import os import sys import asyncio from engineio.static_files import get_static_file class ASGIApp: """ASGI application middleware for Engine.IO. This middleware dispatches traffic to an Engine.IO application. It can also serve a list of static files to the client, or forward unrelated HTTP traffic to another ASGI application. :param engineio_server: The Engine.IO server. Must be an instance of the ``engineio.AsyncServer`` class. :param static_files: A dictionary with static file mapping rules. See the documentation for details on this argument. :param other_asgi_app: A separate ASGI app that receives all other traffic. :param engineio_path: The endpoint where the Engine.IO application should be installed. The default value is appropriate for most cases. :param on_startup: function to be called on application startup; can be coroutine :param on_shutdown: function to be called on application shutdown; can be coroutine Example usage:: import engineio import uvicorn eio = engineio.AsyncServer() app = engineio.ASGIApp(eio, static_files={ '/': {'content_type': 'text/html', 'filename': 'index.html'}, '/index.html': {'content_type': 'text/html', 'filename': 'index.html'}, }) uvicorn.run(app, '127.0.0.1', 5000) """ def __init__(self, engineio_server, other_asgi_app=None, static_files=None, engineio_path='engine.io', on_startup=None, on_shutdown=None): self.engineio_server = engineio_server self.other_asgi_app = other_asgi_app self.engineio_path = engineio_path if not self.engineio_path.startswith('/'): self.engineio_path = '/' + self.engineio_path if not self.engineio_path.endswith('/'): self.engineio_path += '/' self.static_files = static_files or {} self.on_startup = on_startup self.on_shutdown = on_shutdown async def __call__(self, scope, receive, send): if scope['type'] in ['http', 'websocket'] and \ scope['path'].startswith(self.engineio_path): await self.engineio_server.handle_request(scope, receive, send) else: static_file = get_static_file(scope['path'], self.static_files) \ if scope['type'] == 'http' and self.static_files else None if scope['type'] == 'lifespan': await self.lifespan(scope, receive, send) elif static_file and os.path.exists(static_file['filename']): await self.serve_static_file(static_file, receive, send) elif self.other_asgi_app is not None: await self.other_asgi_app(scope, receive, send) else: await self.not_found(receive, send) async def serve_static_file(self, static_file, receive, send): # pragma: no cover event = await receive() if event['type'] == 'http.request': with open(static_file['filename'], 'rb') as f: payload = f.read() await send({'type': 'http.response.start', 'status': 200, 'headers': [(b'Content-Type', static_file[ 'content_type'].encode('utf-8'))]}) await send({'type': 'http.response.body', 'body': payload}) async def lifespan(self, scope, receive, send): if self.other_asgi_app is not None and self.on_startup is None and \ self.on_shutdown is None: # let the other ASGI app handle lifespan events await self.other_asgi_app(scope, receive, send) return while True: event = await receive() if event['type'] == 'lifespan.startup': if self.on_startup: try: await self.on_startup() \ if asyncio.iscoroutinefunction(self.on_startup) \ else self.on_startup() except: await send({'type': 'lifespan.startup.failed'}) return await send({'type': 'lifespan.startup.complete'}) elif event['type'] == 'lifespan.shutdown': if self.on_shutdown: try: await self.on_shutdown() \ if asyncio.iscoroutinefunction(self.on_shutdown) \ else self.on_shutdown() except: await send({'type': 'lifespan.shutdown.failed'}) return await send({'type': 'lifespan.shutdown.complete'}) return async def not_found(self, receive, send): """Return a 404 Not Found error to the client.""" await send({'type': 'http.response.start', 'status': 404, 'headers': [(b'Content-Type', b'text/plain')]}) await send({'type': 'http.response.body', 'body': b'Not Found'}) async def translate_request(scope, receive, send): class AwaitablePayload(object): # pragma: no cover def __init__(self, payload): self.payload = payload or b'' async def read(self, length=None): if length is None: r = self.payload self.payload = b'' else: r = self.payload[:length] self.payload = self.payload[length:] return r event = await receive() payload = b'' if event['type'] == 'http.request': payload += event.get('body') or b'' while event.get('more_body'): event = await receive() if event['type'] == 'http.request': payload += event.get('body') or b'' elif event['type'] == 'websocket.connect': pass else: return {} raw_uri = scope['path'].encode('utf-8') if 'query_string' in scope and scope['query_string']: raw_uri += b'?' + scope['query_string'] environ = { 'wsgi.input': AwaitablePayload(payload), 'wsgi.errors': sys.stderr, 'wsgi.version': (1, 0), 'wsgi.async': True, 'wsgi.multithread': False, 'wsgi.multiprocess': False, 'wsgi.run_once': False, 'SERVER_SOFTWARE': 'asgi', 'REQUEST_METHOD': scope.get('method', 'GET'), 'PATH_INFO': scope['path'], 'QUERY_STRING': scope.get('query_string', b'').decode('utf-8'), 'RAW_URI': raw_uri.decode('utf-8'), 'SCRIPT_NAME': '', 'SERVER_PROTOCOL': 'HTTP/1.1', 'REMOTE_ADDR': '127.0.0.1', 'REMOTE_PORT': '0', 'SERVER_NAME': 'asgi', 'SERVER_PORT': '0', 'asgi.receive': receive, 'asgi.send': send, 'asgi.scope': scope, } for hdr_name, hdr_value in scope['headers']: hdr_name = hdr_name.upper().decode('utf-8') hdr_value = hdr_value.decode('utf-8') if hdr_name == 'CONTENT-TYPE': environ['CONTENT_TYPE'] = hdr_value continue elif hdr_name == 'CONTENT-LENGTH': environ['CONTENT_LENGTH'] = hdr_value continue key = 'HTTP_%s' % hdr_name.replace('-', '_') if key in environ: hdr_value = '%s,%s' % (environ[key], hdr_value) environ[key] = hdr_value environ['wsgi.url_scheme'] = environ.get('HTTP_X_FORWARDED_PROTO', 'http') return environ async def make_response(status, headers, payload, environ): headers = [(h[0].encode('utf-8'), h[1].encode('utf-8')) for h in headers] if environ['asgi.scope']['type'] == 'websocket': if status.startswith('200 '): await environ['asgi.send']({'type': 'websocket.accept', 'headers': headers}) else: if payload: reason = payload.decode('utf-8') \ if isinstance(payload, bytes) else str(payload) await environ['asgi.send']({'type': 'websocket.close', 'reason': reason}) else: await environ['asgi.send']({'type': 'websocket.close'}) return await environ['asgi.send']({'type': 'http.response.start', 'status': int(status.split(' ')[0]), 'headers': headers}) await environ['asgi.send']({'type': 'http.response.body', 'body': payload}) class WebSocket(object): # pragma: no cover """ This wrapper class provides an asgi WebSocket interface that is somewhat compatible with eventlet's implementation. """ def __init__(self, handler): self.handler = handler self.asgi_receive = None self.asgi_send = None async def __call__(self, environ): self.asgi_receive = environ['asgi.receive'] self.asgi_send = environ['asgi.send'] await self.asgi_send({'type': 'websocket.accept'}) await self.handler(self) async def close(self): await self.asgi_send({'type': 'websocket.close'}) async def send(self, message): msg_bytes = None msg_text = None if isinstance(message, bytes): msg_bytes = message else: msg_text = message await self.asgi_send({'type': 'websocket.send', 'bytes': msg_bytes, 'text': msg_text}) async def wait(self): event = await self.asgi_receive() if event['type'] != 'websocket.receive': raise IOError() return event.get('bytes') or event.get('text') _async = { 'asyncio': True, 'translate_request': translate_request, 'make_response': make_response, 'websocket': WebSocket, }