Low-level HTTP Server¶
Note
This topic describes the low-level HTTP support. For high-level
interface please take a look on aiohttp.web
.
Run a basic server¶
Start implementing the basic server by inheriting the
ServerHttpProtocol
object. Your class should
implement the only method ServerHttpProtocol.handle_request()
which must be a coroutine to handle requests asynchronously
from urllib.parse import urlparse, parse_qsl import aiohttp import aiohttp.server from aiohttp import MultiDict import asyncio class HttpRequestHandler(aiohttp.server.ServerHttpProtocol): async def handle_request(self, message, payload): response = aiohttp.Response( self.writer, 200, http_version=message.version ) response.add_header('Content-Type', 'text/html') response.add_header('Content-Length', '18') response.send_headers() response.write(b'<h1>It Works!</h1>') await response.write_eof()
The next step is to create a loop and register your handler within a server.
KeyboardInterrupt
exception handling is necessary so you can stop
your server with Ctrl+C at any time.
if __name__ == '__main__': loop = asyncio.get_event_loop() f = loop.create_server( lambda: HttpRequestHandler(debug=True, keep_alive=75), '0.0.0.0', '8080') srv = loop.run_until_complete(f) print('serving on', srv.sockets[0].getsockname()) try: loop.run_forever() except KeyboardInterrupt: pass
Headers¶
Data is passed to the handler in the message
, while request body is
passed in payload
param. HTTP headers are accessed through
headers
member of the message. To check what the current method of
the request is use the method
member of the message
. It should be one
of GET
, POST
, PUT
or DELETE
strings.
Handling GET params¶
Currently aiohttp does not provide automatic parsing of incoming GET
params. However aiohttp does provide a nice
MulitiDict
wrapper for already parsed params.
from urllib.parse import urlparse, parse_qsl from aiohttp import MultiDict class HttpRequestHandler(aiohttp.server.ServerHttpProtocol): async def handle_request(self, message, payload): response = aiohttp.Response( self.writer, 200, http_version=message.version ) get_params = MultiDict(parse_qsl(urlparse(message.path).query)) print("Passed in GET", get_params)
Handling POST data¶
POST data is accessed through the payload.read()
generator method.
If you have form data in the request body, you can parse it in the same way as
GET params.
from urllib.parse import urlparse, parse_qsl from aiohttp import MultiDict class HttpRequestHandler(aiohttp.server.ServerHttpProtocol): async def handle_request(self, message, payload): response = aiohttp.Response( self.writer, 200, http_version=message.version ) data = await payload.read() post_params = MultiDict(parse_qsl(data)) print("Passed in POST", post_params)
SSL¶
To use asyncio’s SSL support, just pass an SSLContext object to the
asyncio.BaseEventLoop.create_server()
method of the loop.
import ssl sslcontext = ssl.SSLContext(ssl.PROTOCOL_SSLv23) sslcontext.load_cert_chain('sample.crt', 'sample.key') loop = asyncio.get_event_loop() loop.create_server(lambda: handler, "0.0.0.0", "8080", ssl=sslcontext)
Reference¶
simple http server.
-
class
aiohttp.server.
ServerHttpProtocol
(*, loop=None, keep_alive=75, keep_alive_on=True, timeout=0, logger=<logging.Logger object>, access_log=<logging.Logger object>, access_log_format='%a %l %u %t "%r" %s %b "%{Referrer}i" "%{User-Agent}i"', debug=False, log=None, **kwargs)[source]¶ Bases:
aiohttp.parsers.StreamProtocol
Simple http protocol implementation.
ServerHttpProtocol handles incoming http request. It reads request line, request headers and request payload and calls handle_request() method. By default it always returns with 404 response.
ServerHttpProtocol handles errors in incoming request, like bad status line, bad headers or incomplete payload. If any error occurs, connection gets closed.
Parameters: - keep_alive (int or None) – number of seconds before closing keep-alive connection
- keep_alive_on (bool) – keep-alive is o, default is on
- timeout (int) – slow request timeout
- allowed_methods (tuple) – (optional) List of allowed request methods. Set to empty list to allow all methods.
- debug (bool) – enable debug mode
- logger (aiohttp.log.server_logger) – custom logger object
- access_log (aiohttp.log.server_logger) – custom logging object
- access_log_format (str) – access log format string
- loop – Optional event loop
-
closing
(timeout=15.0)[source]¶ Worker process is about to exit, we need cleanup everything and stop accepting requests. It is especially important for keep-alive connections.
-
handle_error
(status=500, message=None, payload=None, exc=None, headers=None, reason=None)[source]¶ Handle errors.
Returns http response with specific status code. Logs additional information. It always closes current connection.
-
handle_request
(message, payload)[source]¶ Handle a single http request.
Subclass should override this method. By default it always returns 404 response.
Parameters: - message (aiohttp.protocol.HttpRequestParser) – Request headers
- payload (aiohttp.streams.FlowControlStreamReader) – Request payload
-
keep_alive_timeout
¶
-
start
()[source]¶ Start processing of incoming requests.
It reads request line, request headers and request payload, then calls handle_request() method. Subclass has to override handle_request(). start() handles various exceptions in request or response handling. Connection is being closed always unless keep_alive(True) specified.