sanic/sanic/server.py
2020-03-26 08:59:33 +02:00

635 lines
20 KiB
Python

import asyncio
import multiprocessing
import os
import sys
from asyncio import CancelledError
from functools import partial
from inspect import isawaitable
from signal import SIG_IGN, SIGINT, SIGTERM, Signals
from signal import signal as signal_func
from socket import SO_REUSEADDR, SOL_SOCKET, socket
from time import monotonic as current_time
from sanic.compat import ctrlc_workaround_for_windows
from sanic.exceptions import RequestTimeout, ServiceUnavailable
from sanic.http import Http, Stage
from sanic.log import logger
from sanic.request import Request
try:
import uvloop # type: ignore
if not isinstance(asyncio.get_event_loop_policy(), uvloop.EventLoopPolicy):
asyncio.set_event_loop_policy(uvloop.EventLoopPolicy())
except ImportError:
pass
OS_IS_WINDOWS = os.name == "nt"
class Signal:
stopped = False
class HttpProtocol(asyncio.Protocol):
"""
This class provides a basic HTTP implementation of the sanic framework.
"""
__slots__ = (
# app
"app",
# event loop, connection
"loop",
"transport",
"connections",
"signal",
# request params
"request",
# request config
"request_handler",
"request_timeout",
"response_timeout",
"keep_alive_timeout",
"request_max_size",
"request_buffer_queue_size",
"request_class",
"router",
"error_handler",
# enable or disable access log purpose
"access_log",
# connection management
"state",
"url",
"_debug",
"_handler_task",
"_can_write",
"_data_received",
"_time",
"_task",
"_http",
"_exception",
"recv_buffer",
)
def __init__(
self,
*,
loop,
app,
request_handler,
error_handler,
signal=Signal(),
connections=None,
request_timeout=60,
response_timeout=60,
keep_alive_timeout=5,
request_max_size=None,
request_buffer_queue_size=100,
request_class=None,
access_log=True,
keep_alive=True,
is_request_stream=False,
router=None,
state=None,
debug=False,
**kwargs,
):
deprecated_loop = loop if sys.version_info < (3, 8) else None
self.loop = loop
self.app = app
self.url = None
self.transport = None
self.request = None
self.router = router
self.signal = signal
self.access_log = access_log
self.connections = connections if connections is not None else set()
self.request_handler = request_handler
self.error_handler = error_handler
self.request_timeout = request_timeout
self.request_buffer_queue_size = request_buffer_queue_size
self.response_timeout = response_timeout
self.keep_alive_timeout = keep_alive_timeout
self.request_max_size = request_max_size
self.request_class = request_class or Request
self.state = state if state else {}
if "requests_count" not in self.state:
self.state["requests_count"] = 0
self._debug = debug
self._data_received = asyncio.Event(loop=deprecated_loop)
self._can_write = asyncio.Event(loop=deprecated_loop)
self._can_write.set()
self._exception = None
async def connection_task(self):
"""Run a HTTP connection.
Timeouts and some additional error handling occur here, while most of
everything else happens in class Http or in code called from there.
"""
try:
self._http = Http(self)
self._time = current_time()
self.check_timeouts()
await self._http.http1()
except CancelledError:
pass
except Exception:
logger.exception("protocol.connection_task uncaught")
finally:
if self._debug and self._http:
ip = self.transport.get_extra_info("peername")
logger.error(
"Connection lost before response written"
f" @ {ip} {self._http.request}"
)
self._http = None
self._task = None
try:
self.close()
except BaseException:
logger.exception("Closing failed")
async def receive_more(self):
"""Wait until more data is received into self._buffer."""
self.transport.resume_reading()
self._data_received.clear()
await self._data_received.wait()
def check_timeouts(self):
"""Runs itself periodically to enforce any expired timeouts."""
try:
if not self._task:
return
duration = current_time() - self._time
stage = self._http.stage
if stage is Stage.IDLE and duration > self.keep_alive_timeout:
logger.debug("KeepAlive Timeout. Closing connection.")
elif stage is Stage.REQUEST and duration > self.request_timeout:
self._http.exception = RequestTimeout("Request Timeout")
elif (
stage in (Stage.HANDLER, Stage.RESPONSE, Stage.FAILED)
and duration > self.response_timeout
):
self._http.exception = ServiceUnavailable("Response Timeout")
else:
interval = (
min(
self.keep_alive_timeout,
self.request_timeout,
self.response_timeout,
)
/ 2
)
self.loop.call_later(max(0.1, interval), self.check_timeouts)
return
self._task.cancel()
except Exception:
logger.exception("protocol.check_timeouts")
async def send(self, data):
"""Writes data with backpressure control."""
await self._can_write.wait()
if self.transport.is_closing():
raise CancelledError
self.transport.write(data)
self._time = current_time()
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 self._http is None or self._http.stage is Stage.IDLE:
self.close()
return True
return False
def close(self):
"""
Force close the connection.
"""
# Cause a call to connection_lost where further cleanup occurs
if self.transport:
self.transport.close()
self.transport = None
# -------------------------------------------- #
# Only asyncio.Protocol callbacks below this
# -------------------------------------------- #
def connection_made(self, transport):
try:
# TODO: Benchmark to find suitable write buffer limits
transport.set_write_buffer_limits(low=16384, high=65536)
self.connections.add(self)
self.transport = transport
self._task = self.loop.create_task(self.connection_task())
self.recv_buffer = bytearray()
except Exception:
logger.exception("protocol.connect_made")
def connection_lost(self, exc):
try:
self.connections.discard(self)
self.resume_writing()
if self._task:
self._task.cancel()
except Exception:
logger.exception("protocol.connection_lost")
def pause_writing(self):
self._can_write.clear()
def resume_writing(self):
self._can_write.set()
def data_received(self, data):
try:
self._time = current_time()
if not data:
return self.close()
self.recv_buffer += data
# Buffer up to request max size
if len(self.recv_buffer) > self.request_max_size:
self.transport.pause_reading()
if self._data_received:
self._data_received.set()
except Exception:
logger.exception("protocol.data_received")
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)
class AsyncioServer:
"""
Wraps an asyncio server with functionality that might be useful to
a user who needs to manage the server lifecycle manually.
"""
__slots__ = (
"loop",
"serve_coro",
"_after_start",
"_before_stop",
"_after_stop",
"server",
"connections",
)
def __init__(
self,
loop,
serve_coro,
connections,
after_start,
before_stop,
after_stop,
):
# Note, Sanic already called "before_server_start" events
# before this helper was even created. So we don't need it here.
self.loop = loop
self.serve_coro = serve_coro
self._after_start = after_start
self._before_stop = before_stop
self._after_stop = after_stop
self.server = None
self.connections = connections
def after_start(self):
"""Trigger "after_server_start" events"""
trigger_events(self._after_start, self.loop)
def before_stop(self):
"""Trigger "before_server_stop" events"""
trigger_events(self._before_stop, self.loop)
def after_stop(self):
"""Trigger "after_server_stop" events"""
trigger_events(self._after_stop, self.loop)
def is_serving(self):
if self.server:
return self.server.is_serving()
return False
def wait_closed(self):
if self.server:
return self.server.wait_closed()
def close(self):
if self.server:
self.server.close()
coro = self.wait_closed()
task = asyncio.ensure_future(coro, loop=self.loop)
return task
def start_serving(self):
if self.server:
try:
return self.server.start_serving()
except AttributeError:
raise NotImplementedError(
"server.start_serving not available in this version "
"of asyncio or uvloop."
)
def serve_forever(self):
if self.server:
try:
return self.server.serve_forever()
except AttributeError:
raise NotImplementedError(
"server.serve_forever not available in this version "
"of asyncio or uvloop."
)
def __await__(self):
"""Starts the asyncio server, returns AsyncServerCoro"""
task = asyncio.ensure_future(self.serve_coro)
while not task.done():
yield
self.server = task.result()
return self
def serve(
host,
port,
app,
request_handler,
error_handler,
before_start=None,
after_start=None,
before_stop=None,
after_stop=None,
debug=False,
request_timeout=60,
response_timeout=60,
keep_alive_timeout=5,
ssl=None,
sock=None,
request_max_size=None,
request_buffer_queue_size=100,
reuse_port=False,
loop=None,
protocol=HttpProtocol,
backlog=100,
register_sys_signals=True,
run_multiple=False,
run_async=False,
connections=None,
signal=Signal(),
request_class=None,
access_log=True,
keep_alive=True,
is_request_stream=False,
router=None,
websocket_max_size=None,
websocket_max_queue=None,
websocket_read_limit=2 ** 16,
websocket_write_limit=2 ** 16,
state=None,
graceful_shutdown_timeout=15.0,
asyncio_server_kwargs=None,
):
"""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 response_timeout: time in seconds
:param keep_alive_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
:param run_async: bool: Do not create a new event loop for the server,
and return an AsyncServer object rather than running it
:param request_class: Request class to use
:param access_log: disable/enable access log
:param websocket_max_size: enforces the maximum size for
incoming messages in bytes.
:param websocket_max_queue: sets the maximum length of the queue
that holds incoming messages.
:param websocket_read_limit: sets the high-water limit of the buffer for
incoming bytes, the low-water limit is half
the high-water limit.
:param websocket_write_limit: sets the high-water limit of the buffer for
outgoing bytes, the low-water limit is a
quarter of the high-water limit.
:param is_request_stream: disable/enable Request.stream
:param request_buffer_queue_size: streaming request buffer queue size
:param router: Router object
:param graceful_shutdown_timeout: How long take to Force close non-idle
connection
:param asyncio_server_kwargs: key-value args for asyncio/uvloop
create_server method
:return: Nothing
"""
if not run_async:
# create new event_loop after fork
loop = asyncio.new_event_loop()
asyncio.set_event_loop(loop)
if debug:
loop.set_debug(debug)
app.asgi = False
connections = connections if connections is not None else set()
server = partial(
protocol,
loop=loop,
connections=connections,
signal=signal,
app=app,
request_handler=request_handler,
error_handler=error_handler,
request_timeout=request_timeout,
response_timeout=response_timeout,
keep_alive_timeout=keep_alive_timeout,
request_max_size=request_max_size,
request_buffer_queue_size=request_buffer_queue_size,
request_class=request_class,
access_log=access_log,
keep_alive=keep_alive,
is_request_stream=is_request_stream,
router=router,
websocket_max_size=websocket_max_size,
websocket_max_queue=websocket_max_queue,
websocket_read_limit=websocket_read_limit,
websocket_write_limit=websocket_write_limit,
state=state,
debug=debug,
)
asyncio_server_kwargs = (
asyncio_server_kwargs if asyncio_server_kwargs else {}
)
server_coroutine = loop.create_server(
server,
host,
port,
ssl=ssl,
reuse_port=reuse_port,
sock=sock,
backlog=backlog,
**asyncio_server_kwargs,
)
if run_async:
return AsyncioServer(
loop,
server_coroutine,
connections,
after_start,
before_stop,
after_stop,
)
trigger_events(before_start, loop)
try:
http_server = loop.run_until_complete(server_coroutine)
except BaseException:
logger.exception("Unable to start server")
return
trigger_events(after_start, loop)
# Ignore SIGINT when run_multiple
if run_multiple:
signal_func(SIGINT, SIG_IGN)
# Register signals for graceful termination
if register_sys_signals:
if OS_IS_WINDOWS:
ctrlc_workaround_for_windows(app)
else:
for _signal in [SIGTERM] if run_multiple else [SIGINT, SIGTERM]:
loop.add_signal_handler(_signal, app.stop)
pid = os.getpid()
try:
logger.info("Starting worker [%s]", pid)
loop.run_forever()
finally:
logger.info("Stopping worker [%s]", 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()
# Gracefully shutdown timeout.
# We should provide graceful_shutdown_timeout,
# instead of letting connection hangs forever.
# Let's roughly calcucate time.
start_shutdown = 0
while connections and (start_shutdown < graceful_shutdown_timeout):
loop.run_until_complete(asyncio.sleep(0.1))
start_shutdown = start_shutdown + 0.1
# Force close non-idle connection after waiting for
# graceful_shutdown_timeout
coros = []
for conn in connections:
if hasattr(conn, "websocket") and conn.websocket:
coros.append(conn.websocket.close_connection())
else:
conn.close()
if sys.version_info < (3, 8):
_shutdown = asyncio.gather(*coros, loop=loop)
else:
_shutdown = asyncio.gather(*coros)
loop.run_until_complete(_shutdown)
trigger_events(after_stop, loop)
loop.close()
def serve_multiple(server_settings, workers):
"""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:
"""
server_settings["reuse_port"] = True
server_settings["run_multiple"] = True
# Handling when custom socket is not provided.
if server_settings.get("sock") is None:
sock = socket()
sock.setsockopt(SOL_SOCKET, SO_REUSEADDR, 1)
sock.bind((server_settings["host"], server_settings["port"]))
sock.set_inheritable(True)
server_settings["sock"] = sock
server_settings["host"] = None
server_settings["port"] = None
processes = []
def sig_handler(signal, frame):
logger.info("Received signal %s. Shutting down.", Signals(signal).name)
for process in processes:
os.kill(process.pid, SIGTERM)
signal_func(SIGINT, lambda s, f: sig_handler(s, f))
signal_func(SIGTERM, lambda s, f: sig_handler(s, f))
mp = multiprocessing.get_context("fork")
for _ in range(workers):
process = mp.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()
server_settings.get("sock").close()