sanic/sanic/server.py
Eli Uriegas 04c8f4a5ed Adds some safety around response types being wrong
Before we didn't check if the response object was actually a response
object. This PR catches the exception should it happen and reports it to
the user.
2017-02-16 17:49:14 -06:00

428 lines
14 KiB
Python

import asyncio
import os
import traceback
import warnings
from functools import partial
from inspect import isawaitable
from multiprocessing import Process, Event
from os import set_inheritable
from signal import SIGTERM, SIGINT
from signal import signal as signal_func
from socket import socket, SOL_SOCKET, SO_REUSEADDR
from time import time
from httptools import HttpRequestParser
from httptools.parser.errors import HttpParserError
try:
import uvloop as async_loop
except ImportError:
async_loop = asyncio
from sanic.log import log
from sanic.request import Request
from sanic.exceptions import (
RequestTimeout, PayloadTooLarge, InvalidUsage, ServerError)
current_time = None
class Signal:
stopped = False
class CIDict(dict):
"""Case Insensitive dict where all keys are converted to lowercase
This does not maintain the inputted case when calling items() or keys()
in favor of speed, since headers are case insensitive
"""
def get(self, key, default=None):
return super().get(key.casefold(), default)
def __getitem__(self, key):
return super().__getitem__(key.casefold())
def __setitem__(self, key, value):
return super().__setitem__(key.casefold(), value)
def __contains__(self, key):
return super().__contains__(key.casefold())
class HttpProtocol(asyncio.Protocol):
__slots__ = (
# event loop, connection
'loop', 'transport', 'connections', 'signal',
# request params
'parser', 'request', 'url', 'headers',
# request config
'request_handler', 'request_timeout', 'request_max_size',
# connection management
'_total_request_size', '_timeout_handler', '_last_communication_time')
def __init__(self, *, loop, request_handler, error_handler,
signal=Signal(), connections=set(), request_timeout=60,
request_max_size=None):
self.loop = loop
self.transport = None
self.request = None
self.parser = None
self.url = None
self.headers = None
self.signal = signal
self.connections = connections
self.request_handler = request_handler
self.error_handler = error_handler
self.request_timeout = request_timeout
self.request_max_size = request_max_size
self._total_request_size = 0
self._timeout_handler = None
self._last_request_time = None
self._request_handler_task = None
# -------------------------------------------- #
# Connection
# -------------------------------------------- #
def connection_made(self, transport):
self.connections.add(self)
self._timeout_handler = self.loop.call_later(
self.request_timeout, self.connection_timeout)
self.transport = transport
self._last_request_time = current_time
def connection_lost(self, exc):
self.connections.discard(self)
self._timeout_handler.cancel()
def connection_timeout(self):
# Check if
time_elapsed = current_time - self._last_request_time
if time_elapsed < self.request_timeout:
time_left = self.request_timeout - time_elapsed
self._timeout_handler = (
self.loop.call_later(time_left, self.connection_timeout))
else:
if self._request_handler_task:
self._request_handler_task.cancel()
exception = RequestTimeout('Request Timeout')
self.write_error(exception)
# -------------------------------------------- #
# Parsing
# -------------------------------------------- #
def data_received(self, data):
# Check for the request itself getting too large and exceeding
# memory limits
self._total_request_size += len(data)
if self._total_request_size > self.request_max_size:
exception = PayloadTooLarge('Payload Too Large')
self.write_error(exception)
# Create parser if this is the first time we're receiving data
if self.parser is None:
assert self.request is None
self.headers = []
self.parser = HttpRequestParser(self)
# Parse request chunk or close connection
try:
self.parser.feed_data(data)
except HttpParserError:
exception = InvalidUsage('Bad Request')
self.write_error(exception)
def on_url(self, url):
self.url = url
def on_header(self, name, value):
if name == b'Content-Length' and int(value) > self.request_max_size:
exception = PayloadTooLarge('Payload Too Large')
self.write_error(exception)
self.headers.append((name.decode().casefold(), value.decode()))
def on_headers_complete(self):
self.request = Request(
url_bytes=self.url,
headers=CIDict(self.headers),
version=self.parser.get_http_version(),
method=self.parser.get_method().decode(),
transport=self.transport
)
def on_body(self, body):
self.request.body.append(body)
def on_message_complete(self):
if self.request.body:
self.request.body = b''.join(self.request.body)
self._request_handler_task = self.loop.create_task(
self.request_handler(self.request, self.write_response))
# -------------------------------------------- #
# Responding
# -------------------------------------------- #
def write_response(self, response):
keep_alive = (
self.parser.should_keep_alive() and not self.signal.stopped)
try:
self.transport.write(
response.output(
self.request.version, keep_alive, self.request_timeout))
except AttributeError:
log.error(
('Invalid response object for url {}, '
'Expected Type: HTTPResponse, Actual Type: {}').format(
self.url, type(response)))
self.write_error(ServerError('Invalid response type'))
except RuntimeError:
log.error(
'Connection lost before response written @ {}'.format(
self.request.ip))
except Exception as e:
self.bail_out(
"Writing response failed, connection closed {}".format(e))
finally:
if not keep_alive:
self.transport.close()
else:
# Record that we received data
self._last_request_time = current_time
self.cleanup()
def write_error(self, exception):
try:
response = self.error_handler.response(self.request, exception)
version = self.request.version if self.request else '1.1'
self.transport.write(response.output(version))
except RuntimeError:
log.error(
'Connection lost before error written @ {}'.format(
self.request.ip))
except Exception as e:
self.bail_out(
"Writing error failed, connection closed {}".format(e),
from_error=True)
finally:
self.transport.close()
def bail_out(self, message, from_error=False):
if from_error and self.transport.is_closing():
log.error(
("Transport closed @ {} and exception "
"experienced during error handling").format(
self.transport.get_extra_info('peername')))
log.debug(
'Exception:\n{}'.format(traceback.format_exc()))
else:
exception = ServerError(message)
self.write_error(exception)
log.error(message)
def cleanup(self):
self.parser = None
self.request = None
self.url = None
self.headers = None
self._request_handler_task = None
self._total_request_size = 0
def close_if_idle(self):
"""Close the connection if a request is not being sent or received
:return: boolean - True if closed, false if staying open
"""
if not self.parser:
self.transport.close()
return True
return False
def update_current_time(loop):
"""Cache the current time, since it is needed at the end of every
keep-alive request to update the request timeout time
:param loop:
:return:
"""
global current_time
current_time = time()
loop.call_later(1, partial(update_current_time, loop))
def trigger_events(events, loop):
"""Trigger event callbacks (functions or async)
:param events: one or more sync or async functions to execute
:param loop: event loop
"""
for event in events:
result = event(loop)
if isawaitable(result):
loop.run_until_complete(result)
def serve(host, port, request_handler, error_handler, before_start=None,
after_start=None, before_stop=None, after_stop=None, debug=False,
request_timeout=60, ssl=None, sock=None, request_max_size=None,
reuse_port=False, loop=None, protocol=HttpProtocol, backlog=100,
register_sys_signals=True, run_async=False):
"""Start asynchronous HTTP Server on an individual process.
:param host: Address to host on
:param port: Port to host on
:param request_handler: Sanic request handler with middleware
:param error_handler: Sanic error handler with middleware
:param before_start: function to be executed before the server starts
listening. Takes arguments `app` instance and `loop`
:param after_start: function to be executed after the server starts
listening. Takes arguments `app` instance and `loop`
:param before_stop: function to be executed when a stop signal is
received before it is respected. Takes arguments
`app` instance and `loop`
:param after_stop: function to be executed when a stop signal is
received after it is respected. Takes arguments
`app` instance and `loop`
:param debug: enables debug output (slows server)
:param request_timeout: time in seconds
:param ssl: SSLContext
:param sock: Socket for the server to accept connections from
:param request_max_size: size in bytes, `None` for no limit
:param reuse_port: `True` for multiple workers
:param loop: asyncio compatible event loop
:param protocol: subclass of asyncio protocol class
:return: Nothing
"""
if not run_async:
loop = async_loop.new_event_loop()
asyncio.set_event_loop(loop)
if debug:
loop.set_debug(debug)
trigger_events(before_start, loop)
connections = set()
signal = Signal()
server = partial(
protocol,
loop=loop,
connections=connections,
signal=signal,
request_handler=request_handler,
error_handler=error_handler,
request_timeout=request_timeout,
request_max_size=request_max_size,
)
server_coroutine = loop.create_server(
server,
host,
port,
ssl=ssl,
reuse_port=reuse_port,
sock=sock,
backlog=backlog
)
# Instead of pulling time at the end of every request,
# pull it once per minute
loop.call_soon(partial(update_current_time, loop))
if run_async:
return server_coroutine
try:
http_server = loop.run_until_complete(server_coroutine)
except:
log.exception("Unable to start server")
return
trigger_events(after_start, loop)
# Register signals for graceful termination
if register_sys_signals:
for _signal in (SIGINT, SIGTERM):
try:
loop.add_signal_handler(_signal, loop.stop)
except NotImplementedError:
log.warn('Sanic tried to use loop.add_signal_handler but it is'
' not implemented on this platform.')
pid = os.getpid()
try:
log.info('Starting worker [{}]'.format(pid))
loop.run_forever()
finally:
log.info("Stopping worker [{}]".format(pid))
# Run the on_stop function if provided
trigger_events(before_stop, loop)
# Wait for event loop to finish and all connections to drain
http_server.close()
loop.run_until_complete(http_server.wait_closed())
# Complete all tasks on the loop
signal.stopped = True
for connection in connections:
connection.close_if_idle()
while connections:
loop.run_until_complete(asyncio.sleep(0.1))
trigger_events(after_stop, loop)
loop.close()
def serve_multiple(server_settings, workers, stop_event=None):
"""Start multiple server processes simultaneously. Stop on interrupt
and terminate signals, and drain connections when complete.
:param server_settings: kw arguments to be passed to the serve function
:param workers: number of workers to launch
:param stop_event: if provided, is used as a stop signal
:return:
"""
if server_settings.get('loop', None) is not None:
if server_settings.get('debug', False):
warnings.simplefilter('default')
warnings.warn("Passing a loop will be deprecated in version 0.4.0"
" https://github.com/channelcat/sanic/pull/335"
" has more information.", DeprecationWarning)
server_settings['reuse_port'] = True
sock = socket()
sock.setsockopt(SOL_SOCKET, SO_REUSEADDR, 1)
sock.bind((server_settings['host'], server_settings['port']))
set_inheritable(sock.fileno(), True)
server_settings['sock'] = sock
server_settings['host'] = None
server_settings['port'] = None
if stop_event is None:
stop_event = Event()
signal_func(SIGINT, lambda s, f: stop_event.set())
signal_func(SIGTERM, lambda s, f: stop_event.set())
processes = []
for _ in range(workers):
process = Process(target=serve, kwargs=server_settings)
process.daemon = True
process.start()
processes.append(process)
for process in processes:
process.join()
# the above processes will block this until they're stopped
for process in processes:
process.terminate()
sock.close()
asyncio.get_event_loop().stop()