Getting 404 error from WS URL in RTMClient#start() with aiohttp 3.7.0 or lower versions #912
Description
RTMClient.start() failing as of 2021-01-09. Connection attempted with both slack_sdk and (legacy) slackclient.
The Slack SDK version
slack-sdk 3.1.1
(Also occuring on slackclient 2.9.3)
Python runtime version
Python 3.6.7
OS info
Microsoft Windows [Version 10.0.18362.1256]
Steps to reproduce:
> import slack_sdk.rtm as rtm
> rtm_client = rtm.RTMClient(token=token) # also attempted with ssl_context provided
> rtm_client.start()
Testing via https://api.slack.com/methods/rtm.connect/test is successful with the same token as used when running code sample above.
Actual result:
File "C:\Program Files\Python36\lib\asyncio\base_events.py", line 473, in run_until_complete
return future.result()
File "D:\Repos\analysis-tools\slack-bot\src\env\lib\site-packages\slack_sdk\rtm\__init__.py", line 360, in _connect_and_read
proxy=self.proxy,
File "D:\Repos\analysis-tools\slack-bot\src\env\lib\site-packages\aiohttp\client.py", line 1012, in __aenter__
self._resp = await self._coro
File "D:\Repos\analysis-tools\slack-bot\src\env\lib\site-packages\aiohttp\client.py", line 738, in _ws_connect
headers=resp.headers)
aiohttp.client_exceptions.WSServerHandshakeError: 404, message='Invalid response status', url=URL('wss://cerberus-xxxx.lb.slack-msgs.com/websocket/XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX')