fix: tear down controller console WebSocket forwarding cleanly on client disconnect

Closing a web console while the node kept streaming output crashed the
ws_console/vnc_console handlers with an uncaught WebSocketDisconnect from
the compute-to-client send path (only the opposite direction was guarded),
producing a full ASGI traceback on every console close.

Restructure both endpoints as symmetric forwarding tasks managed with
asyncio.wait(FIRST_COMPLETED): exceptions from either direction are
collected as task exceptions, the peer task is cancelled, the compute
WebSocket is closed, and the client is notified. The receive loops now
close and log on every exit path instead of only in the exception branch.

Tests patch the in-memory ASGI transport to deliver a conformant
websocket.disconnect on client close (it sends a non-conformant
websocket.close that starlette receive() rejects).
This commit is contained in:
YueGuobin 2026-08-31 01:13:20 +08:00
parent 861b7e86ff
commit eed981fee3
No known key found for this signature in database
2 changed files with 311 additions and 35 deletions

View File

@ -20,6 +20,7 @@ API routes for nodes.
import aiohttp
import asyncio
import contextlib
import ipaddress
from fastapi import APIRouter, Depends, WebSocket, WebSocketDisconnect, Request, Response, status, Query, HTTPException
@ -707,14 +708,34 @@ async def ws_console(
elif "bytes" in msg and msg["bytes"]:
await ws_console_compute.send_bytes(msg["bytes"])
except WebSocketDisconnect:
await ws_console_compute.close()
pass
log.info(
f"Client {websocket.client.host}:{websocket.client.port} has disconnected from controller"
f" console WebSocket"
)
async def ws_send(ws_console_compute):
"""
Receive WebSocket data from compute console WebSocket and forward to client.
"""
try:
async for msg in ws_console_compute:
if msg.type == aiohttp.WSMsgType.TEXT:
await websocket.send_text(msg.data)
elif msg.type == aiohttp.WSMsgType.BINARY:
await websocket.send_bytes(msg.data)
elif msg.type == aiohttp.WSMsgType.ERROR:
break
except WebSocketDisconnect:
# the client disconnected while the compute was still streaming console output
log.info(
f"Client {websocket.client.host}:{websocket.client.port} has disconnected from controller"
f" console WebSocket"
)
try:
# receive WebSocket data from compute console WebSocket and forward to client.
# forward WebSocket data in both directions between the client and the compute console WebSocket
log.info(f"Forwarding console WebSocket to '{ws_console_compute_url}'")
server_config = Config.instance().settings.Server
user = server_config.compute_username
@ -728,20 +749,20 @@ async def ws_console(
auth = aiohttp.BasicAuth(user, "")
ssl_context = Controller.instance().ssl_context()
async with HTTPClient.get_client().ws_connect(ws_console_compute_url, auth=auth, ssl_context=ssl_context) as ws:
asyncio.ensure_future(ws_receive(ws))
async for msg in ws:
if msg.type == aiohttp.WSMsgType.TEXT:
await websocket.send_text(msg.data)
elif msg.type == aiohttp.WSMsgType.BINARY:
await websocket.send_bytes(msg.data)
elif msg.type == aiohttp.WSMsgType.ERROR:
break
except WebSocketDisconnect:
# the client disconnected while the compute was still streaming console output
log.info(
f"Client {websocket.client.host}:{websocket.client.port} has disconnected from controller"
f" console WebSocket"
)
tasks = [
asyncio.ensure_future(ws_receive(ws)),
asyncio.ensure_future(ws_send(ws)),
]
done, pending = await asyncio.wait(tasks, return_when=asyncio.FIRST_COMPLETED)
for task in done:
if task.exception():
log.warning(f"Exception while forwarding console WebSocket data: {task.exception()}")
for task in pending:
task.cancel()
await asyncio.gather(*pending, return_exceptions=True)
# notify the client that the console session has ended (ignore if the client is already gone)
with contextlib.suppress(WebSocketDisconnect):
await websocket.close()
except aiohttp.ClientError as e:
log.error(f"Client error received when forwarding to compute console WebSocket: {e}")
@ -786,18 +807,39 @@ async def vnc_console(
try:
while True:
data = await websocket.receive_bytes()
msg = await websocket.receive()
if msg["type"] == "websocket.disconnect":
break
data = msg.get("bytes")
if data:
await vnc_console_compute.send_bytes(data)
except WebSocketDisconnect:
await vnc_console_compute.close()
pass
log.info(
f"Client {websocket.client.host}:{websocket.client.port} has disconnected from controller"
f" VNC console WebSocket"
)
async def vnc_send(vnc_console_compute):
"""
Receive binary WebSocket data from compute VNC console WebSocket and forward to client.
"""
try:
async for msg in vnc_console_compute:
if msg.type == aiohttp.WSMsgType.BINARY:
await websocket.send_bytes(msg.data)
elif msg.type == aiohttp.WSMsgType.ERROR:
break
except WebSocketDisconnect:
# the client disconnected while the compute was still streaming VNC console output
log.info(
f"Client {websocket.client.host}:{websocket.client.port} has disconnected from controller"
f" VNC console WebSocket"
)
try:
# receive binary data from compute VNC console WebSocket and forward to client
# forward WebSocket data in both directions between the client and the compute VNC console WebSocket
log.info(f"Forwarding VNC console WebSocket to '{vnc_console_compute_url}'")
server_config = Config.instance().settings.Server
user = server_config.compute_username
@ -811,18 +853,20 @@ async def vnc_console(
auth = aiohttp.BasicAuth(user, "")
ssl_context = Controller.instance().ssl_context()
async with HTTPClient.get_client().ws_connect(vnc_console_compute_url, auth=auth, ssl_context=ssl_context) as ws:
asyncio.ensure_future(vnc_receive(ws))
async for msg in ws:
if msg.type == aiohttp.WSMsgType.BINARY:
await websocket.send_bytes(msg.data)
elif msg.type == aiohttp.WSMsgType.ERROR:
break
except WebSocketDisconnect:
# the client disconnected while the compute was still streaming VNC console output
log.info(
f"Client {websocket.client.host}:{websocket.client.port} has disconnected from controller"
f" VNC console WebSocket"
)
tasks = [
asyncio.ensure_future(vnc_receive(ws)),
asyncio.ensure_future(vnc_send(ws)),
]
done, pending = await asyncio.wait(tasks, return_when=asyncio.FIRST_COMPLETED)
for task in done:
if task.exception():
log.warning(f"Exception while forwarding VNC console WebSocket data: {task.exception()}")
for task in pending:
task.cancel()
await asyncio.gather(*pending, return_exceptions=True)
# notify the client that the VNC session has ended (ignore if the client is already gone)
with contextlib.suppress(WebSocketDisconnect):
await websocket.close()
except aiohttp.ClientError as e:
log.error(f"Client error received when forwarding to compute VNC console WebSocket: {e}")

View File

@ -16,9 +16,11 @@
# along with this program. If not, see <http://www.gnu.org/licenses/>.
import aiohttp
import asyncio
import contextlib
import logging
import aiohttp
import pytest
from types import SimpleNamespace
@ -27,8 +29,11 @@ from typing import List, Optional
from fastapi import FastAPI, HTTPException, WebSocketDisconnect, status
from httpx import AsyncClient
from pydantic import SecretStr
from httpx_ws import aconnect_ws
from httpx_ws import WebSocketDisconnect as HttpxWebSocketDisconnect
from httpx_ws.transport import ASGIWebSocketTransport, ASGIWebSocketAsyncNetworkStream
from unittest.mock import MagicMock
from unittest.mock import MagicMock, patch
from tests.utils import AsyncioMagicMock
from gns3server.config import Config
@ -37,6 +42,8 @@ from gns3server.controller.project import Project
from gns3server.controller.compute import Compute
from gns3server.utils.http_client import HTTPClient
from gns3server.api.routes.controller.nodes import ws_console, vnc_console
from gns3server.services import auth_service
from gns3server.services.authentication import DEFAULT_JWT_SECRET_KEY
pytestmark = pytest.mark.asyncio
@ -681,6 +688,8 @@ class TestNodeRoutes:
# compute.http_query.assert_called_with("POST", "/projects/{project_id}/files/project-files/vpcs/{node_id}/hello/nested".format(project_id=project.id, node_id=node.id), data=b'hello', timeout=None, raw=True)
class FakeComputeConsoleWebSocket:
"""
Stand-in for the aiohttp ClientWebSocketResponse returned when connecting
@ -738,13 +747,21 @@ class FakeClientWebSocket:
async def receive(self) -> dict:
# the client is already gone from the receive side
return {"type": "websocket.disconnect"}
# the client never sends anything else and never completes a close
# handshake: block until the forwarding task is cancelled, like a real
# receive side waiting for a disconnect message that only arrives on
# the send path
await asyncio.Event().wait()
async def receive_bytes(self) -> bytes:
raise WebSocketDisconnect(code=1006)
async def close(self, code: int = 1000, reason: Optional[str] = None) -> None:
# notification that the console session ended; nothing to record
pass
async def send_text(self, data: str) -> None:
self._check_client_alive()
@ -855,3 +872,218 @@ class TestNodeConsoleWebSocketRoutes:
assert websocket.sent == []
assert compute_ws.closed
class _FakeComputeWebSocket:
"""
Mimics the aiohttp client WebSocket the controller forwards console traffic to.
Pass a list of WSMessage to emulate a compute that sends data then closes the
session, or None to emulate a busy console streaming binary frames forever
(until the controller cancels the forwarding task).
"""
def __init__(self, messages=None) -> None:
self._messages = messages
self.sent = [] # frames received from the client
self.closed = False
self.stream_cancelled = False
async def send_str(self, data: str) -> None:
self.sent.append(("text", data))
async def send_bytes(self, data: bytes) -> None:
self.sent.append(("bytes", data))
async def close(self) -> None:
self.closed = True
def __aiter__(self):
return self
async def __anext__(self):
if self._messages is not None:
if not self._messages:
raise StopAsyncIteration
return self._messages.pop(0)
try:
await asyncio.sleep(0.05)
except asyncio.CancelledError:
self.stream_cancelled = True
raise
return aiohttp.WSMessage(aiohttp.WSMsgType.BINARY, b"console output", "")
class _FakeComputeWebSocketContext:
"""Async context manager mimicking the object returned by aiohttp ws_connect()."""
def __init__(self, websocket: _FakeComputeWebSocket) -> None:
self._websocket = websocket
async def __aenter__(self) -> _FakeComputeWebSocket:
return self._websocket
async def __aexit__(self, *exc_info) -> bool:
await self._websocket.close()
return False
# The in-memory ASGI WebSocket transport notifies the app of a client close with a
# non-conformant "websocket.close" message, which starlette's receive() rejects.
# Patch it to deliver "websocket.disconnect" like a real ASGI server (uvicorn) does.
_original_stream_send = ASGIWebSocketAsyncNetworkStream.send
async def _conforming_stream_send(self, message):
if message.get("type") == "websocket.close":
message = {"type": "websocket.disconnect", "code": message.get("code") or 1000}
await _original_stream_send(self, message)
class TestConsoleWebSocketRoutes:
"""
Walk the console/VNC WebSocket endpoints through the ASGI stack: data is
forwarded in both directions and both sides tear down cleanly when the
other goes away, instead of letting a WebSocketDisconnect escape as an
ASGI error.
"""
@pytest.fixture
def node(self, project: Project, compute: Compute) -> Node:
node = Node(project, compute, "test", node_type="qemu")
project._nodes[node.id] = node
return node
@staticmethod
def _patches(fake_ws: _FakeComputeWebSocket):
"""
Make HTTPClient.get_client().ws_connect() yield the fake compute WebSocket,
and make the in-memory transport deliver a conformant disconnect message.
"""
stack = contextlib.ExitStack()
http_client = MagicMock()
http_client.ws_connect = MagicMock(return_value=_FakeComputeWebSocketContext(fake_ws))
stack.enter_context(patch(
"gns3server.api.routes.controller.nodes.HTTPClient.get_client",
return_value=http_client
))
stack.enter_context(patch.object(ASGIWebSocketAsyncNetworkStream, "send", _conforming_stream_send))
return stack
@staticmethod
def _admin_token() -> str:
return auth_service.create_access_token("admin", secret_key=DEFAULT_JWT_SECRET_KEY)
@staticmethod
async def _wait_for_teardown(fake_ws: _FakeComputeWebSocket) -> None:
# the handler keeps running on the event loop after the client is gone
for _ in range(100):
if fake_ws.closed:
await asyncio.sleep(0.1) # give cancelled tasks a chance to finish
return
await asyncio.sleep(0.05)
async def test_console_ws_client_disconnect(
self,
app: FastAPI,
client: AsyncClient,
project: Project,
compute: Compute,
node: Node,
caplog
) -> None:
"""
A client disconnecting while the compute keeps streaming console output
must not raise: the forwarding tasks are cancelled and the compute
console WebSocket is closed.
"""
fake_ws = _FakeComputeWebSocket(messages=None)
with self._patches(fake_ws), caplog.at_level(logging.INFO):
async with AsyncClient(base_url="http://test-api", transport=ASGIWebSocketTransport(app=app)) as ws_client:
async with aconnect_ws(
app.url_path_for("ws_console", project_id=project.id, node_id=node.id),
ws_client,
params={"token": self._admin_token()},
) as ws:
# compute -> client
assert await ws.receive_bytes() == b"console output"
# client -> compute
await ws.send_text("dir")
await ws.send_bytes(b"\x01\x02")
await self._wait_for_teardown(fake_ws)
assert fake_ws.sent == [("text", "dir"), ("bytes", b"\x01\x02")]
assert fake_ws.stream_cancelled, "the compute -> client forwarding task should have been cancelled"
assert fake_ws.closed, "the compute console WebSocket should have been closed"
assert any(
"has disconnected from controller console WebSocket" in record.getMessage()
for record in caplog.records
)
async def test_console_ws_compute_closes_session(
self,
app: FastAPI,
client: AsyncClient,
project: Project,
compute: Compute,
node: Node
) -> None:
"""
When the compute closes the console WebSocket the client should receive
the frames sent before the close, then the close itself.
"""
fake_ws = _FakeComputeWebSocket(messages=[
aiohttp.WSMessage(aiohttp.WSMsgType.BINARY, b"output", ""),
aiohttp.WSMessage(aiohttp.WSMsgType.TEXT, "done", ""),
])
with self._patches(fake_ws):
async with AsyncClient(base_url="http://test-api", transport=ASGIWebSocketTransport(app=app)) as ws_client:
async with aconnect_ws(
app.url_path_for("ws_console", project_id=project.id, node_id=node.id),
ws_client,
params={"token": self._admin_token()},
) as ws:
assert await ws.receive_bytes() == b"output"
assert await ws.receive_text() == "done"
with pytest.raises(HttpxWebSocketDisconnect):
await ws.receive_bytes()
assert fake_ws.closed
async def test_vnc_console_ws_client_disconnect(
self,
app: FastAPI,
client: AsyncClient,
project: Project,
compute: Compute,
node: Node,
caplog
) -> None:
"""
Same as the console test, for the VNC endpoint (binary frames only).
"""
fake_ws = _FakeComputeWebSocket(messages=None)
with self._patches(fake_ws), caplog.at_level(logging.INFO):
async with AsyncClient(base_url="http://test-api", transport=ASGIWebSocketTransport(app=app)) as ws_client:
async with aconnect_ws(
app.url_path_for("vnc_console", project_id=project.id, node_id=node.id),
ws_client,
params={"token": self._admin_token()},
) as ws:
assert await ws.receive_bytes() == b"console output"
await ws.send_bytes(b"\x01\x02")
await self._wait_for_teardown(fake_ws)
assert fake_ws.sent == [("bytes", b"\x01\x02")]
assert fake_ws.stream_cancelled, "the compute -> client forwarding task should have been cancelled"
assert fake_ws.closed, "the compute VNC console WebSocket should have been closed"
assert any(
"has disconnected from controller VNC console WebSocket" in record.getMessage()
for record in caplog.records
)