Source code for

import argparse
import json
from typing import TYPE_CHECKING, Any, AsyncIterator, Dict, List, Optional

from jina.clients.request import request_generator
from jina.enums import DataInputType, WebsocketSubProtocols
from jina.excepts import InternalNetworkError
from jina.importer import ImportExtensions
from jina.logging.logger import JinaLogger
from import DataRequest

    from prometheus_client import CollectorRegistry

    from jina.serve.networking import GrpcConnectionPool
    from jina.serve.runtimes.gateway.graph.topology_graph import TopologyGraph

def _fits_ws_close_msg(msg: str):
    # Websocket close messages ('reasons') can't exceed 123 bytes:
    ws_closing_msg_max_len = 123
    return len(msg.encode('utf-8')) <= ws_closing_msg_max_len

[docs]def get_fastapi_app( args: 'argparse.Namespace', topology_graph: 'TopologyGraph', connection_pool: 'GrpcConnectionPool', logger: 'JinaLogger', metrics_registry: Optional['CollectorRegistry'] = None, ): """ Get the app from FastAPI as the Websocket interface. :param args: passed arguments. :param topology_graph: topology graph that manages the logic of sending to the proper executors. :param connection_pool: Connection Pool to handle multiple replicas and sending to different of them :param logger: Jina logger. :param metrics_registry: optional metrics registry for prometheus used if we need to expose metrics from the executor or from the data request handler :return: fastapi app """ from jina.serve.runtimes.gateway.http.models import JinaEndpointRequestModel with ImportExtensions(required=True): from fastapi import FastAPI, Response, WebSocket, WebSocketDisconnect, status class ConnectionManager: def __init__(self): self.active_connections: List[WebSocket] = [] self.protocol_dict: Dict[str, WebsocketSubProtocols] = {} def get_client(self, websocket: WebSocket) -> str: return f'{}:{websocket.client.port}' def get_subprotocol(self, headers: Dict): try: if 'sec-websocket-protocol' in headers: subprotocol = WebsocketSubProtocols( headers['sec-websocket-protocol'] ) elif b'sec-websocket-protocol' in headers: subprotocol = WebsocketSubProtocols( headers[b'sec-websocket-protocol'].decode() ) else: subprotocol = WebsocketSubProtocols.JSON logger.debug( f'no protocol headers passed. Choosing default subprotocol {WebsocketSubProtocols.JSON}' ) except Exception as e: logger.debug( f'got an exception while setting user\'s subprotocol, defaulting to JSON {e}' ) subprotocol = WebsocketSubProtocols.JSON return subprotocol async def connect(self, websocket: WebSocket): await websocket.accept() subprotocol = self.get_subprotocol(dict(websocket.scope['headers'])) f'client {}:{websocket.client.port} connected ' f'with subprotocol {subprotocol}' ) self.active_connections.append(websocket) self.protocol_dict[self.get_client(websocket)] = subprotocol def disconnect(self, websocket: WebSocket): self.protocol_dict.pop(self.get_client(websocket)) self.active_connections.remove(websocket) async def receive(self, websocket: WebSocket) -> Any: subprotocol = self.protocol_dict[self.get_client(websocket)] if subprotocol == WebsocketSubProtocols.JSON: return await websocket.receive_json(mode='text') elif subprotocol == WebsocketSubProtocols.BYTES: return await websocket.receive_bytes() async def iter(self, websocket: WebSocket) -> AsyncIterator[Any]: try: while True: yield await self.receive(websocket) except WebSocketDisconnect: pass async def send(self, websocket: WebSocket, data: DataRequest) -> None: subprotocol = self.protocol_dict[self.get_client(websocket)] if subprotocol == WebsocketSubProtocols.JSON: return await websocket.send_json(data.to_dict(), mode='text') elif subprotocol == WebsocketSubProtocols.BYTES: return await websocket.send_bytes(data.to_bytes()) manager = ConnectionManager() app = FastAPI() from jina.serve.runtimes.gateway.request_handling import RequestHandler from import RequestStreamer request_handler = RequestHandler(metrics_registry, streamer = RequestStreamer( args=args, request_handler=request_handler.handle_request( graph=topology_graph, connection_pool=connection_pool ), result_handler=request_handler.handle_result(), ) streamer.Call = @app.on_event('shutdown') async def _shutdown(): await connection_pool.close() @app.websocket('/') async def websocket_endpoint( websocket: WebSocket, response: Response ): # 'response' is a FastAPI response, not a Jina response await manager.connect(websocket) async def req_iter(): async for request in manager.iter(websocket): if isinstance(request, dict): if request == {}: break else: # NOTE: Helps in converting camelCase to snake_case req_generator_input = JinaEndpointRequestModel(**request).dict() req_generator_input['data_type'] = DataInputType.DICT if request['data'] is not None and 'docs' in request['data']: req_generator_input['data'] = req_generator_input['data'][ 'docs' ] # you can't do `yield from` inside an async function for data_request in request_generator(**req_generator_input): yield data_request elif isinstance(request, bytes): if request == bytes(True): break else: yield DataRequest(request) try: async for msg in await manager.send(websocket, msg) except InternalNetworkError as err: manager.disconnect(websocket) msg = ( err.details() if _fits_ws_close_msg(err.details()) # some messages are too long else f'Network error while connecting to deployment at {err.dest_addr}. It may be down.' ) await websocket.close(code=status.WS_1011_INTERNAL_ERROR, reason=msg) except WebSocketDisconnect:'Client successfully disconnected from server') manager.disconnect(websocket) return app