hass-core/homeassistant/components/websocket_api/http.py
J. Nick Koston 578d4a9b6a
Make the frontend available sooner (Part 1 of 2) (#36263)
* Part 1 of 2 (no breaking changes in part 1).

When integrations configured via the UI block startup or fail to start,
the webserver can remain offline which make it is impossible
to recover without manually changing files in
.storage since the UI is not available.

This change is the foundation that part 2 will build on
and enable a listener to start the webserver when the frontend
is finished loading.

Frontend Changes (home-assistant/frontend#6068)

* Address review comments

* bump timeout to 1800s, adjust comment

* bump timeout to 4h

* remove timeout failsafe

* and the test
2020-06-02 13:54:11 -05:00

264 lines
8.4 KiB
Python

"""View to accept incoming websocket connection."""
import asyncio
from contextlib import suppress
import logging
from typing import Optional
from aiohttp import WSMsgType, web
import async_timeout
from homeassistant.components.http import HomeAssistantView
from homeassistant.const import EVENT_HOMEASSISTANT_STOP
from homeassistant.core import callback
from homeassistant.helpers.event import async_call_later
from homeassistant.util.json import (
find_paths_unserializable_data,
format_unserializable_data,
)
from .auth import AuthPhase, auth_required_message
from .const import (
CANCELLATION_ERRORS,
DATA_CONNECTIONS,
ERR_UNKNOWN_ERROR,
JSON_DUMP,
MAX_PENDING_MSG,
PENDING_MSG_PEAK,
PENDING_MSG_PEAK_TIME,
SIGNAL_WEBSOCKET_CONNECTED,
SIGNAL_WEBSOCKET_DISCONNECTED,
URL,
)
from .error import Disconnect
from .messages import error_message
# mypy: allow-untyped-calls, allow-untyped-defs, no-check-untyped-defs
class WebsocketAPIView(HomeAssistantView):
"""View to serve a websockets endpoint."""
name = "websocketapi"
url = URL
requires_auth = False
async def get(self, request: web.Request) -> web.WebSocketResponse:
"""Handle an incoming websocket connection."""
return await WebSocketHandler(request.app["hass"], request).async_handle()
class WebSocketHandler:
"""Handle an active websocket client connection."""
def __init__(self, hass, request):
"""Initialize an active connection."""
self.hass = hass
self.request = request
self.wsock: Optional[web.WebSocketResponse] = None
self._to_write: asyncio.Queue = asyncio.Queue(maxsize=MAX_PENDING_MSG)
self._handle_task = None
self._writer_task = None
self._logger = logging.getLogger("{}.connection.{}".format(__name__, id(self)))
self._peak_checker_unsub = None
async def _writer(self):
"""Write outgoing messages."""
# Exceptions if Socket disconnected or cancelled by connection handler
with suppress(RuntimeError, ConnectionResetError, *CANCELLATION_ERRORS):
while not self.wsock.closed:
message = await self._to_write.get()
if message is None:
break
self._logger.debug("Sending %s", message)
if isinstance(message, str):
await self.wsock.send_str(message)
continue
try:
dumped = JSON_DUMP(message)
except (ValueError, TypeError):
await self.wsock.send_json(
error_message(
message["id"], ERR_UNKNOWN_ERROR, "Invalid JSON in response"
)
)
self._logger.error(
"Unable to serialize to JSON. Bad data found at %s",
format_unserializable_data(
find_paths_unserializable_data(message, dump=JSON_DUMP)
),
)
continue
await self.wsock.send_str(dumped)
# Clean up the peaker checker when we shut down the writer
if self._peak_checker_unsub:
self._peak_checker_unsub()
self._peak_checker_unsub = None
@callback
def _send_message(self, message):
"""Send a message to the client.
Closes connection if the client is not reading the messages.
Async friendly.
"""
try:
self._to_write.put_nowait(message)
except asyncio.QueueFull:
self._logger.error(
"Client exceeded max pending messages [2]: %s", MAX_PENDING_MSG
)
self._cancel()
if self._to_write.qsize() < PENDING_MSG_PEAK:
if self._peak_checker_unsub:
self._peak_checker_unsub()
self._peak_checker_unsub = None
return
if self._peak_checker_unsub is None:
self._peak_checker_unsub = async_call_later(
self.hass, PENDING_MSG_PEAK_TIME, self._check_write_peak
)
@callback
def _check_write_peak(self, _):
"""Check that we are no longer above the write peak."""
self._peak_checker_unsub = None
if self._to_write.qsize() < PENDING_MSG_PEAK:
return
self._logger.error(
"Client unable to keep up with pending messages. Stayed over %s for %s seconds",
PENDING_MSG_PEAK,
PENDING_MSG_PEAK_TIME,
)
self._cancel()
@callback
def _cancel(self):
"""Cancel the connection."""
self._handle_task.cancel()
self._writer_task.cancel()
async def async_handle(self) -> web.WebSocketResponse:
"""Handle a websocket response."""
request = self.request
wsock = self.wsock = web.WebSocketResponse(heartbeat=55)
await wsock.prepare(request)
self._logger.debug("Connected")
self._handle_task = asyncio.current_task()
@callback
def handle_hass_stop(event):
"""Cancel this connection."""
self._cancel()
unsub_stop = self.hass.bus.async_listen(
EVENT_HOMEASSISTANT_STOP, handle_hass_stop
)
# As the webserver is now started before the start
# event we do not want to block for websocket responses
self._writer_task = asyncio.create_task(self._writer())
auth = AuthPhase(self._logger, self.hass, self._send_message, request)
connection = None
disconnect_warn = None
try:
self._send_message(auth_required_message())
# Auth Phase
try:
with async_timeout.timeout(10):
msg = await wsock.receive()
except asyncio.TimeoutError:
disconnect_warn = "Did not receive auth message within 10 seconds"
raise Disconnect
if msg.type in (WSMsgType.CLOSE, WSMsgType.CLOSING):
raise Disconnect
if msg.type != WSMsgType.TEXT:
disconnect_warn = "Received non-Text message."
raise Disconnect
try:
msg_data = msg.json()
except ValueError:
disconnect_warn = "Received invalid JSON."
raise Disconnect
self._logger.debug("Received %s", msg_data)
connection = await auth.async_handle(msg_data)
self.hass.data[DATA_CONNECTIONS] = (
self.hass.data.get(DATA_CONNECTIONS, 0) + 1
)
self.hass.helpers.dispatcher.async_dispatcher_send(
SIGNAL_WEBSOCKET_CONNECTED
)
# Command phase
while not wsock.closed:
msg = await wsock.receive()
if msg.type in (WSMsgType.CLOSE, WSMsgType.CLOSING):
break
if msg.type != WSMsgType.TEXT:
disconnect_warn = "Received non-Text message."
break
try:
msg_data = msg.json()
except ValueError:
disconnect_warn = "Received invalid JSON."
break
self._logger.debug("Received %s", msg_data)
connection.async_handle(msg_data)
except asyncio.CancelledError:
self._logger.info("Connection closed by client")
except Disconnect:
pass
except Exception: # pylint: disable=broad-except
self._logger.exception("Unexpected error inside websocket API")
finally:
unsub_stop()
if connection is not None:
connection.async_close()
try:
self._to_write.put_nowait(None)
# Make sure all error messages are written before closing
await self._writer_task
except asyncio.QueueFull:
self._writer_task.cancel()
await wsock.close()
if disconnect_warn is None:
self._logger.debug("Disconnected")
else:
self._logger.warning("Disconnected: %s", disconnect_warn)
if connection is not None:
self.hass.data[DATA_CONNECTIONS] -= 1
self.hass.helpers.dispatcher.async_dispatcher_send(
SIGNAL_WEBSOCKET_DISCONNECTED
)
return wsock