@
+from typing import Awaitable
 from typing import Callable
 from typing import Iterable
 from typing import TypeVar
@@ -11,3 +12,6 @@
 
 ErrorsHandlerCallable = Callable[[Iterable[Exception]], ResponseType]
 ValidRequestHandlerCallable = Callable[[RequestUnmarshalResult], ResponseType]
+AsyncValidRequestHandlerCallable = Callable[
+    [RequestUnmarshalResult], Awaitable[ResponseType]
+]

openapi_core/unmarshalling/processors.py

@@ -8,6 +8,7 @@
 from openapi_core.protocols import Request
 from openapi_core.protocols import Response
 from openapi_core.shortcuts import get_classes
+from openapi_core.typing import AsyncValidRequestHandlerCallable
 from openapi_core.typing import ErrorsHandlerCallable
 from openapi_core.typing import RequestType
 from openapi_core.typing import ResponseType
@@ -90,3 +91,74 @@ def handle_response(
         if response_unmarshal_result.errors:
             return errors_handler(response_unmarshal_result.errors)
         return response
+
+
+class AsyncUnmarshallingProcessor(Generic[RequestType, ResponseType]):
+    def __init__(
+        self,
+        spec: SchemaPath,
+        request_unmarshaller_cls: Optional[RequestUnmarshallerType] = None,
+        response_unmarshaller_cls: Optional[ResponseUnmarshallerType] = None,
+        **unmarshaller_kwargs: Any,
+    ):
+        if (
+            request_unmarshaller_cls is None
+            or response_unmarshaller_cls is None
+        ):
+            classes = get_classes(spec)
+            if request_unmarshaller_cls is None:
+                request_unmarshaller_cls = classes.request_unmarshaller_cls
+            if response_unmarshaller_cls is None:
+                response_unmarshaller_cls = classes.response_unmarshaller_cls
+
+        self.request_processor = RequestUnmarshallingProcessor(
+            spec,
+            request_unmarshaller_cls,
+            **unmarshaller_kwargs,
+        )
+        self.response_processor = ResponseUnmarshallingProcessor(
+            spec,
+            response_unmarshaller_cls,
+            **unmarshaller_kwargs,
+        )
+
+    async def _get_openapi_request(self, request: RequestType) -> Request:
+        raise NotImplementedError
+
+    async def _get_openapi_response(self, response: ResponseType) -> Response:
+        raise NotImplementedError
+
+    def _validate_response(self) -> bool:
+        raise NotImplementedError
+
+    async def handle_request(
+        self,
+        request: RequestType,
+        valid_handler: AsyncValidRequestHandlerCallable[ResponseType],
+        errors_handler: ErrorsHandlerCallable[ResponseType],
+    ) -> ResponseType:
+        openapi_request = await self._get_openapi_request(request)
+        request_unmarshal_result = self.request_processor.process(
+            openapi_request
+        )
+        if request_unmarshal_result.errors:
+            return errors_handler(request_unmarshal_result.errors)
+        result = await valid_handler(request_unmarshal_result)
+        return result
+
+    async def handle_response(
+        self,
+        request: RequestType,
+        response: ResponseType,
+        errors_handler: ErrorsHandlerCallable[ResponseType],
+    ) -> ResponseType:
+        if not self._validate_response():
+            return response
+        openapi_request = await self._get_openapi_request(request)
+        openapi_response = await self._get_openapi_response(response)
+        response_unmarshal_result = self.response_processor.process(
+            openapi_request, openapi_response
+        )
+        if response_unmarshal_result.errors:
+            return errors_handler(response_unmarshal_result.errors)
+        return response